Endoscopic Spine Surgeons Research Articles

How to Prevent Nerve Root Injury in Uniportal Full Endoscopic Lumbar Fusion Surgery? Insights From a Cadaveric Anatomic Study With Simulation Surgery.

The study included 2 fresh-frozen cadavers. To elucidate the positional relationship between surgical instruments and nerve roots during full endoscopic facet-sparing (FE fs-TLIF) and full endoscopic facet-resecting (FE fr-TLIF) transforaminal lumbar interbody fusion and propose safe instrumentation insertion procedures and recommend cage glider designs aimed at protecting nerve roots. Endoscopic surgical techniques are increasingly used for minimally invasive lumbar fusion surgery, with FE fr-TLIF and FE fs-TLIF being common approaches. However, the risk of nerve root injury remains a significant concern during these procedures. Eight experienced endoscopic spine surgeons performed uniportal FE fr-TLIF and FE fs-TLIF on cadaveric lumbar spines, totaling 16 surgeries. Postoperation, soft tissues were removed to assess the positional relationship between the cage entry point and nerve roots. Distances between the cage entry point, traversing nerve root, and exiting nerve root were measured. Safe instrumentation design and insertion procedures were determined. In FE fr-TLIF, the mean distance between the cage entry point and traversing nerve root was significantly shorter compared with FE fs-TLIF (3.30 ± 1.35 vs . 8.58 ± 2.47mm, respectively; P < 0.0001). Conversely, the mean distance between the cage entry point and the exiting nerve root was significantly shorter in FE fs-TLIF compared with FE fr-TLIF (3.73 ± 1.97 vs . 6.90 ± 1.36mm, respectively; P < 0.0001). For FE fr-TLIF, prioritizing the protection of the traversing root using a 2-bevel tip cage glider was crucial. In contrast, for FE fs-TLIF, a single-bevel tip cage glider placed in the caudal location was recommended. This study elucidates the anatomic relationship between cage entry points and nerve roots in uniportal endoscopic lumbar fusion surgery. Protection strategies should prioritize the traversing root in FE fr-TLIF and the exiting root in FE fs-TLIF, with corresponding variations in surgical techniques. Level V.

Endoscopic Posterior Cervical Foraminotomy Under Lateral Decubitus Position with Local Anesthesia

Endoscopic posterior cervical foraminotomy is gaining popularity among endoscopic spine surgeons for the treatment of radiculopathy caused by foraminal stenosis. This study describes a technique utilizing lateral decubitus position for an endoscopic posterior cervical foraminotomy under Monitored Anesthesia Care (MAC) and local anesthesia only. 10 patients with contraindications to general anesthesia underwent the procedure, resulting in an improvement in cervical radicular pain with no perioperative complications. The findings suggest that this approach is a viable alternative for high-risk patients for general anesthesia care, expanding the surgical options for the treatment of radiculopathy.

Comparative Analysis of Learning Curve, Complexity, Psychological Stress, and Work Relative Value Units for CPT 62380 Endoscopic Lumbar Spinal Decompression vs Traditional Lumbar Spine Surgeries: A Paired Rasch Survey Study.

Effective 1 January 2017, single-level endoscopic lumbar discectomy received a Category I Current Procedural Terminology (CPT) code 62380. However, no work relative value units (RVUs) are currently assigned to the procedure. An international team of endoscopic spine surgeons conducted a study, endorsed by several spine societies, analyzing the learning curve, difficulty, psychological intensity, and estimated work RVUs of endoscopic lumbar spinal decompression compared with other common lumbar spine surgeries. A survey comparing CPT 62380 to 10 other comparator CPT codes reflective of common spine surgeries was developed to assess the work RVUs in terms of learning curve, difficulty, psychological intensity, and work effort using a paired Rasch method. The survey was sent to 542 spine specialists. Of 322 respondents, 150 completed the survey for a 43.1% completion rate. Rasch analysis of the submitted responses statistically corroborated common knowledge that the learning curve with lumbar endoscopic spinal surgery is steeper and more complex than with traditional translaminar lumbar decompression surgeries. It also showed that the psychological stress and mental and work effort with the lumbar endoscopic decompression surgery were perceived to be higher by responding spine surgeons compared with posterior comparator decompression and fusion surgeries and even posterior interbody and posterolateral fusion surgeries. The regression analysis of work effort vs procedural difficulty showed the real-world evaluation of the lumbar endoscopic decompression surgery described in CPT code 62380 with a calculated work RVU of 18.2464. The Rasch analysis suggested the valuation for the endoscopic lumbar decompression surgery should be higher than for standard lumbar surgeries: 111.1% of the laminectomy with exploration and/or decompression of spinal cord and/or cauda equina (CPT 63005), 118.71% of the laminectomy code (CPT 63047), which includes foraminotomy and facetectomy, 152.1% of the hemilaminectomy code (CPT 63030), and 259.55% of the interlaminar or interspinous process stabilization/distraction without decompression code (CPT 22869). This research methodology was endorsed by the Interamerican Society for Minimally Invasive Spine Surgery (SICCMI), the Mexican Society of Spinal Surgeons (AMCICO), the International Society For Minimally Invasive Spine Surgery (ISMISS), the Brazilian Spine Society (SBC), the Society for Minimally Invasive Spine Surgery (SMISS), the Korean Minimally Invasive Spine Surgery (KOMISS), and the International Society for the Advancement of Spine Surgery (ISASS). This study provides an updated reimbursement recommendation for endoscopic spine surgery. Level 3.

