Álvaro Dowling

Background Endoscopic spine surgery (ESS) is increasingly recognized for its clinical efficacy and patient-centered advantages, including reduced morbidity and faster recovery. However, despite growing global interest, its adoption remains highly variable, shaped more by systemic, economic, and institutional forces than by technical limitations. Objective To evaluate global adoption barriers to ESS using psychometrically validated tools and identify region-specific structural disparities through Rasch analysis and differential item functioning (DIF). Methods A cross-sectional global survey was conducted among 1834 spine surgeons. Of the 1040 individuals who began the survey, 438 (42.6%) from 46 countries completed the survey. A 27-item instrument assessed access, reimbursement, training infrastructure, and institutional support for ESS. Rasch rating scale modeling was used to test internal validity, unidimensionality, and item fit. DIF analysis and 1-way analysis of variance were performed to detect region-specific biases in item responses. Respondents were stratified by country and region, including China, India, Brazil, the United States, Latin America, and Europe. Results Collectively, the responding surgeons reported an extrapolated cumulative experience of 1,286,496 endoscopic spine procedures, suggesting that responses were anchored in substantial clinical experience. Rasch analysis confirmed acceptable model fit. DIF analysis revealed strong regional disparities. Surgeons in China and India reported high institutional support, better training access, and fewer reimbursement obstacles, suggesting high system adaptability. Conversely, respondents from the United States and Latin America cited limited training integration, poor reimbursement, and institutional inertia. Europe exhibited a structural stalemate driven by low surgeon compensation and excessive bureaucratic gatekeeping. Despite these differences, surgeon and patient interest in ESS remained uniformly high across regions, identifying shared global momentum for minimally invasive innovation. Conclusions The global diffusion of ESS is hindered less by clinical limitations than by systemic inertia and fragmented policy frameworks. Countries with flexible, market-responsive systems (eg, China and India) are emerging as innovation leaders, while historically dominant regions (eg, United States and Europe) risk stagnation without structural reform. ESS serves as a diagnostic lens for broader health system adaptability, highlighting the urgent need for investment in training, reimbursement reform, and institutional endorsement. This study provides level II evidence that endoscopic lumbar decompression is a surgical work comparable to open techniques and should be valued accordingly. Grounded in more than 1.2 million cases and expert consensus, this study supports policy recommendations to retire Current Procedural Terminology 62380 and to adopt reimbursement frameworks based on surgical work rather than visualization method. Level of Evidence While this study cannot be reclassified in the strict Oxford Centre for Evidence-Based Medicine hierarchy, the authors employ the following analogy: Rasch/DIF methods filter bias in the same way randomization filters bias in clinical trials. While it relies on self-reported surgeon data rather than direct clinical outcomes, the application of Rasch modeling and DIF analysis strengthens internal validity and minimizes measurement bias. Importantly, surgeon responses were anchored in an extrapolated cumulative experience of more than 1.28 million endoscopic spine procedures, reflecting deeply internalized clinical judgment rather than anecdotal opinion. These methodological features distinguish the study from unvalidated descriptive surveys and support its classification as higher-level clinical evidence—offering a filtered and reliable lens into global surgical practice patterns and systemic barriers to ESS adoption. Based on its cross-sectional observational design enhanced by validated psychometric methodology, the authors consider this survey study a psychometrically validated, high-quality observational survey study. Clinical Relevance This study identifies structural and systemic barriers that limit global adoption of ESS and highlights key targets—such as training, reimbursement, and institutional support—for improving access and accelerating safe implementation.

