Learning Curve for Interlaminar Endoscopic Lumbar Discectomy: A Systematic Review

The learning curve for lumbar discectomy in unilateral biportal endoscopic spine surgery using the cumulative summation method

BACKGROUND

Unilateral biportal endoscopy (UBE) is gaining popularity owing to its versatility as a spinal endoscopic procedure. However, the general value of the learning curve for discectomy by UBE is unknown. This retrospective study aimed to determine the learning curve of UBE for lumbar discectomy using a cumulative summation (CUSUM) method. We examined the learning curves of four surgeons at an institution and factors that shortened the learning curves.

METHODS

The study included 200 patients (mean age 44.2 years) who underwent lumbar discectomy by UBE at our hospital and four male orthopedic surgeons who had performed 50 UBE discectomies. An approximate curve using the CUSUM method was created using the mean operative time for each case as the target. All surgeons had performed lumbar discectomy and over 200 spinal surgeries before inducing UBE. Surgeon A received specialized training in shoulder arthroscopic surgery. The surgical times before and after the curve reached its maximum value were compared; a point of significant difference was defined as case to proficiency.

RESULTS

The mean operative times for surgeons A, B, C, and D were 48, 66, 90, and 87 min, respectively. The approximate curves obtained using the CUSUM method had maxima at x = 22, 20, 27, and 13. The operating times of Surgeons A and B showed significant differences before and after the maxima (59 vs. 39 and 75 vs. 60), whereas those of Surgeons C and D did not (96 vs. 84 and 95 vs. 85).

CONCLUSIONS

UBE is generally considered to have a steep learning curve; in this study, the learning curve differed depending on the surgeon. The surgeon with the best learning curve was trained as an arthroscopic surgeon. Coordination for endoscopic surgery influenced the learning curve compared to the experience with spine surgery.

Complications in Full-Endoscopic Posterior Cervical Surgery: A Review of the Literature and Preventive Strategies

Study DesignNarrative reviewObjectivesFull-endoscopic cervical spinal surgery via a posterior approach has gained popularity for its effectiveness in treating various cervical spine pathologies. However, this technique presents its own set of complications that need to be recognized and addressed. This review aims to comprehensively analyze the complications associated with full-endoscopic posterior cervical spine surgery and provide preventive strategies to minimize these risks and ensure successful surgical outcomes.MethodsA thorough literature search was conducted using public databases, including PubMed and SCOPUS, from January 2000 to June 2024. The review focused on analyzing complications related to full-endoscopic posterior cervical spine surgery and identifying preventive strategies using the keywords "Complication," "Endoscopic," "Full-endoscopic," "Endoscopy," "Uniportal," "Biportal," "Posterior," "Cervical," "Spine," "Surgery," "Foraminotomy," "Decompression," and "Discectomy".ResultsThe review identified a variety of complications associated with full-endoscopic posterior cervical spine surgery, including neurological, vascular, and structural issues. Despite the minimally invasive benefits of this approach, risks such as nerve root injury, dural tears, and epidural hematomas still exist. The study emphasizes preventive strategies like meticulous preoperative planning, refined surgical techniques, and cautious intraoperative management around neural structures to mitigate these risks.ConclusionsWhile full-endoscopic posterior cervical spine surgery provides significant advantages, such as reduced tissue disruption and quicker recovery, it also carries specific complications that must be carefully addressed and managed. Prevention is crucial for ensuring optimal outcomes. By understanding potential risks and implementing effective prevention strategies, surgeons can significantly reduce complications and enhance patient safety.

Learning curve for full-endoscopic lumbar decompression via interlaminar approach using the learning curve cumulative summation analysis

BACKGROUND

Full-endoscopic spine surgery (FESS) is generally considered to have a steep learning curve due to its technical complexity. This study aimed to evaluate the learning curve for full-endoscopic decompressive laminectomy via the interlaminar approach using learning curve cumulative summation test (LC-CUSUM) analysis, which provides objective statistical monitoring of surgical competency acquisition, and determine the number of cases required for surgical competency.

METHODS

We retrospectively analyzed the first 60 consecutive patients who underwent single-level interlaminar endoscopic unilateral lumbar decompression for lumbar spinal stenosis performed by a single surgeon with 4 years of experience. LC-CUSUM analysis was employed with operative time as the primary outcome measure. The target time was set at 80 min, based on the same surgeon's mean operative time for microscopic laminectomy. The patients were divided into the early (≤ 30 cases) and late (> 30 cases) learning periods and compared.

