Full-endoscopic (bi-portal or uni-portal) versus microscopic lumbar decompression laminectomy in patients with spinal stenosis: systematic review and meta-analysis

Endoscopic surgery for multilevel spinal stenosis: a comprehensive meta-analysis and subgroup analysis of uniportal and biportal approaches

Minimally invasive spine surgery (MIS) has shown promising results, and endoscopic spine surgery has emerged as a less invasive approach. Although studies have examined the effectiveness of endoscopic surgery for spinal stenosis, no meta-analyses have focused on multilevel cases. This meta-analysis aimed to evaluate the efficacy and safety of uniportal and biportal endoscopy in patients with multilevel spinal stenosis. The patient, intervention, comparison, outcomes, and study criteria were established to guide study selection. Four databases were searched. The outcome measures included patient-reported outcome measures (PROMs), radiological and analytical data, complications, surgery time, length of hospital stay, and blood loss. Review Manager ver. 5.4 software (RevMan; Cochrane, UK) was used for the analysis. Heterogeneity was assessed using the chi-square and I2 tests. Ten studies (n=686) were included. PROMs showed significant improvements in Visual Analog Scale (VAS) scores for back pain (mean difference [MD], 4.07; 95% confidence intervals [CI], 3.72-4.42), leg pain (MD, 5.49; 95% CI, 5.17-5.80), and Oswestry Disability Index (MD, 35.97; 95% CI, 32.46-39.47). MacNab scale results were as follows: excellent (55.37%), good (34.93%), fair (7.58%), and poor (4.06%). C-reactive protein levels did not change significantly; however, hemoglobin levels decreased postoperatively (MD, 1.28; 95% CI, 0.91-1.65). Complications included dural tears (5.46%), hematoma (4.30%), incomplete decompression (3.12%), root injury (2.90%), reoperations/revisions (2.22%), conversion to open or microscopic surgery (1.97%), and transfusions (8.50%). Analysis by levels showed worse VAS leg pain in studies analyzing >30% multilevel stenosis (MD, 4.99; 95% CI, 4.47-5.51 vs. MD, 5.82; 95% CI, 5.63-6.01). Uniportal and biportal endoscopy had similar outcomes, except for a higher incidence of dural tears on biportal endoscopy (uniportal, 3.33%; biportal, 7.05%). This meta-analysis supports endoscopy as an effective and safe option for multilevel lumbar stenoses. It improves long-term pain and functionality, with no significant radiological changes or postoperative inflammation. Complications are few; however, dural tears are more common in biportal endoscopy. Higher multilevel stenosis rates were associated with increased leg pain and a lower likelihood of achieving incomplete decompression.

Surgical Outcomes of Unilateral Biportal Endoscopy Versus Full Endoscopy for Lumbar Canal Stenosis: A Meta-Analysis

Lumbar canal stenosis (LCS) is a common cause of chronic lower back pain in the elderly. Traditionally, open decompression surgery has a prolonged recovery, higher blood loss, and more complications. As a result, there remains no clear consensus on which of these minimally invasive spine surgery (MISS) techniques, including unilateral biportal endoscopy (UBE) and full endoscopy (FE), is the optimal technique for LCS treatment. A systematic review and meta-analysis were accomplished to compare the surgical results of UBE versus FE for lumbar canal stenosis in regard to surgical success, postoperative pain control, operative times, complication rates, and functional outcomes. Studies from 2024 were searched comprehensively in PubMed, Scopus, and other databases. Randomized controlled trials (RCTs) and experimental studies comparing UBE with FE were included. Surgical success rates, pain scores (visual analog scale (VAS)), recovery time, and complications were the key outcomes analyzed. Five studies (sample size: 32-163) were included. High surgical success and no significant difference in pain relief were demonstrated by both UBE and FE. UBE was associated with significantly quicker recovery times (odds ratio (OR): 0.54, 95% confidence interval (CI): 0.35-0.83, P = 0.01). The complication rates were lower with UBE compared with FE. Both techniques improved functional outcomes, but UBE had a slight advantage in recovery time. Both UBE and FE present effective treatments for LCS, and UBE is superior concerning recovery time. The choice of technique should be based on the patient's characteristics, and surgical goals should be tailored to each individual patient.