The Role and Clinical Outcomes of Endoscopic Spine Surgery of Treating Spinal Metastases; Outcomes of 29 Cases From 8 Countries.

We aim to report the outcomes and feasibility of endoscopic spine surgery used to treat symptomatic spinal metastases patients. This is the most extensive series of spinal metastases patients who underwent endoscopic spine surgery. A worldwide collaborative network group of endoscopic spine surgeons, named 'ESSSORG,' was established. Patients diagnosed with spinal metastases who underwent endoscopic spine surgery from 2012 to 2022 were retrospectively reviewed. All related patient data and clinical outcomes were gathered and analyzed before the surgery and the followtime period of 2 weeks, 1 month, 3 months, and 6 months. A total of 29 patients from South Korea, Thailand, Taiwan, Mexico, Brazil, Argentina, Chile, and India, were included. The mean age was 59.59 years, and 11 of them were female. The total number of decompressed levels was 40. The technique was relatively equal (15 uniportal; 14 biportal). The average length of admission was 4.41 days. Of all patients with an American Spinal Injury Association Impairment Scale of D or lower before surgery, 62.06% reported having at least one recovery grade after the surgery. Almost all clinical outcomes parameters statistically significantly improved and maintained from 2 weeks to 6 months after the surgery. Few surgical-related complications (4 cases) were reported. Endoscopic spine surgery is a valid option for treating spinal metastases patients as it could yield comparable results to other minimally invasive spine surgery techniques. As the aim is to improve the quality of life, this procedure is valuable and holds value in palliative oncologic spine surgery.

Durotomy- and Irrigation-Related Serious Adverse Events During Spinal Endoscopy: Illustrative Case Series and International Surgeon Survey.

Durotomy during endoscopic spine surgery can cause a patient's neurological or cardiovascular status to deteriorate unexpectedly intra- or postoperatively. There is currently limited literature regarding appropriate fluid management strategies, irrigation-related risk factors, and clinical consequences of incidental durotomy during spinal endoscopy, and no validated irrigation protocol exists for endoscopic spine surgery. Thus, the present article sought to (1) describe 3 cases of durotomy, (2) investigate standard epidural pressure measurements, and (3) survey endoscopic spine surgeons on the incidence of adverse effects believed to result from durotomy. The authors first reviewed clinical outcomes and analyzed complications in 3 patients with intraoperatively recognized incidental durotomy. Second, the authors conducted a small case series with intraoperative epidural pressure measurements during gravity-assisted irrigated video endoscopy of the lumbar spine. Measurements were conducted on 12 patients with a transducer assembly that was introduced through the endoscopic working channel of the RIWOSpine Panoview Plus and Vertebris endoscope to the decompression site in the spine. Third, the authors conducted a retrospective, multiple-choice survey of endoscopic spine surgeons to better understand the frequency and seriousness of problems they attributed to irrigation fluid escaping from the surgical decompression site into the spinal canal and neural axis. Descriptive and correlative statistical analyses were performed on the surgeons' responses. In the first part of this study, durotomy-related complications during irrigated spinal endoscopy were observed in 3 patients. Postoperative head computed tomographic (CT) images revealed massive blood in the intracranial subarachnoid space, the basal cisterns, the III and IV ventricle, and the lateral ventricles characteristic of an arterial fisher grade IV subarachnoid hemorrhage, and hydrocephalus without evidence of aneurysms or angiomas. Two additional patients developed intraoperative seizures, cardiac arrhythmia, and hypotension. The head CT image in 1 of these 2 patients had intracranial air entrapment.In the second part, epidural pressure measurements in 12 patients who underwent uneventful routine lumbar interlaminar decompression for L4-L5 and L5-S1 disc herniation showed an average epidural pressure of 24.5 mm Hg.In the third part, the online survey was accessed by 766 spine surgeons worldwide and had a response rate of 43.6%. Irrigation-related problems were reported by 38% of responding surgeons. Only 11.8% used irrigation pumps, with 90% running the pump above 40 mm Hg. Headaches (4.5%) and neck pain (4.9%) were observed by nearly a 10th (9.4%) of surgeons. Seizures in combination with headaches, neck and abdominal pain, soft tissue edema, and nerve root injury were reported by another 5 surgeons. One surgeon reported a delirious patient. Another 14 surgeons thought that they had patients with neurological deficits ranging from nerve root injury to cauda equina syndrome related to irrigation fluid. Autonomic dysreflexia associated with hypertension was attributed by 19 of the 244 responding surgeons to the noxious stimulus of escaped irrigation fluid that migrated from the decompression site in the spinal canal. Two of these 19 surgeons reported 1 case associated with a recognized incidental durotomy and another with postoperative paralysis. Patients should be educated preoperatively about the risk of irrigated spinal endoscopy. Although rare, intracranial blood, hydrocephalus, headaches, neck pain, seizures, and more severe complications, including life-threatening autonomic dysreflexia with hypertension, may arise if irrigation fluid enters the spinal canal or the dural sac and migrates from the endoscopic site along the neural axis rostrally. Experienced endoscopic spine surgeons suspect a correlation between durotomy and irrigation-related extra- and intradural pressure equalization that could be problematic if associated with high volumes of irrigation fluid LEVEL OF EVIDENCE: 3.