RESULTS

LC-CUSUM analysis revealed that competency was achieved after 51 cases. The mean operative time significantly decreased from 90.20 ± 24.44 min in the early period to 71.47 ± 16.65 min in the late period (p = 0.001). Estimated blood loss showed significant reduction (54.83 ± 42.58 ml vs. 34.83 ± 19.10 ml, p = 0.024). Complication rates remained consistent between periods (10% each), with similar rates of dural tears (6.67% in both periods).

CONCLUSIONS

The results of this study have demonstrated that a learning period of 51 cases could be required to achieve proficiency in full-endoscopic interlaminar lumbar decompression. However, the procedure can be safely performed even during the early learning period by surgeons with adequate microscopic surgical experience.

Learning Curve of Endoscopic Lumbar Discectomy - A Systematic Review and Meta-Analysis of Individual Participant and Aggregated Data

STUDY DESIGN

A systematic review and meta-analysis of individual participant and aggregated data.

OBJECTIVES

To define the learning curves of endoscopic discectomies using unified statistical methodologies.

METHODS

Searches returned 913 records, with 118 full-text articles screened. Studies of endoscopic lumbar spine surgery reporting outcomes by case order were included. Mixed-effects nonlinear, logistic, and beta meta-regressions prdwere conducted to define the learning curves.

RESULTS

13 studies involving 864 patients among 15 surgeons were included in total. For transforaminal endoscopic discectomy, the estimated operating time for the first case was 95 min [CI: 87-104], and the estimated plateau was 66 minutes [CI: 51-81]. An estimated 21 cases [CI: 18-25] were required to overcome 80% of this deficit, but near-plateau performance was expected only after 59 cases [CI: 51-70]. The estimated risk of surgical complications on the first case was 25% [CI: 11%-46%], with an 80% reduction in relative risk requiring an estimated 41 cases. The expected postoperative VAS leg pain score after the first case was 2.7 [CI: 1.8-3.8], with an 80% improvement requiring an estimated 96 cases. Similar numbers were required to overcome the learning curves in interlaminar and biportal endoscopic discectomies.

CONCLUSIONS

Approximately 60 cases are required to achieve proficiency in endoscopic lumbar spine surgery, although the greatest part of the learning curve can be overcome with 20 cases. This should be considered when designing implementation programmes for surgeons and service providers that wish to incorporate endoscopic spinal surgery into their practice.

Evaluating the learning curve and operative time of interlaminar and transforaminal endoscopic lumbar discectomy

Introduction

Lumbar disc herniation is common in spine surgery, and endoscopic lumbar discectomy (ELD) offers a minimally invasive alternative with reduced complications. However, the learning curve of ELD, particularly between interlaminar and transforaminal techniques, remains a challenge.

Research question

To determine the learning curve for both interlaminar and transforaminal ELD in terms of operative time, and analyze factors that affect it.

Materials and methods

Single-center retrospective study of 376 patients who underwent ELD between January 2013 and March 2024. In the cohort, 319 were in the interlaminar group and 57 in the transforaminal group. The learning curves were analyzed by CUSUM. The data regarding surgical technique, operative time, and postoperative outcome were analyzed.

Results

The learning curve reached a plateau at 50 cases for the interlaminar technique and 23 cases for the transforaminal technique. Operative time was significantly lower for the transforaminal approach compared to the interlaminar approach: 69.18 ± 28.85 min versus 78.71 ± 28.86 min, p = 0.022. A second learning curve could not be demonstrated for the interlaminar approach in the long term. Operative time was influenced variably by factors such as age, gender, and level of herniated disc between the two techniques.

Discussion and conclusion

Both the interlaminar and transforaminal ELD are minimally invasive techniques with different learning curves. The transforaminal approach shows a steeper learning curve and shorter operative time. The interlaminar approach did not show a second learning curve in the long term.

What is the learning curve for endoscopic spine surgery? A comprehensive systematic review

BACKGROUND CONTEXT

Endoscopic spine surgery (ESS) is rapidly emerging as a viable minimally invasive technique to successfully treat symptomatic degenerative spinal conditions. Widespread adoption has been limited in part due to the learning curve.

PURPOSE

To systematically review the learning curve for uniportal and biportal ESS and compare the 2 techniques.