Comparison between microendoscopic laminectomy and open posterior decompression surgery for two-level lumbar spinal stenosis: a multicenter retrospective cohort study

BACKGROUND

Excellent surgical outcomes of microendoscopic laminectomy (MEL) have been reported for patients with lumbar spinal canal stenosis (LSCS). However, few reports have directly compared MEL with open laminectomy for multi-level LSCS. This study conducted a comparative analysis of patient-reported outcomes (PROs) and perioperative complications in patients undergoing two-level posterior decompression for LSCS by MEL versus open laminectomy.

METHODS

This multicenter retrospective cohort study involved prospectively registered patients who underwent two-level posterior lumbar decompression surgery for LSCS at one of eight high-volume spine centers between April 2017 and February 2020. Chart sheets were used to prospectively evaluate demographic data, including diagnosis, operative procedure, operation time, estimated blood loss, and perioperative complications. The PROs evaluated were the numerical rating scale (NRS) score for lower back pain and leg pain, 12-item Short Form Health Survey (SF-12) score, EuroQol 5-Dimension (EQ-5D) score, Oswestry Disability Index (ODI) score, and patient satisfaction with the treatment.

RESULTS

Of the 882 patients enrolled, 410 underwent MEL (MEL group) and 472 underwent open decompression (open group). A total of 667 (75.6%) patients completed the 1-year follow-up. Intraoperative blood loss was significantly lower in the MEL group than in the open group. The complication rate was comparable (12.4% in MEL group, 12.5% in open group). Although the revision rate did not differ significantly, the incidence of surgical site infection (SSI) was markedly lower in the MEL group (0.0% in MEL group, 1.3% in open group). Propensity score matching was employed to compare 333 patients who underwent MEL with 333 patients who underwent open laminectomy. Intraoperative blood loss was significantly lower in the matched MEL group than in the matched open group. The incidence of SSI was markedly lower in the matched MEL group (0.0% in matched MEL group, 1.2% in matched open group). No significant differences in the preoperative and postoperative values of the PROs or patient satisfaction were observed between the two groups.

CONCLUSIONS

MEL required an equivalent operating time and resulted in less intraoperative blood loss compared with laminectomy in two-level procedures. The incidence of SSI was significantly lower in the MEL group.

Full-endoscopic versus microscopic spinal decompression for lumbar spinal stenosis: a systematic review & meta-analysis

BACKGROUND CONTEXT

Symptomatic lumbar spinal stenosis is routinely treated with spinal decompression surgery, with an increasing trend towards minimally invasive techniques. Endoscopic decompression has emerged as a technique which minimizes approach-related morbidity while achieving similar clinical outcomes to conventional open or microscopic approaches.

PURPOSE

To assess the safety and efficacy of endoscopic versus microscopic decompression for treatment of lumbar spinal stenosis.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic review on randomized and nonrandomized studies comparing endoscopic versus microscopic decompression was conducted, in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Treatment effects were computed using pairwise random-effects meta-analysis. Risk of bias was assessed using the Cochrane Risk-of-bias and ROBINS-I tools for randomized and nonrandomized trials respectively. Quality of the overall body of evidence was appraised using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.

RESULTS

A total of 19 primary references comprising 1,997 patients and 2,132 spinal levels were included. Endoscopic decompression was associated with significantly reduced intraoperative blood-loss (weighted mean differences [WMD]=-33.29 mL, 95% CI:-51.80 to -14.78, p=.0032), shorter duration of hospital stay (WMD=-1.79 days, 95% CI: -2.63 to 0.95, p=.001), rates of incidental durotomy (RR = 0.63, 95% CI: 0.43 to 0.91, p=.0184) and surgical site infections (RR=0.23, 95% CI: 0.10 to-0.51, p=.001), and a nonsignificant trend towards less back pain, leg pain, and better functional outcomes compared to its microscopic counterpart up to 2-year follow up.

CONCLUSIONS

Endoscopic and microscopic decompression are safe and effective techniques for treatment of symptomatic lumbar spinal stenosis. Prospective studies of larger power considering medium to long-term outcomes and rates of iatrogenic instability are warranted to compare potential alignment changes and destabilization from either techniques.

Unilateral biportal endoscopic technique combined with percutaneous transpedicular screw fixation for thoracolumbar burst fractures with neurological symptoms: technical note and preliminary report

BACKGROUND

Previous studies on thoracolumbar fractures with neurological symptoms have focused on how to achieve satisfactory fracture reduction, adequate nerve decompression, and stable spinal alignment. With the development of the minimally invasive spine surgery technique, achieving satisfactory treatment results and reducing iatrogenic trauma at the same time has become a new goal of spinal surgery. This research used percutaneous transpedicular screw distraction to partially reduce the fractured vertebrae, followed by completing nerve decompression and reducing residual displacement bone fragments with the assistance of the unilateral biportal endoscopic (UBE) technique to achieve full protection of bone-ligament tissue and obtain good clinical efficacy.

