Surgery Encyclopedia

International Council on Infertility Information Dissemination. KEY TERMS <http://www.inciid.org/ivf.html>. Endometriosis—An inflammation of the en- L. Fleming Fallon Jr., MD, DrPH Incision care dometrium, the mucous lining of the uterus. Fallopian tubes—In a woman’s reproductive sys- tem, a pair of narrow tubes (one for each ovary) that carries eggs from the ovary to the uterus. Gamete intrafallopian tube transfer (GIFT)—A Incision care process where eggs are taken from a woman’s ovaries, mixed with sperm, and then deposited Definition into the woman’s fallopian tube. Incision care refers to a series of procedures and Intracytoplasmic sperm injection (ICSI)—A process precautions related to closing a wound or surgical inci- used to inject a single sperm into each egg before sion; protecting the cut or injured tissues from contami- fertilized eggs are put back into a woman’s body; nation or infection; and caring properly for the new skin the procedure may be used if the male has a low that forms during the healing process. Incision care be- sperm count. gins in the hospital or outpatient clinic and is continued Zygote intrafallopian tube transfer (ZIFT)—The by the patient during recovery at home. woman’s eggs are fertilized in a laboratory dish and then placed in her fallopian tube. Purpose There are several reasons for caring properly for an incision or wound. These include: • lowering the risk of postoperative complications, par- Squires, J., A. Carter, and P. Kaplan. “Developmental Monitor- ticularly infection ing of Children Conceived by Intracytoplasmic Sperm In- jection and In Vitro Fertilization.” Fertility and Sterility • avoiding unnecessary pain or discomfort 79, no. 2 (2003): 453–454. • minimizing scarring ORGANIZATIONS • preventing blood loss American Board of Obstetrics and Gynecology. 2915 Vine Street, Suite 300, Dallas, TX 75204. (214) 871-1619; Fax: Description (214) 871-1943. [email protected]. <http://www.abog.org>. American College of Obstetricians and Gynecologists. 409 Types of wound or incision closure 12th St., SW, P.O. Box 96920, Washington, DC 20090- Proper care of an incision begins with knowing what 6920. <http://www.acog.org>. material or technique the surgeon used to close the cut. American Infertility Association. 666 Fifth Avenue, Suite 278, There are four major types of closure used in Canada New York, NY 10103. (718) 621-5083. E-mail: <info@ and the United States as of 2003. americaninfertility.org. <http://www.americaninfertility. org>. SURGICAL SUTURES. Sutures, or stitches, are the old- American Society for Reproductive Medicine. 1209 Mont- est method still in use to close an incision. The surgeon gomery Highway, Birmingham, AL 35216-2809. (205) uses a sterilized thread, which may be made of natural 978-5000. <http://www.asrm.com>. materials (silk or catgut) or synthetic fibers, to stitch the International Council on Infertility Information Dissemination, edges of the cut together with a special curved needle. Inc. P.O. Box 6836, Arlington, VA 22206. (703) 379- There are two major types of sutures, absorbable and 9178. <http://www.inciid.org>. nonabsorbable. Absorbable sutures are gradually broken down in the body, usually within two months. Absorbable OTHER sutures do not have to be removed. They are used most American Society for Reproductive Medicine. [cited March 1, commonly to close the deeper layers of tissue in a large 2003]. <http://www.asrm.org/Patients/FactSheets/invitro. incision or in such areas as the mouth. Nonabsorbable su- html>. tures are not broken down in the body and must be re- Columbia University College of Physicians and Surgeons. moved after the incision has healed. They are used most [cited March 2, 2003]. <http://www.columbia.edu/cu/ often to close the outer layers of skin or superficial cuts. news/01/09/in_vitro_prayer.html>. Encyclopedia.Com. [cited March 2, 2003]. <http://www.ency Sutures have several disadvantages. Because they clopedia.com/html/i1/invitro.asp>. are made of materials that are foreign to the body, they GALE ENCYCLOPEDIA OF SURGERY 743

Dressings and drainage devices Incision care must be carefully sterilized and the skin around the inci- dressing of some sort to keep it dry and clean, and pre- sion cleansed with Betadine or a similar antiseptic to After the incision is closed, it is covered with a minimize the risk of infection. Suturing also requires more time than newer methods of closure. If the patient vent infection. Most dressings consist of gauze pads held is not under general anesthesia, the surgeon must first apply or inject a local anesthetic before suturing. Lastly, in place by strips of adhesive tape or ACE bandages. An antibiotic ointment may also be applied to the gauze. A there is a higher risk of scarring with sutures, particular- newer type of dressing, called OpSite, is a thin transpar- ly if the surgeon puts too much tension on the thread ent membrane made of polyurethane coated with adhe- while stitching or selects thread that is too thick for the sive. It keeps disease organisms out of the wound while specific procedure. holding a layer of moisture close to the skin. This moist SURGICAL STAPLES. Surgical staples are a newer environment keeps scabs from forming and speeds up method of incision closure. Staples are typically made of healing of the incision. OpSite can also be used to hold stainless steel or titanium. They are used most common- catheters or drainage tubes in place. It cannot, however, ly to close lacerations on the scalp or to close the outer be used for severe (third-degree) burns or deep incisions. layers of skin in orthopedic procedures. They cannot be Some surgical procedures, such as a mastectomy or used on the face, hand, or other areas of the body where removal of a ruptured appendix, require the surgeon to tendons and nerves lie close to the surface. Staples are insert a drainage device to remove blood, pus, or other usually removed seven to 10 days after surgery. tissue fluids from the area of the incision. It is important Staples are less likely to cause infections than su- to prevent these fluids from collecting under the incision tures, and they also take less time to use. They can, how- because they encourage the growth of disease organisms. ever, leave noticeable scars if the edges of the wound or The drain may be left in place after the patient leaves the incision have not been properly aligned. In addition, sta- hospital. If so, the patient will need to check and empty ples require a special instrument for removal. the drain daily in addition to general incision care. STERI-STRIPS. Steri-strips are pieces of adhesive ma- Home care of incisions terial that can be used in some surgical procedures to help the edges of an incision grow together. They have Guidelines for home care of an incision vary some- several advantages, including low rates of infection, what depending on the material that was used for clo- speed of application, no need for local anesthesia, and no sure, the location and size of the incision, and the nature need for special removal. Steri-strips begin to curl and of the operation. The following section is a general de- peel away from the body, usually within five to seven scription of the major aspects of incision care. days after surgery. They should be pulled off after two Patients should ask their doctor for specific informa- weeks if they have not already fallen off. Steri-strips, tion about caring for their incision: however, have two disadvantages: they are not as precise • the type of closure used as sutures in bringing the edges of an incision into align- ment; and they cannot be used on areas of the body that • whether another appointment will be needed to remove are hairy or that secrete moisture, such as the palms of any sutures or staples the hands or the armpits. • the length of time that the incision should be kept cov- ered, and the type of dressing that should be used LIQUID TISSUE GLUES. Tissue glues are the newest type of incision closure. They are applied to the edges of • whether the incision must be kept dry, and for how long the incision and form a bond that holds the tissues to- • any specific signs or symptoms that should be reported gether until new tissue is formed. The tissue glues most to the doctor commonly used as of 2003 belong to a group of chemi- Most hospitals and surgery clinics provide patients cals known as cyanoacrylates. In addition to speed of use with written handouts or checklists about incision care; and a low infection rate, tissue glues are gradually ab- however, it is always helpful to go over the information sorbed by the body. They are less likely to cause scar- in the handout with the doctor or nurse, and to ask any ring, which makes them a good choice for facial surgery further questions that may arise. and other cosmetic procedures. They are also often used to close lacerations or incisions in children, who find BATHING AND SHOWERING. Incisions should be them less frightening or painful than sutures or staples. kept dry for several days after surgery, with the excep- Like Steri-strips, however, tissue glues cannot be used on tion of incisions closed with tissue glue. Incisions closed areas of high moisture. They are also ineffective for use with nonabsorbable sutures or staples must be kept dry on the knee or elbow joints. until the doctor removes the sutures or staples, usually 744 GALE ENCYCLOPEDIA OF SURGERY

about seven to 10 days after surgery. Incisions closed Patients should observe the following precautions with Steri-strips should be kept dry for about four to five about general cleanliness and personal habits: days. If the incision gets wet accidentally, it must be Incision care • wash hands carefully after using the toilet and after dried at once. Patients with incisions on the face, hands, touching or handling trash or garbage; pets and pet or arms may be able to take showers or tub baths as long equipment; dirty laundry or soiled incision dressings; as they are able to hold the affected area outside the and anything else that is dirty or has been used outdoor water. Patients with incisions in other parts of the body can usually take sponge baths. • ask family members, close friends, and others who touch the patient to wash their hands first It is usually safe to allow incisions closed with tis- • avoid contact with family members and others who are sue glue to get wet during showering or bathing. The pa- sick or recovering from a contagious illness tient should, however, dry the area around the incision carefully after washing. • stop smoking (smoking slows down the healing process) PHYSICAL ACTIVITY AND EXERCISE. Patients should avoid any activity that is likely to pull on the edges of the incision or put pressure on it. Walking and other light ac- Risks tivities are encouraged, as they help to restore normal en- Some patients are more likely to develop infections ergy levels and digestive functions. Patients should not, or to have their incision split open, which is known as however, participate in sports, engage in sexual activity, dehiscence. Risk factors for infection or dehiscence in- or lift heavy objects until they have had a postoperative clude: checkup. • obesity MEDICATIONS. Patients are asked to avoid aspirin • diabetes or over-the-counter medications containing aspirin for a week to 10 days after surgery, because aspirin interferes • malnutrition with blood clotting and makes it easier for bruises to • a weakened immune system form in the skin near the incision. The doctor will usual- ly prescribe codeine or another non-aspirin medication • taking corticosteroid medications prescribed for anoth- for pain control. er disorder or condition • a history of heavy smoking Patients with medications prescribed for other con- ditions or disorders should ask the doctor before starting to take them again. Warning signs SUN EXPOSURE. As an incision heals, the new skin Patients who notice any of the following signs or that is formed over the cut is very sensitive to sunlight and symptoms should call their doctor: will burn more easily than normal skin. Sunburn in turn • fever of 100.5°F (38°C) or higher will lead to worse scarring. Patients should keep the inci- • severe pain in the area of the incision sion area covered for three to nine months from direct sun exposure in order to prevent burning and severe scarring. • intense redness in the area of the incision • bruising SPECIAL CONSIDERATIONS FOR FACIAL INCISIONS. Patients who have had facial surgery are usually given • bleeding or increased drainage of tissue fluid very detailed instructions about incision care because the skin of the face is relatively thin, and incisions in this area can be easily stretched out of alignment. In addition, Normal results patients should not apply any cosmetic creams or make- As an incision heals, it is normal to experience some up after surgery without the surgeon’s approval because redness, swelling, itching, minor skin irritation or oozing of the risk of infection or allergic reaction. of tissue fluid, or small lumps in the skin near the inci- sion. At first, the skin over the incision will feel thick and GENERAL HYGIENE. Infection is the most common hard. After a period of two to six months, the swelling complication of surgical procedures. It can be serious; of and irritation will go down and the scar tissue will soften the 300,000 patients whose incisions become infected and begin to blend into the surrounding tissue. each year in the United States, about 10,000 will die. It is important, therefore, to minimize the risk of an infection See also Bandages and dressings; Hospital-acquired when caring for an incision at home. infections; Postoperative care; Wound care. GALE ENCYCLOPEDIA OF SURGERY 745

Incisional hernia repair Catgut—The oldest type of absorbable suture. In Selo-Ojeme, D. O., and K. B. Lim. “Randomised Clinical Trial of Suture Compared with Adhesive Strip for Skin Closure KEY TERMS After HRT Implant.” BJOG: An International Journal of Obstetrics and Gynaecology 109 (October 2002): 1178– 1180. spite of its name, catgut is made from collagen de- Takahashi, K., T. Muratani, M. Saito, et al. “Evaluation of the rived from sheep or cattle intestines. Synthetic ab- Disinfective Efficacy of Povidone-Iodine with the Use of sorbable sutures have been available since the the Transparent Film Dressing OpSite Wound.” Dermatol- 1980s. Dehiscence—Separation or splitting open of the different layers of tissue in a surgical incision. De- ogy 204 (2002), Supplement 1: 59–62. Rebecca Frey, Ph.D. hiscence may be partial, involving only a few lay- ers of surface tissue; or complete, reopening all the layers of the incision. Drainage—The withdrawal or removal of blood and other fluid matter from an incision or wound. An incision that is oozing blood or tissue fluids is Incisional hernia repair said to be draining. Definition Dressing—A bandage, gauze pad, or other materi- al placed over a wound or incision to cover and Incisional hernia repair is a surgical procedure per- protect it. formed to correct an incisional hernia. An incisional her- nia, also called a ventral hernia, is a bulge or protrusion Incision—The medical term for a cut made by a that occurs near or directly along a prior abdominal sur- surgeon into a tissue or organ. gical incision. The surgical repair procedure is also Laceration—A type of wound with rough, torn, or known as incisional or ventral herniorrhaphy. ragged edges. Suture—A loop of thread, catgut, or synthetic ma- Purpose terial used to draw together and align the edges of a wound or incision. Sutures may be either ab- Incisional hernia repair is performed to correct a sorbable or nonabsorbable. weakened area that has developed in the scarred muscle tissue around a prior abdominal surgical incision, occur- ring as a result of tension (pulling in opposite directions) created when the incision was closed with sutures, or by Resources any other condition that increases abdominal pressure or BOOKS interferes with proper healing. Graber, Mark, MD. “General Surgery: Wound Management,” In The University of Iowa Family Practice Handbook. 4th Demographics edition. Edited by Mark Graber, MD, and Matthew L. Lanternier, MD. St. Louis, MO: Mosby, 2001. Because incisional hernias can occur at the site of PERIODICALS any type of abdominal surgery previously performed on Farion, K., M. H. Osmond, L. Hartling, et al. “Tissue Adhe- a wide range of individuals, there is no outstanding pro- sives for Traumatic Lacerations in Children and Adults.” file of an individual most likely to have an incisional her- Cochrane Database Systems Review 2002: CD003326. nia. Men, women, and children of all ages and ethnic Higgins, Robert V., Wendel Naumann, and James Hall. “Ab- backgrounds may develop an incisional hernia after ab- dominal Incisions and Sutures in Gynecologic Oncologi- dominal surgery. Incisional hernia occurs more com- cal Surgery.” eMedicine. December 11, 2002 [cited Febru- monly among adults than among children. ary 19, 2003]. Mattick, A., G. Clegg, T. Beattie, and T. Ahmad. “A Ran- domised, Controlled Trial Comparing a Tissue Adhesive Description (2-octylcyanoacrylate) with Adhesive Strips (Steri-strips) An incisional hernia can develop in the scar tissue for Paediatric Laceration Repair.” Emergency Medicine around any surgery performed in the abdominal area, Journal 19 (September 2002): 405–407. from the breastbone down to the groin. Depending Passey, Andrew. “Does the Suture Have a Future?” Medica.de, November 15, 2002 [cited February 19, 2003]. <http:// upon the location of the hernia, internal organs may www.11.medica.de/cg i-bin/md_medica/pub/ press through the weakened abdominal wall. The rate content,lang,2/ticket,g_a_s_t/oid,7456/local_lang,2>. of incisional hernia occurrence can be as high as 13% 746 GALE ENCYCLOPEDIA OF SURGERY

Incisional hernia repair Dual-sided mesh Incisional hernia repair Hernia Omentum A. B. C. Tacker D. E. An incisional hernia occurs at the site of a previous incision (A). Intestinal contents break through the abdominal wall and bubble up under the skin. In a laparoscopic repair, the surgeon uses laparoscopic forceps to pull the material, omentum, from the hernia site (B). A mesh pad is inserted into the site to line the hernia site (C and D), and is tacked into place (E). (Il- lustration by GGS Inc.) with some abdominal surgeries. These hernias may healing conditions because of related swelling and occur after large surgeries such as intestinal or vascular wound separation. Tension and abdominal pressure are (heart, arteries, and veins) surgery, or after smaller greater in people who are overweight, creating greater surgeries such as an appendectomy or a laparoscopy, risk of developing incisional hernias following any ab- which typically requires a small incision at the navel. dominal surgery, including surgery for a prior inguinal Incisional hernias themselves can be very small or large (groin) hernia. People who have been treated with and complex, involving growth along the scar tissue of steroids or chemotherapy are also at greater risk for de- a large incision. They may develop months after the veloping incisional hernias because of the affect these surgery or years after, usually because of inadequate drugs have on the healing process. healing or excessive pressure on an abdominal wall The first symptom a person may have with an inci- scar. The factors that increase the risk of incisional her- sional hernia is pain, with or without a bulge in the ab- nia are conditions that increase strain on the abdominal domen at or near the site of the original surgery. Inci- wall, such as obesity, advanced age, malnutrition, poor sional hernias can increase in size and gradually produce metabolism (digestion and assimilation of essential nu- more noticeable symptoms. Incisional hernias may or trients), pregnancy, dialysis, excess fluid retention, and may not require surgical treatment. either infection or hematoma (bleeding under the skin) after a prior surgery. The effectiveness of surgical repair of an incisional hernia depends in part on reducing or eliminating tension Tension created when sutures are used to close a at the surgical wound. The tension-free method used by surgical wound may also be responsible for developing many medical centers and preferred by surgeons who an incisional hernia. Tension is known to influence poor specialize in hernia repair involves the permanent place- GALE ENCYCLOPEDIA OF SURGERY 747

Incisional hernia repair Incisional hernia repair is performed in a hospi- tients may have local or regional anesthesia, depending on the location of the hernia and complexity of the re- WHO PERFORMS pair. A catheter may be inserted into the bladder to re- THE PROCEDURE AND move urine and decompress the bladder. If the hernia is WHERE IS IT PERFORMED? near the stomach, a gastric (nose or mouth to stomach) tube may be inserted to decompress the stomach. tal operating room or a one-day surgical center In an open procedure, an incision is made just large by a general surgeon who may specialize in enough to remove fat and scar tissue from the abdominal hernia repair procedures. wall near the hernia. The outside edges of the weakened hernial area are defined and excess tissue removed from within the area. Mesh is then applied so that it overlaps the weakened area by several inches (centimeters) in all direc- ment of surgical (prosthetic) steel or polypropylene mesh tions. Non-absorbable sutures (the kind that must be re- patches well beyond the edges of the weakened area of moved by the doctor) are placed into the full thickness of the abdominal wall. The mesh is sewn to the area, bridg- the abdominal wall. The sutures are tied down and knotted. ing the hole or weakened area beneath it. As the area heals, the mesh becomes firmly integrated into the inner In the less-invasive laparoscopic procedure, two or abdominal wall membrane (peritoneum) that protects the three small incisions will be made to access the hernia organs of the abdomen. This method creates little or no site—the laparoscope is inserted in one incision and sur- tension and has a lower rate of hernia recurrence, as well gical instruments in the others to remove tissue and as a faster recovery with less pain. Incisional hernias place the mesh in the same fashion as in an open proce- recur more frequently when staples are used rather than dure. Significantly less abdominal wall tissue is removed sutures to secure mesh to the abdominal wall. Autoge- in laparoscopic repair. The surgeon views the entire pro- nous tissue (skin from the patient’s own body) has also cedure on a video monitor to guide the placement and been used for this type of repair. suturing of mesh. Two surgical approaches are used to treat incisional hernias: either a laporoscopic incisional herniorrhaphy, Diagnosis/Preparation which uses small incisions and a tube-like instrument with a camera attached to its tip; or a conventional open Diagnosis repair procedure, which accesses the hernia through a Reviewing the patient’s symptoms and medical his- larger abdominal incision. Open procedures are neces- tory are the first steps in diagnosing an incisional hernia. sary if the intestines have become trapped in the hernia All prior surgeries will be discussed. The doctor will ask (incarceration) or the trapped intestine has become twist- how much pain the patient is experiencing, when it was ed and its blood supply cut off (strangulation). Extreme- first noticed, and how it has progressed. The doctor will ly obese patients may also require an open procedure be- palpate (touch) the area, looking for any abnormal cause deeper layers of fatty tissue will have to be re- bulging or mass, and may ask the patient to cough or moved from the abdominal wall. Mesh may be used with strain in order to see and feel the hernia more easily. To both types of surgical access. confirm the presence of the hernia, an ultrasound exami- Minimally invasive laporoscopic surgery has been nation or other scan such as computed tomography (CT) shown to have advantages over conventional open proce- may be performed. Scans will allow the doctor to visual- dures, including: ize the hernia and to make sure that the bulge is not an- other type of abdominal mass such as a tumor or en- • reduced hospital stays larged lymph gland. The doctor will be able to determine • reduced postoperative pain the size of the defect and whether or not surgery is an ap- propriate way to treat it. A referral to a surgeon will be • reduced wound complications made if the doctor believes that medical treatment will • reduced recovery time not effectively correct the incisional hernia. Surgical procedure Preparation In both open and laparoscopic procedures, the pa- Many months before the surgery, the patient’s doc- tient lies on the operating table, either flat on the back or tor may advise weight loss to help reduce the risks of on the side, depending on the location of the hernia. surgery and to improve the surgical results. Control of General anesthesia is usually given, though some pa- diabetes and smoking cessation are also recommended 748 GALE ENCYCLOPEDIA OF SURGERY

for a better surgical result. Close to the time of the scheduled surgery, the patient will have standard preop- QUESTIONS TO ASK erative blood and urine tests, an electrocardiogram, and a THE DOCTOR chest x ray to make sure that heart and lungs and major organ systems are functioning well. A week or so before • What procedure will be performed to correct Incisional hernia repair surgery, medications may be discontinued, especially as- my hernia? pirin or anticoagulant (blood-thinning) drugs. Starting • What is your experience with this procedure? the night before surgery, patients must not eat or drink How often do you perform this procedure? anything. Once in the hospital, a tube may be placed into • Why must I have the surgery? a vein in the arm (intravenous line) to deliver fluid and medication during surgery. The patient will be given a • What are my options if I do not have the preoperative injection of antibiotics before the proce- surgery? dure. A sedative may be given to relax the patient. • How can I expect to feel after surgery? • What are the risks involved in having this Aftercare surgery? Immediately after surgery, the patient will be ob- • How quickly will I recover? When can I re- served in a recovery area for several hours, for monitor- turn to school or work? ing of body temperature, pulse, blood pressure, and heart • What are my chances of having this type of function, as well as observation of the surgical wound hernia again? for undue bleeding or swelling. Patients will usually be • What can I do to avoid getting this type of discharged on the day of the surgery; only more complex hernia again? hernias such as those with incarcerated or strangulated intestines will require overnight hospitalization. Some patients may have prolonged suture-site pain, which may be treated with pain medication or anti-inflammatory of complications greater. Postoperative infection is higher drugs. Antibiotics may be prescribed to help prevent with open procedures than with laparoscopic procedures. postoperative infection. Postoperative complications may include: Once the patient is home, the hernia repair site must • fluid buildup at the site of mesh placement, sometimes be kept clean, and any sign of swelling or redness reported requiring aspiration (draining off) to the surgeon. Patients should also report a fever or any abdominal pain. Outer sutures may have to be removed by • postoperative bleeding, though seldom enough to re- the surgeon in a follow-up visit about a week after surgery. quire repeat surgery Activities may be limited to non-strenuous movement for • prolonged suture pain, treated with pain medication or up to two weeks, depending on the type of surgery per- anti-inflammatory drugs formed. To allow proper healing of muscle tissue, hernia • intestinal injury repair patients should avoid heavy lifting for at least six to eight weeks after surgery, or longer as advised. • nerve injury • fever, usually related to surgical wound infection Risks • intra-abdominal (within the abdominal wall) abscess Long-term complications seldom occur after inci- • urinary retention sional hernia repair. Short-term risks are greater with • respiratory distress obese patients or those who have had multiple earlier op- erations or the prior placement of mesh patches. The risk of complications has been shown to be about 13%. The Normal results risk of recurrence and repeat surgery is as high as 52%, Good outcomes are expected with incisional hernia particularly with open procedures or those using staples repair, particularly with the laparoscopic method. Pa- rather than sutures for wound closure. Some of the factors tients will usually go home the day of surgery and can that cause incisional hernias to occur in the first place, expect a one- to two-week recovery period at home, and such as obesity and nutritional disorders, will persist in then a return to normal activities. The American College certain patients and encourage the development of a sec- of Surgeons reports that recurrence rates after the first ond incisional hernia and repeat surgery. Each subsequent repair of an incisional hernia range from 25–52%. Re- time, the surgery will become more difficult and the risk currence is more frequent when conventional surgical GALE ENCYCLOPEDIA OF SURGERY 749