A Narrative Review of Full-Endoscopic Lumbar Discectomy Using Interlaminar Approach

Lumbar disc herniation (LDH) is a frequently encountered pathologic condition in orthopedic daily practice. Discectomyis considered when patients with LDH experiencepersistent limb or lumbar pain or neurologic deficits. Various minimally invasive techniques are available for discectomy. Among these techniques, full-endoscopic lumbar discectomy (FED) is one of the least invasive options. During FED, removal of LDH is accomplished using 2 major approaches: transforaminal (TF) or interlaminar (IL). The prototype FED was percutaneous nucelotomy. An endoscope was integrated to percutaneous nucelotomy and TF endoscopic lumbar discectomy (TELD) was first derived. IL endoscopic lumbar discectomy (IELD) was introduced years after TELD. TELD and IELD can compensate for the shortcomings of each other and endoscopic spine surgeons need to acquire both techniques to deal with all type of LDHs. Because of its long history, the TF approach seems to represent the major approach for FED, but the IL approach has numerous benefits in particular types of LDH. The present article focuses on IELD and reviews the history, surgical techniques, indications and contraindications, clinical outcomes, and complications. This review will contribute to improved understanding of IELD as an important technique in full-endoscopic spine surgery.

Surgical Outcomes of Full-Endoscopic Lumbar Discectomy in the Early Adoption Phase.

Background We adopted full-endoscopic lumbar discectomy (FELD) in 2019 with the assistance of the Japanese Society for Minimally Invasive and Endoscopic Techniques of Spinal Neurosurgery (JASMETS). This study analyzed short-term outcomes in our initial FELD cases and compared them with microdiscectomy cases performed during the same period. Methods FELD was performed in 21 patients over a period of 2 years and 6 months (15 men and 6 women; mean age, 57.0±17.0 years). The transforaminal approach was performed in 8 patients, the posterolateral approach in 3, and the interlaminar approach in 10. During the same period, microdiscectomy was performed in 30 patients. Japanese Orthopaedic Association (JOA) and visual analog scale (VAS) scores, operation time, blood loss volume, complications, and incidence of lumbar disc herniation recurrence were compared between the groups. Results Preoperative VAS and JOA scores did not significantly differ between the FELD and microdiscectomy groups. JOA and VAS scores significantly improved in both groups after surgery. Operation time and incidence of recurrence rate did not differ. Conclusion Spine surgeons who adopt FELD can achieve good surgical outcomes similar to those of microdiscectomy, even in the early period. Participation in JASMETS seminars and training and proctoring by a certified endoscopic spine surgeon were instrumental in our experience.

Surgeons' Perspective, Learning Curve, Motivation, and Obstacles of Full-Endoscopic Spine Surgery in Thailand: Results From A Nationwide Survey.

Objective To report a nationwide survey of the endoscopic spine surgeons across Thailand. Furthermore, the survey will be focused on the perspective of experience, learning curve, motivations, and obstacles at the beginning of their practices. Materials and Methods The online survey consisting of 16 items was distributed to spine surgeons who are performing endoscopic spine surgery in Thailand via the Google forms web-based questionnaire to investigate participants' demographics, backgrounds, experience in endoscopic spine surgery, motivations, obstacles, and future perspectives. The data was recorded from January 7, 2020 to January 21, 2022. Descriptive statistics were used for analysis. Results A total of 42 surveys were submitted by 6 neurosurgeons (14.3%) and 36 orthopedic surgeons (85.7%). From the surgeons' perspective, the average number of cases that should be performed until one feels confident, consistently good outcomes, and has minimal complications was 27.44 ± 32.46 cases. For surgeons who starting the endoscopic spine practice, at least 3 workshop participation is needed. Personal interest (39 selected responses) and trending marketing or business purpose (25 selected responses) were the primary motivators for endoscopic spine surgery implementation. Lack of support (18 selected responses) and afraid of complications (16 selected responses) were pertinent obstacles to endoscopic spine surgery implementation. Conclusions The trend of endoscopic spine surgery has continued to grow in Thailand, shown by the rate of implementation of endoscopic spine surgery reported by Thai spine surgeons. The number of appropriate cases until one feels confident was around 28 cases. The primary motivator and obstacles were personal interest and lack of support.