STUDY DESIGN/SETTING

A systematic review based on PRISMA guidelines.

PATIENT SAMPLE

About 29 studies were included with 18 studies investigating uniportal learning curves and 11 biportal studies. There were 1,493 patients across all uniportal studies. There was a total of 1,005 patients across all biportal studies.

OUTCOME MEASURES

Number of patients, technique type, patient reported outcomes, complications, operative time before the learning curve threshold, operative time after learning curve threshold, number of cases required to meet threshold, number of surgeons in the study, and cases per surgeon were collected and analyzed.

METHODS

A comprehensive literature search was conducted using PubMed, Medline, and Embase from 2000 to present date. Data was extracted by 3 independent reviewers.

RESULTS

The learning curve studies were reviewed and summarized. The overall median number of cases to reach the learning curve threshold was significantly less in uniportal vs biportal studies (20 vs. 37.5, p=.0463). When stratifying by various procedures, there was no significant difference between the techniques with number of cases required or improvement of operative time. Operative time for biportal discectomies decreased by a significantly greater amount vs uniportal. (44.5% vs. 21.4%, p=.0332).

CONCLUSIONS

The learning curve literature for ESS was systematically reviewed and ways to overcome the learning curve were discussed. The overall median number of cases for the learning curve was significantly fewer in uniportal vs biportal but the improvement in operative time was significantly greater with biportal discectomies, typically the entry level procedure by novice surgeons. Overcoming the learning curve for ESS is a critical factor to widespread adoption and understanding it may aid surgeons in progressing to proficiency while mitigating the risk of complications.

Full-endoscopic lumbar spine surgery using working-channel endoscopes: technical tips for practical effectiveness

INTRODUCTION

Full-endoscopic spine surgery (FESS) has emerged as an effective and minimally invasive option for the surgical treatment of degenerative lumbar spine disease. FESS can be characterized as endoscopic spine surgery conducted via the percutaneous uniportal approach using working-channel endoscopes under continuous saline irrigation. Despite available evidence, the clinical application of this endoscopic procedure may require more work for standard spine surgeons. Therefore, this review aims to provide comprehensive technical tips to ensure the practical effectiveness of FESS.

AREA COVERED

FESS of the thoracolumbar spine can be performed through the transforaminal and interlaminar approaches according to direction and passing window. Published literature on technical tips and learning were reviewed narratively, after which practical technical pearls were demonstrated specific to the properties of working-channel endoscopes.

EXPERT OPINION

Currently, FESS remains a reliable option for achieving successful surgical outcomes in cases of lumbar disk herniation and spinal stenosis, with few complications and rapid recovery. A comprehensive understanding of the core features of working-channel endoscopes is crucial for expediting the learning process. Importantly, the development of specific instruments, surgical approaches, and optics is a continuous process that is necessary for establishing FESS as the standard technique for degenerative lumbar spine disease.

Outcome of Percutaneous Endoscopic Lumbar Discectomy in Relation to the Surgeon's Experience: Propensity Score Matching

Percutaneous endoscopic lumbar discectomy (PELD) presents a challenging learning curve, and the correlation between surgeon experience and clinical outcomes remains contentious. This retrospective study aimed to compare the outcomes of PELD performed by a single surgeon at beginner and experienced stages. Propensity score matching selected 150 patients (75 per group) with a minimum 3-year follow-up. Clinical and radiological outcomes, perioperative complications, and adverse events were assessed. Baseline characteristics, pain improvement, patient satisfaction, and radiological outcomes did not differ between the groups. However, operation time was longer in the beginner group than in the experienced group (57.5 min [IQR, 50.0-70.0] versus 50.0 min [IQR, 45.0-55.0], p < 0.001). The beginner group had higher perioperative complication rates (eight patients [10.7%] versus one patient [1.3%], with a hazard ratio of 8.836 [95% CI, 1.077-72.514], p = 0.034) and lower 3-year survival without adverse events (19 patients [25.3%] in the beginner group and 10 patients [13.3%] in the experienced group, p = 0.045). Our findings indicate that the clinical outcomes were more favorable in patients operated on at the experienced stage compared to those treated at the beginner stage.

