Microsoft Word - DR GORE SYSTEM book 2018 may

ABSTRACT Summary of philosophy and technique of gore system for stitch less spine surgery under local anesthesia in an awake and aware patient, primarily STITCHLESS SPINE through transforaminal access. satishchandra gore Sssula from mission spine SURGERY UNDER LOCAL ANESTHESIA DR Satishchandra Gore

Chapter 1 EMERGENCE of gore system 1.introduction 2.short history of transforaminal lumbar spine surgery 3.limitations of traditional approach to degenerative lumbar spine 4.changes due to transforaminal surgery under LA 4.1 symptoms analysis, algorithm, and matrix 4.2 Algorithm for back pain 4.3 Algorithm for leg pain 4.4 Algorithm for claudication 4.5 new gore symptom matrix 5 Result: 1: moving away from fusion 6 Result: 2: truly non-morbid minimally invasive spine surgery 7 Precision in targeting fragment: symptom generator 8 in stenosis targeting SAP and tissue around 9 Summary: The change 10 references 1

EMERGENCE of gore system: stitchless surgery under local anesthesia for symptomatic degenerative lumbar spine Introduction Traditional symptom analysis in degenerating lumbar spine is mainly to identify patients needing surgery not to diagnose the symptom of pain or claudication. Based on such thinking treatment plans are a combination of decompression and fusion without much consideration to pain and claudication. They are guided by anatomical changes seen in images. Symptom matching TO PATHOLOGY is many times lacking. There is then over emphasis on posterior midline access and use of hardware that has no evidence in support for use is an auto stabilizing degenerating lumbar spine. Treatment of symptomatic degenerative lumbar spine has drastically changed from traditional decompression and fusion that is guided by images, due to refined understanding of symptom [pain and claudication] generators. This has led to change in philosophy, equipment and access as most symptom generators are in or around intervertebral foramen. I propose a new surgical philosophy of stitchless surgery under local anesthesia TM in awake and aware patient. It is a targeted for precisely identified sub centimeter symptom generator through the natural orifice “intervertebral foramen”. This philosophy breaks away from the past. It does not involve posterior midline access, general anesthesia, blood transfusions, use of hardware, cutting of bone, and use of implants in most cases except instability. This is done by using “gore system” and new “Sneha set” for lumbar canal stenosis that is part of gore system instruments. 2

image 1 Image showing entry site for stitchless surgery under local anesthesia for lumbar disc lesion on left side. Traditional image or anatomy guided approach; totally ignoring physiology has led to many failures and complications and dissatisfaction in mind of patients, fear leading to delay in surgery, over use of hardware. The art and science of diagnosis in symptomatic spine degeneration is sadly skewed. We have ignored chemical radiculitis, use of discography, paradox in images and only concentrated on mechanistic analysis, which to say least is inadequate. Our philosophy is to precisely diagnose pain or claudication generator, its location and then target it in a safe precise way under local anesthesia. 3

Short history and evolution of transforaminal disc surgery Surgery was proposed as transforaminal by kambin and Hijikata. 1,2,3 In 1991 Kuslich first described open posterior mid line surgery for lumbar disc herniation under progressive local anesthesia adding to our understanding of tissue origin of low back pain and sciatica and concepts of pain generators, pain patterns by answering the fundamental question: 4 WHERE IS THE PAIN COMING FROM? Thus, in turn identifying the physiological target; and making transforaminal access surgery possible under local anesthesia as significant pain was not seen in paraspinal structures. In 1995 foraminal anatomy and its relation to size of cannulas that the foramen can accept was studied by Mirkowitz and David Swartz and found maximum size of cannulas which we can safely put in foramen for safe 5 endoscopic surgery. This further stimulated and facilitated transforaminal access. In the same period, Siebert: Endoscopic Laser Disc Surgery - the Foraminal Approach, Leu: Percutaneous Foraminoscopy 6,7 and Casper: Foraminal Laser Endoscopic Disc Ablation published their work. Martin Knight 8,9,10,11 however, was first to use laser for foraminal decompression for lateral and subarticular stenosis. Yeung proposed inside out disc surgery and working outside the disc through a working channel endoscope. The access evolved further as a direct epidural access by undercutting the facet by “outside in access”. This has been popularized by Hoogland ‘s Thessys technique. 12,13,14,15. Some variation in trajectory and angle of access also has been proposed by Hoogland, Ruetten and Choi, et al. when targeting inferior and superior migrated fragments to bring fragment in line of sight. Our system uses hook etc. for mobilizing migrated fragments. Since the “out-side in” procedure is dependent on serial dilation to retract nerves, it usually involves BLIND fluoroscopically guided foraminoplasty with trephines and reamers as well as discectomy. This approach ignores anomalous anatomy such as furcal nerves, sympathetic nerves, epidural vessels and other anomalous nerves documented and described by Yeung and Gore. Complications and adverse risks of dysesthesia is anticipated to be higher. Ruetten has described interlaminar access with the same instruments, mainly for L5-S1 access through the large interlaminar window. Osman and Choi have described trans iliac access with good results. 16,17 In 2001 author and Dr Yeung 4

published 18 evolving methodology with emphasis on skin markings, trajectory to the foramen for precise access to the pathology, visualization of the basic pathology of annular tears which caused the pain of discogenic origin. In 2002, 2004 Yeung and Tsou described the YESS transforaminal endoscopy technique 19,20 to treat all forms of disc herniation by the transforaminal approach. Yeung has published extensively on transforaminal disc surgery. 21,22,23,24,25 Over last 2 decades transforaminal endoscopy for disc herniation as access and treatment methodology has become popular world over. Precision in diagnosis has led to precision in targeting and making surgery least invasive stitchless and under local anesthesia and in awake aware state patient. This makes it possible to do even in patients with medical co morbidity. We have proposed surgery for stenosis thru foramen by concentration on lateral ligamentum flavum anatomy, collagenization of annulus and formation of tissue ridge at lower endplate of cephalad vertebra causing horizontal central stenosis and tissue hypertrophy over the tip of superior articular process or facet. The transforaminal access and ability to tackle peri drg pathology needs further refinement, now being introduced through Sneha set of gore system. 1. What are limitations of traditional management? In traditional degenerative cascade anteriorly, Disc and posteriorly facet changes are staged as dysfunction, instability and then stabilization. Changes seen in cadaver and in images define surgical treatment. The degenerative cascade by Kirkaldy Willis 26 27 has led to emphasis on decompression and stabilization. Kirkaldy Willis later published about matching of symptoms with pathology. The cadaver study first published selectively ignored nerve supply of functional spinal unit, chemical radiculitis, role of inflammation, location of dorsal root ganglion {DRG} in relation to the segment, asymmetry at that level, changes around DRG, and mechanism of pain namely chemical or mechanical? Pain causation was kept in background with emphasis on anatomical variations and later image changes. There is No set time frame in aging patient for the evolution of full cascade of changes. Images depicting minute 5