Background Transforaminal endoscopic lumbar decompression (TELD) has emerged as a minimally invasive alternative for managing lumbar stenosis and disc herniations. While the literature consistently reports favorable outcomes, real-world adoption remains variable, with discrepancies often linked to surgeon experience and case complexity. Objective To evaluate surgeon perspectives on the clinical applicability of TELD across different pathologies and compare these findings with published evidence. Methods An international cross-sectional survey was conducted among spine surgeons. Responses were analyzed using Rasch modeling to assess consensus levels, with agreement categorized as strong, moderate, weak, or disagreement. Differential Item Functioning (DIF) and correlation analyses were applied to identify potential bias between neurosurgeons and orthopedic surgeons and to explore associations between pathologies. Results Analysis of 128 surgeon responses demonstrated clear stratification of consensus across pathologies. Strong agreement was observed for posterolateral herniated nucleus pulposus (HNP), far-migrated HNP, and lateral canal stenosis, reflecting consistent confidence in the applicability of TELD for these conditions. Moderate consensus was found for central HNP and central canal stenosis, where responses were stable but showed slightly greater variability. In contrast, low agreement was reported for lumbar facet cysts and low-grade spondylolisthesis, underscoring areas of ongoing controversy and divergent practice patterns. The Q3 correlation matrix revealed both overlapping and divergent domains of surgical confidence. Positive correlations linked lateral canal and central canal stenosis (r = 0.116), suggesting that surgeons proficient in transforaminal approaches for lateral pathology may also extend these skills to central disease. Similarly, lumbar facet cysts and low-grade spondylolisthesis showed a modest positive relationship (r = 0.073), consistent with their frequent clinical copresentation. Conversely, negative correlations highlighted distinct areas of expertise. For example, central canal stenosis and posterolateral HNP demonstrated a strong negative association (r = –0.475), while far-migrated HNP correlated negatively with both facet cysts (r = –0.348) and low-grade spondylolisthesis (r = –0.317). Conclusion These findings suggest that technical proficiency in 1 domain does not necessarily translate to others, emphasizing the need for specialized training in complex or atypical scenarios. Refinement in training and technique positions transforaminal endoscopic surgery to redefine spinal stenosis care, moving past the entrenched notion that its use is confined to foraminal and lateral canal disease while central canal pathology belongs exclusively to interlaminar methods. Clinical Relevance This study signals a shift away from the rigid notion that transforaminal endoscopy is limited to compressive painful pathology in the lateral canal while interlaminar approaches are preferable for central stenosis. In expert hands, modern endoscopic techniques demonstrate that low-risk transforaminal decompression can be successfully applied to more complex conditions, including central stenosis with or without low-grade spondylolisthesis. These findings emphasize the importance of advanced training programs to enable practicing spine surgeons to achieve outcomes comparable to those reported by key opinion leaders. Level of Evidence Psychometrically validated, high-quality observational survey study (see also Authors’ Note).

Endoscopic spine surgery has become increasingly popular among specialized surgeons, driven by its minimally invasive approach and increasing clinical versatility. Initially restricted to the lumbar spine, its indications have expanded to the cervical region and, to a lesser extent, the thoracic region, offering a less aggressive and more affordable alternative to traditional procedures such as laminectomy, costotransversectomy, and the anterior extracavitary approach to the thoracic spine. During interventions in this segment, it is common to identify segmental vessels, whose anatomical position may vary depending on the surgical level. In certain cases, the segmental artery and vein overlap or invade the disc space, becoming critical structures to consider during endoscopic decompression. This study’s primary objective was to highlight the relevance of Adamkiewicz’s artery in endoscopic spinal surgery. To this end, a narrative review was conducted according to the PRISMA method guidelines, structured according to the PICOS criteria: adults, as defined by the World Health Organization (Population); endoscopic procedures involving the artery of Adamkiewicz (Intervention); surgical techniques that do not consider this vascular structure (Comparison); and clinical trials and case studies (Outcome). The analysis culminated in the selection of 20 articles, which supported the discussion and the findings presented. It is concluded that accurate identification of the artery of Adamkiewicz is essential for preventing neurological complications, and its preservation is a determining factor in reducing the risk of spinal cord ischemia during spinal procedures. Advanced imaging techniques, such as magnetic resonance angiography, have demonstrated high efficacy in locating this vessel, allowing surgeons to plan minimally invasive approaches with greater precision and safety. Level of Evidence III; Review Article.

Objective: This retrospective study describes the clinical and functional outcomes of 80 patients who underwent totally endoscopic inter-laminar surgery for lumbar disc herniation between May 2018 and May 2020 at a private healthcare facility. Methods: Medical records were analyzed to collect demographic data, pre- and postoperative pain levels using the Visual Analog Scale (VAS), functional disability according to the Oswestry Disability Index (ODI), and procedure-related complications. Results: Fifteen days after surgery, a significant improvement in pain and disability levels was observed (p < 0.001). Pain decreased significantly in the first 30 days, remaining stable between 60 and 90 days (p < 0.05) and 90 and 180 days (p = 0.82). Regarding functional disability, patients achieved almost complete improvement at 30 days, with no statistically significant variation at subsequent intervals of 60, 90, and 180 days (p = 0.4; p = 1; p = 1, respectively). Conclusion: Minimally invasive techniques, such as interlaminar endoscopic lumbar discectomy, have been consolidating as a trend in modern neurosurgical practice, as they allow for faster, more precise procedures with lower morbidity. Level of Evidence IV; Series of Cases.