METHODS

Guide wires were safely inserted into the fractured vertebra and adjacent upper and lower vertebra under the surveillance of anteroposterior and lateral X-ray fluoroscopy. Transpedicular screws were implanted via guide wires on the side with mild neurological deficits or bone fragment compression (the opposite side of the endoscopic operation). A titanium rod was installed and moderately distracted to reduce the fractured vertebra. Then, under the guidance of the endoscopic view, the laminectomy and ligamentum flavum resection were completed according to the position of the protruding bone fragment into the spinal canal, and the compressed dural sac or nerve root was fully exposed and decompressed. An L-shaped replacer was used to reduce residual bone fragments. The ipsilateral transpedicular screws and rod were installed and adjusted to match the contralateral side. The drainage tube was indwelled, and the incision was closed. The preoperative and postoperative images of the patients were evaluated, and the recovery of neurological symptoms was observed.

RESULTS

Surgery was successfully completed on all six patients, and no intraoperative conversion to open surgery was performed. Postoperative images showed good reduction of the protruding bone fragment and good placement of all screws. At the last follow-up, the neurological symptoms of all patients returned to normal.

CONCLUSION

The UBE technique combined with percutaneous transpedicular screw fixation in the treatment of thoracolumbar fractures with neurological symptoms can effectively achieve the reduction of displaced bone fragments, improve damaged nerve function, stabilize spinal alignment, and protect the integrity of bone-ligament tissue.

Full-endoscopic bilateral over-the-top decompression in lumbar central stenosis: surgical technique and outcomes

Decompression of spinal stenosis represents one of the most commonly performed procedures in spine surgery. With constantly increasing patient age and changing demographics, reducing the invasiveness of surgical procedures has become increasingly important. Over the past decades, microsurgical decompression has been established as a gold standard technique for the surgical treatment of spinal stenosis. In comparison with open techniques or surgeries that were performed with loop lenses, which required larger skin incisions, and which consecutively raised the access-related collateral damage, the microscope served to significantly reduce the invasiveness of the decompression interventions. Advantages included smaller skin incisions, reduced collateral tissue damage, less blood loss, lower infection rates and wound healing problems, shorter hospital stay, and multiple others, as widely known across various MIS techniques. For the same reasons as outlined above, the introduction of full-endoscopic surgical techniques aims to further reduce the invasiveness of surgical interventions. The present manuscript provides a delineation of the surgical technique of LE-ULBD (Lumbar Endoscopic Unilateral Laminotomy for Bilateral Decompression), gives an overview on the current state of literature, and aims to put this surgery into context with other currently available decompression techniques.

Development of an Endoscopic Spine Surgery Program: Overview and Basic Considerations for Implementation

Endoscopic spine surgery (ESS) is an innovative technique allowing for minimally invasive, direct visualization of spinal abnormalities. The growth of ESS in the United States has been stunted by high start-up costs, low reimbursement rates, and the steep learning curve associated with mastering endoscopic techniques. Hergrae, we describe the current state and future direction of ESS and provide key action items for ESS program implementation.

Percutaneous Biportal Endoscopic Fenestration for Symptomatic Foraminal Tarlov Cyst

Perineural (Tarlov) cysts are a common benign pathology in the lumbosacral area but are rarely symptomatic, even when compressing the spinal root. Despite the rarity of Tarlov cyst formation in the foramen of the spine, this type is more symptomatic than those in other sites due to the narrow space. We introduce a biportal endoscopic fenestration for symptomatic foraminal Tarlov cysts. We present the case of a 40-year-old woman experiencing radiating pain in her right lower leg for 4 years. On seeking treatment, her great toe and ankle plantar flexion power had decreased. Magnetic resonance imaging revealed a cystic mass located in the L5-S1 intervertebral foramen that compressed the lumbar nerve root. Partial laminotomy was performed using a percutaneous biportal endoscopic system with a far lateral approach. An oval cystic mass of 2.6×1.1 cm was identified on high-definition images. Partial bone and foraminal ligament removal and cystic membrane fenestration were performed for nerve decompression. After decompression, the patient's motor weakness and radiating pain improved. Due to high-definition images and the minimally invasive laminotomy procedures associated with percutaneous biportal endoscopic fenestration, a foraminal Tarlov cyst was fenestrated safely, and weakness arising from radiculopathy was resolved in the current case. [Orthopedics. 2023;46(2):e125-e128.].