anatomical changes are known NOT to correlate with symptoms and pathology in 30% patients. Thus, all these years our main QUESTION “Where is pain and claudication 28 coming from? Why it persists?” remained unanswered. The clinical assessment alone is inadequate to address these present issues as we have no OBJECTIVE sign for pain, or for differentiating mechanical and chemical radicular pain, to monitor progress of sciatica or back ache when treated non-operatively. We have proposed an objective sign” gore sign” for sciatica detection confirmation and monitoring. Technology like navigation, robotics is proposed for targeting pathology, but we do not understand the biochemistry of pain and biomechanics causing claudication and symptom to pathology correlation so may continue to fail as surgeons in precisely targeting and relieving symptom causing pathology. There are severe limitations in analysis of the patients’ clinical inputs, or images and they lead to uncertainty about the effectiveness of the surgical plan. This is wrongly complemented by “untimely” and “premature” stabilizations which allegedly mimic natural end stage of stabilization in degenerative cascade. The traditional methodology has become so skewed now that more aggressive decompression is recommended, and stabilization is promoted for almost all disc surgeries. WE see multiple examples associated with failed surgery where patient remains symptomatic, only with a better- looking image as end- point of the intervention. We have graduated from image guided decision making to in vivo visualization of the pathology with better symptom correlation and then shared decision making. The in vivo 29 endoscopic visualization of an annular tear, chronically healing annulus with collagenization, conjoined nerves, furcal nerve branches, and anomalous anatomy such as sympathetic nerves sheds light on why current imaging studies alone cannot fully explain the reason(s) that some patients with identical imaging studies have debilitating pain and others do not. Intervention under awake and aware condition can explain where is pain coming from? Better. Learning from large data and repeated analysis of the symptoms with operative correlation has led to change of focus away from images alone to symptoms and their relief. From anatomy to physiology! IN gore system it has further 6

led to an algorithm and matrix and clinical cascade for a precise clinical diagnosis helping a treatment plan. Uncertainty is unmeasurable risk and risk is MEASURABLE uncertainty. Many times, in spine surgery patient is afraid about risks and surgeon has uncertainty about outcomes. Pain being subjective impression of the patient, if there is a lack of correlation in symptoms, pathology and images; analysis in lumbar degenerative spine surgery for treating pain and claudication results in uncertain interventions. We need to reduce the risk and overcome the uncertainty. This is possible by an algorithmic approach and not traditional trial and error methodology and exploratory nature of surgery. Our algorithm and 6-point matrix 30 pinpoints “symptom generators” making surgery safe precise and surgical corridor sub centimeter. 2. What changed due to stitchless spine surgery thru foramen? IN era of evidence-based surgery and medicine there is no evidence to support mandatory posterior midline access and use of stabilization and it is only legacy. Patient’s Main concern is symptoms and we need to make best attempt to resolve the concern. It is more prudent to direct all our energies to symptom analysis and planning of access to symptom generating and persisting pathology. Our insight from surgery under local anesthesia and in vivo visualization of symptomatic pathology has led us to concept of symptom [pain] generator. Pain generator is a CHANGED Interface between degenerated and failed structure [ eg: annular tear in a disc] and its neurovascular supply. The neuro vascular 31 supply decides symptoms in degenerative spine. 7

A SYMPTOM ANALYSIS AND ALGORITHM AND MATRIX Decision making in traditional surgery is based mostly on anatomical changes in degenerative cascade, so IMAGES depicting these changes become supreme. Imaging evolved from “myelography” with negative imaging of structures around the dural sac to CT [computerized tomography]. Advent of CT scan made us aware of bony structures and cross sectional [in plane of disc] anatomy. To correlate symptoms and pathology, we in past and even now use invasive imaging “discography” for pain correlation. Real change however is advent of MRI. But MRI lacks correlation with pain!! In 30% patients either way 32,33,34,35,36,37 Once MRI was available; understanding of pathoanatomy changed but still biochemistry and neuro physiology was out of thinking of the surgeons. Creating a very unusual situation where over emphasis on anatomy and pathoanatomy led to “image guided decision making” which prevails even today. 38,39,40,41,42,43,44 MRI tech further evolved with added use of dye, and correlation with discography and evoked symptoms. In our philosophy initially, we used discography but later we changed to visualization in awake and aware patient of the interface where symptoms are generated. WE correlated pathoanatomy and physiology and probed in vivo in awake aware patient to elicit concordant symptoms [if needed] overcoming all limitations above. ALGORITHM for back pain axial or paraspinal, acute or chronic. Image30 8

Identifying where is pain coming from and why it persists and plan an action. Basis of 45 this algorithm in patients with low back pain is McKenzie test. If on repeated end stage movement of extension pain centralizes to midline it signifies a good annulus with integrity. Extension gives movement of nucleus ventrally and temporary destressing of the annular tear. Basically, most back pain can be diagnosed by this algorithm as facet related as pain [increases with extension] or disc related in in midline vertical or horizontal, and we can predict need for surgery depending on pain intensity and commonly its response to end stage movements of extension. If pain quickly centralizes it may be treated by non-operative measures. THIS New correlation of chronic non- healing posterior annular tear with central axial back pain is a significant learning from our work. IN most chronic back pain is due to trapped fragments of nucleus in annular tear not allowing the tear to heal. Persistence then is due to leaking inflamatogenic cytokines from the tear and neuro vascular reaction on the surface and outer layers of annulus. Algorithm for leg pain. Image32 location of pain, centralisation of pain on extension, tenderness of nerve at ankle two spots, effect of local anesthetic block at ankle on pain, use of imaging is needed. 9

46 Diagnosing sciatic pain Main basis is GORE sign . GORE SIGN is the first and ONLY objective sign for pain it adds value to our solution. This can distinguish mechanical and chemical pain. In combination with McKenzie test it can predict need for surgery. It is also used to monitor sciatica during non-operative treatment. It can be used in acute, chronic, recurrent, post-operative pain. Older way of assessing pain based on effect of movement on nerve mobility only [SLR] has limitations. It also helps in diagnosing any lower limb pain if it is neuralgia. Commonly knee [lateral] and heel pain are subsets of sciatic pain in early degeneration. Algorithm for claudication This is a self-filled questionnaire form. Commonly answers to question 1,2,3 is affirmative in mild form of stenosis. Yes, as answer to 6 questions is indicative of moderate and yes to all 10 questions is indicative of severe form of lumbar canal stenosis. We do post void residual urine on ultra sound examination to detect an associated detrusor underactivity associated with sacral root pathology; in all patients over age of 65 and predict need for urgency in intervention and a pre-operative likely neurogenic bladder. Image 33 based on SSHQ by konno et al. 47 Image33 10