Background Regenerative and wellness medicine is rapidly reshaping health care, particularly in the management of degenerative spine conditions. Noninvasive or minimally invasive options such as stem cell therapy, platelet-rich plasma (PRP) injections, and holistic wellness programs are increasingly selected by patients who wish to avoid the risks, costs, and prolonged recovery associated with elective spine surgery. Purpose This perspective article examines whether regenerative and wellness approaches function primarily as a boon or a barrier to innovation in spine surgery and explores their impact on traditional, insurance-based surgical care models. Methods Using a narrative, opinion-based framework, this article synthesizes current trends in regenerative and wellness treatments, their economic growth relative to conventional spine care, and their penetration into nonsurgical spine markets. It further considers how these trends intersect with policy, reimbursement, and professional society initiatives. Results The rapid expansion of regenerative and wellness interventions has created a powerful economic sector that, in some areas of nonsurgical spine care, is projected to surpass traditional medicine. Many of these therapies lack robust clinical evidence, yet the absence of data does not equate to inefficacy. These resulting strategic challenges will likely have a greater effect on spine surgeons who aredependent primarily on insurance-based reimbursement. At the same time, integrating validated regenerative options can broaden the surgical practice portfolio and better match patient preferences for personalized, minimally invasive care. Policy changes expanding coverage for evidence-based regenerative treatments may further accelerate this shift. Conclusions To remain relevant in an increasingly patient-driven health care environment, spine surgeons and organizations such as the International Society for the Advancement of Spine Surgery must proactively adapt to the growth of regenerative and wellness medicine. Failure to engage may relegate spine surgery largely to trauma, tumor, and infection, while regenerative and wellness strategies could dominate the management of painful degenerative spine disorders. Clinical Relevance Regenerative and wellness medicine is rapidly reshaping how patients with degenerative spine conditions seek care, forcing spine surgeons to decide whether to integrate these modalities or risk losing a growing segment of nonsurgical spine patients. Level of Evidence 5.

Introduction: Postoperative C5 paralysis is defined as new‐onset and/or progressive muscle weakness with mild or no sensory disturbances occurring as a result of probable neuropraxia of the cervical root due to injury during surgery. Case Report: A 40‐year‐old female patient underwent endoscopic technique for treatment of cervical foraminal stenosis, level C4–C5. The procedure proceeded without incident in the intraoperative period. In the immediate postoperative period, the patient developed a motor deficit, Grade 2 muscle strength of the right deltoid muscle, and right C5 allodynia. Early and multidisciplinary treatment resulted in complete recovery of the neurological deficit and satisfactory evolution of the presented case. Discussion: Although postoperative C5 palsy is one of the most common postoperative complications after multilevel cervical decompression surgery, its exact mechanism remains poorly understood. Despite the various studies in this field and the possible causes described, there is still no absolute confirmation, so the formulation of hypotheses depends on clinical monitoring and postoperative examinations. The indicated treatment depends on the causal suspicion and pathophysiology and ranges from clinical drug therapy to physical therapies and/or rehabilitation. Conclusion: C5 paralysis after endoscopic surgery, although rare, is a potential complication. The likely pathophysiology is multifactorial: anatomic features of C5, manipulation of the root, and use of the bipolar in the foraminal region.

Please remember the following text: "Posterior-assisted cervical decompression is a 20-year-old technique that has been considered an excellent method for treating cervical foraminal decompression and is now also used for myelopathy. The surgery is...