Durability of Endoscopes Used During Routine Lumbar Endoscopy: An Analysis of Use Patterns, Common Failure Modes, Impact on Patient Care, and Contingency Plans.

Successful implementation of endoscopic spinal surgery programs hinges on reliable performance and case cost similar to traditional decompression surgeries of the lumbar spine. To improve the statistical power of studying the durability of endoscopes with routine lumbar endoscopy, the authors performed a retrospective survey study among endoscopic spine surgeons by email and chat groups on social media networks WhatsApp and WeChat. Descriptive and correlative statistics were done on the surgeon's responses recorded in multiple-choice questions. Surgeons were asked about their clinical experience with spinal endoscopy, training background, the types of lumbar endoscopic decompression they perform by approach, their preferred decompression instruments, and their experience with endoscopic equipment failure. A total of 485 surgeons responded, of whom 85 submitted a valid survey recording, rendering a completion rate of 27.1%. These 85 respondents reported a case volume of 12,650 lumbar endoscopies within the past year and, to date, had performed a total of 120,150 spinal endoscopies over their collective career years. The majority of respondents performed endoscopic surgery for herniated disc (65.9%) vs spinal stenosis (34.1%) in a hospital setting, preferentially employing the transforaminal (76.5%), interlaminar (51.8%), and unilateral biportal endoscopic (UBE; 15.3%) approach technique. The most commonly used endoscopic spine systems were Wolf/Riwo Spine (38.8%), Joimax (36.5%), Storz (24.7%), unspecified Chinese brand (22.4%), Maxmore (15.3%), Spinendos (12.9%), Elliquence (10.6%), unspecified Korean brand (7.1%), and asap Endosystems GmbH (2.4%). The most frequent failure mode of the endoscope reported by survey respondents was a blurry image (71.8%), followed by the loss of focus (21.2%), the loss of illumination of the surgical site (18.8%), and the failure of the irrigation/suction system integrated into the endoscope (4.7%). Most respondents thought they had problems with the lens (67.1%), the fiberglass light conductor (23.5%), the prism (16.5%), or the rod system (4.7%). Motorized high-speed power burrs and hand reamers and trephines were the reported favorite decompression tools that were presumably associated with the endoscope's failure. The majority of respondents (49.5%) performed up to 50 endoscopies before the endoscope had to be either exchanged or repaired. Another 15.3% of respondents reported their endoscope lasted between 101 and 200 cases and only 12.9% reported more than 300 cases. Besides abuse during surgery (25.9%), bad handling by staff was the most common suspected reason (45.9%), followed by the wrong sterilization technique (21.2%). Some 23.5% of respondents noted that the endoscope failed during their surgery. In that case, 66.3% asked for a replacement endoscope, and 36.1% completed the surgery with the broken endoscope. However, 10.8% stopped and another 6% of respondents woke the patient up and rescheduled the surgery to complete the decompression at another time. Spinal endoscopes used during routine lumbar decompression surgeries for herniated disc and spinal stenosis have an estimated life cycle between 50 and 100 surgeries. Abusive use by surgeons, mishandling by staff, and deviation for prescribed cleaning and sterilization protocols may substantially shorten the life cycle. Contingency protocols should be in place to readily replace a broken spinal endoscope during surgery. More comprehensive implementation of endoscopic spine surgery techniques will hinge on technology advancements to make these hightech surgical instruments more resistant to the stress of daily use and abuse of expanded clinical indications' for surgery. The regulatory burden on endoscope makers is likely to increase, calling for increased reimbursement for facilities to cover the added expense for capital equipment purchase, disposables, and the endoscopic spine surgery program's maintenance. 3. End user surgeon survey study.

Difficulties, Challenges, and the Learning Curve of Avoiding Complications in Lumbar Endoscopic Spine Surgery.

Spinal endoscopy has the stigma of being reserved for only a few surgeons who can figure out how to master the steep learning curve and develop clinical practice settings where endoscopic spine surgery can thrive. In essence, endoscopic treatment of herniated discs specifically and nerve root compression in the lumbar spine in general amounts to replacing traditional open spine surgery protocols with spinal endoscopic surgery techniques. In doing so, the endoscopic spine surgeon must be confident that the degenerative spine's common painful problems can be handled with endoscopic spinal surgery techniques with at least comparable clinical results and complication rates. In this review article, the authors illustrate the difficulties and challenges of the endoscopic lumbar decompression procedure. In addition, they shed light on how to master the learning curve by systematically looking at all sides of the problem, ranging from the ergonomic aspects of the endoscopic platform and its instruments, surgical access planning, challenging clinical scenarios, complications, and sequelae, as well as the training gaps after postgraduate residency and fellowship programs.