Claudication has been diagnosed more on narration and various tests to differentiate the vascular cause. In case of involvement of sacral roots and detrusor underactivity as detected and proposed by our concept of usg for post void residue estimation , intervention may be emergent. NEW Gore symptom matrix replaces cadaver degenerative cascade or image based decisions 30 Very detailed analysis of inputs from patients pre intra and post-operative period, degeneration and resulting symptoms can be put into 6 distinct groups 1. knee and heel pain: due to Annular tear and leak 2. low back pain: Chronic non-healing central posterior annular tear with or without trapped fragments. 3. sciatica: annular tear with Herniated posterolateral nuclear fragment. 4.Facet degeneration and inflammation: Facetogenic back pain. 5.Hypertrophied tissue around SAP and chronic annular changes in upper foramen with or without collapse of disc: claudication.6. Unstable spine: Claudication. Symptoms primarily drive our decision making adding to certainty of outcomes of our interventions. We combine symptoms, visualized pathology to improve diagnosis and decision making. We have tried to incorporate the learning of several years from our interventions under awake aware state into new matrix. Six common variants of symptoms and relevant treatment targets summarized as GORE MATRIX © and Clinical cascade are described in detail. Left column is traditional approach, mid is symptoms as seen, right is our approach. 46,48,49,50,51,52 11

Symptoms Gore system approach Traditional approach Local XRAYS of 1 Lateral Knee and Detect confirm monitor pain by painful areas done heel pain “gore sign”. No imaging and non-specific correlation needed routinely. ->early disc cause treated with degeneration and Diagnosis of chemical radiculitis, analgesics and anti- annular tear; leak based not on dermatomal inflammatory affecting L5 or S1 distribution of pain but palpation medicines. Namely root. Common thread of nerve distally and distal block KNEE osteoarthrosis, of neuralgia should at ankle helps. This is counter or plantar fasciitis. and can be intuitive. GORE SIGN published. established. 46 in most further evolution and wellness can be predicted at early degenerative stage. XRAYS CT mri 2 Low back pains pain increases on extension [facet origin]: while doing McKenzie test. Non-specific Paraspinal well Treatment is Facet block, Analgesics etc. localized, bilateral, Treatment generally distinct symptoms. or visualized denervation of to mask pain. or MEDIAL BRANCH OF DORSAL fusion. RAMUS. IMAGING correlation needed. 48 49 12

No specific diagnosis 3 Low back pain Discography important. axials either vertical Traction diathermy Treatment by intradiscal or horizontal due to IFT. injection of anti-inflammatory if chronic inflamed only leaking tear. If fragment, PAIN generator is not central annular tear. then Endoscopic cleaning of diagnosed or Vertical of 45 and CHRONIC POST ANNULAR TEAR visualized, and horizontal off 5S1 and shrinking annulus may images alone may not disc. work. clarify the Chronic non-healing etiopathology. Added Use of PRP or PRF Der1 of tear due to nuclear PLUG HELPS. [published] 50 fragments trapped in tear initiating inflammation. Rest traction surgery 4 sciatica along L5 or Diagnosis more based on nerve S1, signified by palpation than only dermatomal open affection of deep thinking detected at ankle. Post midline access peroneal or sural GORE SIGN nerve. SLR and neuro Removal of unrelated exam needed. Selective Nerve Root Block if bony structures may chemical pain, result in instability stitchless endoscopy by gore system if mechanical. INFLAMED AND COMPRESSED SCIATIC NERVE ROOTS and DRG is target. 51 13

Open surgery wide 5 Claudication in a collapse of disc allowing SAP to post midline move up in foramen. stable spine. imaging decompression and HYPERTROPHIED SOFT TISSUE confirms stability. fixation use of cages IN FORAMEN OVER SAP for and screws done. lumbar canal stenosis. Deroofing of DRG is basis. IMP: Coronal oblique MRI essential to understand lateral ligamentum flavum and its contribution to claudication generation. 52 Stabilization screws 6 Claudication Hybrid surgery combination as and heavy metal below: With spinal Instability Understanding and and or deformity. 1.UNSTABLE LEVEL needs isolation of pain stabilization either generators not done. transpedicular, or facet, or intradiscal. 2.SAP TIP TISSUE HYPERTROPHIED needs removal. 3.Facet pain needs additional denervation. Matrix has resulted in a shared decision focused on a broader spectrum of surgical as well as non-surgical treatments, and not only masking the pain generator or medical pain management. I have moved away from decisions based on diagnostic images alone, that cannot explain the pain experienced by everyone as images do not always show variations in nerve supply and patho-anatomy. Attention to pain pattern and mechanisms and nerve 14

supply of the functional spinal segment is important. The ability to isolate and visualize “pain” and other symptom generators in the foramen and treating persistent pain or claudication by visualizing inflammation and compression of dorsal root ganglion and nerves, essentially located in a small limited juxtra foraminal area in the lumbar spine is the basis for stitchless surgery under local anesthesia. Our ability to visualize pain generator and put back learning about symptom pathology correlation in clinical analysis has resulted into our algorithm and matrix [GORE MATRIX] changing our approach to plan back and leg pain management. GORE Matrix is a clinical symptom-based cascade adding an element of time and some predictability to the progression of changes . We changed focus from images to symptoms and related pathology as the base of clinical analysis and from decompression and stabilization to precise treatment of symptom [pain or claudication] generating pathology. We have conceptually replaced degenerative cascade with our matrix that includes 6 symptom complexes and an algorithm to diagnose symptomatic degenerative lumbar spine. B RESULT MOVING AWAY FROM FUSION Proposing Microdiscectomy as gold standard, stopped further refinements and evolution 53 of traditional philosophy. Micro discectomy and supposed refined versions of targeting disc herniation are practiced widely. The surgery evolved from discectomy and laminectomy to more OF SAME decompression and stabilization for all stages of the degenerative cascade. It highlighted better visualization of “tip of the iceberg in cases of herniation “completely ignoring early stage basic annular tear, changes inside the annular walls and disc, leaking disc and inflammatory change at disc and nerve interface and symptoms correlated therein. Decompression was promoted as therapeutic and refinement only came in form of better decompression by use of access tubes and camera, light source and scope at site of interlaminar surgery. More aggressive decompression slowly set in as better modalities 15

of stabilization emerged. More aggressive decompression many times leads to instabilities begetting more stabilization. So, change in traditional surgery started with more decompression and stopped at more stabilization. Today even though we do not have any evidence supporting use of stabilization and hardware in auto stabilizing degenerative 54 spine except may be in instability or deformity it is taken as norm. Now more complex, technically demanding and higher risk interbody fusion techniques, such as ALIF or TLIF, 55 are advocated for younger, active patients or patients with a higher risk of non-union. Fusion patients have been known to use significant resources postoperatively, and have long-term pain and psychotropic medication utilization. 56 Recently there is a surge in restoring sagittal balance in degenerated lumbar spine. The measure of radiographic pelvic and spinal parameters for sagittal balance analysis has gained importance in reconstructive surgery of the spine and particularly in degenerative spinal diseases. It will need a critical analysis to see if this alters the natural history and outcomes of the degenerative symptoms and pathology at all. 57 Recently professional societies have reconsidered guidelines for fusion and critical analysis of the evolving evidence shows its limited indications. 58 Conditions in which Lumbar Fusion is NOT Medically Appropriate 1. Pure Stenosis (without any of the other diagnoses). 2. Initial Disk Herniation (in the absence of any other diagnosis). 3. Chronic Low Back Pain without Any Clear Cause on Imaging. However, these are our endoscopy prime target areas. Access itself at times is promoted as treatment modality e.g. laminectomy and “decompression” is talked; about never highlighting the key target “inflammation” at disc or facet and nerve interface. Degenerative annular tear starts inside out. Once it reaches out to nerve supply depending on location and type of the tear and neuro vascular changes at this interface; it becomes symptomatic as back or leg pain . It may heal and 31 become asymptomatic. Traditional surgery never had an inside view of the “disc” ignoring the truth that the problem started inside as” annular tear”. It never highlighted interface of disc, facet and nerve or DRG and changes in this interface and how to precisely target this symptom generating structural failure or natural resolution failure. Traditional surgery 16