Informed consent Autogenous tissue—Tissue or skin taken from any • Learning to lift heavy objects in a safe, low-strain way KEY TERMS using arm and leg muscles. • Controlling diabetes and poor metabolism with regular medical care and dietary changes as recommended. part of a person’s body to graft onto another part of the body that needs repairing; laid on as a patch. essential nutrients, including whole grains, fruits and Herniorrhaphy—The surgical repair of any type of • Eating a healthy, balanced diet of whole foods, high in vegetables, limited meat and dairy, and eliminating pre- hernia. pared and refined foods. Incarcerated intestine—Intestines trapped in the weakened area of the hernia that cannot slip back See also Femoral hernia repair; Inguinal hernia repair. into the abdominal cavity. Resources Incisional hernia—Hernia occuring at the site of a BOOKS prior surgery. Maddern, Guy J. Hernia Repair: Open vs. Laparoscopic Ap- Inguinal hernia—A weak spot in the lower ab- proaches. London: Churchill Livingstone, 1997. dominal muscles of the groin through which body organs, usually the large intestines, can push ORGANIZATIONS through as a result of abdominal pressure. American College of Surgeons (ACS), Office of Public Infor- mation. 633 North Saint Clair Street, Chicago, IL 60611- Laparoscopy—The use of a camera-tipped view- 3211. (312) 202-5000. <http://www.facs.org>. ing tube called a laparoscope to perform minimal- The National Digestive Diseases Information Clearinghouse ly invasive surgery while viewing the procedure (NIDDK). 2 Information Way, Bethesda, MD 20892-3570. on a video screen. <http://www.niddk.nih.gov/health/digest/nddic.htm>. Strangulated hernia—A twisted piece of herniated OTHER intestine that can block blood flow to the in- “Focus on Men’s Health: Hernia.” January 2003. MedicineNet testines. Home.<http://www.medicinenet.com>. Incisional and Ventral Hernias (Patient Information). Central Montgomery Medical Center, Outpatient Surgery Depart- ment. 2100 N. Broad Street, Lansdale, PA 19446. (215) wound closure with standard sutures (stitches) is used. 368-1122. Recurrence after open procedures has been shown to be L. Lee Culvert less likely when mesh is used, although complications, especially infection, have been shown to increase be- cause of the larger abdominal incisions. Laparoscopy Inflatable sphincter see Artificial sphincter with mesh has shown rates of recurrence as low as 3.4%, insertion with fewer complications as well. Morbidity and mortality rates Deaths are not reported resulting directly from the Informed consent performance of herniorrhaphy for incisional hernia. Definition Alternatives Informed consent is a legal document in all 50 states. It is an agreement for a proposed medical treat- The alternatives to first-time and recurrent incisional ment or non-treatment, or for a proposed invasive proce- hernia repair begin with preventive measures such as: dure. It requires physicians to disclose the benefits, risks, • Losing weight; maintaining suitable weight for age and and alternatives to the proposed treatment, non-treat- height. ment, or procedure. It is the method by which fully in- • Strengthening abdominal muscles through regular formed, rational persons may be involved in choices moderate exercise such as walking, tai chi, yoga, or about their health care. stretching exercises and gentle aerobics. Description • Reducing abdominal pressure by avoiding constipation and the buildup of excess body fluids, achieved by Informed consent stems from the legal and ethical adopting a high-fiber, low-salt diet. right an individual has to decide what is done to his or 750 GALE ENCYCLOPEDIA OF SURGERY

her body, and from the physician’s ethical duty to make Today, all of the 50 United States have legislation sure that individuals are involved in decisions about their that delineates the required standards for informed con- own health care. The process of securing informed con- sent. For example, the State of Washington employs the sent has three phases, all of which involve information second approach outlined as the reasonable patient stan- Informed consent exchange between doctor and patient and are part of pa- dard (what an average patient would need to know to be tient education. First, in words an individual can under- an informed participant in the decision). This approach stand, the physician must convey the details of a planned ensures that a doctor fulfills all professional responsibili- procedure or treatment, its potential benefits and serious ties and provides the best care possible and that patients risks, and any feasible alternatives. The patient should be have choices in decisions about their health care. How- presented with information on the most likely outcomes ever, the patient’s competence in making a decision is of the treatment. Second, the physician must evaluate considered. This points to the issue of the patient’s men- whether or not the person has understood what has been tal capacity. Anyone suffering from an illness, anticipat- said, must ascertain that the risks have been accepted, ing surgery, or undergoing treatment for a disease is and that the patient is giving consent to proceed with the under a great deal of stress and anxiety. It may be natural procedure or treatment with full knowledge and fore- for a patient to be confused or indecisive. When the at- thought. Finally, the individual must sign the consent tending physician has serious doubts about the patient’s form, which documents in generic format the major understanding of the intervention and its risks, the pa- points of consideration. The only exception to this is se- tient may be referred for a psychiatric consultation. This curing informed consent during extreme emergencies. is strictly a precaution to ensure that the patient under- stands what has been explained; declining to be treated It is critical that a patient receive enough informa- or operated on does not necessarily mean the person is tion on which to base informed consent, and that the incompetent. It could mean that the person is exercising consent is wholly voluntary and has not been forced in the right to make his or her own health care decisions. any way. It is the responsibility of the physician who dis- cusses the particulars with the patient to detail the con- Although the law requires a formal presentation of versation in the medical record. A physician may, at his the procedure or treatment to the patient, physicians do or her discretion, appoint another member of the health express doubt as to the wisdom of this. Some believe that care team to obtain the patient’s signature on the consent informing patients of the risks of treatment might scare form, with the assurance that the physician has satisfied them into refusing it, even when the risks of non-treatment the requirements of informed consent. are even greater. But patients might have a different view. The law requires that a reasonable physician/patient Without the complete story, for example, a patient might standard be applied when determining how much infor- consent to beginning a particular course of chemotherapy. mation is considered adequate when discussing a proce- Convinced by the pressures from a pharmaceutical com- dure or treatment with the patient. There are three ap- pany, it is conceivable that a doctor will use an agent less proaches to making this discussion: what the typical effective than a newer treatment. By withholding informa- physician would say about the intervention (the reason- tion about treatment alternatives, the physician may be able physician standard); what an average patient would denying the patient a choice and, worse, perhaps a chance need to know to be an informed participant in the deci- of an extended life of greater quality. sion (the reasonable patient standard); and what a patient Undeniably, physicians in surgery, anesthesia, on- would need to know and understand to make a decision cology, infectious disease, and other specialties are faced that is informed (the subjective standard). with issues regarding informed consent. As the federal There is a theory that the practice of acquiring in- government takes a more active role in deciding the ex- formed consent is rooted in the post-World War II Nurem- tent to which patients must be informed of treatments, berg Trials. At the war crimes tribunal in 1949, 10 stan- procedures, and clinical trials in which they voluntarily dards were put forth regarding physicians’ requirements become enrolled, more and more health care providers for experimentation on human subjects. This established a must become educated in what must be conveyed to pa- new standard of ethical medical behavior for the post-WW tients. This is emphasized by the report of a case in II human rights age, and the concept of voluntary in- which a federal court (Hutchinson vs. United States [91 formed consent was established. A number of rules ac- F2d 560 (9th Cir. 1990)]) ruled in favor of the physician, companied voluntary informed consent. It could only be despite his failure to advise his asthmatic patient, for requested for experimentation for the gain of society, for whom he had prescribed the steroid, prednisone, of the the potential acquisition of knowledge of the pathology of drug’s well-known risk of developing aseptic necrosis disease, and for studies performed that avoided physical (bone death), which did occur. The practitioner neglected and mental suffering to the fullest extent possible. to inform the patient that there were other drugs avail- GALE ENCYCLOPEDIA OF SURGERY 751

Inguinal hernia repair able with much less serious side effects that could have Consent—Permission or agreement. KEY TERMS treated the asthma. However, a higher appellate court re- versed the ruling and found the physician guilty. Appar- ently, the patient had used more conservative drugs in the past with good results. The court believed that if the Informed—From full knowledge; not coerced. physician had merely advised the patient of the more se- rious side effects of prednisone and offered the patient more conservative treatment, the physician would have avoided liability. Luce, J. M. “Is the Concept of Informed Consent Applicable to Clinical Research Involving Critically Ill Patients?” Criti- Nursing professionals have a greater role than they cal Care Medicine 31, no. 3 (2003): S153–S160. might believe in evaluating whether or not consent is in- Marr, S. “Protect Your Practice: Informed Consent.” Plastic formed. When a nurse witnesses the signature of a patient Surgical Nursing 22, no. 4 (2002): 180–197. for a procedure, or surgery, he or she is not responsible Meadows, M. “Drug Research and Children.” FDA Consumer for providing the details. Rather, the role is to be the pa- 37, no. 1 (2003): 12–17. tient’s advocate, to protect the patient’s dignity, to identi- ORGANIZATIONS fy any fears, and to determine the patient’s degree of American Academy of Family Physicians. 11400 Tomahawk comprehension and approval of care to be received. Each Creek Parkway, Leawood, KS 66211-2672. (913) 906- patient is an individual, and each one will have a different 6000. [email protected]. <http://www.aafp.org>. and unique response depending on his or her personality, American Bar Association. 750 N Lake Shore Drive, Chicago, level of education, emotions, and cognitive status. If a pa- IL 60611. 312-988-5000. <http://www.abanet.org/home. tient can restate the information that has been imparted, html>. then that will help to confirm that he or she has received American College of Physicians. 190 N Independence Mall enough information and has understood it. The nurse is West, Philadelphia, PA 19106-1572. (800) 523-1546, obligated to report any doubts about the patient’s under- x2600, or (215) 351-2600. <http://www.acponline.org>. standing regarding what has been said or any concerns American Medical Association. 515 N. State Street, Chicago, about his or her capacity to make decisions. IL 60610. 312) 464-5000. <http://www.ama-assn.org>. OTHER Results American Academy of Pediatrics. [cited March 23, 2003]. <http://www.aap.org/policy/00662.html>. The result of informed consent is greater safety and Food and Drug Administration. [cited March 23, 2003]. protection for patients, physicians, and society. <http://www.fda.gov/opacom/morechoices/fed996.html>. See also Do not resuscitate order; Patient confiden- Office for Protection from Research Risks, Department of Health and Human Services. [cited March 23, 2003]. tiality; Patient rights. <http://ohrp.osophs.dhhs.gov/humansubjects/guidance/ ictips.htm>. Resources University of Washington School of Medicine. [cited March BOOKS 23, 2003]. <http://eduserv.hscer.washington.edu/bioethics/ Berg, J. W., C. W. Lidz, P. S. Appelbaum, and L. S. Parker. In- topics/consent.html>. formed Consent: Legal Theory and Clinical Practice, 2nd edition. London: Oxford University Press, 2001. L. Fleming Fallon Jr., MD, DrPH Donnelly, Mary. Consent. Crosses Green, Ireland: Cork Uni- versity Press, 2002. Jonsen, A. R., W. J. Winslade, and M. Siegler. Clinical Ethics: A Practical Approach to Ethical Decisions in Clinical Medicine, 5th edition. New York: McGraw-Hill, 2002. Radford, Roger. Informed Consent. Bangor, Maine: Booklocker. com, 2002. Inguinal hernia repair PERIODICALS Definition Hanson, L. R. “Informed Consent and the Scope of a Physi- Inguinal hernia repair, also known as herniorrhaphy, is cian’s Duty of Disclosure.” Specialty Law Digest: Health the surgical correction of an inguinal hernia. An inguinal Care Law 285 (2003): 9–34. hernia is an opening, weakness, or bulge in the lining tissue Karpman, A. “Informed Consent: Does the First Amendment Protect a Patient’s Right to Choose Alternative Treat- (peritoneum) of the abdominal wall in the groin area be- ment?” New York Law School Journal of Human Rights tween the abdomen and the thigh. The surgery may be a 16, no. 3 (2000): 933–957. standard open procedure through an incision large enough 752 GALE ENCYCLOPEDIA OF SURGERY

Inguinal hernia repair Hernial sac Inguinal hernia repair Inguinal canal Indirect hernia A. B. C. Hernia sac Neck of hernia sac Sutures D. E. F. This patient has an indirect inguinal hernia (A).To repair it, the surgeon makes an incision over the area and separates the muscle and tisses to expose the hernia sac (B).The sac is cut open (C), and the contents are replaced into the abdomen (D). The neck of the hernia sac is tied off (E), and the muscles and tissues are sutured (F). (Illustration by GGS Inc.) to access the hernia or a laparoscopic procedure performed Description through tiny incisions, using an instrument with a camera About 75% of all hernias are classified as inguinal her- attached (laparoscope) and a video monitor to guide the re- nias, which are the most common type of hernia occurring pair. When the surgery involves reinforcing the weakened in men and women as a result of the activities of normal liv- area with steel mesh, the repair is called hernioplasty. ing and aging. Because humans stand upright, there is a greater downward force on the lower abdomen, increasing Purpose pressure on the less muscled and naturally weaker tissues of Inguinal hernia repair is performed to close or mend the groin area. Inguinal hernias do not include those caused the weakened abdominal wall of an inquinal hernia. by a cut (incision) in the abdominal wall (incisional hernia). According to the National Center for Health Statistics, about 700,000 inguinal hernias are repaired annually in the Demographics United States. The inguinal hernia is usually seen or felt The majority of hernias occur in males. Nearly 25% first as a tender and sometimes painful lump in the upper of men and only 2% of women in the United States will groin where the inguinal canal passes through the abdomi- develop inguinal hernias. Inguinal hernias occur nearly nal wall. The inguinal canal is the normal route by which three times more often in African American adults than testes descend into the scrotum in the male fetus, which is in Caucasians. Among children, the risk of groin hernia one reason these hernias occur more frequently in men. is greater in premature infants or those of low birth weight. Indirect inguinal hernias will occur in 10–20 Hernias are divided into two categories: congenital children in every 1,000 live births. (from birth), also called indirect hernias, and acquired, GALE ENCYCLOPEDIA OF SURGERY 753

Inguinal hernia repair Inguinal hernia repair is performed in a hospi- can sometimes confuse the diagnosis of inguinal hernias WHO PERFORMS because they curve over the inguinal area. They are more THE PROCEDURE AND often accompanied by intestinal obstruction than in- WHERE IS IT PERFORMED? guinal hernias. Because inguinal hernias do not heal on their own and can become larger or twisted, which may close off tal operating room or one-day surgical facility by a general surgeon who may specialize in nias must be treated surgically when they cause pain or hernia surgery. the intestines, the prevailing medical opinion is that her- limit activity. Protruding intestines can sometimes be pushed back temporarily into the abdominal cavity, or an external support (truss) may be worn to hold the area in place until surgery can be performed. Sometimes, other also called direct hernias. Among the 75% of hernias medical conditions complicate the presence of a hernia classified as inguinal hernias, 50% are indirect or con- by adding constant abdominal pressure. These condi- genital hernias, occurring when the inguinal canal en- tions, including chronic coughing, constipation, fluid re- trance fails to close normally before birth. The indirect tention, or urinary obstruction, must be treated simulta- inguinal hernia pushes down from the abdomen and neously to reduce abdominal pressure and the recurrence through the inguinal canal. This condition is found in 2% of hernias after repair. A relationship between smoking of all adult males and in 1–2% of male children. Indirect and hernia development has also been shown. Groin her- inguinal hernias can occur in women, too, when abdomi- nias occur more frequently in smokers than nonsmokers, nal pressure pushes folds of genital tissue into the in- especially in women. A hernia may become incarcerated, quinal canal opening. In fact, women will more likely which means that it is trapped in place and cannot slip have an indirect inguinal hernia than direct. Direct or ac- back into the abdomen. This causes bowel obstruction, quired inguinal hernias occur when part of the large in- which may require the removal of affected parts of the testine protrudes through a weakened area of muscles in intestines (bowel resection) as well as hernia repair. If the groin. The weakening results from a variety of fac- the herniated intestine becomes twisted, blood supply to tors encountered in the wear and tear of life. the intestines may be cut off (intestinal ischemia) and the hernia is said to be strangulated, a condition causing se- Inguinal hernias may occur on one side of the groin vere pain and requiring immediate surgery. or both sides at the same or different times, but occur most often on the right side. About 60% of hernias found Surgical procedures in children, for example, will be on the right side, about 30% on the left, and 10% on both sides. The muscular In open inguinal hernia repair procedures, the pa- weak spots develop because of pressure on the abdominal tient is typically given a light general anesthesia of short muscles in the groin area occurring during normal activi- duration. Local or regional anesthetics may be given to ties such as lifting, coughing, straining during urination some patients. Open surgical repair of an indirect hernia or bowel movements, pregnancy, or excessive weight begins with sterilizing and draping the inguinal area of gain. Internal organs such as the intestines may then push the abdomen just above the thigh. An incision is made in through this weak spot, causing a bulge of tissue. A con- the abdominal wall and fatty tissue removed to expose genital indirect inguinal hernia may be diagnosed in in- the inguinal canal and define the outer margins of the fancy, childhood, or later in adulthood, influenced by the hole or weakness in the muscle. The weakened section of same causes as direct hernia. There is evidence that a ten- tissue is dissected (cut and removed) and the inguinal dency for inguinal hernia may be inherited. canal opening is sutured closed (primary closure), mak- ing sure that no abdominal organ tissue is within the su- A direct and an indirect inguinal hernia may occur tured area. The exposed inguinal canal is examined for at the same time; this combined hernia is called a pan- any other trouble spots that may need reinforcement. taloon hernia. Closing the underlayers of tissue (subcutaneous tissue) with fine sutures and the outer skin with staples com- A femoral hernia is another type of hernia that ap- pletes the procedure. A sterile dressing is then applied. pears in the groin, occurring when abdominal organs and tissue press through the femoral ring (passageway where An open repair of a direct hernia begins just as the the major femoral artery and vein extend from the leg repair of an indirect hernia, with an incision made in the into the abdomen) into the upper thigh. About 3% of all same location above the thigh, just large enough to allow hernias are femoral, and 84% of all femoral hernias visualization of the hernia. The surgeon will look for and occur in women. These are not inquinal hernias, but they palpate (touch) the bulging area of the hernia and will re- 754 GALE ENCYCLOPEDIA OF SURGERY