The Use of Ultrasonic Bone Scalpel (UBS) in Unilateral Biportal Endoscopic Spine Surgery (UBESS): Technical Notes and Outcomes

STUDY DESIGN

Case Series and Technical Note, Objective: UBS has been extensively used in open surgery. However, the use of UBS during UBESS has not been reported in the literature. The aim of this study was to describe a new spinal surgical technique using an ultrasonic bone scalpel (UBS) during unilateral biportal endoscopic spine surgery (UBESS) and to report the preliminary results of this technique.

METHODS

We enrolled patients diagnosed with lumbar spinal stenosis who underwent single-level UBESS. All patients were followed up for more than 12 months. A unilateral laminotomy was performed after bilateral decompression under endoscopy. We used the UBS system after direct visualization of the target for a bone cut. We evaluated the demographic characteristics, diagnosis, operative time, and estimated blood loss of the patients. Clinical outcomes included the visual analog scale (VAS), the Oswestry Disability Index (ODI), the modified MacNab criteria, and postoperative complications.

RESULTS

A total of twenty patients (five males and fifteen females) were enrolled in this study. The mean follow-up period was 13.2 months (range 12-17 months). The VAS score, ODI, and modified MacNab criteria classification improved after the surgery. A minimal mean blood loss of 22.1 mL was noted during the operation. Only one patient experienced neuropraxia, which resolved within 2 weeks. There was no durotomy, iatrogenic pars fracture, or infection.

CONCLUSIONS

In conclusion, our study represents the first report of the use of UBS during UBESS. Our findings demonstrate that this technique is safe and efficient, with improved clinical outcomes and minimal complications. These preliminary results warrant further investigation through larger clinical studies with longer follow-up periods to confirm the effectiveness of this technique in the treatment of lumbar spinal stenosis.

Comparative Effects and Safety of Full-Endoscopic Versus Microscopic Spinal Decompression for Lumbar Spinal Stenosis: A Meta-Analysis and Statistical Power Analysis of 6 Randomized Controlled Trials

OBJECTIVE

This meta-analysis with statistical power analysis aimed to evaluate the difference between full-endoscopic and microscopic spinal decompression in treating spinal stenosis.

METHODS

We searched PubMed, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), and CNKI (China National Knowledge Infrastructure) for relevant randomized controlled trials (RCTs) regarding the comparison of full-endoscopic versus microscopic spinal decompression in treating lumbar spinal stenosis through February 28, 2022. Two independent investigators selected studies, extracted information, and appraised methodological quality. Meta-analysis was conducted using RevMan 5.4 and STATA 14.0, and statistical power analysis was performed using G*Power 3.1.

RESULTS

Six RCTs involving 646 patients met selection criteria. Meta-analysis suggested that, compared with microscopic decompression, full-endoscopic spinal decompression achieved more leg pain improvement (mean difference [MD], -0.20; 95% confidence interval [CI], -0.30 to -0.10; p = 0.001), shortened operative time (MD, -12.71; 95% CI, -18.27 to -7.15; p < 0.001), and decreased the incidence of complications (risk ratio, 0.43; 95% CI, 0.22-0.82; p = 0.01), which was supported by a statistical power of 98.57%, 99.97%, and 81.88%, respectively.

CONCLUSION

Full-endoscopic spinal decompression is a better treatment for lumbar spinal stenosis, showing more effective leg pain improvement, shorter operative time, and fewer complications than microscopic decompression.

Full Endoscopic Ligamentum Flavum Sparing Unilateral Laminotomy for Bilateral Recess Decompression: Surgical Technique and Clinical Results

OBJECTIVE

Interlaminar endoscopic spine surgery has been introduced and utilized for lumbar lateral recess decompression. We modified this technique and utilized it for bilateral lateral recess stenoses without significant central stenosis. Here we present the surgical details and clinical outcome of ligamentum flavum sparing unilateral laminotomy for bilateral recess decompression (ULBRD).

METHODS

Prospectively collected registry for full-endoscopic surgeries was reviewed retrospectively. One hundred eighty-two consecutive cases from a single center between September 2015 and March 2021 were reviewed and 57 of them whom underwent ULBRD were enrolled for analysis. Basic patient demographic data, perioperative details, surgeryrelated complications, and clinical outcome were reviewed. The detailed surgical technique is presented as well.