was and is BLIND to these changes. Historically early stages of degeneration namely 59 annular tear were ignored in traditional treatment. Now we can visualize pain generator eg: annular tear during awake aware surgery under local anesthesia [in vivo visualization] by transforaminal endoscopy and correlate symptom and pathology better. Ignoring pain generator has led to many failures in past e.g. in case of disc if the outline of the disc is not changed in a SYMPTOMATIC patient most clinicians are clue less as to what intervention is relevant and would be effective? Minute structural changes in early part of degeneration namely trapped fragments in non- healing central annular tears giving chronic back pain; are now appreciated better due to in vivo visualization. C RESULT TRULY NON-MORBID MINIMALLY INVASIVE SURGERY Our new philosophy has evolved from basic idea of taking care of pain or symptom generator in all its manifestations and at all stages of symptom cascade and has evolved over time. We take care by ablating, washing, irrigating, excising symptom generating 0 tissue. We are aware of 360 stabilizations; that by its very nature destroys the pain generators and nerve supply. It still may not relieve the pain if all pain generators are not removed. Pain generation in common cases of radiculitis is well understood. In cases of claudication it needs further refinement in understanding. The importance of DRG in foramen forming lateral wall of the safe triangle and importance of transforaminal ligament and flavum tissue over SAP is not yet appreciated fully. 60,61,62 Location of L45 DRG is intra foraminal L5S1 it is intracanal just inside foramen, so access through foramen to peri DRG area forms basis of our transforaminal percutaneous stitchless surgery under local anesthesia. 63,64,65 Simultaneous social changes in expectations from surgery and predicted surgical morbidity, issues about general anesthesia, complications from surgery, access related inevitable negative outcomes, age and medical co morbidities related limitations and fear 17

of surgery has now led to more acceptable new idea of stitchless surgery under local anesthesia in symptomatic lumbar spine. Image below shows the schematic change at skin and target. In open traditional or micro lumbar disc surgery, surgical damage is like a funnel or cone. Skin cut is long and working target area smaller but with destruction or denervation of intervening tissue. This muscles damage and long-term morbidity is ignored under name of next evolution of “minimally invasive at skin” surgery 66to83 . In endoscope assisted surgery it is like tent, small skin cut hiding large tissue dissection by mobility of the tube under the skin. These techniques are nothing new but just a refinement in hiding the paraspinal damage just because skin cut is small. It may be easy for a traditional surgeon to just use the new tools, but basic philosophy and limitations and complications remain same. 84 to 96 Blue arrow shows an area “mobilized” or targeted in surgery and may result in significant morbidity. 18

However, in transforaminal endoscopy there is sub centimeter skin cut, muscles are not cut but dilated and access is thru natural orifice and only small 6 mm cut at intended target. It is safe and precise and extremely less morbid. It is visualized surgery, under irrigation. We see a herniation on right of image at L5S1 showing an altered image of KAMBIN’s triangle we access this thru foramen on patient left. The arrow points a black shadow of fragment lying ventral to dural sac and the root. Image 15 below is analysis of morphometric changes and evoked pain in discography that is replaced by in vivo visualization of the tear and elicit pain at site of inflammation 19

or “pain generator” in disc herniation by probing as shown on right in cadaver dissection. Image15 D Precision in targeting symptom generator: Precision in targeting pain generators namely posterior annulus tear and inflammation at tear and anterior surface and tip of the SAP [superior articular process] in claudication is a prominent part of philosophy. Following images show stages of a cannula reaching the commonest symptom generators that is posterior annulus and superior facet. This lands on the annulus in kambin’s triangle that has TWO live borders. Lateral border is exiting nerve has the DRG in it. The margin of error is very low. Newer anatomical studies highlight a complex neurovascular network in kambin’s triangle on the floor, that is annulus. This supports an INSIDE out approach where we go inside the disc first sub annular and as disc is avascular and aneural resultant surgery can be bloodless and painless. Withdrawal of the cannula for about 1cm up to edge of the annulus can dorsally 20

show us the roof of the lower foramen that is facet and its under surface and turning cannula towards head can take us to the tip of superior articular process. Images below show the progressive journey of the cannula or working sheath in an awake aware patient towards the commonest target “posterior annulus”. Cannula on right at subcutaneous level entering muscular plane in image 16. Image16 Image17 Cannula near intertransverse plane just above the transverse process. We are directed at an angle so safe wrt lumbar plexus that is just 5 mm ventral to intertransverse ligament in image 17. 21

Image18 Cannula tip now just below facet and is seen to be mid pedicle just entering annulus. image 18 HERE we can access under surface of facet in stenosis. We access the tip of SAP by turning our cannula towards head. Image19 Cannula tip now just inside annulus. White dye is seen post discography in this patient. The dye is just inside posterior annulus. Image 19 22

Image20 Cannula is now seen intradiscal sub annular looking towards the main pain generator that is a central annular tear in patient with back pain. image 20 Image21 Cannula seen sub annular in sagittal view. Image 21 If withdrawn a little cannula faces facet. 23

Image22 Cannula is intra discal but just sub annular and not central at disc. image 22 Image23 Dilator seen at foramen of L45 in a bony image from CT. image 23 24

E Transiliac access At L5S1 we go above the iliac crest. Image 24 add a b c d e or may go transiliac. A above crest b above crest 5S1 c transiliac d transiliac bony e trans iliac cs. a b 25

c D E 26

F: IN STENOSIS TARGETING SAP AND TISSUE AROUND: In case of stenosis newer 3D visualization in {fusion CT MRI} images of the lateral ligamentum flavum in foraminal juxtra DRG area has made us refine our targets in claudication. We move away from midline to foraminal area and deroof the DRG in and around foramen. Main tissue involved can be 1. SAP hypertrophied tissue. It is NOT bone hypertrophy. Line drawn along lower endplate of vertebra above normally passes above tip of superior articular process in sagittal section. [as shown below] If the disc collapses this relation is disturbed. In a collapsed disc central interlaminar ligamentum flavum also may bulge in addition to sap tip hurting the exiting or traversing nerve. 27