duce it by placing sutures in the fat layer of the abdomi- nal wall. The hernial sac itself will be closed, as in the QUESTIONS TO ASK repair of the indirect hernia, by using a series of sutures THE DOCTOR from one end of the weakened hernia defect to the other. The repair will be checked for sturdiness and for any ten- • What procedure will be performed to correct Inguinal hernia repair sion on the new sutures. The subcutaneous tissue and my hernia? skin will be closed and a sterile dressing applied. • What is your experience with this procedure? Laparoscopic procedures are conducted using gen- How often do you perform this procedure? eral anesthesia. The surgeon will make three tiny inci- • Why must I have the surgery now rather than sions in the abdominal wall of the groin area and inflate waiting? the abdomen with carbon dioxide to expand the surgical • What are my options if I do not have the area. A laparoscope, which is a tube-like fiber-optic in- surgery? strument with a small video camera attached to its tip, will be inserted in one incision and surgical instru- • How can I expect to feel after surgery? ments inserted in the other incisions. The surgeon will • What are the risks involved in having this view the movement of the instruments on a video moni- surgery? tor, as the hernia is pushed back into place and the her- • How quickly will I recover? When can I re- nial sac is repaired with surgical sutures or staples. La- turn to school or work? paroscopic surgery is believed to produce less postopera- • What are my chances of having another hernia? tive pain and a quicker recovery time. The risk of infec- tion is also reduced because of the small incisions required in laparoscopic surgery. The use of surgical (prosthetic) steel mesh or poly- To confirm the presence of the hernia, an ultrasound ex- propylene mesh in the repair of inguinal hernias has been amination may be performed. The ultrasound scan will shown to help prevent recurrent hernias. Instead of the allow the doctor to visualize the hernia and to make sure tension that develops between sutures and the skin in a that the bulge is not another type of abdominal mass conventionally repaired area, hernioplasty using mesh such as a tumor or enlarged lymph gland. It is not usual- patches has been shown to virtually eliminate tension. ly possible to determine whether the hernia is direct or The procedure is often performed in an outpatient facili- indirect until surgery is performed. ty with local anesthesia and patients can walk away the same day, with little restrictions in activity. Tension-free Preparation repair is also quick and easy to perform using the laparo- Patients will have standard preoperative blood and scopic method, although general anesthesia is usually urine tests, an electrocardiogram, and a chest x ray to used. In either open or laparoscopic procedures, the make sure that the heart, lungs, and major organ systems mesh is placed so that it overlaps the healthy skin around are functioning well. A week or so before surgery, med- the hernia opening and then is sutured into place with ications may be discontinued, especially aspirin or anti- fine silk. Rather than pulling the hole closed as in con- coagulant (blood-thinning) drugs. Starting the night be- ventional repair, the mesh makes a bridge over the hole fore surgery, patients must not eat or drink anything. Once and as normal healing take place, the mesh is incorporat- in the hospital, a tube may be placed into a vein in the arm ed into normal tissue without resulting tension. (intravenous line) to deliver fluid and medication during surgery. A sedative may be given to relax the patient. Diagnosis/Preparation Diagnosis Aftercare Reviewing the patient’s symptoms and medical his- The hernia repair site must be kept clean and any tory are the first steps in diagnosing a hernia. The sur- sign of swelling or redness reported to the surgeon. Pa- geon will ask when the patient first noticed a lump or tients should also report a fever, and men should report bulge in the groin area, whether or not it has grown larg- any pain or swelling of the testicles. The surgeon may re- er, and how much pain the patient is experiencing. The move the outer sutures in a follow-up visit about a week doctor will palpate the area, looking for any abnormal after surgery. Activities may be limited to non-strenuous bulging or mass, and may ask the patient to cough or movement for up to two weeks, depending on the type of strain in order to see and feel the hernia more easily. This surgery performed and whether or not the surgery is the may be all that is needed to diagnose an inguinal hernia. first hernia repair. To allow proper healing of muscle tis- GALE ENCYCLOPEDIA OF SURGERY 755

Inguinal hernia repair Incarcerated hernia—An inguinal hernia that is nia will recur. Unfortunately, 10–15% of hernias may de- KEY TERMS velop again at the same site in adults, representing about 100,000 recurrences annually. The risk of recurrence in children is only about 1%. Recurrent hernias can present trapped in place and cannot slip back into the ab- a serious problem because incarceration and strangula- dominal cavity, often causing intestinal obstruction. tion are more likely and because additional surgical re- pair is more difficult than the first surgery. When the first Incisional hernia—Hernia occurring at the site of hernia repair breaks down, the surgeon must work a prior surgery. around scar tissue as well as the recurrent hernia. Inci- Inguinal hernia—A weak spot in the lower ab- dominal muscles of the groin through which body sional hernias, which are hernias that occur at the site of organs, usually the large intestines, can push a prior surgery, present the same circumstance of com- through as a result of abdominal pressure. bined scar tissue and hernia and even greater risk of re- currence. Each time a repair is performed, the surgery is Ischemia—The death of tissue that results from less likely to be successful. Recurrence and infection lack of blood flow and oxygen. rates for mesh repairs have been shown in some studies Laparoscopy—The use of a camera-tipped view- to be lower than with conventional surgeries. ing tube called a laparoscope to perform minimal- Complications that can occur during surgery include ly invasive surgery while viewing the procedure injury to the spermatic cord structure; injuries to veins or on a video screen. arteries, causing hemorrhage; severing or entrapping Strangulated hernia—A twisted piece of herniated nerves, which can cause paralysis; injuries to the bladder intestine that can block blood flow to the in- or bowel; reactions to anesthesia; and systemic compli- testines. cations such as cardiac arrythmias, cardiac arrest, or death. Postoperative complications include infection of the surgical incision (less in laparoscopy); the formation of blood clots at the site that can travel to other parts of sue, hernia repair patients should avoid heavy lifting for the body; pulmonary (lung) problems; and urinary reten- six to eight weeks after surgery. The postoperative activi- tion or urinary tract infection. ties of patients undergoing repeat procedures may be even more restricted. Normal results Prevention of indirect hernias, which are congenital, is not possible. However, preventing direct hernias and Inguinal hernia repair is usually effective, depending reducing the risk of recurrence of direct and indirect her- on the size of the hernia, how much time has gone by be- nias can be accomplished by: tween its first appearance and the corrective surgery, and the underlying condition of the patient. Most first-time • maintaining body weight suitable for age and height hernia repair procedures will be one-day surgeries, in • strengthening abdominal muscles through regular exer- which the patient will go home the same day or in 24 cise hours. Only the most challenging cases will require an overnight stay. Recovery times will vary, depending on • reducing abdominal pressure by avoiding constipation the type of surgery performed. Patients undergoing open and the build-up of excess body fluids, achieved by surgery will experience little discomfort and will resume adopting a high-fiber, low-salt diet normal activities within one to two weeks. Laparoscopy • lifting heavy objects in a safe, low-stress way, using patients will be able to enjoy normal activities within arm and leg muscles one or two days, returning to a normal work routine and lifestyle within four to seven days, with the exception of heavy lifting and contact sports. Risks Hernia surgery is considered to be a relatively safe Morbidity and mortality rates procedure, although complication rates range from 1–26%, most in the 7–12% range. This means that about Mortality related to inguinal hernia repair or postop- 10% of the 700,000 inguinal hernia repairs each year erative complications is unlikely, but with advanced age will have complications. Certain specialized clinics re- or severe underlying conditions, deaths do occur. Recur- port markedly fewer complications, often related to rence is a notable complication and is associated with in- whether open or laparoscopic technique is used. One of creased morbidity, with recurrence rates for indirect her- the greatest risks of inquinal hernia repair is that the her- nias from less than 1–7% and 4–10% for direct. 756 GALE ENCYCLOPEDIA OF SURGERY

Alternatives Although the criteria for admission to an ICU are somewhat controversial—excluding patients who are ei- If a hernia is not surgically repaired, an incarcerated ther too well or too sick to benefit from intensive care— or strangulated hernia can result, sometimes involving there are four recommended priorities that intensivists Intensive care unit life-threatening bowel obstruction or ischemia. (specialists in critical care medicine) use to decide this question. These priorities include: Resources • Critically ill patients in a medically unstable state who BOOKS require an intensive level of care (monitoring and treat- Maddern, Guy J. Hernia Repair: Open vs. Laparoscopic ap- ment). proaches. London: Churchill Livingstone, 1997. • Patients requiring intensive monitoring who may also ORGANIZATIONS require emergency interventions. American College of Surgeons (ACS), Office of Public Infor- mation. 633 North Saint Clair Street, Chicago, IL 60611- • Patients who are medically unstable or critically ill and 3211. (312) 202-5000. <http://www.facs.org>. who do not have much chance for recovery due to the The National Digestive Diseases Information Clearinghouse severity of their illness or traumatic injury. (NIDDK). 2 Information Way, Bethesda, MD 20892-3570. • Patients who are generally not eligible for ICU admis- <http://www.niddk.nih.gov/health/digest/nddic.htm>. sion because they are not expected to survive. Patients OTHER in this fourth category require the approval of the direc- “Focus on Men’s Health: Hernia.” MedicineNet Home Jan. tor of the ICU program before admission. 2003. <http://www.medicinenet.com>. ICU care requires a multidisciplinary team that con- “Inguinal Hernia.” Healthwise, Inc. February 2001. <http:// sists of but is not limited to intensivists (clinicians who www.laurushealth.com/library.>. specialize in critical illness care); pharmacists and nurses; respiratory care therapists; and other medical consultants L. Lee Culvert from a broad range of specialties including surgery, pedi- atrics, and anesthesiology. The ideal ICU will have a team representing as many as 31 different health care pro- Inner ear tube insertion see Endolymphatic fessionals and practitioners who assist in patient evalua- shunt tion and treatment. The intensivist will provide treatment management, diagnosis, interventions, and individualized care for each patient recovering from severe illness. Demographics Intensive care unit A large and comprehensive study conducted in 1992 by the Society of Critical Care Medicine in collaboration Definition with the American Hospital Association found that ap- An intensive care unit, or ICU, is a specialized sec- proximately 8% of all licensed hospital beds in the Unit- tion of a hospital that provides comprehensive and con- ed States were designated for intensive care. The average tinuous care for persons who are critically ill and who size of an adult or pediatric ICU averaged 10–12 beds can benefit from treatment. per unit. Small hospitals with fewer than 100 beds usual- ly had one ICU, whereas larger hospitals with more than 300 beds usually had several ICUs designated for med- Purpose ical, surgical, and coronary patients. Smaller hospitals do not usually have a full-time board-certified specialist in The purpose of the intensive care unit (ICU) is sim- critical care medicine, whereas larger medical centers ple even though the practice is complex. Healthcare pro- generally employ certified intensivists—60% of hospi- fessionals who work in the ICU or rotate through it dur- tals with more than 500 beds had full-time specialist di- ing their training provide around-the-clock intensive rectors at the time the survey was conducted. monitoring and treatment of patients seven days a week. Patients are generally admitted to an ICU if they are like- With regard to the nursing staff in ICUs, the propor- ly to benefit from the level of care provided. Intensive tion of nurses with specialized and advanced training in care has been shown to benefit patients who are severely critical care medicine is higher in larger medical cen- ill and medically unstable—that is, they have a potential- ters—about 16% in hospitals with 100 beds or fewer, but ly life-threatening disease or disorder. 21% in hospitals with more than 500 beds. GALE ENCYCLOPEDIA OF SURGERY 757

Intensive care unit This man is recovering from quadruple bypass surgery in an intensive care unit. (Custom Medical Stock Photo. Reproduced by permission.) Most pediatric ICUs have four to six beds per unit. In addition to the intensivist’s role in direct patient The mortality rate in pediatric ICUs tends to increase in care, he or she is usually the lead physician when multi- proportion to size, with larger units reporting more deaths ple consultants are involved in an intensive care pro- (approximately 8% in the larger units). Eighty percent of gram. The intensivist coordinates the care provided by pediatric ICUs have full-time medical directors. the consultants, which allows for an integrated treatment approach to the patient. Description Nursing care has an important role in an intensive ICUs are highly regulated departments, typically care unit. The nurse’s role usually includes clinical as- limiting the number of visitors to the patient’s immedi- sessment, diagnosis, and an individualized plan of ex- ate family even during visiting hours. The patient usu- pected treatment outcomes for each patient (implementa- ally has several monitors attached to various parts of tion of treatment and patient evaluation of results). The his or her body for real-time evaluation of medical sta- ICU pharmacist evaluates all drug therapy, including bility. The intensivist will make periodic assessments of dosage, route of administration, and monitoring for signs the patient’s cardiac status, breathing rate, urinary out- of allergic reactions. In addition to checking and super- put, and blood levels for nutritional and hormonal prob- vising all levels of medication administration, the ICU lems that may arise and require urgent attention or pharmacist is also responsible for enteral and parenteral treatment. Patients who are admitted to the ICU for ob- nutrition (tube feeding) for patients who cannot eat on servation after surgery may have special requirements their own. ICUs also have respiratory care therapists for monitoring. These patients may have catheters with specialized training in cardiorespiratory (heart and placed to detect hemodynamic (blood pressure) lung) care for critically ill patients. Respiratory thera- changes, or require endotracheal intubation to help pists generally provide medications to help patients their breathing, with the breathing tube connected to a breathe as well as the care and support of mechanical mechanical ventilator. ventilators. Respiratory therapists also evaluate all respi- 758 GALE ENCYCLOPEDIA OF SURGERY

ratory therapy procedures to maximize efficiency and cost-effectiveness. KEY TERMS Large medical centers may have more than one ICU. These specialized intensive care units typically include a Critical care—Care given to a severely ill person who requires continuous medical monitoring and CCU (coronary care unit); a pediatric ICU (PICU, dedi- may require urgent treatment. cated to the treatment of critically ill children); a new- Intensive care unit equipment born ICU or NICU, for the care of premature and criti- Intensivist—A physician who specializes in caring cally ill infants; and a surgical ICU (SICU, dedicated to for patients in intensive care units. the treatment of postoperative patients). Preparation the patient’s current status. For example, a chronically ill inpatient may grow markedly worse within a few hours Persons who are critically ill may be admitted to the and may be transferred to the ICU, where the staff must ICU from the emergency room, a surgical ward, or from reevaluate orders for his or her care. any other hospital department. ICUs are arranged around a central station so that patients can be seen either Resources through the room windows or from a nursing station a PERIODICALS few steps away. Patients are given 24-hour assessments Brilli, R. J., A. Spevetz, R. D. Branson, et al. “Critical Care De- by the intensivist. Preparatory orders for the ICU gener- livery in the Intensive Care Unit: Defining Clinical Roles ally vary from patient to patient since treatment is indi- and the Best Practice Model.” Critical Care Medicine 29 vidualized. The initial workup should be coordinated by (October 2001): 2007-2019. the attending ICU staff (intensivist and ICU nurse spe- Ethics Committee, Society of Critical Care Medicine. “Con- cialist), pharmacists (for medications and IV fluid thera- sensus Statement of the SCCM Ethics Committee Regard- py), and respiratory therapists for stabilization, improve- ing Futile and Other Possibly Inadvisable Treatments.” ment, or continuation of cardiopulmonary care. Well-co- Critical Care Medicine 25 (May 1997): 887-891. ordinated care includes prompt consultation with other Truog, R. D., A. F. Cist, S. E. Brackett, et al. “Recommendations specialists soon after the patient is admitted to the ICU. for End-of-Life Care in the Intensive Care Unit: The Ethics The patient is connected to monitors that record his or Committee of the Society of Critical Care Medicine.” Criti- her vital signs (pulse, blood pressure, and breathing cal Care Medicine 29 (December 2001): 2332-2348. rate). Orders for medications, laboratory tests, or other ORGANIZATIONS procedures are instituted upon arrival. American Hospital Association. One North Franklin, Chicago, In general there are eight categories of diseases and IL 60606-3421. (312) 422-3000. <www.hospitalconnect. disorders that are regarded as medical justification for com>. Joint Commission on Accreditation of Healthcare Organiza- admission to an ICU. These categories include disorders tions (JCAHO). One Renaissance Blvd., Oakbrook Ter- of the cardiac, nervous, pulmonary, and endocrine (hor- race, IL 60181. (630) 792-5000 or (630) 792-5085. monal) systems, together with postsurgical crises and <www.jcaho.org/>. medication monitoring for drug ingestion or overdose. Society of Critical Care Medicine (SCCM). 701 Lee Street, Cardiac problems can include heart attacks (myocardial Suite 200, Des Plaines, IL 60016. (847) 827-6869; Fax: infarction), shock, cardiac arrhythmias (abnormal heart (847) 827-6869. <www.sccm.org>. rhythm), heart failure (congestive heart failure or CHF), high blood pressure, and unstable angina (chest pain). Laith Farid Gulli, M.D., M.S. Lung disorders can include acute respiratory failure, pul- Bilal Nasser, M.D., M.S. monary emboli (blood clots in the lungs), hemoptysis Uchechukwu Sampson, M.D., M.P.H., M.B.A. (coughing up blood), and respiratory failure. Neurologi- cal disorders may include acute stroke (blood clot in the brain), coma, bleeding in the brain (intracranial hemor- rhage), such infections as meningitis, and traumatic brain injury (TBI). Medication monitoring is essential, including careful attention to the possibility of seizures Intensive care unit equipment and other drug side effects. Definition When patients are transferred to the ICU from an- other hospital department, treatment orders and planning Intensive care unit (ICU) equipment includes pa- must be reviewed and new treatment plans written for tient monitoring, respiratory and cardiac support, pain GALE ENCYCLOPEDIA OF SURGERY 759

Intensive care unit equipment management, emergency resuscitation devices, and monitor detects cessation of breathing in infants and adults at risk of respiratory failure, displays respiration other life support equipment designed to care for patients parameters, and triggers an alarm if a certain amount of who are seriously injured, have a critical or life-threaten- time passes without a patient’s breath being detected. ing illness, or have undergone a major surgical proce- Apnea monitoring may be a capability included in a dure, thereby requiring 24-hour care and monitoring. physiologic monitor. Purpose Life support and emergency resuscitative equipment An ICU may be designed and equipped to provide care to patients with a range of conditions, or it may be Intensive care equipment for life support and emer- designed and equipped to provide specialized care to pa- tients with specific conditions. For example, a neuromed- gency resuscitation includes the following: • Ventilator (also called a respirator)—assists with or ical ICU cares for patients with acute conditions involving controls pulmonary ventilation in patients who cannot the nervous system or patients who have just had neuro- breathe on their own. Ventilators consist of a flexible surgical procedures and require equipment for monitoring breathing circuit, gas supply, heating/humidification and assessing the brain and spinal cord. A neonatal ICU is mechanism, monitors, and alarms. They are micro- designed and equipped to care for infants who are ill, born processor-controlled and programmable, and regulate prematurely, or have a condition requiring constant moni- the volume, pressure, and flow of patient respiration. toring. A trauma/burn ICU provides specialized injury and Ventilator monitors and alarms may interface with a wound care for patients involved in auto accidents and central monitoring system or information system. patients who have gunshot injuries or burns. • Infusion pump—device that delivers fluids intra- Description venously or epidurally through a catheter. Infusion pumps employ automatic, programmable pumping Intensive care unit equipment includes patient moni- mechanisms to deliver continuous anesthesia, drugs, toring, life support and emergency resuscitation devices, and blood infusions to the patient. The pump is hung and diagnostic devices. on an intravenous pole placed next to the patient’s bed. Patient monitoring equipment • Crash cart—also called a resuscitation or code cart. This is a portable cart containing emergency resuscita- Patient monitoring equipment includes the following: tion equipment for patients who are “coding.” That is, • Acute care physiologic monitoring system—compre- their vital signs are in a dangerous range. The emer- hensive patient monitoring systems that can be config- gency equipment includes a defibrillator, airway intu- ured to continuously measure and display a number of bation devices, a resuscitation bag/mask, and medica- parameters via electrodes and sensors that are connect- tion box. Crash carts are strategically located in the ed to the patient. These may include the electrical ac- ICU for immediate availability for when a patient expe- tivity of the heart via an EKG, respiration rate (breath- riences cardiorespiratory failure. ing), blood pressure, body temperature, cardiac output, • Intraaortic balloon pump—a device that helps reduce and amount of oxygen and carbon dioxide in the blood. the heart’s workload and helps blood flow to the coro- Each patient bed in an ICU has a physiologic monitor nary arteries for patients with unstable angina, myocar- that measure these body activities. All monitors are net- dial infarction (heart attack), or patients awaiting organ worked to a central nurses’ station. transplants. Intraaortic balloon pumps use a balloon • Pulse oximeter—monitors the arterial hemoglobin oxy- placed in the patient’s aorta. The balloon is on the end gen saturation (oxygen level) of the patient’s blood of a catheter that is connected to the pump’s console, with a sensor clipped over the finger or toe. which displays heart rate, pressure, and electrocardio- gram (ECG) readings. The patient’s ECG is used to • Intracranial pressure monitor—measures the pressure time the inflation and deflation of the balloon. of fluid in the brain in patients with head trauma or other conditions affecting the brain (such as tumors, edema, or hemorrhage). These devices warn of elevated Diagnostic equipment pressure and record or display pressure trends. Intracra- The use of diagnostic equipment is also required in nial pressure monitoring may be a capability included the ICU. Mobile x-ray units are used for bedside radiog- in a physiologic monitor. raphy, particularly of the chest. Mobile x-ray units use a • Apnea monitor—continuously monitors breathing via battery-operated generator that powers an x-ray tube. electrodes or sensors placed on the patient. An apnea Handheld, portable clinical laboratory devices, or point- 760 GALE ENCYCLOPEDIA OF SURGERY