Learning Curve for Endoscopic Transsphenoidal Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Endoscopic transsphenoidal surgery (ETSS) is emerging as an effective, minimally invasive surgery technique for brain tumors of the pituitary fossa. Using a surgical endoscope, surgeons can obtain a broader, nearer, and more apparent visual field with minimal keyhole entrance. However, ETSS may require a steep learning curve to achieve technical competence and relevant outcomes. Moreover, there is no consensus on the learning process of ETSS. We aimed to review and determine the technical proficiency points of ETSS and discuss how to accelerate the learning curve.

METHODS

Core databases, including PubMed, Embase, and the Cochrane Library, were systematically searched for learning curve studies that demonstrated the clinical outcomes and learning status of ETSS for pituitary adenomas using numerical data. Quality assessments of the included articles were performed using the Newcastle-Ottawa scale. The cutoff points were evaluated based on various outcome measures.

RESULTS

Eleven full-text articles, representing 2780 cases, were selected from 317 screened studies. The outcome measures were operative time, tumor removal, endocrinological results, visual field, and surgical complications. The plateaus or cutoff points in the learning curve varied with a mean of 103 ± 139.43 (range, 9-500) cases.

CONCLUSIONS

ETSS is an efficient and minimally invasive alternative surgical option for pituitary tumors. Plateau points may differ according to outcome measures, patient selection, training status, and surgical conditions. Therefore, great care should be taken when interpreting the learning curve. A systematic training program is essential to improve the learning process of endoscopic neurosurgical procedures.

Comparative analysis of patient-reported outcomes after percutaneous endoscopic lumbar discectomy between transforaminal and interlaminar approach: a minimum two year follow-up

PURPOSE

Percutaneous endoscopic lumbar discectomy has been increasingly used in the treatment of lumbar disc herniation. However, there is no consensus on which method would be more effective between the transforaminal and interlaminar approach.

OBJECTIVE

To compare clinical outcomes, patient satisfaction rate, reoperation rate, and residual symptoms between percutaneous endoscopic transforaminal discectomy (PETD) and percutaneous endoscopic interlaminar discectomy (PEID).

STUDY DESIGN

A comparative, retrospective, controlled trial.

SETTING

The study was conducted at the Department of Orthopaedics at a local hospital.

METHODS

From January 2015 to September 2020, consecutive patients who underwent PETD or PEID treatment for lumbar disk herniation (LDH) at the L5/S1 level in our department were retrospectively collected. Baseline data including age, gender, body mass index (BMI), smoking status, alcohol drinking, clinical symptoms, physical examination, and radiographic characteristics were documented. During the two to three year follow-up periods, patients were evaluated clinically, including clinical outcomes assessed by the visual analog score (VAS), patient satisfaction rates assessed by the North American Spine Society patient satisfaction index (PSI), recurrent rate, and residual symptoms.

RESULTS

A total of 113 patients with PELD in our department were included in the current study, with 65 patients in the PETD group and 48 in the PEID group. Demographic characteristics including age, gender, height, BMI, cigarette smoking, alcohol consumption status, and diabetes did not show any significant difference between the PETD and PEID groups. The VAS scores of the two groups were similar preoperatively, but the postoperative VAS score of the PEID group was lower than that of the PETD group. There were 90.8% of patients in the PETD group who were satisfied with the operation compared to 97.9% in the PEID group. The recurrence rate did not differ between groups, with three patients in both groups. Regarding residual symptoms, there were more patients in the PETD group who reported low back pain during the follow-up periods.

LIMITATION

The main limitations are that all patients were operated by the same surgical team from the same site, and there was a lack of multicenter data.

CONCLUSION

Both PETD and PEID have satisfactory patient-reported outcomes for treating LDH. The PEID procedure results in fewer low back pain residual symptoms than the PELD procedure.

Learning curve for endoscopic posterior cervical foraminotomy

PURPOSE

While anterior cervical discectomy and fusion as well as cervical disk arthroplasty are gold standard treatments for the surgical treatment of cervical radiculopathy, posterior endoscopic cervical foraminotomy (PECF) as a substitute procedure is gaining popularity. To date, studies investigating the number of surgeries needed to achieve proficiency in this procedure are lacking. The purpose of the study is to examine the learning curve for PECF.

METHODS

The learning curve in operative time for two fellowship-trained spine surgeons at independent institutions was retrospectively assessed for 90 uniportal PECF procedures (PBD: n = 26, CPH: n = 64) performed from 2015 to 2022. Operative time was assessed across consecutive cases using a nonparametric monotone regression, and a plateau in operative time was used as a proxy to define the learning curve. Secondary outcomes assessing achievement of endoscopic prowess before and after the initial learning curve included number of fluoroscopy images, visual analog scale (VAS) for neck and arm, Neck Disability Index (NDI), and the need for reoperation.