28

There is a large amount of ligamentum flavum lateral to medial pedicle line if seen in ventral dissection of the lumbar spine as above. Image25 Use of hook under the pedicle in foramen, tip towards the pedicle to mobilize the nerve. This ability to land next to the dorsal root ganglion and root in kambin’s triangle is part of safety in awake and aware surgery. We are mobilizing the root. Image 25 we use the same access to sap tip and tissue. Precise targeting of sap as seen above: 29

Gore operating system is a comprehensive group of solutions covering all spectrum of symptoms in degenerative lumbar spine extended to development and design of specific instruments to achieve the surgical goals. The minimum is a needle that helps in accessing the pain generator and mask it. This masking sometimes and in uncertain times may aid in better pre-operative decision making and prediction. SUMMARY: WE ADDRESS symptom generators AT POSTERIOR ANNULUS, ANTERIOR EPIDURAL SPACE, ANTERIOR FACET SURFACE OR ROOF OF FORAMEN IN UPPER PART, INFLAMED AND OR COMPRESSED NERVE ROOT. All these are juxtra foraminal and we can land in foramen and access them as kambin’s triangle [floor] or roof of the upper foramen. THE CHANGE: FROM MID LINE POSTERIOR TO TRANSFORAMINAL Our approach changed from decisions based on history, images and cadaver anatomy in degenerative cascade to in vivo visualized pathology of symptom generator resulting in surgery under local anesthesia with awake and aware patient. Learning from this gave us algorithm, matrix and the clinical cascade. This led to targeted surgery for the symptom generator with stitchless sub centimeter access under local anesthesia. Surgery for disc and stenosis included irrigation, ablation, lavage, decompression, mobilization, stabilization. 30

Chapter one references: 1. Parviz Kambin, MD Arthroscopic and Endoscopic Spinal Surgery: Text and Atlas: Second Edition Edited by: P. Kambin © Humana Press Inc Totowa, NJ History of Surgical Management of Herniated Lumbar Discs from Cauterization to Arthroscopic and Endoscopic Spinal Surgery 2. Hijikata S: Percutaneous nucleotomy. A new concept technique and 12 years' experience. Clin Orthop 1989; 238: 9-23 3. Hijikata S, Yamagishi M, Nakayama T, Oohashi K: Percutaneous nuclectomy: A new treatment method for lumbar disc herniation. Toden Iho (J Tokyo Den-ryoku Hosp) 1975: 5: 39-44 (in Japanese) 4. Kuslich SD1, Ulstrom CL, Michael CJ. The tissue origin of low back pain and sciatica: a report of pain response to tissue stimulation during operations on the lumbar spine using local anesthesia. Orthop Clin North Am. 1991 Apr;22(2):181-7 5. Mirkovic, S.R., D.G. Schwartz, and K.D. Glazier, Anatomic considerations in lumbar posterolateral percutaneous procedures. Spine, 1995. 20(18): p. 1965-71. 6. Leu H, Schreiber A (1991) Percutaneous nucleotomy with disk endoscopy—a minimally invasive therapy in non-sequestrated intervertebral disk hernia. Schweiz Rundsch Med Prax 80:364–368 7. Schreiber A, Leu H (1991) Percutaneous nucleotomy: technique with discoscopy. Orthopedics 14:439–444 49. 8. Knight M, Goswami A, Patko JT (1999) Endoscopic laser foraminoplasty and aware- state surgery: a treatment concept and 2-year outcome analyses. Arthroskopie 12:62–73 9. Knight MT, Ellison DR, Goswami A et al (2001) Review of safety in endoscopic laser foraminoplasty for the management of back pain. J Clin Laser Med Surg 19:147– 157 29. 10. Knight MT, Vajda A, Jakab GV et al (1998) Endoscopic laser foraminoplasty on the lumbar spine—early experience. Minim Invasive Neurosurg 41:5–9 31

11. Knight MT, Goswami A, Patko JT et al (2001) Endoscopic foraminoplasty: a prospective study on 250 consecutive patients with independent evaluation. J Clin Laser Med Surg 19:73–81E (27 28 29 30). 12. Hoogland T (2003) Transforaminal endoscopic discectomy with foraminoplasty for lumbar disc herniation. Surg Tech Orthop 1–6 13. Hoogland T, Scheckenbach C (1998) Die endoskopische transforminale diskektomie bei lumbalen bandscheibenforfallen. Orthop Prax 34:352–355 14. Hoogland T, Schubert M, Miklitz B et al (2006) Transforaminal posterolateral endoscopic discectomy with or without the combination of a low-dose chymopapain: a prospective randomized study in 280 consecutive cases. Spine 31: E890–E897 15. Hoogland T, van den Brekel-Dijkstra K, Schubert M et al (2008) Endoscopic transforaminal discectomy for recurrent lumbar disc herniation: a prospective, cohort evaluation of 262 consecutive cases. Spine 33:973–978 16. Osman SG1, Marsolais EB. Endoscopic transiliac approach to L5-S1 disc and foramen. A cadaver study Spine (Phila Pa 1976). 1997 Jun 1;22(11):1259-63. 17. Choi G1, Kim JS, Lokhande P, Lee SH. Percutaneous endoscopic lumbar discectomy by transiliac approach: a case report Spine (Phila Pa 1976). 2009 May 20;34(12): E443-6. 18. Yeung AT, Gore SR. Evolving methodology in treating discogenic back pain by Selective Endoscopic Discectomy (SED) and thermal annuloplasty. Journal of Minimally Invasive Spinal Technique 2001; 1:8–16. 19. Tsou PM, Yeung AC, Yeung AT. Posterolateral transforaminal selective endoscopic discectomy and thermal annuloplasty for chronic lumbar discogenic pain: a minimal access visualized intradiscal surgical procedure. Spine J. 2004;4(5):564 73. 20. A.T. Yeung, P.M. Tsou Posterolateral endoscopic excision for lumbar disc herniation: surgical technique, outcome, and complications in 307 consecutive cases Spine (Phila Pa 1976), 27 (7) (2002), pp. 722–731 32

21. Yeung AT: Minimally invasive surgery with the Yeung endoscopic spine system (YESS). Surg Tech Int 2000; VIII:267-27730. 22. Yeung AT, Yeung CA: Advances in Endoscopic Disc and Spine Surgery: The Foraminal Approach. Surgical Tech Int XI, 2003 June; 253-61 23. Yeung AT: Percutaneous Endoscopic Discectomy: The Posterolateral Approach, Minimal Access Spine Surgery, 2nd Edition, edited by Drs Regan and Lieberman, Quality Medical Publishing October 2003. 24. Yeung AT, Yeung CA In-vivo endoscopic visualization of patho-anatomy in painful degenerative conditions of the lumbar spine. Surg Technol Int. 2006; 15:243-56. 25. Anthony T. Yeung, MD the Evolution and Advancement of Endoscopic Foraminal Surgery: One Surgeon's Experience Incorporating Adjunctive Technologies SAS Journal Volume 1, Issue 3, Pages 108-117, September 2007] 26. Kirkaldy-Willis WH, Wedge JH, Yong Hing K, et al. Pathology and pathogenesis of lumbar spondylosis and stenosis. Spine. 1978; 3:319 28. 27. Kirkaldy-Willis WH. The relationship of structural pathology to the nerve root. Spine (Phila Pa 1976). 1984;9(1):49-52.] 28. James M. Cox Low Back Pain: Mechanism, Diagnosis and Treatment Lippincott Williams & Wilkins, 18-Jan-2012 - Medical - 736 pages. 29. Yeung AT, Gore SR In-vivo Endoscopic Visualization of Patho-anatomy in Symptomatic Degenerative Conditions of the Lumbar Spine II: Intradiscal, Foraminal, and Central Canal Decompression. Surg Technol Int. 2011 Dec 1; XXI:299-319 30. Gore S. New emerging Gore Matrix: Basis of stitchless spine surgery under local anesthesia. J Orthop Allied Sci 2017; 5:1-5. 31. Brisby H. Pathology and possible mechanisms of nervous system response to disc degeneration. J Bone Joint Surg Am. 2006;88(Suppl 2):68-71. 33