Nurse monitoring a central station for intensive care unit (ICU) equipment. (Custom Medical Stock Photo. Reproduced by Intensive care unit equipment permission.) of-care analyzers, are used for blood analysis at the bed- tion to the types of devices and the variations between side. A small amount of whole blood is required, and different models of the same type of device so they do not blood chemistry parameters can be provided much faster make an error in operation or adjustment. Although many than if samples were sent to the central laboratory. hospitals make an effort to standardize equipment—for example, using the same manufacturer’s infusion pumps Other ICU equipment or patient monitoring systems, older devices and nonstan- dardized equipment may still be used, particularly when Disposable ICU equipment includes urinary (Foley) the ICU is busy. Clinical staff should be sure to check all catheters, catheters used for arterial and central venous devices and settings to ensure patient safety. lines, Swan-Ganz catheters, chest and endotracheal tubes, gastrointestinal and nasogastric feeding tubes, and Intensive care unit patient monitoring systems are monitoring electrodes. Some patients may be wearing a equipped with alarms that sound when the patient’s posey vest, also called a Houdini jacket for safety; the vital signs deteriorate—for instance, when breathing purpose is to keep the patient stationary. Spenco boots stops, blood pressure is too high or too low, or when are padded support devices made of lamb’s wool to posi- heart rate is too fast or too slow. Usually, all patient tion the feet and ankles of the patient. Support hose may monitors connect to a central nurses’ station for easy also be placed on the patient’s legs to support the leg supervision. Staff at the ICU should ensure that all muscles and aid circulation. alarms are functioning properly and that the central sta- tion is staffed at all times. Operation For reusable patient care equipment, clinical staff The ICU is a demanding environment due to the crit- make certain to properly disinfect and sterilize devices ical condition of patients and the variety of equipment that have contact with patients. Disposable items, such necessary to support and monitor patients. Therefore, as catheters and needles, should be disposed of in a prop- when operating ICU equipment, staff should pay atten- erly labeled container. GALE ENCYCLOPEDIA OF SURGERY 761

Intensive care unit equipment Apnea—Cessation of breathing. KEY TERMS The pads are connected to an electrocardiogram machine. Arterial line—A catheter inserted into an artery and connected to a physiologic monitoring system Infectious disease team—A team of physicians to allow direct measurement of oxygen, carbon who help control the hospital environment to pro- dioxide, and invasive blood pressure. tect patients against harmful sources of infection. Catheter—A small, flexible tube used to deliver fluids or medications. A catheter may also be used a failing bodily function, such as using mechanical to drain fluid or urine from the body. Life support—Methods of replacing or supporting ventilation to support breathing. In treatable or Central venous line—A catheter inserted into a curable conditions, life support is used temporarily vein and connected to a physiologic monitoring to aid healing, until the body can resume normal system to directly measure venous blood pressure. functioning. Chest tube—A tube inserted into the chest to drain fluid and air from around the lungs. Nasogastric tube—A tube inserted through the nose and throat and into the stomach for direct Critical care—The multidisciplinary health care feeding of the patient. specialty that provides care to patients with acute, life-threatening illness or injury. Sepsis—The body’s response to infection. Normal- Edema—An abnormal accumulation of fluids in in- ly, the body’s own defense system fights infection, tercellular spaces in the body; causes swelling. but in severe sepsis, the body “overreacts,” causing widespread inflammation and blood clotting in Endotracheal tube—A tube inserted through the patient’s nose or mouth that functions as an airway tiny vessels throughout the body. and is connected to the ventilator. Swan-Ganz catheter—Also called a pulmonary Foley catheter—A catheter inserted into the blad- artery catheter. This type of catheter is inserted into der to drain urine into a bag. a large vessel in the neck or chest and is used to measure the amount of fluid in the heart and to de- Gastrointestinal tube—A tube surgically inserted into the stomach for feeding a patient unable to eat termine how well the heart is functioning. by mouth. Tracheostomy tube—A breathing tube inserted in Heart monitor leads—Sticky pads placed on the the neck, used when assisted breathing is needed chest to monitor the electrical activity of the heart. for a long period of time. Maintenance apists, pharmacologists, physical therapists, and dietitians. Physicians trained in other specialties, such as anesthesiol- Since ICU equipment is used continuously on criti- ogy, cardiology, radiology, surgery, neurology, pediatrics, cally ill patients, it is essential that equipment be proper- and orthopedics, may be consulted and called to the ICU to ly maintained, particularly devices that are used for life treat patients who require their expertise. Radiologic tech- support and resuscitation. Staff in the ICU should per- nologists perform mobile x ray examinations (bedside radi- form daily checks on equipment and inform biomedical ography). Either nurses or clinical laboratory personnel engineering staff when equipment needs maintenance, perform point-of-care blood analysis. Equipment in the repair, or replacement. For mechanically complex de- ICU is maintained and repaired by hospital biomedical en- vices, service and preventive maintenance contracts are gineering staff and/or the equipment manufacturer. available from the manufacturer or third-party servicing companies, and should be kept current at all times. Some studies have shown that patients in the ICU following high-risk surgery are at least three times as likely to survive when cared for by “intensivists,” physi- Health care team roles cians trained in critical care medicine. Equipment in the ICU is used by a team specialized in their use. The team usually comprises a critical care attend- Training ing physician (also called an intensivist), critical care nurs- Manufacturers of more sophisticated ICU equipment, es, an infectious disease team, critical care respiratory ther- such as ventilators and patient monitoring devices, provide 762 GALE ENCYCLOPEDIA OF SURGERY

clinical training for all staff involved in ICU treatment when the device is purchased. All ICU staff must have un- WHO PERFORMS dergone specialized training in the care of critically ill pa- THE PROCEDURE AND tients and must be trained to respond to life-threatening sit- WHERE IS IT PERFORMED? uations, since ICU patients are in critical condition and may experience respiratory or cardiac emergencies. Ileoanal anastomoses are usually performed in Intestinal obstruction repair a hospital operating room. Surgery may be per- Resources formed by a general surgeon or a colorectal PERIODICALS surgeon, a medical doctor who focuses on the Savino, Joseph S., C. William Hanson III, and Timothy J. surgical treatment of diseases of the colon, rec- Gardner. “Cardiothoracic Intensive Care: Operation and tum, and anus. Administration.” Seminars in Thoracic and Cardiovascu- lar Surgery 12 (October 2000): 362–70. ORGANIZATIONS American Association of Critical Care Nurses (ACCN). 101 Purpose Columbia, Aliso Viejo, CA 92656-4109. (800) 889- The small intestine is composed of three major sec- AACN [(800) 889-2226] or (949) 362-2000. <http://www. tions: the duodenum just below the stomach; the je- aacn.org>. National Association of Neonatal Nurses. 4700 West Lake junum, or middle portion; and the ileum, which empties Ave., Glenview, IL 60025-1485. (847) 375-3660 or (800) into the large intestine. The large intestine is composed 451-3795. <http://www.nann.org>. of the colon, where stool is formed; and the rectum, National Heart, Lung and Blood Institute. Information Center. which empties to the outside of the body through the P.O. Box 30105, Bethesda, MD 20824-0105. (301) 251- anal canal. A blockage that occurs in the small intestine 2222. <http://www.nhlbi.nih.gov >. is called a small bowel obstruction, and one that occurs National Institutes of Health, U.S. Department of Health and in the colon is a colonic obstruction. Human Services, 9000 Rockville Pike, Bethesda, MD 20892. (301) 496-4000. <http://www.nih.gov>. There are numerous conditions that may lead to an Society of Critical Care Medicine. 701 Lee St., Suite 200, Des intestinal obstruction. The three most common causes of Plaines, IL 60016. (847) 827-6869. [email protected]. small bowel obstruction are adhesions, which are bands <http://www.sccm.org>. of scar tissue that form in the abdomen following injury OTHER or surgery; hernias, which develop when a portion of the ICU Guide. 2002. <http://www.waiting.com/waitingicu.html>. intestine protrudes through a weak spot in the abdominal ICU-USA, Society of Critical Care Medicine, 2002 <http:// wall; and cancerous tumors. Adhesions account for ap- www.icu-usa.com/tour/>. proximately 50% of all small bowel obstructions, hernias “Intensive Care Units.” 2003. <http://www.pulmonologychannel. for 15%, and tumors for 15%. Other causes include com/icu/index.html>. volvulus, or formation of kinks or knots in the bowel; the Pediatric Critical Care Medicine <http://pedsccm.wustl.edu/>. presence of foreign bodies in the digestive tract; intus- Virtual Pediatric Intensive Care Unit <http://www.picu.net/>. susception, which occurs when a portion of the intestine Jennifer E. Sisk, M.A. telescopes or pulls over another portion; infection; and Angela M. Costello congenital defects. While most small bowel blockages can be treated with the administration of intravenous (IV) fluids and decompression of the bowel by the inser- Interpositional reconstruction see tion of a nasogastric (NG) tube, surgical intervention is Arthroplasty necessary in approximately 25% of patients with a par- Intestinal anastomosis see Ileoanal tial obstruction, and 50%–65% of patients with a com- anastomosis plete obstruction. An obstruction of the large intestine is less common than blockages of the small intestine. Blockages of the large bowel are usually caused by colon cancer; volvu- Intestinal obstruction repair lus; diverticulitis (inflammation of sac-like structures called diverticula that form in the intestines); ischemic Definition colitis (inflammation of the colon resulting from insuffi- An intestinal obstruction is a partial or complete cient blood flow); Crohn’s disease (a disease that causes blockage of the small or large intestine. Surgery is some- chronic inflammation of the intestines); inflammation times necessary to relieve the obstruction. due to radiation therapy; and the presence of foreign GALE ENCYCLOPEDIA OF SURGERY 763

Intestinal obstruction repair • Why are you recommending intestinal ob- mon surgical procedures used to treat bowel obstructions QUESTIONS TO ASK include: THE DOCTOR • Lysis of adhesions. The process of removing these bands of scar tissue is called lysis. After the abdominal cavity has been opened, the surgeon locates the ob- struction repair? structed area and delicately dissects the adhesions from • What diagnostic tests will be performed to the intestine using surgical scissors and forceps. determine if an obstruction is present? • Hernia repair. This procedure involves an incision • Will an ileostomy or colostomy be created? Will it be temporary or permanent? the hernia sac is opened. The herniated intestine is placed back in the abdominal cavity and the muscle • Are any nonsurgical treatments available? placed near the location of the hernia through which wall is repaired. • How soon after surgery may normal diet and activities be resumed? • Resection with end-to-end anastomosis. “Resection” means to remove part or all of a tissue or structure. Re- section of the small or large intestine, therefore, in- volves the removal of the obstructed or diseased sec- bodies. As in the case of small bowel obstruction, most tion. Anastomosis is the connection of two cut ends of patients with a blockage of the large intestine can be a tubular structure to form a continuous channel; the treated with IV fluids and bowel decompression. anastomosis of the intestine is most often accomplished with sutures or surgical staples. Demographics • Resection with ileostomy or colostomy. In some pa- Approximately 300,000 intestinal obstruction re- tients, an anastomosis is not possible because of the ex- pairs are performed in the United States each year. tent of the diseased tissue. After the obstruction and Among patients who are admitted to the hospital for se- diseased tissue is removed, an ileostomy or colostomy vere abdominal pain, 20% have an intestinal obstruction. is created. Ileostomy is a surgical procedure in which While bowel obstruction can affect individuals of any the small intestine is attached to the abdominal wall; age, different conditions occur at higher rates in certain waste then exits the body through an artificial opening age groups. Children under the age of two, for example, called a stoma and collects in a bag attached to the skin are more likely to present with intussusceptions or con- with adhesive. Colostomy is a similar procedure with genital defects. Elderly patients, on the other hand, have the exception that the colon is the part of the digestive a higher rate of colon cancer. tract that is attached to the abdominal wall. Description Diagnosis/Preparation After the patient has been prepared for surgery and given general anesthesia, the surgeon usually enters the To diagnose an intestinal obstruction, the physician abdominal cavity by way of a laparotomy, which is a first gives a physical examination to determine the large incision made through the patient’s abdominal wall. severity of the patient’s condition. The abdomen is ex- This type of surgery is sometimes referred to as open amined for evidence of scars, hernias, distension, or surgery. An alternative to laparotomy is laparoscopy,a pain. The patient’s medical history is also taken, as cer- surgical procedure in which a laparoscope (a thin tube tain factors increase a person’s risk of developing a with a built-in light source) and other instruments are in- bowel obstruction (including previous surgery, older age, serted into the abdomen through small incisions. The in- and a history of constipation). A series of x rays may be ternal operating field is then visualized on a video moni- taken of the abdomen, as a definitive diagnosis of ob- tor that is connected to the scope. In some patients, the struction can be made by x ray in 50–60% of patients. technique may be used for abdominal exploration in Computed tomography (CT; an imaging technique that place of a laparotomy. Laparoscopy is associated with uses x rays to produce two-dimensional cross-sections faster recovery times, shorter hospital stays, and smaller on a viewing screen) or ultrasonography (an imaging surgical scars, but requires advanced training on the part technique that uses high-frequency sounds waves to vi- of the surgeon as well as costly equipment. Moreover, it sualize structures inside the body) may also be used to offers a more limited view of the operating field. diagnosis intestinal obstruction. Treating an intestinal obstruction depends on the Unless a patient presents with symptoms that indi- condition causing the blockage. Some of the more com- cate immediate surgery may be necessary (high fever, se- 764 GALE ENCYCLOPEDIA OF SURGERY

vere pain, a rapid heart beat, etc.), a course of IV fluids, NG decompression, and antibiotic therapy is usually pre- KEY TERMS scribed in an effort to avoid surgery. Adhesion—A band of fibrous tissue forming an Aftercare abnormal bond between two adjacent tissues or organs. Intestinal obstruction repair After surgery, the patient’s NG tube remains until bowel function returns. The patient is closely monitored Anastomosis (plural, anastomoses)—A surgically for signs of infection, leakage from an anastomosis, or created joining or opening between two organs or other complications. body spaces that are normally separate. Congenital defect—A defect present at birth. Risks Gangrenous—Referring to tissue that is dead. Complications associated with intestinal obstruction Intestinal perforation—A hole in the intestinal wall. repair include excessive bleeding; infection; formation Intussusception—The telescoping of one part of of abscesses (pockets of pus); leakage of stool from an the intestine inside an immediately adjoining part. anastomosis; adhesion formation; paralytic ileus (tempo- Lysis—The process of removing adhesions from an rary paralysis of the intestines); and reoccurrence of the organ. The term comes from a Greek word that obstruction. means “loosening.” Simple obstruction—A blockage in the intestine Normal results that does not affect the flow of blood to the area. Most patients who undergo surgical repair of an in- Stoma (plural, stomata)—A surgically created testinal obstruction have an uneventful recovery and do opening in the abdominal wall to allow digestive not experience a recurrence of the obstruction. wastes to pass to the outside of the body. Strangulation obstruction—A blockage in the in- Morbidity and mortality rates testine that closes off the flow of blood to the area. Volvulus—An intestinal obstruction caused by a The mortality rate of small bowel obstruction ranges from 2% for a simple obstruction to 25% for a strangula- knotting or twisting of the bowel. tion obstruction that compromises the blood supply and is treated after a lapse of 36 hours. Large bowel obstruc- tion carries a mortality rate of 2% for volvulus to 40% if Torrey, Susan P., and Philip L. Henneman. “Small Intestine.” In part of the bowel is gangrenous. Rosen’s Emergency Medicine. 5th ed. St. Louis, MO: Mosby, Inc., 2002. Alternatives PERIODICALS Such nonsurgical techniques as the administration Basson, Marc D. “Colonic Obstruction.” eMedicine, September of IV fluids and bowel decompression with a NG tube 26, 2001 [cited May 2, 2003]. <http://www.emedicine. are often successful in relieving an intestinal obstruction. com/med/topic415.htm>. Khan, Ali Nawaz, and John Howat. “Small-Bowel Obstruc- Patients who present with more severe symptoms that tion.” eMedicine, April 18, 2003 [cited May 2, 2003]. are indicative of a bowel perforation or strangulation, <http://www.emedicine.com/radio/topic781.htm>. however, require immediate surgery. ORGANIZATIONS Resources American Society of Colon and Rectal Surgeons. 85 W. Algo- nquin Rd., Suite 550, Arlington Heights, IL 60005. (847) BOOKS 290-9184. <www.fascrs.org>. Bitterman, Robert A., and Michael A. Peterson. “Large Intes- United Ostomy Association, Inc. 19772 MacArthur Blvd., tine.” In Rosen’s Emergency Medicine. 5th ed. St. Louis, Suite 200, Irvine, CA 92612-2405. (800) 826-0826. MO: Mosby, Inc., 2002. <www.uoa.org>. Evers, B. Mark. “Small Bowel.” In Sabiston Textbook of Surgery. Philadelphia, PA: W. B. Saunders Company, Stephanie Dionne Sherk 2001. “Mechanical Intestinal Obstruction.” In The Merck Manual of Diagnosis and Therapy, edited by Mark H. Beers, MD, Intracranial aneurysm repair see Cerebral and Robert Berkow, MD. Whitehouse Station, NJ: Merck Research Laboratories, 1999. aneurysm repair GALE ENCYCLOPEDIA OF SURGERY 765

Intravenous rehydration loss in which a sterile water solution containing small Intravenous rehydration is typically prescribed Intravenous rehydration WHO PERFORMS THE PROCEDURE AND Definition WHERE IS IT PERFORMED? Intravenous (IV) rehydration is a treatment for fluid by a doctor and administered by a nurse, physi- amounts of salt or sugar is injected into the patient’s bloodstream. may be performed in a hospital setting, an am- bulatory care center, or a home care setting. Purpose cian’s assistant, or home health care aide. It Rehydration is usually performed to treat the symp- toms associated with dehydration, or excessive loss of body water. Fever, vomiting, and diarrhea can cause a In infants, dehydration may also be indicated by a person to become dehydrated fairly quickly. Infants and sunken fontanelle (the soft spot on the head). children are especially vulnerable to dehydration. Pa- A doctor orders the IV solution and any additional tients can become dehydrated due to an illness, surgery, nutrients or drugs to be added to it. The doctor also speci- metabolic disorder, hot weather, or accident. Athletes fies the rate at which the IV will be infused. The intra- who have overexerted themselves may also require rehy- venous solutions are prepared under the supervision of a dration with IV fluids. An IV for rehydration can be used pharmacist using sanitary techniques that prevent bacteri- for several hours to several days, and is generally used if al contamination. Just like a prescription, the IV is clearly a patient is unable to keep down oral fluids due to exces- labeled to show its contents and the amounts of any addi- sive vomiting. tives. A nurse will examine the patient’s arm to find a suitable vein for insertion of the intravenous line. Once Description the vein is located, the skin around the area is cleaned and disinfected. The needle is inserted and is taped to the skin A basic IV rehydration solution consists of sterile to prevent it from moving out of the vein. water with small amounts of sodium chloride (NaCl; Patients receiving IV therapy must be monitored to salt) and dextrose (sugar) added. It is supplied in bottles ensure that the IV solutions are providing the correct or thick plastic bags that can hang on a pole or rolling amounts of fluids and minerals needed. People with kid- stand mounted next to a patient’s bed. Additional elec- ney and heart disease are at increased risk for overhydra- trolytes (i.e., potassium, calcium, bicarbonate, phos- tion, so they must be carefully monitored when receiving phate, magnesium, chloride), vitamins, or drugs can be IV therapy. added as needed either in a separate minibag or via an injection into the intravenous line. Aftercare Patients must be able to take (and keep down) fluids Diagnosis/Preparation by mouth before an IV rehydration solution is discontin- Signs and symptoms of dehydration include: ued. After the needle is removed, the insertion site should be inspected for any signs of bleeding or infection. • extreme thirst • sunken eyes • reduced urine output; urine that is dark in color QUESTIONS TO ASK • weakness and fatigue THE DOCTOR • rapid weight loss • dry, warm skin • Can I take rehydration therapy orally instead of intravenously? • skin that is wrinkled or has little elasticity • What are the warning signs that might indi- • rapid pulse cate a problem with the IV therapy? • dry mouth • How should I treat the underlying disorder • “tearless” crying (e.g., gastroenteritis) that caused the dehydra- • muscle cramps tion? • headache 766 GALE ENCYCLOPEDIA OF SURGERY