RESULTS

Among the 57 patients enrolled, 37 were males while the other 20 were females. The mean age was 58.53 ± 14.51 years, and a bimodal age distribution at the age of mid-fifties and mid-sixties or older was noted. The later age-peak was related to coexistence of degenerative scoliosis. The average operative time per lamina was 70.34 ± 20.51 minutes and mean length of stay was 0.56 ± 0.85 days. Four perioperative complications were reported (7.0%) and the overall reoperation rate at the index level within 1 year was 8.8%. The preoperative back/leg visual analogue scale scores and functional outcome scales including EuroQol-5 dimension questionnaire, Oswestry Disability Index presented significant improvement immediately after surgery and were maintained until final follow-up.

CONCLUSION

ULBRD for bilateral lateral recess stenoses without significant central stenosis resulted in good clinical outcomes with acceptably low perioperative complications rates. Sufficient decompression was achieved with the central ligamentum flavum being preserved.

Complications of Unilateral Biportal Endoscopic Spinal Surgery for Lumbar Spinal Stenosis: A Systematic Review of the Literature and Meta-analysis of Single-arm Studies

PURPOSE

This article aims to summarize the incidence of these complications through a meta-analysis, analyze the causes of complications and provide clinical promotion and recommendations.

METHODS

Databases and retrieval platform including PubMed, Web of science, Springer link, Cochrane clinical trials, ProQuest, ScienceDirect, Europe PMC, Wiley online, OVID, Clinical trials, CNKI and WanFang, and supplement the literature through Google Scholar, collect all the unilateral biportal endoscopy (UBE) controlled trials and non-controlled trials of UBE in the treatment of lumbar spinal stenosis (LSS). The search time limit is from January 1, 2000 to December 25, 2021. After two reviewers independently screened the literature, extracted data and evaluated the risk of bias in the included studies, meta-analysis was performed using Stata 15.1 software.

RESULTS

Finally, 24 studies were included, including 999 patients. The results of a single-arm rate meta-analysis showed that the overall complication rate of UBE treatment of LSS was 6.27% [95% CI (0.0412, 0.0876)], and the incidence of dural tear was 2.49% [95% CI (0.0133, 0.0390)], the incidence of transient paresthesia was 0.14% [95% CI (0.0000, 0.0072)], the incidence of postoperative spinal epidural hematoma was 0.27% [95% CI (0.0000, 0.0096)], the incidence of postop headache, inadequate decompression, root injury and infection was 0.00%.

CONCLUSION

Current evidence shows that the complication rate of UBE in the treatment of LSS is low, mainly due to dural tears. Limited by the number and quality of included studies, the above conclusions still need to be confirmed by more studies.

Endoscopic decompression for the treatment of lumbar spinal stenosis: an updated systematic review and meta-analysis

OBJECTIVE

Lumbar stenosis treatment has evolved with the introduction of minimally invasive surgery (MIS) techniques. Endoscopic methods take the concepts applied to MIS a step further, with multiple studies showing that endoscopic techniques have outcomes that are similar to those of more traditional approaches. The aim of this study was to perform an updated meta-analysis and systematic review of studies comparing the outcomes between endoscopic (uni- and biportal) and microscopic techniques for the treatment of lumbar stenosis.

METHODS

Following PRISMA guidelines, a systematic search was performed using the Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Ovid Embase, and PubMed databases from their dates of inception to December 14, 2020. All identified articles were then systematically screened against the following inclusion criteria: 1) studies comparing endoscopic (either uniportal or biportal) with minimally invasive approaches, 2) patient age ≥ 18 years, and 3) diagnosis of lumbar spinal stenosis. Bias was assessed using quality assessment criteria and funnel plots. Meta-analysis using a random-effects model was used to synthesize the metadata.

RESULTS

From a total of 470 studies, 14 underwent full-text assessment. Of these 14 studies, 13 comparative studies were included for quantitative analysis, totaling 1406 procedures satisfying all criteria for selection. Regarding postoperative back pain, 9 studies showed that endoscopic methods resulted in significantly lower pain scores compared with MIS (mean difference [MD] -1.0, 95% CI -1.6 to -0.4, p < 0.01). The length of stay data were reported by 7 studies, with endoscopic methods associated with a significantly shorter length of stay versus the MIS technique (MD -2.1 days, 95% CI -2.7 to -1.4, p < 0.01). There was no significant difference with respect to leg visual analog scale scores, Oswestry Disability Index scores, blood loss, surgical time, and complications, and there were not any significant quality or bias concerns.