RESULTS

There was no significant difference in operative time between surgeons (p = 0.420). The start of a plateau for Surgeon 1 occurred at 9 cases and 111.6 min. The start of a plateau for Surgeon 2 occurred at 29 cases and 114.7 min. A second plateau for Surgeon 2 occurred at 49 cases and 91.8 min. Fluoroscopy use did not significantly change before and after surmounting the learning curve. The majority of patients achieved minimally clinically important differences in VAS and NDI after PECF, but postoperative VAS and NDI did not significantly differ before and after achieving the learning curve. There were no significant differences in revisions or postoperative cervical injections before and after reaching a steady state in the learning curve.

CONCLUSION

PECF is an advanced endoscopic technique with an initial improvement in operative time that occurred after as few as 8 cases to as many as 28 cases in this series. A second learning curve may occur with additional cases. Patient-reported outcomes improve following surgery, and these outcomes are independent of the surgeon's position on the learning curve. Fluoroscopy use does not change significantly along the learning curve. PECF is a safe and effective technique that current and future spine surgeons should consider as part of their armamentarium.

Minimally invasive endoscopy in spine surgery: where are we now?

INTRODUCTION

Endoscopic spine surgery (ESS) is a minimally invasive surgical technique that offers comparable efficacy and safety with less collateral damage compared to conventional surgery. To achieve clinical success, it is imperative to stay abreast of technological advancements, modern surgical instruments and technique, and updated evidence.

PURPOSES

To provide a comprehensive review and updates of ESS including the nomenclature, technical evolution, bibliometric analysis of evidence, recent changes in the spine communities, the prevailing of biportal endoscopy, and the future of endoscopic spine surgery.

METHODS

We conducted a comprehensive review of the literature on ESS for the mentioned topics from January 1989 to November 2022. Three major electronic databases were searched, including MEDLINE, Scopus, and Embase. Covidence Systematic Review was used to organize the eligible records. Two independent reviewers screened the articles for relevance.

RESULTS

In total, 312 articles were finally included for review. We found various use of nomenclatures in the field of ESS publication. To address this issue, we proposed the use of distinct terms to describe the biportal and uniportal techniques, as well as their specific approaches. In the realm of technical advancement, ESS has rapidly evolved from addressing disc herniation and spinal stenosis to encompassing endoscopic fusion, along with technological innovations such as navigation, robotics, and augmented reality. According to bibliometric analysis, China, South Korea, and the USA have accounted for almost three-quarters of total publications. The studies of the biportal endoscopy are becoming increasingly popular in South Korea where the top ten most-cited articles have been published. The biportal endoscopy technique is relatively simple to adopt, as it relies on a more familiar approach, requires less expensive instruments, has a shorter learning curve, and is also well-suited for interbody fusion. The uniportal approach provided the smallest area of soft tissue dissection. While robotics and augmented reality in ESS are not widely embraced, the use of navigation in ESS is expected to become more streamlined, particularly with the emergence of recent electromagnetic-based navigation technologies.

CONCLUSIONS

In this paper, we provide a comprehensive overview of the evolution of ESS, as well as an updated summary of current trends in the field, including the biportal and uniportal approaches. Additionally, we summarize the nomenclature used in ESS, present a bibliometric analysis of the field, and discuss future directions for the advancement of the field.

Efficacy of Transforaminal Endoscopic Lumbar Discectomy in Elderly Patients Over 65 Years of Age Compared to Young Adults

OBJECTIVE

Spine surgery rates are increasing in the elderly population due to social aging, and it is known that prognoses related to surgery are worse for the elderly compared to younger individuals. However, minimally invasive surgery, such as full endoscopic surgery, is considered safe with low complication rates due to minimal damage to surrounding tissues. In this study, we compared outcomes of transforaminal endoscopic lumbar discectomy (TELD) in elderly and younger patients with disc herniation in the lumbosacral region.

METHODS

We retrospectively analyzed the data of 249 patients who underwent TELD at a single center between January 2016 to December 2019, with a minimum follow-up of 3 years. Patients were allocated to 2 groups: a young group aged ≤ 65 years (n = 202) or an elderly group aged > 65 years (n = 47). We evaluated baseline characteristics, clinical outcomes, surgery-related outcomes, radiological outcomes, perioperative complications, and adverse events during the 3-year follow-up period.