32. Takatalo J1, Karppinen J, Niinimäki J, Taimela S, Näyhä S, Mutanen P, Sequeiros RB, Kyllönen E, Tervonen O. Does lumbar disc degeneration on magnetic resonance imaging associate with low back symptom severity in young Finnish adults? Spine (Phila Pa 1976). 2011 Dec 1;36(25):2180-9. doi: 10.1097/BRS.0b013e3182077122. 33. Fu MC, Buerba RA, Long WD, Blizzard DJ, Lischuk AW, Haims AH, Grauer JN. Interrater and intrarater agreements of magnetic resonance imaging findings in the lumbar spine: significant variability across degenerative conditions. Spine J. 2014 Oct 1;14(10):2442-8. doi: 10.1016/j.spinee.2014.03.010. Epub 2014 Mar 15. 34. Yong XZ1, Sutherland T. Making sense of MRI of the lumbar spine. Aust Fam Physician. 2012 Nov;41(11):887-90. 35. Herrera I1, Moreno de la Presa R, González Gutiérrez R, Bárcena Ruiz E, García Benassi JM. Evaluation of the postoperative lumbar spine. [Article in English, Spanish] Radiologia. 2013 Jan-Feb;55(1):12-23. doi: 10.1016/j.rx.2011.12.004. Epub 2012 Apr 19. 36. Lao LF1, Zhong GB, Li QY, Liu ZD. Kinetic magnetic resonance imaging analysis of spinal degeneration: a systematic review. Orthop Surg. 2014 Nov;6(4):294-9. doi: 10.1111/os.12137. 37. Lee JC1, Cha JG, Yoo JH, Kim HK, Kim HJ, Shin BJ. Radiographic grading of facet degeneration, is it reliable? - a comparison of MR or CT grading with histologic grading in lumbar fusion candidates. Spine J. 2012 Jun;12(6):507-14. doi: 10.1016/j.spinee.2012.06.003. Epub 2012 Jul 6.] 38. Sirvanci M, Kara B, Duran C, Ozturk E, Karatoprak O, Onat L, Ulusoy OL, Mutlu A Acta Radiologica (Stockholm, Sweden: 1987) [2009, 50(2):205-11] Value of perineural edema/inflammation detected by fat saturation sequences in lumbar magnetic resonance imaging of patients with unilateral sciatica. 34

39. Weiner BK, Patel R. The accuracy of MRI in the detection of Lumbar Disc Containment. J Orthop Surg. 2008; 3:46. 40. Manchikanti L, Glaser SE, Wolfer L, et al. Systematic review of lumbar discography as a diagnostic test for chronic low back pain. Pain Physician. 2009;12(3):541 59. 41. Ross JS, Modic MT, Masaryk TJ. Tears of the anulus fibrosus: assessment with Gd-DTPA-Enhanced MR imaging. AJR AmJ Roentgenol. 1990;154(1):159-62. 42. Kim SY, Lee IS, Kim BR, et al. Magnetic resonance findings of acute severe lower back pain. Ann Rehabil Med.2012;36(1):47 54. 43. Munter FM, Wasserman BA, Wu HM, et al. Serial MR Imaging of Annular Tears in Lumbar Intervertebral Disks. AJNR Am J Neuroradiol. 2002; 23:1105-9. 44. Osti OL, Fraser RD. MRI and discography of annular tears and intervertebral disc degeneration. A prospective clinical comparison. J Bone Joint Surg Br. 1992;74(3):431-5. 45. Donelson R, Aprill C, Medcalf R, et al. A prospective study of centralization of lumbar and referred pain. A predictor of symptomatic discs and annular competence. Spine (Phila Pa 1976). 1997;22(10):1115 22. 46. Gore S, Nadkarni S. Sciatica: detection and confirmation by new method. Int J Spine Surg. 2014 Dec 1;8. doi: 10.14444/1015. eCollection 2014. PMID: 25694916 Free PMC Article 47. Shin-ichi Konno, 1 Shin-ichi Kikuchi,1 Yasuhisa Tanaka,2 Ken Yamazaki,3You-ichi Shimada,4 Hiroshi Takei,5 Toru Yokoyama,6 Masahiro Okada,6 and Shou-ichi Kokubun2 BMC Musculoskeletal Disord. 2007; 8: 102. A diagnostic support tool for lumbar spinal stenosis: a self-administered, self-reported history questionnaire 48. Bogduk N, Long DM. Spine (Phila Pa 1976). 1980 Mar-Apr;5(2):193- 200.Percutaneous lumbar medial branch neurotomy: a modification of facet denervation. 49. Anthony Yeung, MD,1 Satishchandra Gore, MD2 http://ijssurgery.com/10.14444/1023 Endoscopically Guided Foraminal and Dorsal 35

Rhizotomy for Chronic Axial Back Pain Based on Cadaver and Endoscopically Visualized Anatomic Study 50. Dr Sunil Nadkarni, Dr Pavankumar Kohli, Dr Satishchandra Gore, Dr Bhupesh Patel, Ms Bhagyashri Kulkarni IOSR Journal of Dental and Medical Sciences (IOSR-JDMS) e-ISSN: 2279-0853, p-ISSN: 2279-0861.Volume 15, Issue 10 Ver. IV (October. 2016), PP 52-57\"Use of Biological Solutions for Annular Healing During and End of Surgery: Dervan Platelet Plug in Transforaminal Disc Surgery 51. Satishchandra Gore, MD,1 Anthony Yeung, MD2 The \"inside out\" transforaminal technique to treat lumbar spinal pain in an awake and aware patient under local anesthesia: results and a review of the literature http://ijssurgery.com/10.14444/1028 52. Gore S. Lumbar Stenosis: Oblique Coronal Images in MRI for assessment of Ligamentum Flavum. J Spinal Surg 2016;3(3):117. 53. Apostolides PJ1, Jacobowitz R, Sonntag VK Clin Neurosurg. 1996;43:228-38. Lumbar discectomy microdiscectomy: \"the gold standard”. 54. Peter Försth, M.D., Ph.D., Gylfi Ólafsson, M.Sc., Thomas Carlsson, M.D., Anders Frost, M.D., Ph.D., Fredrik Borgström, Ph.D., Peter Fritzell, M.D., Ph.D., Patrik Öhagen, Karl Michaëlsson, M.D., Ph.D., N Engl J Med 2016;374:1413-23. A Randomized, Controlled Trial of Fusion Surgery for Lumbar Spinal Stenosis 55. Yu Chao Lee,1 Mario Giuseppe Tedesco Zotti, 1 and Orso Lorenzo Osti2Asian Spine J. 2016 Aug; 10(4): 801–819.Operative Management of Lumbar Degenerative Disc Disease 56. David E. Mino, James E. Munterich, and Liana D. Castel J Spine Surg. 2017 Jun; 3(2): 141–148.Lumbar fusion surgery for degenerative conditions is associated with significant resource and narcotic use 2 years postoperatively in the commercially insured: a medical and pharmacy claims study 36