Dural Tears During Lumbar Spinal Endoscopy: Surgeon Skill, Training, Incidence, Risk Factors, and Management.

Incidental dural tears during lumbar endoscopy can be challenging to manage. There is limited literature on their appropriate management, risk factors, and the clinical consequences of this typically uncommon complication. To improve the statistical power of studying durotomy with lumbar endoscopy, we performed a retrospective survey study among endoscopic spine surgeons by email and chat groups on social media networks, including WhatsApp and WeChat. Descriptive and correlative statistics were done on the surgeons' recorded responses to multiple-choice questions. Surgeons were asked about their clinical experience with spinal endoscopy, training background, the types of lumbar endoscopic decompression they perform by approach, the decompression instruments they use, and incidental durotomy incidence with routine lumbar endoscopy. There were 689 dural tears in 64 470 lumbar endoscopies, resulting in an incidental durotomy incidence of 1.07%. Seventy percent of the durotomies were reported by 20.4% of the surgeons. Eliminating these 19 outlier surgeons yielded an adjusted durotomy rate of 0.32. Endoscopic stenosis decompression (54.8%; P < .0001), rather than endoscopic discectomy (44.1%; 41/93), was significantly more associated with durotomy. Medium-sized dural tears (1-10 mm) were the most common (52.2%; 48/93). Small pinhole durotomies (less than 1 mm) were the second most common type (46.7%; 43/93). Rootlet herniations were seen by 46.2% (43/93) of responding surgeons. The posterior dural sac injury during the interlaminar approach (57%; 53/93) occurred more frequently than traversing nerve-root injuries (31.2%) or anterior dural sac (23.7%; 22/93). Exiting nerve-root injuries (10.8%;10/93) were less common. Over half of surgeons did not attempt any repair or closure (52.2%; 47/90). Forty percent (36/90) used sealants. Only 7.8% (7/90) of surgeons attempted an endoscopic repair or sutures (11.1%; 10/90). DuralSeal was the most commonly used brand of commercially available sealant used (42.7%; 35/82). However, other sealants such as Tisseal (15.9%; 13/82), Evicel (2.4%2/82), and additional no-brand sealants (38; 32/82) were also used. Nearly half of the patients (48.3%; 43/89) were treated with 24-48 hours of bed rest. The majority of participating surgeons (64%; 57/89) reported that the long-term outcome was unaffected. Only 18% of surgeons reported having seen the development of a postoperative cerebrospinal fluid (CSF)-fistula (18%;16/89). However, the absolute incidence of CSF fistula was only 0.025% (16/64 470). Severe radiculopathy with dysesthesia; sensory loss; and motor weakness in association with an incidental durotomy were reported by 12.4% (11/89), 3.4% (3/89), and 2.2% (2/89) of surgeons, respectively. The incidence of dural tears with lumbar endoscopy is about 1%. The incidence of durotomy is higher with the use of power drills and the interlaminar approach. Stenosis decompression that typically requires the more aggressive use of these power instruments has a slightly higher incidence of dural tears than does endoscopic decompression for a herniated disc. Most dural tears are small and can be successfully managed with mechanical compression with Gelfoam and sealants. Two-thirds of patients with incidental dural tears had an entirely uneventful postoperative course. The remaining one-third of patients may develop a persistent CSF leak, radiculopathy with dysesthesia, sensory loss, or motor function loss. Patients should be educated preoperatively and reassured. 3.

A Systematic Review of Complications Associated with Initial Learning Curve of Endoscopic Spine Surgery Highlighting the Necessity of Introducing an Effective Fellowship to Train Competent Endoscopic Spine Surgeons

Background: There is an increase in interest of endoscopic spine surgery as an option of minimally invasive spine surgery. Complications associated with learning curve are a big obstacle to starting a successful endoscopic career. A good endoscopic spine surgery fellowship can mitigate the risk of practice in early phase in endoscopic spine surgery. Methods: We conducted a systematic review in the PubMed database using the terms using three successive searches.10 articles met the criteria of learning curve in endoscopic surgeries evaluation of complications and operation timing. The most consistent parameters used in these studies to evaluate the learning curve were procedure time and complication rate as a function of chronologic case number, our analysis focused on these. The search strategy identified 10 original studies that included 618 endoscopic spine surgery procedures. Results: In the 10 studies, total number of complications was 45 cases (7.2%). 33 cases (5.3%) occurred in the early phase of learning curve. The most frequent reported complications were incomplete decompression (18 cases, 2.9%), incidental durotomies (13 cases; 2.1%), nerve root injuries (11 cases; 1.77%), discitis (2 cases; 0.32% of complications) and hematoma (1 case; 0.16%). The operative time was observed to decrease throughout these case series with no general consensus of number of cases required to reach asymptote. Conclusion: There is steep learning curve with high complications in the initial learning phase of endoscopic spine surgery. It is recommended to have an effective training or fellowship programme to train competent endoscopic spine surgeons.