CONCLUSIONS

Both endoscopic and MIS techniques are safe and effective methods for treating patients with symptomatic lumbar stenosis. Patients who undergo endoscopic surgery seem to report less postoperative low-back pain and significantly reduced hospital stay with a trend toward less perioperative blood loss. Future large prospective randomized trials are needed to confirm the findings in this study.

Letter to the editor regarding "Full‑endoscopic (bi‑portal or uni‑portal) versus microscopic lumbar decompression laminectomy in patients with spinal stenosis: systematic review and meta‑analysis"

A recent article entitled "Full‑endoscopic (bi‑portal or uni‑portal) versus microscopic lumbar decompression laminectomy in patients with spinal stenosis: systematic review and meta‑analysis" written by Pairuchvej et al. (Eur J Orthop Surg Traumatol 30(4):595-611, 2019) published in "European Journal of Orthopaedic Surgery & Traumatology" has aroused our great interest. The authors concluded that compared with minimally invasive decompression surgery, full endoscopic spinal surgery had better pain relief (back pain and leg pain) in the treatment of lumbar spinal stenosis and had a lower complication rate, but no statistical difference in oswestry disability index score and operative time between both groups. Comparing to minimally invasive spinal surgery, bi-portal endoscopic spinal surgery had better back pain relief in the early stage, while uni-portal full endoscopic spinal surgery had better pain relief in the leg and a lower rate of complications.

Evaluation of the efficacy and safety of conventional and biportal endoscopic decompressive laminectomy in patients with lumbar spinal stenosis (ENDO-B trial): a protocol for a prospective, randomized, assessor-blind, multicenter trial

BACKGROUND

Recent studies on biportal endoscopic spine surgery in patients with lumbar spinal stenosis have reported good clinical results. However, these studies have been limited by the small sample sizes and use of a retrospective study design. Therefore, we aim to compare the efficacy and safety of biportal endoscopic decompressive laminectomy with those of conventional decompressive laminectomy in a multicenter, prospective, randomized controlled trial.

METHODS

This study will include 120 patients (60 per group, aged 20-80 years) with 1- or 2-level lumbar spinal stenosis, who will be recruited from six hospitals. The study will be conducted from July 2021 to December 2024. The primary outcome (Oswestry Disability Index at 12 months after surgery) will be evaluated through a modified intention-to-treat method. The secondary outcomes will include the following: visual analog scale score for low back and lower extremity radiating pain, EuroQol 5-dimensions score, surgery satisfaction, walking time, postoperative return to daily life period, postoperative surgical scars, and some surgery-related variables. Radiographic outcomes will be analyzed using magnetic resonance imaging or computed tomography. All outcomes will be evaluated before the surgery and at 2 weeks, 3 months, 6 months, and 12 months postoperatively. This protocol adheres to the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines for reporting of clinical trial protocols.

DISCUSSION

It is hypothesized that the efficacy and safety of biportal endoscopic and conventional decompressive laminectomy will be comparable in patients with lumbar spinal stenosis. The results of this trial will provide a high level of evidence for the efficacy and safety of the biportal endoscopic technique in patients with lumbar spinal stenosis and facilitate the development of clinical practice guidelines. Furthermore, the results of this study may indicate the feasibility of the biportal endoscopic technique for other types of spinal surgery.

TRIAL REGISTRATION

The ENDO-B trial is registered at Clinical Research Information Service (CRIS, cris.nih.go.kr ) (KCT0006057; April 52,021).

A Narrative Review of Development of Full-Endoscopic Lumbar Spine Surgery

In the first phase of development of lumbar endoscopic spine surgery, the focus was on removal of soft disc material through the working corridor of Kambin’s triangle using transforaminal endoscopic lumbar discectomy. With the introduction of the interlaminar approach and increased interest from both industry and surgeons, there has been an exponential development of endoscopic surgical equipment and a corresponding expansion of endoscopic techniques. Endoscopic treatment strategies are applied to conditions ranging from contained prolapsed intervertebral discs to noncontained migrated herniated discs, hard calcified discs, spinal stenosis in the central or lateral recess and the foraminal and extraforaminal region, and other combinations of degenerative conditions requiring decompression or fusion surgery. The further expansion of endoscopic surgical management involving complicated spinal cases and the final quartet of trauma, infections, tumors, and possibly deformities could be the future stage of endoscopic spine surgery development. This article covers the full range of current treatment strategies and presents possible future developments of endoscopic spine surgery for the management of lumbar spinal conditions.