PERIODICALS KEY TERMS Suhayda, Rosemarie, and Jane C. Walton. “Preventing and Managing Dehydration.” MedSurg Nursing 11 (December Dehydration—A condition that results from ex- 2002): 267-278. cessive loss of body water. The water may be lost OTHER Intussusception reduction through the digestive system, through sweating, or Rehydration Project. P. O. Box 1, Samara, 5235, Costa Rica. through the urinary tract. (506) 656-0504. <www.rehydrate.org>. Hypodermoclysis—A technique for restoring the body’s fluid balance by injecting a solution of salt Altha Roberts Edgren and water into the tissues beneath the skin rather Paula Ford-Martin than directly into a vein. Intravenous—Into a vein; a needle is inserted into a vein in the back of the hand, inside the elbow, or some other location on the body. Intussusception reduction Definition Risks Intussusception is a condition in which one portion of As with any invasive procedure, there is a small risk the intestine “telescopes” into or folds itself inside another of infection or bruising at the injection site. It is possible portion. The term comes from two Latin words, intus, that the IV solution may not provide all of the nutrients which means “inside” and suscipere, which means “to re- needed, leading to a deficiency or an imbalance. If the ceive.” The outer “receiving” portion of an intussusception needle becomes dislodged, the solution may flow into is called the intussuscipiens; the part that has been re- tissues around the injection site rather than into the vein, ceived inside the intussuscipiens is called the intussuscep- resulting in swelling. tum. The result of an intussusception is that the bowel is obstructed and its blood supply gradually cut off. Surgery Morbidity and mortality rates is sometimes necessary to relieve the obstruction. According to the United Nations Children’s Fund (UNICEF), over two million children die of diarrhea-re- Purpose lated dehydration each year. Eighty percent of these chil- dren were two years of age or younger. In the United The purpose of an intussusception reduction is to States, an estimated 300 people (children and adults) die prevent gangrene of the bowel, which may lead to perfo- of dehydration annually. ration of the bowel, severe infection, and death. The cause of intussusception is idiopathic in most Alternatives children diagnosed with the condition (88–99%). Idio- pathic means that the condition has developed sponta- For patients who are able to tolerate fluids by neously or that the cause is unknown. In the remaining mouth, oral rehydration therapy (ORT) with oral rehy- 1–12% of child patients, certain conditions called lead dration salts (ORS) in solution is the preferred treatment points have been associated with intussusception. These alternative. Another technique in which fluid replace- lead points include cystic fibrosis; recent upper respira- ment is injected subcutaneously (under the skin into tis- tory or gastrointestinal illness; congenital abnormalities sues) rather than into a vein is called hypodermoclysis. of the digestive tract; benign or malignant tumors; Hypodermoclysis is easier to administer than IV therapy, chemotherapy; or the presence of foreign bodies. especially in the home setting. It may be used to treat mild to moderate dehydration in patients who are unable In contrast to children, there is a lead point in 90% to take in adequate fluids by mouth and who prefer to be of adults diagnosed with intussusception. treated at home (geriatric or terminally ill patients). Resources Demographics About 95% of all cases of intussusception occur in BOOKS children. Children under two years of age are most likely Hankins, Judy, et al., eds. Infusion Therapy in Clinical Prac- tice. 2nd ed. Philadelphia: WB Saunders, 2001. to be affected by the condition; the average age at diag- Otto, Shirlie. Pocket Guide to Intravenous Therapy. 4th ed. St. nosis is seven to eight months. Among children, the rate Louis: Mosby Inc., 2001. of intussusception is one to four per 1000. Conversely, GALE ENCYCLOPEDIA OF SURGERY 767

Intussusception reduction Intussusception reduction Area of intussusception Intussusception A. B. Incision Sutures C. D. Intussusception of the bowel results in the bowel telescoping onto itself (A and B). An incision is made in the baby’s ab- domen to expose the bowel (C). If the surgeon cannot manipulate the bowel into a normal shape manually, the area of intus- susception wil be removed and remaining bowel sutured together (D). (Illustration by GGS Inc.) only two to three adults out of every 1,000,000 are diag- tomy, a large incision made through the abdominal wall. nosed with intussusception each year. Intussusception is The intestines are examined until the intussusception is more likely to affect males than females in all age identified and brought through the incision for closer groups. Among children, the male: female ratio is 3:2; in examination. The surgeon first attempts to reduce the in- persons over the age of four, the male:female ratio is 8:1. tussusception by “milking” or applying gentle pressure to ease the intussusceptum out of the intussuscipiens; As of 2003, racial or ethnic differences do not ap- this technique is called manual reduction. If manual re- pear to affect the occurrence of intussusception. duction is not successful, the surgeon may perform a re- section of the intussusception. Resect means to remove Description part or all of a tissue or structure; resection of the intus- Surgical correction of an intussusception is done susception, therefore, involves the removal of the area with the patient under general anesthesia. The surgeon of the intestine that has prolapsed. The two cut ends of usually enters the abdominal cavity by way of a laparo- the intestine may then be reconnected with sutures or 768 GALE ENCYCLOPEDIA OF SURGERY

WHO PERFORMS QUESTIONS TO ASK THE PROCEDURE AND THE DOCTOR WHERE IS IT PERFORMED? • What diagnostic tests will be needed to con- Intussusception reduction Intussusception reduction is usually performed firm the presence of an intussusception? in a hospital operating room under general • Is there a lead point in this case? anesthesia. The operation may be performed by • Can the intussusception be treated success- a general surgeon, a pediatric surgeon (in the fully without surgery? case of pediatric intussusception), or a colorec- • If resection becomes necessary, will an en- tal surgeon (a medical doctor who focuses on terostomy be performed? the surgical treatment of diseases of the colon, • How soon after surgery may normal diet and rectum, and anus). activities be resumed? surgical staples; this reconnection is called an end-to- X rays may be taken of the abdomen with the patient end anastomosis. lying down or sitting upright. Ultrasonography (an imag- More rarely, the segment of bowel that is removed is ing technique that uses high-frequency sounds waves to too large to accommodate an end-to-end anastomosis. visualize structures inside the body) and computed tomog- These patients may require a temporary or permanent raphy (an imaging technique that uses x rays to produce enterostomy. In this procedure, the surgeon creates an ar- two-dimensional cross-sections on a viewing screen) are tificial opening in the abdomen wall called a stoma, and also used to diagnose intussusception. A contrast enema is attaches the intestine to it. Waste then exits the body a diagnostic tool that has the potential to reduce the intus- through the stoma and empties into a collection bag. susception; during this procedure, x-ray photographs are taken of the intestines after a contrast material such as bar- An alternative to the traditional abdominal incision ium or air is introduced through the anus. is laparoscopy, a surgical procedure in which a laparo- scope (a thin, lighted tube) and other instruments are in- Children diagnosed with intussusception are started serted into the abdomen through small incisions. The in- on intravenous (IV) fluids and nasogastric decompres- ternal operating field is then visualized on a video moni- sion (in which a flexible tube is inserted through the nose tor that is connected to the scope. In some patients, the down to the stomach) in an effort to avoid surgery. An surgeon may perform a laparoscopy for abdominal ex- enema may also be given to the patient, as 40–90% of ploration in place of a laparotomy. Laparoscopy is asso- cases are successfully treated by this method. If these ciated with speedier recoveries shorter hospital stays, noninvasive treatments fail, surgery becomes necessary and smaller surgical scars; on the other hand, however, it to relieve the obstruction. requires costly equipment and advanced training on the There is some controversy among doctors about the surgeon’s part. In addition, it offers a relatively limited usefulness of barium enemas in reducing intussuscep- view of the operating field. tions in adults. In general, enemas are less successful in adults than in children, and surgical treatment should not be delayed. Diagnosis/Preparation The diagnosis of intussusception is usually made Aftercare after a complete physical examination, medical history, After surgical treatment of an intussusception, the and series of imaging studies. In children, the pediatrician patient is given fluids intravenously until bowel function may suspect the diagnosis on the basis of such symptoms returns; he or she may then be allowed to resume a nor- as abdominal pain, fever, vomiting, and “currant jelly” mal diet. Follow-up care may be indicated if the intus- stools, which consist of blood-streaked mucus and pieces susception occurred as a result of a specific condition of the tissue that lines the intestine. When the doctor pal- (e.g., cancerous tumors). pates (feels) the child’s abdomen, he or she will typically find a sausage-shaped mass in the right lower quadrant of the abdomen. Diagnosis of intussusception in adults, Risks however, is much more difficult, partly because the disor- Complications associated with intussusception re- der is relatively rare in the adult population. duction include reactions to general anesthesia; perfora- GALE ENCYCLOPEDIA OF SURGERY 769

Alternatives Iridectomy KEY TERMS of IV fluids, bowel decompression with a nasogastric Such nonsurgical techniques as the administration Adhesion—A fibrous band of tissue that forms an abnormal connection between two adjacent or- tube, or a therapeutic enema are often successful in re- gans or other structures. ducing intussusception. Patients whose symptoms point to bowel perforation or strangulation, however, require Anastomosis—The connection of separate parts of immediate surgery. If left untreated, gangrene of the a body organ or an organ system. bowel is almost always fatal. Benign tumor—A noncancerous growth that does not have the potential to spread to other parts of Resources the body. BOOKS Congenital—Present at birth. “Congenital Anomalies: Gastrointestinal Defects.” In The Gangrene—The death of a considerable mass of Merck Manual of Diagnosis and Therapy, edited by Mark tissue, usually associated with loss of blood sup- H. Beers, MD, and Robert Berkow, MD. Whitehouse Sta- ply and followed by bacterial infection. tion, NJ: Merck Research Laboratories, 1999. Engum, Scott A. and Jay L. Grosfeld. “Pediatric Surgery: In- Idiopathic—Having an unknown cause or arising tussusception.” In Sabiston Textbook of Surgery. Philadel- spontaneously. Most cases of intussusception in phia: W. B. Saunders Company, 2001. children are idiopathic. Wyllie, Robert. “Ileus, Adhesions, Intussusception, and Lead point—A well-defined abnormality in the Closed-Loop Obstructions.” In Nelson Textbook of Pedi- area where the intussusception begins. atrics, 16th ed. Philadelphia, PA: W. B. Saunders Compa- ny, 2000. Malignant tumor—A cancerous growth that has the potential to spread to other parts of the body. PERIODICALS Stoma (plural, stomata)—A surgically created Chahine, A. Alfred, MD. “Intussusception.” eMedicine,April opening in the abdominal wall to allow digestive 4, 2002 [cited May 4, 2003]. <www.emedicine.com/PED/ wastes to pass to the outside of the body. topic1208.htm>. Irish, Michael, MD. “Intussusception: Surgical Perspective.” Strangulation—A condition in which the blood eMedicine, April 29, 2003 [cited May 4, 2003]. <www. circulation in a part of the body is shut down by emedicine.com/PED/topic2972.htm>. pressure. Intussusception can lead to strangulation Waseem, Muhammad and Orlando Perales. “Diagnosis: Intus- of a part of the intestine. susception.” Pediatrics in Review 22, no. 4 (April 1, 2001): 135-140. ORGANIZATIONS American Academy of Family Physicians. PO Box 11210, tion of the bowel; wound infection; urinary tract infec- Shawnee Mission, KS 66207. (800) 274-2237. <www. tion; excessive bleeding; and formation of adhesions aafp.org>. (bands of scar tissue that form after surgery or injury to American Academy of Pediatrics. 141 Northwest Point Blvd., the abdomen). Elk Grove Village, IL 60007-1098. (847) 434-4000. <www.aap.org>. American College of Radiology. 1891 Preston White Dr., Normal results Reston, VA 20191-4397. (800) 227-5463. <www.acr. If intussusception is treated in a timely manner, org>. most patients are expected to recover fully, retain normal bowel function, and have only a small chance of recur- Stephanie Dionne Sherk rence. The mortality rate is lowest among patients who are treated within the first 24 hours. Morbidity and mortality rates Intussusception recurs in approximately 1–4% of Iridectomy patients after surgery, compared to 5–10% after nonsur- Definition gical reduction. Adhesions form in up to 7% of patients who undergo surgical reduction. The rate of intussuscep- An iridectomy is a procedure in eye surgery in tion-related deaths in Western countries is less than 1%. which the surgeon removes a small, full-thickness piece 770 GALE ENCYCLOPEDIA OF SURGERY

of the iris, which is the colored circular membrane be- hind the cornea of the eye. An iridectomy is also known Iridectomy as a corectomy. In recent years, lasers have also been Iridectomy used to perform iridectomies. Purpose Incision Pupil Today, an iridectomy is most often performed to treat closed-angle glaucoma or melanoma of the iris. An iridectomy performed to treat glaucoma is sometimes Cornea called a peripheral iridectomy, because it removes a por- tion of the periphery or root of the iris. IrIs A. In some cases, an iridectomy is performed prior to cataract surgery in order to make it easier to remove the lens of the eye. This procedure is referred to as a preparatory iridectomy. Closed-angle glaucoma Flap of Closed-angle glaucoma is a condition in which fluid cornea pressure builds up inside the eye because the fluid, or aqueous humor, that is produced in the anterior chamber at the front of the eye cannot leave the chamber through the usual opening. This opening lies at the angle where the iris meets the cornea, which is the clear front portion of the exterior cover of the eye. In closed-angle glauco- B. ma, the fluid is blocked because a part of the iris has moved forward and closed off the angle. As a result, fluid pressure in the eye rises rapidly, which can damage the optic nerve and lead to blindness. About 10% of all cases of glaucoma reported in the United States is Iridectomy Iris closed-angle. This type of glaucoma is also called angle- closure glaucoma, acute congestive glaucoma, narrow- angle glaucoma, and pupillary block glaucoma. It usual- ly develops in only one eye at a time. Lens There are two major types of closed-angle glauco- ma: primary and secondary. Primary closed-angle glau- coma most commonly results from pupillary block, in which the iris closes off the angle when the pupil of the eye becomes dilated. In some cases, the blockage hap- pens only occasionally, as when the pupil dilates in dim light, in situations of high stress or anxiety, or in re- C. sponse to the drops instilled by a doctor during an eye Ciliary body Aqueous flow examination. This condition is referred to as intermittent, subacute, or chronic open-angle glaucoma. In other cases, the blockage is abrupt and complete, leading to an For an iridectomy, an incision is made in the cornea just attack of acute closed-angle glaucoma. In primary glau- below the iris (A). A piece of the iris is removed (B).This al- coma, the difference between the chronic or intermittent lows fluid to flow between the areas to the front and rear of forms and an acute attack is usually due to small varia- the iris (C). (Illustration by GGS Inc.) tions in the anatomical structure of the eye. These in- clude an unusually shallow anterior chamber; a lens that is thicker than average and situated further forward in the the iris and the cornea, which is about 45° in the normal eye; or a cornea that is smaller in diameter than average. eye. In addition, as people age, the lens tends to grow Any of these differences can narrow the angle between larger and thicker; this change may cause fluid pressure GALE ENCYCLOPEDIA OF SURGERY 771

Iridectomy WHERE IS IT PERFORMED? to replace the vitreous body in front of the retina follow- ing a vitrectomy. WHO PERFORMS THE PROCEDURE AND Melanoma of the iris Melanoma of the iris is a malignant tumor that devel- Iridectomies are performed by ophthalmologists, ops within the pigmented cells of the iris; it is not a cancer who are physicians who have completed four to that has developed elsewhere in the body and then spread five years of specialized training in the medical to the eye. Melanoma of the iris can, however, enlarge and and surgical treatment of eye disorders. Oph- gradually destroy the patient’s vision. If left untreated, it thalmology is one of 24 specialties recognized can also metastasize or spread to other organs—most by the American Board of Medical Specialties. commonly the liver—and eventually cause death. Laser iridotomies or iridectomies are done as an outpatient procedure, either in the oph- Demographics thalmologist’s office or in an ambulatory surgery center. Surgical iridectomy is done in Closed-angle glaucoma affects between 350,000 an operating room, either in a surgery center and 400,000 people in the United States; in some Asian that specializes in ophthalmology or in a spe- countries such as China, however, it is more common cialized eye hospital. than open-angle glaucoma. Risk factors for closed-angle glaucoma include: • a family history of this type of glaucoma to build up behind the iris. Eventually, pressure from the • farsightedness aqueous humor may force the iris forward, blocking the drainage angle. • small eyes Secondary closed-angle glaucoma results from • age over 40 changes in the angle caused by disorders, medications, • scarring inside the eye from diabetes or uveitis trauma, or surgery, rather than by the anatomy of the eye • a cataract in the lens that is growing itself. In some cases, the iris is pulled up into the angle by scar tissue resulting from the abnormal formation of • Eskimo or Asian heritage (Eskimos have the highest blood vessels in diabetes. Another common cause of sec- rate of closed-angle glaucoma of any ethnic group) ondary closed-angle glaucoma is uveitis, or inflamma- Melanoma of the iris is a relatively rare form of can- tion of the uvea, which is the covering of the eye that in- cer, representing only about 10% of cases of intraocular cludes the iris. Cases have been reported in which uveitis melanoma. The American Cancer Society estimates that related to HIV infection has led to closed-angle glauco- about 220 cases of melanoma of the iris are diagnosed in ma. Melanoma of the iris has also been associated with the United States each year. People over 50 are the most closed-angle glaucoma. likely to develop this form of cancer, although it can Any medication that causes the pupil of the eye to occur at any age. It appears to affect men and women dilate may cause an acute attack of closed-angle glauco- equally. Melanoma of the iris is more common in Cau- ma, including antihistamines and over-the-counter cold casians and in people with light-colored irides than in preparations. Medications that are given to treat anxiety people of Asian or African descent. Suspected causes in- and depression, particularly the tricyclic antidepressants clude genetic mutations and exposure to sunlight. and the selective serotonin reuptake inhibitors (SSRIs), may trigger the onset of closed-angle glaucoma in some Description patients. In other instances, anesthesia for procedures on other parts of the body produces an acute attack. Laser iridotomy/iridectomy In terms of trauma, a direct blow to the eye can dis- A person who is at risk for an acute episode of locate the lens, bringing it forward and blocking the closed-angle glaucoma or who has already had emer- angle; overly vigorous exercise may have the same ef- gency medical treatment for an attack may be treated fect. Lastly, certain types of eye surgery performed to with a laser iridotomy to reduce the level of fluid pres- treat other conditions may result in secondary closed- sure in the affected eye. The drawback of a laser iridoto- angle glaucoma. These procedures include implantation my in treating closed-angle glaucoma is that the hole of an intraocular lens; cataract surgery; scleral buckling may not remain open, requiring repeated iridotomies, a to treat retinal detachment; and injection of silicone oil laser iridectomy, or a surgical iridectomy. In addition, 772 GALE ENCYCLOPEDIA OF SURGERY

laser iridotomies have a higher rate of success when used preventively rather than after the patient has already had QUESTIONS TO ASK an acute attack. THE DOCTOR Iridectomy To perform a laser iridotomy, the ophthalmologist uses a laser, usually an argon or an Nd:YAG laser, to • What are the alternatives to a surgical iridec- burn a small hole into the iris to relieve fluid pressure be- tomy for my condition? hind the iris. If the procedure is an iridectomy, the laser • What are the risks of my having an acute at- is used to remove a full-thickness section of the iris. The tack of closed-angle glaucoma? patient sits in a special chair with his or her chin resting • What further treatment would you recom- on a frame or support to prevent the head from moving. mend if an iridectomy is unsuccessful? The ophthalmologist numbs the eye with anesthetic eye drops. After the anesthetic has taken effect, the doctor shines the laser beam into the affected eye. The entire procedure takes between 10–30 minutes. with a local anesthetic and touches the outside of the cornea with the gonioscopic lens. He or she can use a slit Conventional (surgical) iridectomy lamp to magnify what appears on the lens. Patients with subacute, intermittent, or chronic closed-angle glaucoma Melanoma of the iris is usually treated by surgical can then be treated before they develop acute symptoms. iridectomy to prevent the tumor from causing secondary closed-angle glaucoma and from spreading to other parts If the patient is having a sudden attack of closed- of the body. angle glaucoma, he or she will feel intense pain, and is likely to be seen on an emergency basis with the follow- A surgical iridectomy is a more invasive procedure ing symptoms: that requires an operating room. The patient lies on an operating table with a piece of sterile cloth placed around • nausea and vomiting the eye. The procedure is usually done under general • severe pain in or above the eye anesthesia. The surgeon uses a microscope and special • visual disturbances that include seeing halos around miniature instruments to make an incision in the cornea lights and hazy or foggy vision and remove a section of the iris, usually at the 12 o’clock position. The incision in the cornea is self-sealing. • headache • redness and watering in the affected eye Diagnosis/Preparation • a dilated pupil that does not close normally in bright light Closed-angle glaucoma These symptoms are produced by the sharp rise in Closed-angle glaucoma may be diagnosed in the intraocular pressure (IOP) that occurs when the angle is course of a routine eye examination or during emergency completely blocked. This increase can occur in a matter treatment for symptoms of an acute attack. A doctor who of hours and cause permanent loss of vision in as little as is performing a standard eye examination may notice two to five days. An acute attack of closed-angle glauco- that the patient’s eye has a shallow anterior chamber or a ma is a medical emergency requiring immediate treat- narrow angle between the iris and the cornea. He or she ment. Emergency treatment includes application of eye may perform one or both of the following tests to evalu- drops to reduce the pressure in the eye quickly, other eye ate the patient’s risk of developing closed-angle glauco- drops to shrink the size of the pupil, and acetazolamide ma. One test, called tonometry, measures the amount of or a similar medication to stop the production of aqueous fluid pressure in the eye. It is a painless procedure that humor. In severe cases, the patient may be given drugs involves blowing a puff of pressurized air toward the pa- intravenously to lower the intraocular pressure. After the tient’s eye as the patient sits near a lamp and measuring pressure has been relieved with medications, the eye will the changes in the light reflections on the patient’s require surgical treatment. corneas. Other methods of tonometry involve the appli- cation of a local anesthetic to the outside of the eye and Melanoma of the iris touching the cornea briefly with an instrument that mea- sures the fluid pressure directly. The second test, go- Melanoma of the iris is usually discovered in the nioscopy, involves the use of a special mirrored contact course of a routine eye examination because it will be lens to evaluate the anatomy of the angle between the iris visible to the ophthalmologist as he or she looks through and the cornea. The doctor numbs the outside of the eye the pupil in the center of the iris. A melanoma on the iris GALE ENCYCLOPEDIA OF SURGERY 773