Inside-Out Approach of Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression: A Detailed Technical Description, Rationale and Outcomes.

Although lumbar stenosis was recognized as a contraindication for endoscopic spine surgery in the past, the advancement in endoscopic system design and development of approach techniques and strategies now enabled the endoscopic spine surgeons to manage all types of lumbar stenosis safely and more effectively. A full-endoscopic lumbar technique for surgical management of spinal canal stenosis is now used today in many advanced spine centers around the world as one of their standard procedures which can be done under general, regional, local anesthesia with sedation. In this technical report, we described in detail the inside-out approach of performing lumbar endoscopic unilateral laminotomy with bilateral decompression (LE-ULBD) and retrospectively reviewed hospital records of 127 patients who underwent the approach from December 2018 to March 2019 to address 1 level lumbar spinal stenosis and determined its outcome after 12-month follow-up period. Perioperative outcomes, operation time, length of hospital stay, and surgical complications were recorded and analyzed. The cross-sectional area of the thecal sac at the operated level was measured. The visual analogue scale (VAS) was assessed preoperatively, 1 month, and 12 months as well as the Oswestry Disability Index (ODI). The data were statistically analyzed (using SPSS ver. 17.0). The inside-out approach LE-ULBD was shown to effect statistically significant improvement in the VAS of leg and back pain as well as the ODI. It is a familiar, safe, and effective way of performing spinal stenosis decompression with good reproducible outcomes.

AOSpine Consensus Paper on Nomenclature for Working-Channel Endoscopic Spinal Procedures.

Study Design:International consensus paper on a unified nomenclature for full-endoscopic spine surgery.Objectives:Minimally invasive endoscopic spinal procedures have undergone rapid development during the past decade. Evolution of working-channel endoscopes and surgical instruments as well as innovation in surgical techniques have expanded the types of spinal pathology that can be addressed. However, there is in the literature a heterogeneous nomenclature defining approach corridors and procedures, and this lack of common language has hampered communication between endoscopic spine surgeons, patients, hospitals, and insurance providers.Methods:The current report summarizes the nomenclature reported for working-channel endoscopic procedures that address cervical, thoracic, and lumbar spinal pathology.Results:We propose a uniform system that defines the working-channel endoscope (full-endoscopic), approach corridor (anterior, posterior, interlaminar, transforaminal), spinal segment (cervical, thoracic, lumbar), and procedure performed (eg, discectomy, foraminotomy). We suggest the following nomenclature for the most common full-endoscopic procedures: posterior endoscopic cervical foraminotomy (PECF), transforaminal endoscopic thoracic discectomy (TETD), transforaminal endoscopic lumbar discectomy (TELD), transforaminal lumbar foraminotomy (TELF), interlaminar endoscopic lumbar discectomy (IELD), interlaminar endoscopic lateral recess decompression (IE-LRD), and lumbar endoscopic unilateral laminotomy for bilateral decompression (LE-ULBD).Conclusions:We believe that it is critical to delineate a consensus nomenclature to facilitate uniformity of working-channel endoscopic procedures within academic scholarship. This will hopefully facilitate development, standardization of procedures, teaching, and widespread acceptance of full-endoscopic spinal procedures.

Indication and Contraindication of Endoscopic Transforaminal Lumbar Decompression

The indications and contraindications to the endoscopic transforaminal approach for lumbar spinal stenosis are not well defined. We performed a Kaplan-Meier durability survival analysis of patients with the following types of spinal stenosis: type I, central canal; type II, lateral recess; type III, foraminal; and type IV, extraforaminal. The 304 patients comprised 140 men and 164 women, with an average age of 51.68 ± 15.78 years. The average follow-up was 45.3 years (range, 18-90 years). The primary clinical outcome measures were the Oswestry Disability Index, visual analog scale, and the modified Macnab criteria. Of 304 study patients, 70 had type I (23.0%) stenosis, 42 type II (13.7%), 151 type III (49.7%), and 41 type IV (13.5%). Excellent outcomes were obtained in 114 patients (37.5%), good in 152 (50.0%), fair in 33 (10.9%), and poor in 5 (1.6%). Kaplan-Meier durability analysis of the clinical treatment benefit with the endoscopic transforaminal decompression surgery showed statistically significance differences (P < 0.0001) on log-rank (Mantel-Cox) χ2 testing between the estimated median (50% percentile) survival times of type I (28 months), type II (53 months), type III (32 months), and type IV (66 months). We recommend stratifying patients based on the underlying compressive disease and the skill level of the endoscopic spine surgeon to decide preoperatively whether more difficult central or complex foraminal stenotic lesions should be considered for alternative endoscopic approaches.