Background The International Society for the Advancement of Spine Surgery hosted the first of a series of 4 webinars on endoscopic spine surgery techniques, focusing on end§oscopic discectomy, foraminotomy, instrumented endoscopic fusion, standalone lumbar interbody fusion with innovative materials, and the role of patient feedback in awake procedures. This series aims to share knowledge and discuss the complexities and clinical evidence of modern endoscopic spine surgery. Objective To analyze the level of surgeon endorsement for the presented endoscopic spine surgery techniques before and after the webinar, utilizing polytomous Rasch analysis, and to evaluate the potential for these insights to inform clinical guideline recommendations. Methods A survey was available to 1311 potential respondents during the Zoom webinar, collecting data on surgeon endorsements using a Likert scale. The polytomous Rasch model was employed to analyze responses, considering the complexity of decisions against surgeon expertise, developing a logarithmic measurement scale, allowing objective statistical analysis of categorical variables, highlighting incongruent or out-of-order items vs congruent and in-order items, and driving improvement in clinical guidelines. Results All 4 topics received higher confidence ratings demonstrated by descriptive statistics, highlighting the webinar’s effective role in surgeon education and in identifying ongoing trends in spine surgery. The logarithmic transformation of these data during Rasch analysis showed noticeable shifts in surgeon confidence levels postwebinar, with increased endorsement for transforaminal full-endoscopic thoracolumbar interbody fusion for hard disc herniation and standalone endoscopic lumbar interbody fusion. The Wright plot and person-item map analyses demonstrated that the webinar effectively targeted areas of initial low confidence, significantly impacting surgeons’ perceptions. Disordered endorsement thresholds remained in the topics of uniportal transforaminal discectomy/foraminotomy and patient feedback during endoscopic spine surgery, indicating issues in response category discrimination or confounding factors not captured by the survey. Ongoing controversies were highlighted by the influence of confounding factors, stemming from preconceived notions and limited familiarity with high-grade evidence. Conclusion The first in the 4-part webinar series effectively shifted professional confidence and acceptance of innovative surgical approaches among spine surgeons. Observations indicated a high level of interest in applying the endoscopic surgery platform with other advanced technologies. The polytomous Rasch analysis provided nuanced insights into ongoing trends and areas in need of further clarification. Clinical Relevance Assessing surgeon confidence and acceptance of endoscopic spinal surgeries using polytomous Rasch analysis. Level of Evidence Level 2 (inferential) and 3 (observational) evidence because Rasch analysis provides statistical validation of instruments rather than direct clinical outcomes.

Background With the growing prevalence of lumbar spinal stenosis, endoscopic surgery, which incorporates techniques such as transforaminal, interlaminar, and unilateral biportal (UBE) endoscopy, is increasingly considered. However, the patient selection criteria are debated among spine surgeons. Objective This study used a polytomous Rasch analysis to evaluate the factors influencing surgeon decision-making in selecting patients for endoscopic surgical treatment of lumbar spinal stenosis. Methods A comprehensive survey was distributed to a representative sample of 296 spine surgeons. Questions encompassed various patient-related and clinical factors, and responses were captured on a logit scale graphically displaying person-item maps and category probability curves for each test item. Using a Rasch analysis, the data were subsequently analyzed to determine the latent traits influencing decision-making. Results The Rasch analysis revealed that surgeons’ preferences for transforaminal, interlaminar, and UBE techniques were easily influenced by comfort level and experience with the endoscopic procedure and patient-related factors. Harder-to-agree items included technological aspects, favorable clinical outcomes, and postoperative functional recovery and rehabilitation. Descriptive statistics suggested interlaminar as the best endoscopic spinal stenosis decompression technique. However, logit person-item analysis integral to the Rasch methodology showed highest intensity for transforaminal followed by interlaminar endoscopic lumbar stenosis decompression. The UBE technique was the hardest to agree on with a disordered person-item analysis and thresholds in category probability curve plots. Conclusion Surgeon decision-making in selecting patients for endoscopic surgery for lumbar spinal stenosis is multifaceted. While the framework of clinical guidelines remains paramount, on-the-ground experience-based factors significantly influence surgeons’ selection of patients for endoscopic lumbar spinal stenosis surgeries. The Rasch methodology allows for a more granular psychometric evaluation of surgeon decision-making and accounts better for years-long experience that may be lost in standardized clinical guideline development. This new approach to assessing spine surgeons’ thought processes may improve the implementation of evidence-based protocol change dictated by technological advances was endorsed by the Interamerican Society for Minimally Invasive Spine Surgery (SICCMI), the International Society for Minimal Intervention in Spinal Surgery (ISMISS), the Mexican Spine Society (AMCICO), the Brazilian Spine Society (SBC), the Society for Minimally Invasive Spine Surgery (SMISS), the Korean Minimally Invasive Spine Society (KOMISS), and the International Society for the Advancement of Spine Surgery (ISASS).

Background 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. Methods 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. Results 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. Conclusion 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). Clinical Relevance This study provides an updated reimbursement recommendation for endoscopic spine surgery. Level of Evidence Level 3.