Iridectomy KEY TERMS Angle—The open point in the anterior chamber of the eye at which the iris meets the cornea. Block- Ocular melanoma—A malignant tumor that arises within the structures of the eye. It is the most com- age of the angle prevents fluid from leaving the an- mon eye tumor in adults. terior chamber, resulting in closed-angle glaucoma. Ophthalmology—The branch of medicine that Aqueous humor—The watery fluid produced in deals with the diagnosis and treatment of eye dis- the eye that ordinarily leaves the eye through the orders. angle of the anterior chamber. Pupil—The opening in the center of the iris of the Corectomy—Another term for iridectomy. eye that allows light to enter the eye. Cornea—The transparent front portion of the exte- Tonometry—Measurement of the fluid pressure in- rior cover of the eye. side the eye. Enucleation—Surgical removal of the eyeball. Tunica (plural, tunicae)—The medical term for a Glaucoma—A group of eye disorders characterized membrane or piece of tissue that covers or lines a by increased fluid pressure inside the eye that even- body part. The eyeball is surrounded by three tuni- tually damages the optic nerve. As the cells in the cae. optic nerve die, the patient gradually loses vision. Uvea—The middle of the three tunicae surround- Gonioscopy—A technique for examining the angle ing the eye, comprising the choroid, iris, and cil- between the iris and the cornea with the use of a iary body. The uvea is pigmented and well sup- special mirrored lens applied to the cornea. plied with blood vessels. Iridotomy—A procedure in which a laser is used Uveitis—Inflammation of any part of the uvea. to make a small hole in the iris to relieve fluid pressure in the eye. Vitrectomy—Surgical removal of the vitreous body. Iris (plural, irides)—The circular pigmented mem- Vitreous body—The transparent gel that fills the brane behind the cornea of the eye that gives the inner portion of the eyeball between the lens and eye its color. The iris surrounds a central opening the retina. It is also called the vitreous humor or called the pupil. crystalline humor. may look like a dark spot or ring, or it may resemble for a conventional iridectomy are asked to avoid eating tapioca. The doctor can perform a gonioscopy, and use or drinking for about eight hours before the procedure. specialized imaging studies to rule out other possible eye disorders. An ultrasound study can be made by using a small probe placed on the eye that directs sound waves Aftercare in the direction of the tumor. Another test is called fluo- Short-term aftercare following laser iridectomy or rescein angiography, which involves injecting a fluores- iridotomy is minimal. Patients are asked to make arrange- cent dye into a vein in the patient’s arm. As the dye cir- ments for someone to drive them home after surgery, but culates throughout the body, it is carried to the blood can usually go to work the next day and resume other ac- vessels in the back of the eye. These blood vessels can be tivities with no restrictions. They should not need any photographed through the pupil. medication stronger than aspirin for discomfort. In a minority of patients, melanoma of the iris is dis- Short-term aftercare following a surgical iridecto- covered because the patient is experiencing eye pain re- my includes wearing a patch over the affected eye for sulting from a rise in IOP caused by tumor growth. several days and using eye drops to minimize the risk of infection. The surgeon may also prescribe medica- tion for discomfort. It will take about six weeks for vi- Preparation for treatment sion to return to normal. Long-term aftercare following Patients scheduled for a laser iridotomy or iridecto- an iridectomy for closed-angle glaucoma usually in- my are not required to fast or make other special prepa- volves taking medications to help control the fluid rations before the procedure. They may, however, be pressure in the eye and seeing the ophthalmologist for given a sedative to help them relax. Patients scheduled periodic checkups. 774 GALE ENCYCLOPEDIA OF SURGERY

Aftercare for melanoma of the iris includes eye Alternatives to iridectomy in the treatment of checkups to be certain that the tumor has not recurred. In melanoma of the iris include watchful waiting, periodic addition, patients are advised to reduce their exposure to eye examinations, and the use of medication to control Iridectomy sunlight and other sources of ultraviolet light. any symptoms of closed-angle glaucoma. See also Laser iridotomy. Risks Resources The risks of a laser iridotomy or iridectomy include the following: BOOKS “Angle-Closure Glaucoma.” In The Merck Manual of Diagno- • irritation in the eye for two to three days after the pro- sis and Therapy, edited by Mark H. Beers and Robert cedure Berkow. Whitehouse Station, NJ: Merck Research Labo- • bleeding ratories, 1999. • scarring PERIODICALS • failure to relieve fluid pressure in the eye Aung, T., and P. T. Chew. “Review of Recent Advancements in the Understanding of Primary Angle-Closure Glaucoma.” The risks of a conventional iridectomy include: Current Opinion in Ophthalmology 13 (April 2002): • infection 89–93. Cardine, S., et al. “Iris Melanomas. A Retrospective Study of • bleeding 11 Patients Treated by Surgical Excision.” [in French] • scarring in the area of the incision Journal français d’ophtalmologie 26 (January 2003): • failure to relieve fluid pressure 31–37. Chang, B. M., J. M. Liebmann, and R. Ritch. “Angle Closure • formation of a cataract in Younger Patients.” Transactions of the American Oph- The risks of an iridectomy for melanoma of the iris thalmological Society 100 (2002): 201–212. include glaucoma resulting from the formation of new Goldberg, D. E., and W. R. Freeman. “Uveitic Angle Closure blood vessels near the angle, cataract formation, and re- Glaucoma in a Patient with Inactive Cytomegalovirus Re- currence of the tumor. In the event of a recurrence, the tinitis and Immune Recovery Uveitis.” Ophthalmic Surgery standard treatment is enucleation, or surgical removal of and Lasers 33 (September–October 2002): 421–425. Jackson, T. L., et al. “Pupil Block Glaucoma in Phakic and the entire eye. Pseudophakic Patients After Vitrectomy with Silicone Oil Inhection.” American Journal of Ophthalmology 132 Normal results (September 2001): 414–416. Normal results for a laser-assisted or conventional Jacobi, P. C., et al. “Primary Phacoemulsification and Intraocu- lar Lens Implantation for Acute Angle-Closure Glauco- iridectomy are long-term lowering of IOP and/or com- ma.” Ophthalmology 109 (September 2002): 1597–1603. plete removal of a melanoma on the iris. Jiminez-Jiminez, F. J., M. Orti-Pareja, and J. M. Zurdo. “Ag- gravation of Glaucoma with Fluvoxamine.” Annals of Morbidity and mortality rates Pharmacotherapy 35 (December 2001): 1565–1566. About 60% of patients who have had conventional Kumar, A., S. Kedar, V. K. Garodia, and R. P. Singh. “Angle iridectomies consider the operation a success; 15%, on Closure Glaucoma Following Pupillary Block in an Aphakin Perfluoropropane Gas-Filled Eye.” Indian Jour- the other hand, maintain that their vision was better be- nal of Ophthalmology 50 (September 2002): 220–221. fore the procedure. Lentschener, C., et al. “Acute Postoperative Glaucoma After Fortunately for patients, melanoma of the iris is a Nonocular Surgery Remains a Diagnostic Challenge.” relatively slow-growing form of cancer; it metastasizes Anesthesia and Analgesia 94 (April 2002): 1034–1035. to the liver in only 2–4% of cases. If treated promptly, it Schwartz, G. P., and L. W. Schwartz. “Acute Angle Closure has a high survival rate of 95–97% after five years. Glaucoma Secondary to a Choroidal Melanoma.” CLAO Journal 28 (April 2002): 77–79. Shields, C. L., et al. “Factors Associated with Elevated Intraoc- Alternatives ular Pressure in Eyes with Iris Melanoma.” British Jour- nal of Ophthalmology 85 (June 2001): 666–669. Alternatives to a conventional iridectomy for the Shields, C. L., et al. “Iris Melanoma: Risk Factors for Metasta- treatment of closed-angle glaucoma include repeated sis in 169 Consecutive Patients.” Ophthalmology 108 laser iridotomies or the long-term use of such medica- (January 2001): 172–178. tions as pilocarpine. Another surgical alternative, which Waheed, Nadia K., and C. Stephen Foster. “Melanoma, Iris.” is most commonly done when the size of the lens is a eMedicine February 28, 2003 [cited April 2, 2003]. factor in pupillary block, is removal of the lens. <http://www.emedicine.com/oph/topic405.htm>. GALE ENCYCLOPEDIA OF SURGERY 775

Islet cell transplantation Wang, N., H. Wu, and Z. Fan. “Primary Angle Closure Glauco- A specialist in transplantation would perform ma in Chinese and Western Populations.” Chinese Med- WHO PERFORMS ical Journal 115 (November 2002): 1706–1715. THE PROCEDURE AND WHERE IS IT PERFORMED? ORGANIZATIONS American Academy of Ophthalmology. P. O. Box 7424, San Francisco, CA 94120-7424. (415) 561-8500. <http:// www.aao.org>. this procedure, and it would be done in a spe- Canadian Ophthalmological Society (COS). 610-1525 Carling Avenue, Ottawa ON K1Z 8R9 Canada. <http://www.eye about 15 centers around the world are perform- site.ca>. cialized center for diabetic research. Currently, ing this procedure. National Eye Institute. 2020 Vision Place, Bethesda, MD 20892-3655. (301) 496-5248. <http://www.nei.nih.gov>. Prevent Blindness America. 500 East Remington Road, Schaumburg, IL 60173. (800) 331-2020. <http://www. creas removed or damaged from other medical condi- prevent-blindness.org>. tions or injuries. Wills Eye Hospital. 840 Walnut Street, Philadelphia, PA 19107. (215) 928-3000. <http://www.willseye.org>. Demographics OTHER National Cancer Institute (NCI) Physician Data Query (PDQ). An estimated 120–140 million people worldwide Intraocular (Eye) Melanoma: Treatment January 2, 2003 suffer from type 1 diabetes and could benefit from this [cited April 2, 2003]. <http://www.nci.nih.gov/cancerinfo/ procedure. However, islet cell transplantation remains pdq/treatment/intraocularmelanoma/healthprofessional>. highly experimental at this time and occurs only as part National Eye Institute (NEI). Facts About Glaucoma. 2001. of a clinical trial. The latest available data from the Inter- NIH Publication No. 99–651. national Islet Transplant Registry indicate that, as of De- Prevent Blindness America. Vision Problems in the U.S.: Prevalence of Adult Vision Impairment and Age-Related cember 2000, about 500 procedures had been performed. Eye Disease in America. 2002. Tanasescu, I., and F. Grehn. “Advantage of Surgical Iridectomy Description Over Nd:YAG Laser Iridotomy in Acute Primary Angle Closure Glaucoma.” Presentation on September 29, 2001, The transplantation procedure is very straightfor- at the 99th annual meeting of the Deutsche Ophthalmolo- ward, relatively noninvasive, and takes less than an gische Gesellschaft. <http://www.dog.org/2001/abstract- hour to complete. After the patient is given light seda- german/Tanasescu-e.htm>. tion, the surgeon begins by using an ultrasound to guide the placement of a small plastic tube, known as a Rebecca Frey, PhD catheter, through the upper abdomen into the liver. The liver is used as the site for transplantation because the portal vein of liver is larger and easier to access than Irodotomy see Laser iridotomy the veins that supply the pancreas, also, it is known that islet cells that grow in the liver closely mimic normal insulin secretion. Once the catheter is in place, the surgeon takes the cells that have been extracted from the donor pancreas Islet cell transplantation and infuses them into the liver. Extraction is done as close as possible to the time of transplantation because Definition of the fragility of the islet cells. The extraction process uses specialized enzymes to isolate the islet cells from Pancreatic islet cell transplantation involves taking the other cell types found in the pancreas. Only 1–2% of the cells that produce insulin from a second source such the pancreas is made up of islet cells, an average of two as a donor pancreas and transplanting them into a patient. pancreases are needed for one successful transplant. Recent study has shown that the use of perfluorocar- Purpose bon in the solution that preserves the pancreas before Once transplanted, the new islet cells make and re- transplant allows older organs to be used as islet cell lease insulin. Islet cell transplantation is primarily a donors. New techniques have also been developed that treatment method for type 1 (juvenile) diabetes, but it allow the organs to be transported before being used for can also be used to treat patients who have had their pan- transplantation. These developments are initial steps to 776 GALE ENCYCLOPEDIA OF SURGERY

relieving the extreme shortage of donor pancreases need- ed for the procedure. QUESTIONS TO ASK During the infusion process, the cells travel through THE DOCTOR the portal vein and become lodged in the capillaries of the liver, where they remain to produce insulin as they • What are the chances that the procedure will Islet cell transplantation normally would in the pancreas. allow me to no longer require insulin or is being able to reduce the amount that I use a more realistic outcome? Diagnosis/Preparation • Will the immunosuppression before my pro- To qualify as a candidate for islet cell transplanta- cedure involve the use of steroids? tion, the patient must suffer from type 1 (juvenile) dia- betes and current insulin treatment methods must be in- • What are my risks concerning long-term use sufficient. For example, some participants suffer from hy- of immunosuppressive drugs? poglycemic unawareness, a condition where low blood sugar will cause very dangerous, unpredictable blackouts that cannot be controlled with insulin injections. The po- tential patient must also undergo extensive medical and It takes some time for the cells to attach to the liver psychological tests to determine their physical and men- blood vessels and begin producing insulin. Until then, tal appropriateness for enrollment in the trial. If the re- numerous blood glucose tests are performed, and inject- sults of these tests support the candidacy, then sufficient ed insulin is used to keep blood glucose levels within donor pancreas tissue in the patient’s blood type must be normal ranges. located. The patient is placed on an organ donor list. Waiting for more than a year is common. Risks In response to this long wait, research is ongoing to Until recently, success rates for this procedure were provide alternative sources of donor islet cells such as not promising. With success being defined as not requir- animal cells, a process known as a xenograft. Pigs are a ing insulin for a full year after transplantation, the success particularly advantageous source of islet cells because rate from 1998–2000 was only about 14% of patients human and pig insulin proteins differ by only one amino transplanted. However, newer procedures have been acid, and there is an extensive amount of fresh pancreas- achieving at least short-term success rates approaching es available from the pork industry. Other potential 80–100%, making the possibility of widespread use of sources of donor islets cells include embryonic stem this procedure much more feasible in the near future. cells and cell lines of islet beta cells. Because of the newness of these procedures, the Prior to the transplantation, the patient must undergo long-term success rate of these new protocols is not yet a drug regime that suppresses the immune system so that known. Graft death is significant risk even years after a the new cells will be accepted. Even though only cells successful transplant. The longest reported successful are being transplanted, the amount of immunosuppres- graft using the older protocols was six years. As time sion is the same as that required for a whole organ trans- goes on, the ability of the graft transplanted using the plant. Current protocols for islet transplantation use a new protocols and sustained by the new immunosuppres- mixture of non-steroidal drugs, as those that include sive drug mixtures will be determined. steroids have been shown to aggravate the diabetic con- dition of the patient and inhibit the insulin-producing A third important risk is the long-term use of im- function of the transplanted cells. munosuppressive drugs by the patient. There is relatively little experience with the long-term use of these drugs, Future research in this area may include the use of so it is difficult to predict what the exact physical effects monoclonal antibody therapy to induce tolerance in pa- long-term immunosuppression may have. Some of the tients prior to transplantation. known side effects include high blood pressure, toxicity of the kidneys, and opportunistic infections. Aftercare Recovery time from the procedure itself is minimal. Alternatives However, current technology requires that patients con- tinuously remain on immunosuppressive drugs to avoid One alternative to islet cell transplantation is a trans- rejection of the new islet cells. Side effects from these plant with a whole pancreas, a much more invasive pro- drugs can increase the amount of time that the patient cedure. Whole organ transplant has historically had a must remain hospitalized. better success rate than islet transplantation. However, GALE ENCYCLOPEDIA OF SURGERY 777

ology, and Disease, edited by Vay Liang W. Go, et al. New Islet cell transplantation Immunosuppression—A drug-induced state that Robertson, R. Paul. “Pancreas and Islet Transplantation.” In York: Raven Press, 1993. KEY TERMS Endocrinology, edited by Leslie J. DeGroot, et al. Philadelphia: W.B. Saunders Company, 2001. prevents rejection of transplanted body parts. PERIODICALS Invasive—Used to describe a procedure that in- “Islet Cell Transplantation for Diabetes Turns Corner.” Science volves surgical cutting into the body. Daily Magazine (August 28, 2002). Islet cell—The cell type within the pancreas that produces insulin. day Evening Post (January/February 2002): 38–43. Portal vein—The main vessel that carries blood to Perry, Patrick. “Zeroing in on a Cure for Diabetes.” The Satur- ORGANIZATIONS the liver. American Diabetes Association. 1701 North Beauregard Street, Steroids—A component of commonly used im- Alexandria, VA 22311. (800) 342-2383. <www.diabetes. munosuppressive drugs that have negative effects org>. on insulin production. Immune Tolerance Network (ITN). 5743 South Drexel Avenue, Suite 200, Chicago, IL 60637. (773) 834-5341. <www. immunetolerance.org>. newer islet cell transplant protocols are approaching Michelle Johnson, MS, JD whole organ results, thus overcoming one of the most important differences between the two procedures. IV rehydration see Intravenous rehydration Resources Joint radiography see Arthrography BOOKS Joint resection see Arthroplasty Farney, Alan C., and David E. R. Sutherland. “Pancrease and Islet Transplantation.” In The Pancreas: Biology, Pathobi- Joint x rays see Arthrography 778 GALE ENCYCLOPEDIA OF SURGERY

K Keratoplasty see Corneal transplantation WHO PERFORMS Ketone test see Urinalysis THE PROCEDURE AND WHERE IS IT PERFORMED? The dialysis treatment prescription and regimen is usually overseen by a nephrologist (a doctor Kidney dialysis that specializes in the kidney). The hemodialy- Definition sis treatment itself is typically administered by a nurse or patient care technician in outpatient Dialysis treatment replaces the function of the kid- clinics known as dialysis centers, or in hospital- neys, which normally serve as the body’s natural filtra- based dialysis units. In-home hemodialysis tion system. Through the use of a blood filter and a treatment is also an option for some patients, chemical solution known as dialysate, the treatment re- although access to this type of treatment may moves waste products and excess fluids from the blood- be limited by financial and lifestyle factors. An stream, while maintaining the proper chemical balance investment in equipment is required and anoth- of the blood. There are two types of dialysis treatment: er person in the household should be available hemodialysis and peritoneal dialysis. for support and assistance with treatments. Peritoneal dialysis is also performed at home by Purpose the patient, perhaps with the aide of a home health-care worker. Dialysis is most commonly prescribed for patients with temporary or permanent kidney failure. People with end-stage renal disease (ESRD) have kidneys that are no longer capable of adequately removing fluids and wastes (USRDS), 42% of non-Hispanic dialysis patients in the from their body or of maintaining the proper level of cer- United States have ESRD caused by diabetes. People of tain kidney-regulated chemicals in the bloodstream. For Native American and Hispanic descent are at an elevated these individuals, dialysis is the only treatment option high risk for both kidney disease and diabetes. ESRD available outside of kidney transplantation. Dialysis caused by diabetes occurred in 65% of Hispanic dialysis may also be used to simulate kidney function in patients patients. And of those Native Americans who had been on awaiting a transplant until a donor kidney becomes avail- dialysis for one year in 1999, 82% had diabetes. able. Also, dialysis may be used in the treatment of pa- tients suffering from poisoning or overdose in order to Hypertension (high blood pressure) is the second quickly remove drugs from the bloodstream. leading cause of ESRD in adults, accounting for 25.5% of the patient population, followed by glomerulonephri- Demographics tis (8.4%). African-Americans are more likely to develop hypertension-related ESRD than whites and Hispanics. As of December 31, 2000, in the United States, over 275,000 people were undergoing regular dialysis treat- Among children and young adults under 20 on dial- ments to manage their ESRD. Diabetes mellitus is the ysis, glomerulonephritis is the leading cause of ESRD leading single cause of ESRD. According to the 2002 An- (31%), and hereditary, cystic, and congenital diseases ac- nual Data Report of the United States Renal Data System count for 37%. Pediatric patients typically spend less GALE ENCYCLOPEDIA OF SURGERY 779