RESULTS

Baseline characteristics, including age, general condition based on American Society of Anesthesiologist physical status classification grade, age-Charlson Comorbidity Index, and disc degeneration, were worse in elderly group (p < 0.001). However, except for leg pain at 4 weeks after surgery, overall outcomes, including pain improvement, radiological change, operation time, blood loss, and hospital stay, were not different between the 2 groups. Furthermore, the rates of perioperative complications (9 patients [4.46%] in the young group and 3 patients [6.38%] in the elderly group, p = 0.578) and adverse events over the 3-year follow-up period (32 patients [15.84%] in the young group and 9 patients [19.15%] in the elderly group, p = 0.582) were comparable in the 2 groups.

CONCLUSION

Our findings suggest that TELD produces similar outcomes in both elderly and younger patients with a herniated disc in the lumbosacral region. TELD can be considered a safe option for appropriately selected elderly patients.

Full endoscopic spine surgery

Background

With a dramatic increase in elderly population worldwide, the prevalence of degenerative spine disease is steadily rising. Even though the entire spinal column is affected the problem is more commonly seen in the lumbar, cervical spine and to some extent the thoracic spine. The treatment of symptomatic lumbar disc or stenosis is primarily conservative with analgesics, epidural steroids and physiotherapy. Surgery is advised only if conservative treatment is ineffective. Conventional open microscopic procedures even though are still a gold standard, have the disadvantages of excessive muscle damage and bone resection, epidural scarring along with prolonged hospital stay and increased need of postoperative analgesics. Minimal access spine surgeries minimize surgical access related injury by minimizing soft tissue and muscle damage and also bony resection thus preventing iatrogenic instability and unnecessary fusions. This leads to good functional preservation of the spine and enhances early postoperative recovery and early return to work. Full endoscopic spine surgeries are one of the more sophisticated and advanced form of MIS surgeries.

Purpose

Full endoscopy has definitive benefits over conventional microsurgical techniques. These include better and clear vision of the pathology due to presence of irrigation fluid channel, minimal soft tissue and bone trauma, better and relatively easy approach to deep seated pathologies like thoracic disc herniations and a possibility to avoid fusion surgeries. The purpose of this article is to describe these benefits, give an overview of the two main approaches - transforaminal and interlaminar, their indications, contraindications and their limitations. The article also describes about the challenges in overcoming the learning curve and its future prospectives.

Conclusion

Full endoscopic spine surgery is one of the fastest growing technique in the field of modern spine surgery. Better intraoperative visualization of the pathology, lesser incidence of complications, faster recovery time, less postoperative pain, better relief of symptoms and early return to activity are the main reasons behind this rapid growth. With better patient outcomes and reduced medical costs, the procedure is going to be more accepted, relevant and popular procedure in future.

Uniportal versus biportal endoscopic spine surgery: a comprehensive review

INTRODUCTION

Endoscopic spine surgery techniques are minimally invasive alternatives to conventional open surgery for degenerative spinal diseases. Clinical studies and meta-analyses have proven the usefulness of uniportal full-endoscopic spine procedures. However, a steep learning curve is a critical barrier for endoscopic procedures. Recently, biportal endoscopic spine surgeries have been developed to make it easier for spine surgeons to learn and perform. Consequently, the biportal approach has gained popularity among aspiring endoscopic spine surgeons. This review compared the characteristics of uniportal and biportal surgeries to help spine surgeons perform endoscopic procedures more effectively.

AREA COVERED

The review analyzed English-language clinical literature in Core databases and compared uniportal and biportal endoscopic spine surgery techniques. Clinical studies have compared the technical principles of both techniques, and the authors suggested appropriate strategies for learning and practicing endoscopic procedures.

EXPERT OPINION

Uniportal, full-endoscopic spine surgery is a minimally invasive procedure that preserves muscles and uses a keyhole approach under local anesthesia. In contrast, biportal surgery is more familiar to a surgeon and can be performed more widely, although the keyhole approach is limited. Aspiring endoscopic spine surgeons can learn either method according to the surgeon's preference and the clinical situation.