Surgeon training and clinical implementation of spinal endoscopy in routine practice: results of a global survey.

Training of spine surgeons may impact the availability of contemporary minimally invasive spinal surgery (MIS) to patients and drive spine surgeons' clinical decision-making when applying minimally invasive spinal surgery techniques (MISST) to the treatment of common degenerative conditions of the lumbar spine. Training requirements and implementation of privileges vary in different parts of the world. The purpose of this study was to analyze the training in relation to practice patterns of surgeons who perform lumbar endoscopic spinal surgery the world over. The authors solicited responses to an online survey sent to spine surgeons by email, and chat groups in social media networks including Facebook, WeChat, WhatsApp, and Linkedin. Surgeons were asked the following questions: (I) please indicate your training? (II) What type of MISST spinal surgery do you perform? (III) How would you rate your experience in MIS lumbar spinal surgery and what percentage of your practice is MISST? And (IV) which avenue did you use to train for the MISST you currently employ in your clinical practice today? Descriptive statistics were applied to count responses and cross-tabulated them to the surgeon's training. Pearson Chi-square measures, kappa statistics, and linear regression analysis of agreement or disagreement were performed by analyzing the distribution of variances using statistical package SPSS version 25.0. A total of 430 surgeons accessed the survey. The completion rate was 67.4%. Analyzing the responses of 292 surveys submitted by 97 neurosurgeons (33.2%), 161 orthopaedic surgeons (55.1%), and 34 surgeons of other postgraduate training (11.6%) showed that only 14% (41/292) of surgeons had completed a fellowship. Surgeons rated their skill level 33.5% of the time as master and experienced surgeon, and 35.6% of the time as novice or surgeon with some experience. There were more master (64.6% versus 29.2%) and experienced (52% versus 40%) surgeons amongst orthopaedic surgeons than amongst neurosurgeons at a statistically significant level (P=0.11). There were near twice as many orthopaedic surgeons (54.3%) using endoscopic procedures in the lumbar spine as their favorite MISST than neurosurgeons (35.4%; P=0.096). Endoscopic spine surgeons' main sources of knowledge acquisition were (I) learning in small meetings (57.3%), (II) attending workshops (63.1%), and (III) national and international conferences (59.8%). The majority of spine surgeons reported more than half of their cases employing MISST at a high skill level. Very few MISST surgeons are fellowship trained but attend workshops and various meetings suggesting that many of them are self-thought. Orthopaedic surgeons were more likely to implement endoscopic spinal surgery into the routine clinical practice. As endoscopic spine surgery gains more traction and patient demand, minimal adequate training will be part of the ongoing debate.

Complications and limitations of endoscopic spine surgery and percutaneous instrumentation

Endoscopic spine surgery has started replacing conventional microdiscectomy in various centers across the globe. With development in the field of optics and instrumentation, the field of percutaneous endoscopic spine surgery has evolved immensely. With increasing experience, endoscopic spine surgeons have expanded the indications not only to lumbar paramedian disc herniations but also to central disc herniations, high-grade migrated disc herniations, sequestered herniations, thoracic and cervical disc herniations, and more recently, lumbar canal stenosis. With broadening indications, unexpected adverse events are bound to increase. Hence, it is essential for the endoscopic spine surgeons to be aware of the potential hazards and unexpected complications of the procedure so that appropriate care is taken to avoid adverse events as much as possible. In this article, we summarize all the complications of transforaminal endoscopic discectomy reported in the literature. We have classified the complications into intraoperative, immediate postoperative, and late postoperative complications. The senior author has also suggested the tips to avoid these complications and carry out the procedure as safely as possible. As percutaneous instrumentation, particularly, percutaneous pedicular screws, is also becoming common with the development of minimally invasive spine surgery, we have also summarized its complications and limitations. An insight into these complications will help the endoscopic surgeons to take special precautions when performing the procedure.

Navigating the learning curve of spinal endoscopy as an established traditionally trained spine surgeon.