Kidney dialysis Nurse working in a kidney dialysis unit. (Custom Medical Stock Photo. Reproduced by permission.) time on dialysis than adults; according to the USRDS the hollow fiber dialyzers. A hollow fiber dialyzer is com- average waiting period for a kidney transplant for pa- posed of thousands of tube-like hollow fiber strands en- tients under age 20 is 10 months, compared to the adult cased in a clear plastic cylinder several inches in diame- wait of approximately two years. ter. There are two compartments within the dialyzer (the blood compartment and the dialysate compartment). Description The membrane that separates these two compart- ments is semipermeable. This means that it allows the There are two types of dialysis treatment: hemodial- passage of certain sized molecules across it, but prevents ysis and peritoneal dialysis. the passage of other, larger molecules. As blood is pushed through the blood compartment in one direction, Hemodialysis suction or vacuum pressure pulls the dialysate through the dialysate compartment in a countercurrent, or oppo- Hemodialysis is the most frequently prescribed type site direction. These opposing pressures work to drain of dialysis treatment in the United States. The treatment excess fluids out of the bloodstream and into the involves circulating the patient’s blood outside of the dialysate, a process called ultrafiltration. body through an extracorporeal circuit (ECC), or dialysis circuit. Two needles are inserted into the patient’s vein, A second process called diffusion moves waste or access site, and are attached to the ECC, which con- products in the blood across the membrane and into the sists of plastic blood tubing, a filter known as a dialyzer dialysate compartment, where they are carried out of the (artificial kidney), and a dialysis machine that monitors body. At the same time, electrolytes and other chemicals and maintains blood flow and administers dialysate. in the dialysate solution cross the membrane into the Dialysate is a chemical bath that is used to draw waste blood compartment. The purified, chemically balanced products out of the blood. blood is then returned to the body. Since the 1980s, the majority of hemodialysis treat- Most hemodialysis patients require treatment three ments in the United States have been performed with times a week, for an average of three to four hours per 780 GALE ENCYCLOPEDIA OF SURGERY

dialysis “run.” Specific treatment schedules depend on the type of dialyzer used and the patient’s current physi- QUESTIONS TO ASK cal condition. THE DOCTOR Kidney dialysis Blood pressure changes associated with hemodialy- sis may pose a risk for patients with heart problems. • When and where will my dialysis treatments Peritoneal dialysis may be the preferred treatment option be scheduled? in these cases. • How should my diet change now that I’m on dialysis? Peritoneal dialysis • What kind of vascular access will I get? In peritoneal dialysis, the patient’s peritoneum, or lin- • Does my new dialysis center have a dialyzer ing of the abdomen, acts as a blood filter. A catheter is sur- reuse program? If so, what safety checks are gically inserted into the patient’s abdomen. During treat- in place to ensure I receive a properly treated ment, the catheter is used to fill the abdominal cavity with dialyzer? dialysate. Waste products and excess fluids move from the • What can I do to make dialysis more effective? patient’s bloodstream into the dialysate solution. After a • Can you refer me to any ESRD patient sup- waiting period of six to 24 hours, depending on the treat- port groups? ment method used, the waste-filled dialysate is drained • Should I change my medication routine? from the abdomen and replaced with clean dialysate. There are three types of peritoneal dialysis: • Continuous ambulatory peritoneal dialysis (CAPD). CAPD is a continuous treatment that is self-adminis- tient is assessed for physical changes since their last dialysis tered and requires no machine. The patient inserts fresh run. Regular blood tests monitor chemical and waste levels dialysate solution into the abdominal cavity, waits four in the blood. Prior to treatment, patients are typically ad- to six hours, and removes the used solution. The solu- ministered a dose of heparin, an anticoagulant that prevents tion is immediately replaced with fresh dialysate. A bag blood clotting, to ensure the free flow of blood through the attached to the catheter is worn under clothing. dialyzer and an uninterrupted dialysis run for the patient. • Continuous cyclic peritoneal dialysis (CCPD). Also called automated peritoneal dialysis (APD), CCPD is Aftercare an overnight treatment that uses a machine to drain and Both hemodialysis and peritoneal dialysis patients refill the abdominal cavity, CCPD takes 10 to 12 hours need to be vigilant about keeping their access sites and per session. catheters clean and infection-free during and between • Intermittent peritoneal dialysis (IPD). This hospital- dialysis runs. based treatment is performed several times a week. A Dialysis is just one facet of a comprehensive treat- machine administers and drains the dialysate solution, ment approach for ESRD. Although dialysis treatment is and sessions can take 12 to 24 hours. very effective in removing toxins and fluids from the Peritoneal dialysis is often the treatment option of body, there are several functions of the kidney it cannot choice in infants and children, whose small size can make mimic, such as regulating high blood pressure and red vascular (through a vein) access difficult to maintain. Peri- blood cell production. Patients with ESRD need to watch toneal dialysis can also be done outside of a clinical set- their dietary and fluid intake carefully and take medica- ting, which is more conducive to regular school attendance. tions as prescribed to manage their disease. Peritoneal dialysis is not recommended for patients with abdominal adhesions or other abdominal defects, Risks such as a hernia, that might compromise the efficiency of Many of the risks and side effects associated with the treatment. It is also not recommended for patients dialysis are a combined result of both the treatment and who suffer frequent bouts of diverticulitis, an inflamma- the poor physical condition of the ESRD patient. Dialy- tion of small pouches in the intestinal tract. sis patients should always report side effects to their healthcare provider. Diagnosis/Preparation Anemia Patients are weighed immediately before and after each hemodialysis treatment to evaluate their fluid reten- Hematocrit (Hct) levels, a measure of red blood tion. Blood pressure and temperature are taken and the pa- cells, are typically low in ESRD patients. This deficiency GALE ENCYCLOPEDIA OF SURGERY 781

Kidney dialysis Access site—The vein tapped for vascular access Erythropoietin—A hormone produced by the kid- KEY TERMS neys that stimulates the production of red blood in hemodialysis treatments. For patients with tem- porary treatment needs, access to the bloodstream is gained by inserting a catheter into the subcla- cells by bone marrow. ESRD—End-stage renal disease; chronic or perma- vian vein near the patient’s collarbone. Patients in nent kidney failure. long-term dialysis require stronger, more durable access sites, called fistulas or grafts, that are surgi- Extracorporeal circuit (ECC)—The path the he- cally created. modialysis patient’s blood takes outside of the body. It typically consists of plastic tubing, a he- Dialysate—A chemical bath used in dialysis to modialysis machine, and a dialyzer. draw fluids and toxins out of the bloodstream and supply electrolytes and other chemicals to the Glomerulonephritis—A disease of the kidney that bloodstream. causes inflammation and scarring and impairs the kidney’s ability to filter waste products from the Dialysis prescription—The general parameters of blood. dialysis treatment that vary according to each pa- tient’s individual needs. Treatment length, type of Hematocrit (Hct) level—A measure of red blood dialyzer and dialysate used, and rate of ultrafiltra- cells. tion are all part of the dialysis prescription. Glomerulonephritis—Kidney disease caused by scarring of the glomeruli, the small blood vessels Dialyzer—An artificial kidney usually composed in the nephrons, or filtering centers, of the kidneys. of hollow fiber which is used in hemodialysis to eliminate waste products from the blood and re- Peritoneum—The abdominal cavity; the peri- move excess fluids from the bloodstream. toneum acts as a blood filter in peritoneal dialysis. is caused by a lack of the hormone erythropoietin, which keep their access sites clean and watch for signs of red- is normally produced by the kidneys. The problem is ele- ness and warmth that could indicate infection. Peritoneal vated in hemodialysis patients, who may incur blood loss dialysis patients must follow the same precautions with during hemodialysis treatments. Epoetin alfa, or EPO their catheter. Peritonitis, an infection of the peritoneum, (sold under the trade name Epogen), a hormone therapy, causes flu-like symptoms and can disrupt dialysis treat- and intravenous or oral iron supplements are used to ments if not caught early. manage anemia in dialysis patients. Infectious diseases Cramps, nausea, vomiting, and headaches Some hemodialysis patients experience cramps and Because there is a great deal of blood exposure in- flu-like symptoms during treatment. These can be caused volved in dialysis treatment, a slight risk of contracting by a number of factors, including the type of dialysate hepatitis B and hepatitis C exists. The hepatitis B vacci- used, composition of the dialyzer membrane, water qual- nation is recommended for most hemodialysis patients. ity in the dialysis unit, and the ultrafiltration rate of the As of 2001, there has only been one documented case of treatment. Adjustment of the dialysis prescription often HIV being transmitted in a United States dialysis unit to helps alleviate many symptoms. a staff member, and no documented cases of HIV ever being transmitted between dialysis patients in the United Hypotension States. The strict standards of infection control practiced in modern hemodialysis units minimizes the chance of Because of the stress placed on the cardiovascular contracting one of these diseases. system with regular hemodialysis treatments, patients are at risk for hypotension, a sudden drop in blood pres- sure. This can often be controlled by medication and ad- justment of the patient’s dialysis prescription. Normal results Because dialysis is an ongoing treatment process for Infection many patients, a baseline for normalcy can be difficult to Both hemodialysis and peritoneal dialysis patients gauge. Puffiness in the patient related to edema, or fluid are at risk for infection. Hemodialysis patients should retention, may be relieved after dialysis treatment. The 782 GALE ENCYCLOPEDIA OF SURGERY

patient’s overall sense of physical well being may also PERIODICALS be improved. Eknoyan G., G. J. Beck, et al. “Effect of Dialysis Dose and Membrane Flux in Maintenance Hemodialysis.” New Monthly blood tests to check the levels of urea, a England Journal of Medicine 347 (December 19, 2002): waste product, help to determine the adequacy of the dial- Kidney function tests 2010–2019. ysis prescription. Another test, called Kt/V (dialyzer clear- ance multiplied by time of treatment and divided by the ORGANIZATIONS total volume of water in the patient’s body), is also per- American Association of Kidney Patients. 3505 E. Frontage formed to assess patient progress. A urea reduction ratio Rd., Suite 315, Tampa, FL 33607. (800) 749-2257. (URR) of 65% or higher, and a Kt/V of at least 1.2 are <http://www.aakp.org>. American Kidney Fund (AKF). Suite 1010, 6110 Executive considered the benchmarks of dialysis adequacy by the Boulevard, Rockville, MD 20852. (800) 638-8299. Kidney Disease Outcomes Quality Initiative (K/DOQI) of <http://www.akfinc.org>. the National Kidney Foundation. National Kidney Foundation. 30 East 33rd St., Suite 1100, New York, NY 10016. (800) 622-9010. <http://www. Morbidity and mortality rates kidney.org>. United States Renal Data System (USRDS), Coordinating Cen- The USRDS reports that mortality rates for individ- ter. The University of Minnesota, 914 South 8th Street, uals on dialysis are also significantly higher than both Suite D-206, Minneapolis, MN 55404. 1-888-99USRDS. kidney transplant patients and the general population, <http://www.usrds.org>. and expected remaining lifetimes of chronic dialysis pa- tients are only one-fourth to one-fifth that of the general Paula Anne Ford-Martin population. The hospitalization rates for people with ESRD are four times greater than that of the general population. Alternatives Kidney function tests The only alternative to dialysis for ESRD patients is Definition a successful kidney transplant. However, demand for donor kidneys has traditionally far exceeded supply. As Kidney function tests is a collective term for a variety of March 1, 2003, there were 53,619 patients on the of individual tests and procedures that can be done to eval- United Network for Organ Sharing (UNOS) waiting list uate how well the kidneys are functioning. A doctor who for a kidney transplant, with an additional 2,405 waiting orders kidney function tests and uses the results to assess for a combination kidney and pancreas transplant. In the the functioning of the kidneys is called a nephrologist. entire year of 2001, only 14,095 donors gave kidneys, according to UNOS. Purpose For patients with diabetes, the number one cause of The kidneys, the body’s natural filtration system, chronic kidney failure in adults, the best way to avoid perform many vital functions, including removing meta- ESRD and subsequent dialysis is to maintain tight con- bolic waste products from the bloodstream, regulating the trol of blood glucose levels through diet, exercise, and body’s water balance, and maintaining the pH (acidity/al- medication. Controlling high blood pressure is also im- kalinity) of the body’s fluids. Approximately one and a portant. half quarts of blood per minute are circulated through the kidneys, where waste chemicals are filtered out and elim- Resources inated from the body (along with excess water) in the BOOKS form of urine. Kidney function tests help to determine if the kidneys are performing their tasks adequately. Cameron, J. S. Kidney Failure: The Facts. New York: Oxford University Press, 1999. National Kidney Foundation. Dialysis Outcomes Quality Ini- Precautions tiatives (NOQI). Vol. 1-5. New York: National Kidney The doctor should take a complete history prior to Foundation, 1997. conducting kidney function tests to evaluate the pa- U.S. Renal Data System. USRDS 2002 Annual Data Report: tient’s food and drug intake. A wide variety of prescrip- Atlas of End-Stage Renal Disease in the United States. Bethesda, MD: The National Institutes of Health, National tion and over-the-counter medications can affect blood Institute of Diabetes and Digestive and Kidney Diseases, and urine kidney function test results, as can some food 2002. and beverages. GALE ENCYCLOPEDIA OF SURGERY 783

Description Kidney function tests to carry out their vital functions. Some conditions can the urine, making creatinine clearance a very specific measurement of kidney function. The test is performed Many conditions can affect the ability of the kidneys on a timed urine specimen—a cumulative sample col- lected over a two to 24-hour period. Determination of lead to a rapid (acute) decline in kidney function; others the blood creatinine level is also required to calculate lead to a gradual (chronic) decline in function. Both can the urine clearance. result in a build-up of toxic waste substances in the blood. A number of clinical laboratory tests that measure ated by protein metabolism and excreted in the urine. the levels of substances normally regulated by the kid- • Urea clearance test. Urea is a waste product that is cre- neys can help to determine the cause and extent of kid- The urea clearance test requires a blood sample to mea- ney dysfunction. Urine and blood samples are used for sure the amount of urea in the bloodstream and two these tests. urine specimens, collected one hour apart, to determine the amount of urea that is filtered, or cleared, by the The nephrologist uses these results in a number of kidneys into the urine. ways. Once a diagnosis is made that kidney disease is • Urine osmolality test. Urine osmolality is a measurement present and what kind of kidney disease is causing the of the number of dissolved particles in urine. It is a more problem, the nephrologist may recommend a specific precise measurement than specific gravity for evaluating treatment. Although there is no specific drug therapy that the ability of the kidneys to concentrate or dilute the will prevent the progression of kidney disease, the doctor urine. Kidneys that are functioning normally will excrete will make recommendations for treatment to slow the more water into the urine as fluid intake is increased, di- disease as much as possible. For instance, the doctor luting the urine. If fluid intake is decreased, the kidneys might prescribe blood pressure medications, or treat- excrete less water and the urine becomes more concen- ments for patients with diabetes. If kidney disease is get- trated. The test may be done on a urine sample collected ting worse, the nephrologist may discuss hemodialysis first thing in the morning, on multiple timed samples, or (blood cleansing by removal of excess fluid, minerals, on a cumulative sample collected over a 24-hour period. and wastes) or kidney transplantation (surgical proce- The patient will typically be prescribed a high-protein dure to implant a healthy kidney into a patient with kid- diet for several days before the test and be asked to drink ney disease or kidney failure) with the patient. no fluids the night before the test. Laboratory tests • Urine protein test. Healthy kidneys filter all proteins from the bloodstream and then reabsorb them, allowing There are a number of urine tests that can be used no protein, or only slight amounts of protein, into the to assess kidney function. A simple, inexpensive screen- urine. The persistent presence of significant amounts of ing test—a routine urinalysis—is often the first test con- protein in the urine, then, is an important indicator of ducted if kidney problems are suspected. A small, ran- kidney disease. A positive screening test for protein (in- domly collected urine sample is examined physically for cluded in a routine urinalysis) on a random urine sam- things like color, odor, appearance, and concentration ple is usually followed up with a test on a 24-hour urine (specific gravity); chemically, for substances such a pro- sample that more precisely measures the quantity of tein, glucose, and pH (acidity/ alkalinity); and micro- protein. scopically for the presence of cellular elements (red There are also several blood tests that can aid in blood cells [RBCs], white blood cells [WBCs], and ep- evaluating kidney function. These include: ithelial cells), bacteria, crystals, and casts (structures formed by the deposit of protein, cells, and other sub- • Blood urea nitrogen test (BUN). Urea is a byproduct of stances in the kidneys’s tubules). If results indicate a protein metabolism. Formed in the liver, this waste possibility of disease or impaired kidney function, one product is then filtered from the blood and excreted in or more of the following additional tests is usually per- the urine by the kidneys. The BUN test measures the formed to pinpoint the cause and the level of decline in amount of nitrogen contained in the urea. High BUN kidney function. levels can indicate kidney dysfunction, but because BUN is also affected by protein intake and liver func- • Creatinine clearance test. This test evaluates how effi- tion, the test is usually done together with a blood crea- ciently the kidneys clear a substance called creatinine tinine, a more specific indicator of kidney function. from the blood. Creatinine, a waste product of muscle energy metabolism, is produced at a constant rate that • Creatinine test. This test measures blood levels of crea- is proportional to the individual’s muscle mass. Be- tinine, a by-product of muscle energy metabolism that, cause the body does not recycle it, all creatinine filtered similar to urea, is filtered from the blood by the kidneys by the kidneys in a given amount of time is excreted in and excreted into the urine. Production of creatinine 784 GALE ENCYCLOPEDIA OF SURGERY

KEY TERMS Blood urea nitrogen (BUN)—The nitrogen portion solved in it. Values are expressed as milliosmols Kidney function tests of urea in the bloodstream. Urea is a waste prod- per kilogram (mOsm/kg) of water. uct of protein metabolism in the body. Nephrologist—A doctor specializing in kidney dis- Creatinine—The metabolized by-product of creati- ease. nine, an organic compound that assists the body in producing muscle contractions. Creatinine is Specific gravity—The ratio of the weight of a body found in the bloodstream and in muscle tissue. It is fluid when compared with water. removed from the blood by the kidneys and ex- creted in the urine. Urea—A by-product of protein metabolism that is formed in the liver. Because urea contains ammo- Creatinine clearance rate—The clearance of crea- nia, which is toxic to the body, it must be quickly tinine from the plasma compared to its appearance filtered from the blood by the kidneys and excreted in the urine. Since there is no reabsorption of crea- in the urine. tinine, this measurement can estimate glomerular filtration rate. Uric acid—A product of purine breakdown that is Diuretic—A drug that increases the excretion of excreted by the kidney. High levels of uric acid, salt and water, increasing the output of urine. caused by various diseases, can cause the forma- tion of kidney stones. Kilogram—Metric unit of weight. Osmolality—A measurement of urine concentra- Urine—A fluid containing water and dissolved tion that depends on the number of particles dis- substances excreted by the kidney. depends on an person’s muscle mass, which usually mOsm/kg of water. With increased fluid intake (dilu- fluctuates very little. With normal kidney function, tion testing), osmolality should be less than 100 then, the amount of creatinine in the blood remains rel- mOSm/kg in at least one of the specimens collected. A atively constant and normal. For this reason, and be- 24-hour urine osmolality should average 300–900 cause creatinine is affected very little by liver function, mOsm/kg. A random urine osmolality should average an elevated blood creatinine level is a more sensitive 500–800 mOsm/kg. indicator of impaired kidney function than the BUN. • Urine protein. A 24-hour urine collection should con- • Other blood tests. Measurement of the blood levels of tain no more than 150 mg of protein. other elements regulated in part by the kidneys can also • Urine sodium. A 24-hour urine sodium should be with- be useful in evaluating kidney function. These include in 75–200 mmol/day. sodium, potassium, chloride, bicarbonate, calcium, magnesium, phosphorus, protein, uric acid, and glucose. Blood tests Results • Blood urea nitrogen (BUN) should average 8–20 mg/dL. Normal values for many tests are determined by the patient’s age and gender. Reference values can also vary by • Creatinine should be 0.8–1.2 mg/dL for males, and laboratory, but are generally within the following ranges: 0.6–0.9 mg/dL for females. • Uric acid levels for males should be 3.5–7.2 mg/dL and Urine tests for females 2.6–6.0 mg/dL. • Creatinine clearance. For a 24-hour urine collection, Low clearance values for creatinine indicate a di- normal results are 90 mL/min–139 mL/min for adult minished ability of the kidneys to filter waste products males younger than 40, and 80–125 mL/min for adult from the blood and excrete them in the urine. As clear- females younger than 40. For people over 40, values ance levels decrease, blood levels of creatinine, urea, and decrease by 6.5 mL/min for each decade of life. uric acid increase. Because it can be affected by other • Urine osmolality. With restricted fluid intake (concen- factors, an elevated BUN, alone, is suggestive, but not tration testing), osmolality should be greater than 800 diagnostic for kidney dysfunction. An abnormally elevat- GALE ENCYCLOPEDIA OF SURGERY 785

Kidney transplant ed plasma creatinine is a more specific indicator of kid- OTHER ney disease than is BUN. National Institutes of Health. [cited April 5, 2003]. <http:// www.nlm.nih.gov/medlineplus/encyclopedia.html>. Low clearance values for creatinine and urea indi- National Institutes of Health. [cited June 29, 2003] cate a diminished ability of the kidneys to filter these <http://www.nlm.nih.gov/medlineplus/ency/article/0030 waste products from the blood and to excrete them in the urine. As clearance levels decrease, blood levels of crea- tinine and urea nitrogen increase. Since it can be affected 05.htm>. Paula Ann Ford-Martin by other factors, an elevated BUN alone is certainly sug- Mark A. Best, M.D. gestive for kidney dysfunction. However, it is not diag- nostic. An abnormally elevated blood creatinine, a more specific and sensitive indicator of kidney disease than Kidney removal see Nephrectomy the BUN, is diagnostic of impaired kidney function. The inability of the kidneys to concentrate the urine in response to restricted fluid intake, or to dilute the urine in response to increased fluid intake during osmo- lality testing, may indicate decreased kidney function. Because the kidneys normally excrete almost no protein Kidney transplant in the urine, its persistent presence, in amounts that ex- Definition ceed the normal 24-hour urine value, usually indicates some type of kidney disease. Kidney transplantation is a surgical procedure to re- move a healthy, functioning kidney from a living or brain-dead donor and implant it into a patient with non- Patient education functioning kidneys. Some kidney problems are the result of another dis- ease process, such as diabetes or hypertension. Doctors Purpose should take the time to inform patients about how their disease or its treatment will affect kidney function, as Kidney transplantation is performed on patients well as the different measures patients can take to help with chronic kidney failure, or end-stage renal disease prevent these changes. (ESRD). ESRD occurs when a disease, disorder, or con- genital condition damages the kidneys so that they are Resources no longer capable of adequately removing fluids and wastes from the body or of maintaining the proper level BOOKS of certain kidney-regulated chemicals in the blood- Brenner, Barry M. and Floyd C. Rector Jr., eds. The Kidney, 6th stream. Without long-term dialysis or a kidney trans- Edition. Philadelphia, PA: W. B. Saunders Company, plant, ESRD is fatal. 1999. Burtis, Carl A. and Edward R. Ashwood. Tietz Textbook of Clinical Chemistry. Philadelphia, PA: W.B. Saunders Demographics Company, 1999. Henry, J. B. Clinical Diagnosis and Management by Laborato- Diabetes mellitus is the leading single cause of ry Methods, 20th ed. Philadelphia, PA: W. B. Saunders ESRD. According to the 2002 Annual Data Report of the Company, 2001. United States Renal Data System (USRDS), 42% of Pagana, Kathleen Deska. Mosby’s Manual of Diagnostic and non-Hispanic dialysis patients in the United States have Laboratory Tests. St. Louis, MO: Mosby, Inc., 1998. ESRD caused by diabetes. People of Native American Wallach, Jacques. Interpretation of Diagnostic Tests, 7th ed. and Hispanic descent are at an elevated risk for both kid- Philadelphia: Lippincott Williams & Wilkens, 2000. ney disease and diabetes. ORGANIZATIONS Hypertension (high blood pressure) is the second National Kidney Foundation (NKF). 30 East 33rd Street, New leading cause of ESRD in adults, accounting for 25.5% York, NY 10016. (800)622-9020. <http://www.kidney. of the patient population, followed by glomeru- org>. lonephritis (8.4%). African Americans are more likely National Institute of Diabetes and Digestive and Kidney Dis- to develop hypertension-related ESRD than Cau- eases (NIDDK). National Institutes of Health, Building casians and Hispanics. 31, Room 9A04, 31 Center Drive, MSC 2560, Bethesda, MD 208792-2560. (301) 496-3583. <http://www. Among children and young adults under 20 on dial- niddk.nih.gov/health/kidney/kidney.htm>. ysis, glomerulonephritis is the leading cause of ESRD 786 GALE ENCYCLOPEDIA OF SURGERY