Uniportal, Transforaminal Endoscopic Thoracic Discectomy: Review and Technical Note

Symptomatic thoracic disc herniations are a rare entity and their operative treatment is challenging. Open approaches, despite providing excellent access, are associated with significant access morbidity from thoracotomy, and this has led to an increased interest in minimally invasive techniques such as mini-open approach, thoracoscopic approach and the endoscopic approach. In this article, we describe the technical points for performing a transforaminal endoscopic thoracic discectomy and summarize its literature outcomes in the context of other minimally invasive approaches.

Modified lumbar foraminoplasty using a power-aided reciprocating burr for percutaneous transforaminal endoscopic lumbar discectomy: A technical note and clinical report

Background

One of the main difficulties in a transforaminal endoscopic lumbar discectomy (TELD), and simultaneously the most critical step, is performing an effective and safe foraminoplasty, which is especially difficult for beginners. To make it safer and faster for beginners to perform, we have used a specially designed power-aided reciprocating burr for TELD and reported the technical details.

Methods

From Jan. 2019 to Nov. 2022, 432 patients with single-level, symptomatic L4/5 or L5/S1 disc herniation were treated with TELD using a novel power-aided reciprocating burr. The surgical procedure is described in detail. Magnetic resonance imaging (MRI) was performed the following day and 3 months after the operation. The learning curves of surgeons with different seniority levels are displayed. The Visual Analogue Scale (VAS) score and the Oswestry Disability Index (ODI) were used to measure low back pain, leg pain, and lumbar function. All patients were followed up for at least 1 year.

Results

All patients underwent endoscopic surgery successfully. Among the 432 patients, radicular outer membrane damage was observed in 6 cases, and 1 case had hernia of the nerve tract. Except for this patient with aggravation of postoperative numbness, the postoperative neurological symptoms of all patients were significantly improved. The mean VAS scores for low back pain and leg pain and ODI scores were significantly decreased 6 w post-operatively and were maintained until 12 months post-operatively compared to preoperative scores (P < 0.05). All three doctors involved in the study had substantial experience in traditional open spinal surgery. The more operations all three surgeons completed, the more time spent on intervertebral foraminoplasty decreased (P < 0.05). Among them, doctors without experience in TELD surgery became proficient in this technique after accumulating experience in 13 cases. There was no significant difference in foraminoplasty time among these three surgeons during the same growing period (P > 0.05).

Conclusions

Current clinical data demonstrated the safety and efficacy of modified TELD using a power-aided reciprocating burr for treating lumbar disc herniation (LDH) and showed that this technique significantly reduces the learning curve for beginners when performing foraminoplasty.

Current Status and research hotspots in the field of full endoscopic spine surgery: A bibliometric analysis

Purpose

We aimed to comprehensively analyze the current status, hotspots, and trends in full endoscopic spine surgery (FESS) research using bibliometric analysis and knowledge domain mapping.

Methods

The Web of Science database was used to screen FESS-related articles published between January 1, 1993 and June 10, 2022. The evaluation involved the following criteria: total number of articles; H-index; and contributions from countries/regions, institutions, journals, and authors.

Results

A total of 1,064 articles were included. Since 2016, there have been a significant number of publications in the field of FESS. The country/region contributing the largest number of articles was China (37.8%), followed by South Korea (24%), the United States (16.1%), Japan (5.7%), and Germany (5.1%). South Korea (35) had the highest H-index, followed by the United States (27), China (22), Japan (21), and Germany (20). World Neurosurgery (15.7%) published the largest number of FESS-related articles. However, among the top 10 most cited articles, six were published in Spine. The author who contributed the most was S.H. Lee (5.4%), and the largest number of contributions in this field originated from Wooridul Spine Hospital (South Korea; 6.1%). Notably, six of the 10 most published authors in this field were from South Korea. Of the top five productive institutions, three were from South Korea. The keywords with the strongest citation bursts in the field of FESS were “lumbar spine,” “discectomy,” “interlaminar,” “surgical technique,” “follow-up,” “excision,” “thoracic spine,” and “endoscopic surgery.” The 10 clusters generated in this study were: “endoscopic discectomy” (#0), “thoracic myelopathy” (#1), “recurrent lumbar disc herniation” (#2), “low back pain” (#3), “cervical vertebrae” (#4), “lumbar spinal stenosis” (#5), “transforaminal lumbar interbody fusion” (#6), “radiation exposure” (#7), “management” (#8), and “lumbar spine” (#9).