Traditionally trained spine surgeons may want to transition from open spinal surgeries to endoscopic decompressions. The aspiring endoscopic spine surgeon may have to overcome multiple hurdles to master a learning curve without readily available training. Replacing traditional time-proven open spinal surgeries with endoscopic decompression may put the surgeons' reputation at risk and have an additional negative impact on his or her practice due to reduced revenue. The authors report on the utility of the mentor- and proctorship concepts to facilitate the transition from traditional open to endoscopic outpatient spine surgeries. The study population (learning curve groups) was provided by two traditionally trained "apprentice" surgeons who have been in practice for 12 and 28 years, respectively. They trained with the remaining two authors under mentorship and proctorship arrangements. A VAS and Macnab outcomes analysis was performed by one surgeon laminectomy versus endoscopy in relationship to the case log representative of the initial learning curve. The second surgeon performed a postoperative narcotic utilization analysis as a representative way of favorable clinical outcomes in relation to his increasing case log with spinal endoscopy. The learning curve study by the first author (NA Ransom-under the proctorship program) consisted of 40 patients with 20 patients each divided into the traditional laminectomy control group and 20 patients in the endoscopic group. There were 22 females and 18 males with an average age of 57.38 years and a mean follow-up of 38.58 months. The preoperative VAS for patients in both groups was 7.95 compared to the postoperative VAS at final follow-up of 4.01 with a statistically significant postoperative VAS reduction (P<0.001) but without any significant difference between open laminectomy control- and endoscopic decompression groups. The endoscopic learning curve group outcomes improved significantly after 15 cases (P<0.048). The second author (S Gollogly-under mentorship program) performed a similar review of his surgical cases log and noted a significant reduction of postoperative narcotic utilization as a result of improved outcomes after an initial learning curve of 15 cases. Clinical outcomes for both authors showed improved Macnab outcomes in the majority of patients (NA Ransom =65%; S Gollogly =57%) with a slightly higher success rate in the laminectomy group (70%) versus the endoscopy group (65%) at a statistical significant level (P=0.036). The mentorship and proctorship approach is useful in helping traditionally trained spine surgeons to integrate spinal endoscopy into their well-established spine practices. Under the close guidance of an endoscopic master spine surgeon, the endoscopic learning curve may be comprehended by the experienced traditionally trained spine surgeon in approximately 15 lumbar decompression cases. During this initial 15-case learning curve, clinical outcomes with endoscopy may be slightly inferior to open laminectomy but may ultimately improve to equivalent levels.

Surgical outcome of workman’s comp patients undergoing endoscopic foraminal decompression for lumbar herniated disc

Worker's compensation (WC) patients undergoing spine surgery typically experience delayed return to work (RTW) compared with non-WC patients, especially those approved for surgery undergoing traditional open spine surgery. The purpose of this study was to describe the observe RTW rates in WC patients after minimally invasive "selective endoscopic discectomy" (SED™) for a lumbar herniated disc. Clinical outcomes using the modified Macnab criteria and RTW data were analyzed in 118 WC patients following the outpatient SED™ procedure in an ambulatory surgery center (ASC) using only local anesthesia with or without sedation. This endoscopic transforaminal decompression was trademarked by Anthony Yeung as SED. Single-level SED™ was performed in 62 patients, a two-level in 48 patients, a three-level decompression in 6, and a four-level decompression in another two patients, respectively. Patient selection was augmented by diagnostic and therapeutic injections performed preoperatively to determine how many levels of spine segments required surgical intervention. At the two-year follow-up, Excellent Macnab outcome in 36 patients, Good in 53, Fair in another 21, and Poor in the remaining eight patients, respectively. Of the 118 WC patients, 89 (75.42%) were released back to their original job within in 6 weeks from the index operation. The average time to work release was 4.2 months. Twenty-one patients who had previous spine surgery were working. Twenty-nine of the 118 study patients (24.58%) were unable to return to their original job. In the hands of a well-trained endoscopic spine surgeon, RTW rates with SED™ are higher than with traditional open translaminar surgery. Therefore, endoscopic surgery should be considered for WC patients and further be validated as a cost-effective alternative to open spine surgery.

The isthmic corridor- a novel anatomical approach for L5-S1 postero-lateral endoscopic lumbar discectomy (PELD)

BackgroundLumbosacral junction (L5-S1) with its distinctive anatomical features, presents a unique challenge to endoscopic spine surgeons.1–7 The choice between interlaminar and postero-lateral (transforaminal) routes for L5-S1 endoscopic discectomy remains controversial. PurposeDescribe a novel isthmic approach for postero-lateral endoscopic lumbar discectomy (PELD) at L5-S1 level and critically analyze the surgical results. Study DesignTechnical note. Case series. Patient Sample25 patients with symptomatic L5-S1 disc herniation. Outcome MeasureDemographics, radiological features, bony anatomy, and clinical outcomes. MethodsEach patient underwent postero-lateral endoscopic lumbar discectomy utilizing isthmic approach. The patient data was prospectively collected and retrospectively analyzed. ResultsAverage pain score for back pain and leg pain significantly improved from pre-op level of 3.09 and 7.81 to 2.17 and 2.15, respectively. Statistically significant improvement was also observed in post-op ODI score (pre-op = 58, post-op 33.85, p ≤ 0.00001). There were no intra-op complications of nerve or thecal sac injury. ConclusionCombining isthmus trajectory to L5-S1 postero-lateral endoscopic discectomy adds to the applicability of this already well established surgical procedure. Isthmic approach offers a safe and effective anatomical corridor for performing endoscopic discectomy via transforaminal route, even in individuals with high iliac crest.