57. Le Huec, JC., Faundez, A., Dominguez, D. et al. International Orthopaedics (SICOT) (2015) 39: 87Evidence showing the relationship between sagittal balance and clinical outcomes in surgical treatment of degenerative spinal diseases: a literature review 58. www.isass.org/pdf/2011-07-15_policy_statement_lumbar_surgery.pdf 59. Parviz Kambin, MD Arthroscopic and Endoscopic Spinal Surgery: Text and Atlas: Second Edition Edited by: P. Kambin © Humana Press Inc Totowa, NJ History of Surgical Management of Herniated Lumbar Discs from Cauterization to Arthroscopic and Endoscopic Spinal Surgery 60. Min JH1, Kang SH, Lee JB, Cho TH, Suh JG. Anatomic analysis of the transforaminal ligament in the lumbar intervertebral foramen. Neurosurgery. 2005 Jul;57(1 Suppl):37-41; discussion 37-41. 61. Jin Woo Shin, MD A New Approach to Neuroplasty Korean J Pain. 2013 Oct; 26(4): 323–326. Published online 2013 Oct doi: 10.3344/kjp.2013.26.4.323 PMCID: PMC3800703 62. Percutaneous extra foraminotomy with foraminal ligament resection and instrument tool used for the same PATENT US 20140163598 A1 63. Hyun Seog Moon,2 Yeon Dong Kim,2 Bang Hoon Song,1 Young Deog Cha,1 Jang Ho Song,1 and Mi Hyeon Lee corresponding author1 Position of dorsal root ganglia in the lumbosacral region in patients with radiculopathy Korean J Anesthesiol. 2010 Dec; 59(6): 398–402. Published online 2010 Dec 31. 64. http://www.ajnr.org/content/27/10/2098.full 65. http://www.ijssurgery.com/10.14444/2003 66. Sihvonen T, Herno A, Paljarvi L, Airaksinen O, Partanen J, Tapaninaho A. Local denervation atrophy of paraspinal muscles in postoperative failed back syndrome. Spine (Phila Pa 1976). 1993; 18(5):575–581. 37

67. Kim DY, Lee SH, Chung SK, Lee HY. Comparison of multifidus muscle atrophy and trunk extension muscle strength: percutaneous versus open pedicle screw fixation. Spine (Phila Pa 1976). 2005; 30(1):123–129. 68. Fleckenstein JL, Watumull D, Conner KE, et al. Denervated human skeletal muscle: MR imaging evaluation. Radiology. 1993; 187(1):213–218. doi:10.1148/radiology.187.1.8451416 69. Motosuneya T, Asazuma T, Tsuji T, Watanabe H, Nakayama Y, Nemoto K. Postoperative change of the cross-sectional area of back musculature after 5 surgical procedures as assessed by magnetic resonance imaging. J Spinal Disord Tech. 2006; 19(5):318–322 70. Suwa H, Hanakita J, Ohshita N, Gotoh K, Matsuoka N, Morizane A. Postoperative changes in paraspinal muscle thickness after various lumbar back surgery procedures. Neurol Med Chir (Tokyo). 2000; 40(3):151–154. 71. de Coul AA, Lie TA. A comparative electromyographic study before and after operations for protruded lumbar disc. Electromyography. 1970; 10(2):193–199. 72. Hodges P, Holm AK, Hansson T, Holm S. Rapid atrophy of the lumbar multifidus follows experimental disc or nerve root injury. Spine (Phila Pa 1976). 2006; 31(25):2926–2933. 73. Hyun SJ, Kim YB, Kim YS, et al. Postoperative changes in paraspinal muscle volume: comparison between paramedian interfacial and midline approaches for lumbar fusion. J Korean Med Sci. 2007; 22(4):646–651. 74. Fan S, Hu Z, Zhao F, Zhao X, Huang Y, Fang X. Multifidus muscle changes and clinical effects of one-level posterior lumbar interbody fusion: minimally invasive procedure versus conventional open approach. Eur Spine J. 2010; 19(2):316–324. 75. Boelderl A, Daniaux H, Kathrein A, Maurer H. Danger of damaging the medial branches of the posterior rami of spinal nerves during a dorsomedian approach to the spine. Clin Anat. 2002; 15(2):77–81. 38

76. Mori E, Okada S, Ueta T, et al. Spinous process-splitting open pedicle screw fusion provides favorable results in patients with low back discomfort and pain compared to conventional open pedicle screw fixation over 1 year after surgery. Eur Spine J. 2012; 21(4):745–753. 77. Gejo R, Matsui H, Kawaguchi Y, Ishihara H, Tsuji H. Serial changes in trunk muscle performance after posterior lumbar surgery. Spine (Phila Pa 1976). 1999; 24(10):1023–1028. 78. Watanabe K, Matsumoto M, Ikegami T, et al. Reduced postoperative wound pain after lumbar spinous process-splitting laminectomy for lumbar canal stenosis: a randomized controlled study. J Neurosurg Spine. 2011; 14:51–58. 79. Tsutsumimoto T, Shimogata M, Ohta H, Misawa H. Mini-open versus conventional open posterior lumbar interbody fusion for the treatment of lumbar degenerative spondylolisthesis: comparison of paraspinal muscle damage and slip reduction. Spine (Phila Pa 1976). 2009; 34:1923–1928. 80. Remes V, Lamberg T, Tervahartiala P, et al. Long-term outcome after posterolateral, anterior, and circumferential fusion for high-grade isthmic spondylolisthesis in children and adolescents: magnetic resonance imaging findings after average of 17-year follow-up. Spine (Phila Pa 1976). 2006; 31:2491– 2499. 81. Hartwig T, Streitparth F, Gross C, et al. Digital 3-dimensional analysis of the paravertebral lumbar muscles after circumferential single-level fusion. J Spinal Disord Tech. 2011; 24:451–454 82. Stevens KJ, Spenciner DB, Griffiths KL, et al. Comparison of minimally invasive and conventional open posterolateral lumbar fusion using magnetic resonance imaging and retraction pressure studies. J Spinal Disord Tech. 2006; 19:77–86. 39