Conclusion

Global research on FESS is mostly concentrated in a few countries/regions and authors. South Korea has made the largest contribution to the field of FESS. Based on the most cited keyword bursts and clusters, the focus of FESS research was found to include its indications, management, and applications.

Knowledge Areas and New Trends in Lumbar Disc Herniation Research: Bibliometrics and Knowledge Mapping Analysis

OBJECTIVE

To determine the coalitions and impact of authors, countries, institutions, and journals, evaluate the knowledge base, find the hotspot trends, and identify the emerging topics in lumbar disc herniation (LDH).

METHOD

The articles related to LDH were obtained from the Web of Science Core Collection on August 21, 2021. Two scientometric software (CiteSpace 5.8.R.1 and VOSviewer 1.6.17) were used to perform bibliometric and knowledge-map analysis.

RESULTS

From the set parameters, 4642 articles were included in the literature. Although the total number of publications fluctuated between 2001 and 2020, a general trend toward increase was observed. Respectively, the most productive country and institution in the field were the United States and Wooridul Spine Hospital. The most active and cited authors were Lee and Weinstein. Spine was the most impactful and cited journal. Weinstein (JAMA 296:2441-2450, 2006) had the highest number of co-citations and Weinstein(N Engl J Med 358:794-810, 2008) had the highest number of citations. The keyword "low back pain" was ranked first for frequency and total link strength, whereas "risk factor" was ranked first for centrality. Topics including pathogenesis (disc herniation), examination methods (MRI), treatment methods (non-surgical treatment, surgical treatment), surgical options (laminectomy, discectomy), clinical observations (double-blind, efficacy, outcome, learning curve), and evaluation of efficacy (meta-analysis) of LDH have been the focus of leading-edge research in 2001-2020.

CONCLUSION

Using bibliometric methods, this study mapped the knowledge map of LDH research in the past 20 years. The study identifies existing trends to provide a framework for further research.

Full endoscopic versus open discectomy for sciatica: randomised controlled non-inferiority trial

OBJECTIVE

To assess whether percutaneous transforaminal endoscopic discectomy (PTED) is non-inferior to conventional open microdiscectomy in reduction of leg pain caused by lumbar disc herniation.

DESIGN

Multicentre randomised controlled trial with non-inferiority design.

SETTING

Four hospitals in the Netherlands.

PARTICIPANTS

613 patients aged 18-70 years with at least six weeks of radiating leg pain caused by lumbar disc herniation. The trial included a predetermined set of 125 patients receiving PTED who were the learning curve cases performed by surgeons who did not do PTED before the trial.

INTERVENTIONS

PTED (n=179) compared with open microdiscectomy (n=309).

MAIN OUTCOME MEASURES

The primary outcome was self-reported leg pain measured by a 0-100 visual analogue scale at 12 months, assuming a non-inferiority margin of 5.0. Secondary outcomes included complications, reoperations, self-reported functional status as measured with the Oswestry Disability Index, visual analogue scale for back pain, health related quality of life, and self-perceived recovery. Outcomes were measured until one year after surgery and were longitudinally analysed according to the intention-to-treat principle. Patients belonging to the PTED learning curve were omitted from the primary analyses.

RESULTS

At 12 months, patients who were randomised to PTED had a statistically significantly lower visual analogue scale score for leg pain (median 7.0, interquartile range 1.0-30.0) compared with patients randomised to open microdiscectomy (16.0, 2.0-53.5) (between group difference of 7.1, 95% confidence interval 2.8 to 11.3). Blood loss was less, length of hospital admission was shorter, and timing of postoperative mobilisation was earlier in the PTED group than in the open microdiscectomy group. Secondary patient reported outcomes such as the Oswestry Disability Index, visual analogue scale for back pain, health related quality of life, and self-perceived recovery, were similarly in favour of PTED. Within one year, nine (5%) in the PTED group compared with 14 (6%) in the open microdiscectomy group had repeated surgery. Per protocol analysis and sensitivity analyses including the patients of the learning curve resulted in similar outcomes to the primary analysis.

CONCLUSIONS

PTED was non-inferior to open microdiscectomy in reduction of leg pain. PTED resulted in more favourable results for self-reported leg pain, back pain, functional status, quality of life, and recovery. These differences, however, were small and may not reach clinical relevance. PTED can be considered as an effective alternative to open microdiscectomy in treating sciatica.

TRIAL REGISTRATION

NCT02602093ClinicalTrials.gov NCT02602093.