Kidney transplantation Kidney transplant Diseased kidneys Aorta Incision Transplanted Vena cava kidney Ureter Transplanted ureter Bladder A. B. Vena cava Aorta Transplanted kidney Sutures Transplanted ureter Bladder C. For a kidney transplant, an incision is made in the lower abdomen (A).The donor kidney is connected to the patient’s blood supply lower in the abdomen than the native kidneys, which are usually left in place (B). A transplanted ureter connects the donor kidney to the patient’s bladder (C). (Illustration by GGS Inc.) (31%), and hereditary, cystic, and congenital diseases ac- Description count for 37%. According to USRDS, the average wait- ing period for a kidney transplant for patients under age Kidney transplantation involves surgically attaching 20 is 10 months, compared to the adult wait of approxi- a functioning kidney, or graft, from a brain-dead organ mately two years. donor (a cadaver transplant) or from a living donor to a GALE ENCYCLOPEDIA OF SURGERY 787

A modified laparoscopic technique called hand-as- Kidney transplant WHERE IS IT PERFORMED? sisted laparoscopic nephrectomy may also be used to re- WHO PERFORMS move the kidney. In the hand-assisted surgery, a small in- THE PROCEDURE AND cision of 3–5 in (7.6–12.7 cm) is made in the patient’s ab- domen. The incision allows the surgeon to place his hand A kidney transplant is performed by a trans- also maintains a seal for the inflation of the abdominal plant surgeon in one of more than 200 UNOS- in the abdominal cavity using a special surgical glove that approved hospitals nationwide. If the patient cavity with carbon dioxide. The technique gives the sur- has no living donor, he or she must go through geon the benefit of using his or her hands to feel the kid- an evaluation procedure to get on the UNOS ney and related structures. The kidney is then removed national waiting list and the UNOS Organ Cen- through the incision by hand instead of with a bag. ter’s UNet database. Once removed, kidneys from live donors and cadav- ers are placed on ice and flushed with a cold preservative solution. The kidney can be preserved in this solution for 24–48 hours until the transplant takes place. The sooner patient with ESRD. Living donors may be related or un- the transplant takes place after harvesting the kidney, the related to the patient, but a related donor has a better better the chances are for proper functioning. chance of having a kidney that is a stronger biological match for the patient. Kidney transplant Open nephrectomy During the transplant operation, the kidney recipient is typically under general anesthesia and administered The surgical procedure to remove a kidney from a antibiotics to prevent possible infection. A catheter is living donor is called a nephrectomy. In a traditional, placed in the bladder before surgery begins. An incision open nephrectomy, the kidney donor is administered is made in the flank of the patient, and the surgeon im- general anesthesia and a 6–10-in (15.2–25.4-cm) inci- plants the kidney above the pelvic bone and below the sion through several layers of muscle is made on the side existing, non-functioning kidney by suturing the kidney or front of the abdomen. The blood vessels connecting artery and vein to the patient’s iliac artery and vein. The the kidney to the donor are cut and clamped, and the ureter of the new kidney is attached directly to the kid- ureter is also cut and clamped between the bladder and ney recipient’s bladder. Once the new kidney is attached, kidney. The kidney and an attached section of ureter are the patient’s existing, diseased kidneys may or may not removed from the donor. The vessels and ureter in the be removed, depending on the circumstances surround- donor are then tied off and the incision is sutured togeth- ing the kidney failure. Barring any complications, the er again. A similar procedure is used to harvest cadaver transplant operation takes about three to four hours. kidneys, although both kidneys are typically removed at Since 1973, Medicare has picked up 80% of ESRD once, and blood and cell samples for tissue typing are treatment costs, including the costs of transplantation for also taken. both the kidney donor and the recipient. Medicare also covers 80% of immunosuppressive medication costs for Laparoscopic nephrectomy up to three years. To qualify for Medicare ESRD bene- Laparoscopic nephrectomy is a form of minimally fits, a patient must be insured or eligible for benefits invasive surgery using instruments on long, narrow rods under Social Security, or be a spouse or child of an eligi- to view, cut, and remove the donor kidney. The surgeon ble American. Private insurance and state Medicaid pro- views the kidney and surrounding tissue with a flexible grams often cover the remaining 20% of treatment costs. videoscope. The videoscope and surgical instruments Patients with a history of heart disease, lung disease, are maneuvered through four small incisions in the ab- cancer, or hepatitis may not be suitable candidates for re- domen, and carbon dioxide is pumped into the abdominal ceiving a kidney transplant. cavity to inflate it for an improved visualization of the kidney. Once the kidney is freed, it is secured in a bag and pulled through a fifth incision, approximately 3 in Diagnosis/Preparation (7.6 cm) wide, in the front of the abdominal wall below Patients with chronic renal disease who need a the navel. Although this surgical technique takes slightly transplant and do not have a living donor registered with longer than an open nephrectomy, studies have shown United Network for Organ Sharing (UNOS) to be placed that it promotes a faster recovery time, shorter hospital on a waiting list for a cadaver kidney transplant. UNOS stays, and less postoperative pain for kidney donors. is a non-profit organization that is under contract with 788 GALE ENCYCLOPEDIA OF SURGERY

the federal government to administer the Organ Procure- ment and Transplant Network (OPTN) and the national QUESTIONS TO ASK Scientific Registry of Transplant Recipients (SRTR). THE DOCTOR Kidney allocation is based on a mathematical for- Kidney transplant mula that awards points for factors that can affect a suc- • How many kidney transplants have both you cessful transplant, such as time spent on the transplant and the hospital performed? list, the patient’s health status, and age. The most impor- • What are your transplant success rates? How tant part of the equation is that the kidney be compatible about those of the hospital? with the patient’s body. A human kidney has a set of six • Who will be on my transplant team? antigens, substances that stimulate the production of an- • Can I get on the waiting list at more than one tibodies. (Antibodies then attach to cells they recognize hospital? as foreign and attack them.) Donors are tissue matched for 0–6 of the antigens, and compatibility is determined • Will my transplant be performed with a la- by the number and strength of those matched pairs. paroscopic or an open nephrectomy? Blood type matching is also important. Patients with a • What type of immunosuppressive drugs will I living donor who is a close relative have the best chance be on post-transplant? of a close match. Before being placed on the transplant list, potential kidney recipients must undergo a comprehensive physi- donor and recipient may undergo a psychological or psy- cal evaluation. In addition to the compatibility testing, chiatric evaluation to ensure that they are emotionally pre- radiological tests, urine tests, and a psychological evalu- pared for the transplant procedure and aftercare regimen. ation will be performed. A panel of reactive antibody (PRA) is performed by mixing the patient’s serum (white blood cells) with serum from a panel of 60 randomly se- Aftercare lected donors. The patient’s PRA sensitivity is deter- A typical hospital stay for a transplant recipient is mined by how many of these random samples his or her about five days. Both kidney donors and recipients will serum reacts with; for example, a reaction to the antibod- experience some discomfort in the area of the incision ies of six of the samples would mean a PRA of 10%. after surgery. Pain relievers are administered following the High reactivity (also called sensitization) means that the transplant operation. Patients may also experience numb- recipient would likely reject a transplant from the donor. ness, caused by severed nerves, near or on the incision. The more reactions, the higher the PRA and the lower A regimen of immunosuppressive, or anti-rejection, the chances of an overall match from the general popula- medication is prescribed to prevent the body’s immune tion. Patients with a high PRA face a much longer wait- system from rejecting the new kidney. Common im- ing period for a suitable kidney match. munosuppressants include cyclosporine, prednisone, Potential living kidney donors also undergo a com- tacrolimus, mycophenolate mofetil, sirolimus, baxsilix- plete medical history and physical examination to evalu- imab, daclizumab, and azathioprine. The kidney recipi- ate their suitability for donation. Extensive blood tests are ent will be required to take a course of immunosuppres- performed on both donor and recipient. The blood sam- sant drugs for the lifespan of the new kidney. Intra- ples are used to tissue type for antigen matches, and con- venous antibodies may also be administered after trans- firm that blood types are compatible. A PRA is performed plant surgery and during rejection episodes. to ensure that the recipient antibodies will not have a neg- Because the patient’s immune system is suppressed, ative reaction to the donor antigens. If a reaction does he or she is at an increased risk for infection. The inci- occur, there are some treatment protocols that can be at- sion area should be kept clean, and the transplant recipi- tempted to reduce reactivity, including immunosuppresant ent should avoid contact with people who have colds, drugs and plasmapheresis (a blood filtration therapy). viruses, or similar illnesses. If the patient has pets, he or The donor’s kidney function will be evaluated with a she should not handle animal waste. The transplant team urine test as well. In some cases, a special dye that will provide detailed instructions on what should be shows up on x rays is injected into an artery, and x rays avoided post-transplant. After recovery, the patient will are taken to show the blood supply of the donor kidney still have to be vigilant about exposure to viruses and (a procedure called an arteriogram). other environmental dangers. Once compatibility is confirmed and the physical Transplant recipients may need to adjust their di- preparations for kidney transplantation are complete, both etary habits. Certain immunosuppressive medications GALE ENCYCLOPEDIA OF SURGERY 789

Studies have shown that after they recover from Kidney transplant cause increased appetite or sodium and protein retention, surgery, kidney donors typically have no long-term com- and the patient may have to adjust his or her intake of plications from the loss of one kidney, and their remain- calories, salt, and protein to compensate. ing kidney will increase its functioning to compensate for the loss of the other. Risks As with any surgical procedure, the kidney trans- Morbidity and mortality rates plantation procedure carries some risk for both a living donor and a graft recipient. Possible complications in- Survival rates for patients undergoing kidney trans- clude infection and bleeding (hemorrhage). A lympho- plants are 95–96% one year post-transplant, and 91% cele, a pool of lymphatic fluid around the kidney that is three years after transplant. More than 2,900 patients on generated by lymphatic vessels damaged in surgery, oc- the transplant waiting list died in 2001. The success of a curs in up to 20% of transplant patients and can obstruct kidney transplant graft depends on the strength of the urine flow and/or blood flow to the kidney if not diag- match between donor and recipient and the source of the nosed and drained promptly. Less common is a urine kidney. According to the OPTN 2002 annual report, ca- leak outside of the bladder, which occurs in approxi- daver kidneys have a five-year survival rate of 63%, mately 3% of kidney transplants when the ureter suffers compared to a 76% survival rate for living donor kid- damage during the procedure. This problem is usually neys. However, there have been cases of cadaver and liv- correctable with follow-up surgery. ing, related donor kidneys functioning well for over 25 years. In addition, advances in transplantation over the A transplanted kidney may be rejected by the pa- past decade have decreased the rate of graft failure; the tient. Rejection occurs when the patient’s immune sys- USRDS reports that graft failure dropped by 23% in the tem recognizes the new kidney as a foreign body and at- years 1998–2000 compared to failures occurring be- tacks the kidney. It may occur soon after transplantation, tween 1994 and 1997. or several months or years after the procedure has taken place. Rejection episodes are not uncommon in the first weeks after transplantation surgery, and are treated with Alternatives high-dose injections of immunosuppressant drugs. If a rejection episode cannot be reversed and kidney failure Patients who develop chronic kidney failure must ei- continues, the patient will typically go back on dialysis. ther go on dialysis treatment or receive a kidney trans- Another transplant procedure can be attempted at a later plant to survive. date if another kidney becomes available. Resources The biggest risk to the recovering transplant recipi- ent is not from the operation or the kidney itself, but BOOKS from the immunosuppressive medication he or she must Cameron, J. S. Kidney Failure: The Facts. New York: Oxford take. Because these drugs suppress the immune system, University Press, 1999. the patient is susceptible to infections such as cy- Finn, Robert, ed., et al. Organ Transplants: Making the Most of Your Gift of Life. Cambridge, MA: O’Reilly Publishing, tomegalovirus (CMV) and varicella (chickenpox). Other 2000. medications that fight viral and bacterial infections can Mitch, William, and Saulo Klahr, eds. Handbook of Nutrition offset this risk to a degree. The immunosuppressants can and the Kidney, 4th edition. Philadelphia: Lippincott, also cause a host of possible side effects, from high Williams, and Wilkins, 2002. blood pressure to osteoporosis. Prescription and dosage Parker, James, and Philip Parker, eds. The 2002 Official Patient adjustments can lessen side effects for some patients. Sourcebook on Kidney Failure. San Diego: Icon Health Publications, 2002. University Renal Research and Education Associates Normal results (URREA); United Network for Organ Sharing (UNOS). 2002 Annual Report of the U.S. Organ Procurement and The new kidney may start functioning immediately, Transplantation Network and the Scientific Registry of or may take several weeks to begin producing urine. Liv- Transplant Recipients: Transplant Data 1992–2001. ing donor kidneys are more likely to begin functioning Rockville, MD: HHS/HRSA/OSP/DOT, 2003. <http:// earlier than cadaver kidneys, which frequently suffer www.optn.org/data/annualReport.asp.>. some reversible damage during the kidney transplant and U.S. Renal Data System. USRDS 2002 Annual Data Report. storage procedure. Patients may have to undergo dialysis Bethesda, MD: The National Institutes of Health, National for several weeks while their new kidney establishes an Institute of Diabetes and Digestive and Kidney Diseases, acceptable level of functioning. 2003. 790 GALE ENCYCLOPEDIA OF SURGERY

OTHER KEY TERMS Infant Kidney Transplantation. Lucille Packard Children’s Hospi- tal. 725 Welch Road, Palo Alto, CA 94304. (650) 497-8000. Arteriogram—A diagnostic test that involves <http://www.lpch.org/clinicalSpecialtiesServices/COE/Trans viewing the arteries and/or attached organs by in- plant/KidneyTransplant/infantAdultToinfantKidneyTrans Knee arthroscopic surgery jecting a contrast medium, or dye, into the artery plant.html>. and taking an x ray. A Patient’s Guide to Kidney Transplant Surgery. University of Southern California Kidney Transplant Program. <http:// Congenital—Present at birth. www.kidneytransplant.org/patientguide/index.html>. Dialysis—A blood filtration therapy that replaces the function of the kidneys, filtering fluids, and Paula Anne Ford-Martin waste products out of the bloodstream. There are two types of dialysis treatment: hemodialysis, which uses an artificial kidney, or dialyzer, as a blood filter; and peritoneal dialysis, which uses the patient’s abdominal cavity (peritoneum) as a blood filter. Knee arthroscopic surgery Glomerulonephritis—A disease of the kidney that Definition causes inflammation and scarring and impairs the kidney’s ability to filter waste products from the Knee arthroscopic surgery is a procedure per- blood. formed through small incisions in the skin to repair in- Iliac artery—Large blood vessel in the pelvis that juries to tissues such as ligaments, cartilage, or bone leads into the leg. within the knee joint area. The surgery is conducted with the aid of an arthroscope, which is a very small instru- Immunosuppressive medication—Drugs given to a transplant recipient to prevent his or her im- ment guided by a lighted scope attached to a television mune system from attacking the transplanted monitor. Other instruments are inserted through three in- organ. cisions around the knee. Arthroscopic surgeries range from minor procedures such as flushing or smoothing Rejection—The process in which the immune sys- out bone surfaces or tissue fragments (lavage and de- tem attacks foreign tissue such as a transplanted bridement) associated with osteoarthritis, to the realign- organ. ment of a dislocated knee and ligament grafting surg- Videoscope—A surgical camera. eries. The range of surgeries represents very different procedures, risks, and aftercare requirements. While the clear advantages of arthrocopic surgery lie in surgery with less anesthetic, less cutting, and less PERIODICALS recovery time, this surgery nonetheless requires a very Waller, J. R., et al. “Living Kidney Donation: A Comparison of thorough examination of the causes of knee injury or Laparoscopic and Conventional Open Operations.” Post- pain prior to a decision for surgery. graduate Medicine Journal 78, no. 917 (March 2002): 153. ORGANIZATIONS Purpose American Association of Kidney Patients. 3505 E. Frontage Rd., Suite 315, Tampa, FL 33607. (800) 749-2257. There are many procedures that currently fall under [email protected]. <http://www.aakp.org>. the general surgical category of knee arthroscopy. They American Kidney Fund (AKF). Suite 1010, 6110 Executive fall into roughly two groups—acute injuries that destabi- Boulevard, Rockville, MD 20852. (800) 638-8299. lize the knee, and pain management for floating or dis- [email protected]. <http://www.akfinc.org>. placed cartilage and rough bone. Acute injuries are usual- National Kidney Foundation. 30 East 33rd St., Suite 1100, ly the result of traumatic injury to the knee tissues such as New York, NY 10016. (800) 622-9010. <http://www. ligaments and cartilage through accidents, sports move- kidney.org>. ments, and some overuse causes. Acute injuries involve United Network for Organ Sharing (UNOS). 700 North 4th St., damage to the mechanical features, including ligaments Richmond, VA 23219. (888) 894-6361. <http://www. transplantliving.org>. and patella of the knee. These injuries can result in knee United States Renal Data System (USRDS). USRDS Coordi- instability, severe knee dislocations, and complete lack of nating Center, 914 S. 8th St., Suite D-206, Minneapolis, knee mobility. Ligament, tendon, and patella placements MN 55404. (612) 347-7776. <http://www.usrds.org>. are key elements of the surgery. The type of treatment for GALE ENCYCLOPEDIA OF SURGERY 791

Pain management surgeries, on the other hand, are Knee arthroscopic surgery used to relieve severe discomfort of the knee due to os- teoarthritis conditions. These treatments aim at relieving pain and instability caused by more chronic, “wear and tear” kinds of conditions and involve minor and more optional surgical procedures to treat cartilage and bone surfaces. These include arthroscopic techniques to re- move detached or obtruding pieces of cartilage in the joint space such as the meniscus (a fibrous cushion for the patella), to smooth aged, rough surface bone, or to remove parts of the lining of the joint that are inflamed. Treatment distinctions between arthroscopic surgery for acute injuries and those for pain management are im- portant and should be kept in mind. They have implica- tions for the necessity for surgery, risks of surgery, com- plications, aftercare, and expectations for improvement. Arthroscopic surgery for acute injuries is less controver- sial because clear dysfunction and/or severe instability are measurable indications for surgery and easily identi- fiable. Surgery indications for pain management are largely for chronic damage and for the milder grades or stages of acute injuries (severity Grade I and II). These are controversial due to the existence of pain manage- ment and rehabilitation alternatives. Arthroscopic surgery for pain management is currently under debate. Demographics More than five and a half million people visit ortho- pedic surgeons each year because of knee problems. Surgeons watching a monitor showing the inside of a pa- Over 600,000 arthroscopic surgeries are performed an- tient’s knee during arthroscopic knee surgery. (Custom nually; 85% of them are for knee surgery. One very com- Medical Stock Photo. Reproduced by permission.) mon knee injury is a torn anterior cruciate ligament (ACL) that often occurs in athletic activity. The most acute injuries depends in large part on a strict grading common source of ACL injury is skiing. Approximately system that rates the injury. For instance, grades I and II 250,000 people in the United States sustain a torn or rup- call for rest, support by crutches or leg brace, pain man- tured ACL each year. Research indicates that ACL in- agement, and rehabilitation. Grades III and IV indicate juries are on the rise in the United States due to the in- the need for surgery. Acute injuries to the four stabilizing crease in sport activity. ligaments of the knee joint—the anterior cruciate liga- The incidence of ACL injuries in women is two to ment (ACL), the posterior cruciate ligament (PCL), the eight times greater than in men. While the exact causes medial collateral ligament (MCL), and the lateral collat- are not clear, differences in anatomy, strength, or condi- eral ligament (LCL)—as well as to the “tracking,” or tioning are thought to play major roles. Women also seem seating of the patella, can be highly debilitating. to be more prone to patella-femoral syndrome (PFS), Treatment of these acute injuries include such com- which is the inability of the patella to track smoothly with mon surgeries as: the femur. PFS is due primarily to development of ten- dons that influence the ways in which the knee tracks in • Repairs of a torn ligament or reconstruction of the liga- movement. It can also be due to misalignments to other ment. parts of the lower body like foot pronation. Other liga- • Release of a malaligned kneecap. This involves tendon ment surgeries can be caused by injury or overuse. surgery to release and fit the patella better into its groove. Knee dislocations are a focus of recent research be- • Grafts to ligaments to support smoother tracking of the cause of their increasing frequency. Incidences range knee with the femur. from 0.001% to 0.013% of all patients evaluated for or- 792 GALE ENCYCLOPEDIA OF SURGERY