83. Kim K, Isu T, Sugawara A, Matsumoto R, Isobe M. Comparison of the effect of 3 different approaches to the lumbar spinal canal on postoperative paraspinal muscle damage. Surg Neurol. 2008; 69:109–113. 84. Surg Neurol Int. 2016; 7(Suppl 3): S96–S101.More nerve root injuries occur with minimally invasive lumbar surgery: Let's tell someone Nancy E. Epstein* 85. Abumi K, Panjabi MM, Kramer KM, Duranceau J, Oxland T, Crisco JJ: Biomechani cal evaluation of lumbar spinal stability after graded facetectomies. Spine (Phila Pa 1976) 15:1142–1147, 1990 86. Ghiselli G, Wang JC, Bhatia NN, Hsu WK, Dawson EG: Adjacent segment degeneration in the lumbar spine. J Bone Joint Surg Am 86-A:1497–1503, 2004 87. Ikuta K, Arima J, Tanaka T, Oga M, Nakano S, Sasaki K, et al.: Short-term results of microendoscopic posterior decompression for lumbar spinal stenosis. Technical note. J Neurosurg Spine 2:624–633, 2005 88. Khoo LT, Fessler RG: Microendoscopic decompressive laminotomy for the treatment of lumbar stenosis. Neurosurgery 51:5 SupplS146–S154, 2002 89. Matsumoto M, Hasegawa T, Ito M, Aizawa T, Konno S, Yamagata M, et al.: Incidence of complications associated with spinal endoscopic surgery: nationwide survey in 2007 by the Committee on Spinal Endoscopic Surgical Skill Qualification of Japanese Orthopaedic Association. J Orthop Sci 15:92–96, 2010 90. McCulloch JA, Microsurgical spinal laminectomies. Frymoyer JW: The Adult Spine: Principles and Practice New York, Raven Press, 1991. 1821–1831 91. Oertel MF, Ryang YM, Korinth MC, Gilsbach JM, Rohde V: Long-term results of microsurgical treatment of lumbar spinal stenosis by unilateral laminotomy for bilateral decompression. Neurosurgery 59:1264–1270, 2006 40

92. Palmer S, Turner R, Palmer R: Bilateral decompression of lumbar spinal stenosis involving a unilateral approach with microscope and tubular retractor system. J Neurosurg 97:2 Suppl213–217, 2002 93. Pao JL, Chen WC, Chen PQ: Clinical outcomes of microendoscopic decompressive laminotomy for degenerative lumbar spinal stenosis. Eur Spine J 18:672– 678, 2009 94. Perez-Cruet MJ, Foley KT, Isaacs RE, Rice-Wyllie L, Wellington R, Smith MM, et al.: Microendoscopic lumbar discectomy: technical note. Neurosurgery 51:5 SupplS129–S136, 2002 95. Sairyo K, Sakai T, Higashino K, Inoue M, Yasui N, Dezawa A: Complications of endoscopic lumbar decompression surgery. Minim Invasive Neurosurg 53:175– 178, 2010 96. Shibayama M, Mizutani J, Takahashi I, Nagao S, Ohta H, Otsuka T: Patch technique for repair of a dural tear in microendoscopic spinal surgery. J Bone Joint Surg Br 90:1066–1067, 2008 41

Chapter 2: philosophy and concepts: how i do it? A Target A1. anatomy of target in disc degeneration A2. pain generator: correlating anatomy and pain A3. sciatica detection and confirmation A4. target in canal stenosis B Technique B1. Technique of sssula for disc herniation B2 Illustrative case step by step in disc herniation B3. variations in access: disc first or facet first C. Instruments a. access instruments b. instruments for disc surgery c. instruments for stenosis D. post op care D1. Dysesthesia in sssula E. advantages of sssula F. results and literature review F1. before 1995 F2. between 1995 and 2005 F3. between 2005 and 2015 F4. evolution after 2015 G. contraindications H summary: moving away from fusion and towards symptom and pathology directed intervention 42

A Target A1. anatomy of target in disc degeneration A2. pain generator: correlating anatomy and pain A3. sciatica detection and confirmation A4. target in canal stenosis A1 ANATOMY OF TARGET AREA surgery for the disc herniations is done thru foramen of the symptomatic side by landing on the posterolateral annulus in kambin’s triangle. The kambin’s triangle is formed by exiting root as hypotenuse, traversing root as height and base is formed by upper end plate of the caudad vertebra. The entry is always same for the disc surgery. This area is safe and devoid of any important structures on posterior annulus. 43

KAMBIN’S TRAINGLE Image53 Access to kambin’s triangle is retro psoas, intra muscular, paraspinal, under facet and transforaminal shown here as red line targeting symptomatic posterior annulus and peri DRG tissue. The anatomy for posterolateral transforaminal access has been proposed by Mirkowiz. Studies by Vialle emphasize “DRG” as lateral wall of the “kambin” safe triangle and can be injured if access is not precise and properly targeted. 44

Image54 Foraminal size increases from L1 to L5 in the ventral to dorsal and cephalad to caudal direction. Pedicle width increases from L1 to L5. Greatest width of the DRG is 6.5mm bilaterally at L5 (range 3.2-6.5mm). In the fourth lumbar spine, dorsal root ganglia position is intraforaminal [IF], fifth lumbar spine 75% IF at S1 83% IS [intra spinal]. Position of DRG can be ascertained by doing a epidurogram. This refined understanding of the foraminal contents can improve the safety of access and effectiveness of the intervention. 45

Image55 The lumbar vertebrae and their coronal profile. The laminae become wider as we go caudad. The interpedicular distance also increases. The size of the body, foramen, dorsal root ganglion too increases. Interpedicular distance average at L5 is 36mm. 46

Image56 the philosophy of transforaminal access. Image57 This is a coronal image on MRI of lower lumbar spine highlighting kambin’s triangle.Red circles denote the pedicles and triangle is seen with height is the traversing root, base is upper endplate of the lower vertebra and the hypotenuse of the right angle traingle is the exiting root. IMPORTANT: Dorsal root ganlion is in the lateral wall or hypotenuse of the traingle and is susceptible to injury during access. 47

Image58 Kambin’s traingle is seen in red. Yellow is exiting ventral root. The pink is dorsal root exiting in lower foraminal part going over transverse process and giving lateral, intermediate and medial branch. Medial branch curves around the lateral wall of facet and ending on medial aspect of the facet below.During its course over the transverse process red dot indicates where it is accessed and ablated for facet denervation. 48

Image59 Orange dot in upper foramen below the pedicle is spinal root, yellow is its dorsal branch and it continues in orange color as ventral root combining with roots above to form lumbar plexus. Lumbosacral plexus lies in posterior 1/3 of the psoas muscle. P is psoas muscle, L is lumbodorsalis and M is multifidus. When seen in sagittal plane the foramen lies between the psoas muscle and the posterior paraspinal muscles.This also is a physiological plane the posterior muscles being supplied by dorsal ramus. 49