Biportal Endoscopic Spinal Surgery for Recurrent Lumbar Disc Herniations

Biportal Endoscopic Spinal Cord Stimulation Paddle Lead Implantation: Technical Note and Preliminary Clinical Results

OBJECTIVE

This study aims to elucidate a novel, minimally invasive surgical technique using a biportal endoscope for the implantation of spinal cord stimulation (SCS) paddle leads and to report the preliminary results of its clinical application.

MATERIALS AND METHODS

The perioperative data of patients who underwent the biportal endoscopic SCS paddle lead implantation in our department were collected; the surgical procedure was delineated, and the clinical outcomes were assessed.

RESULTS

From February 2022 to December 2023, six patients underwent biportal endoscopic SCS paddle lead implantation. The median follow-up time was nine months (range one to three months). The median intraoperative blood loss was 30 mL (range 25-50 mL), and the median operative time was 87.5 minutes (range 75-110 minutes). One patient experienced severe neck pain during the operation, whereas the other five patients experienced no surgical complications. One patient was found to have a slight lead migration three months after surgery, which did not affect the therapeutic effect. The median visual analogue scale (VAS) of the surgical area was 0.5 (range 0-2), 2.5 (range 1-4), and 0.5 (range 0-1) during the operation and one day and one week after the operation, respectively. The median VAS of the six patients' primary disease was 8 (range 7-9) before surgery and 2.5 (range 1-4) at the last postoperative follow-up (pain reduction ≥50%).

CONCLUSION

Paddle lead systems for SCS can be implanted successfully using a biportal endoscopic technique.

Is YouTube a Reliable and Quality Source on Unilateral Biportal Endoscopic Spine Surgery? A Cross-Sectional Study

OBJECTIVE

This study aimed to evaluate the quality and reliability of YouTube videos focusing on unilateral biportal endoscopic spine surgery, a novel technique for spinal decompression in degenerative spinal disease.

METHODS

This cross-sectional study, conducted in February 2023, involved an online search on YouTube using the term "unilateral biportal endoscopic spine surgery". Video popularity was assessed using the Video Power Index. Video reliability and quality were measured using the Global Quality Scale, the Journal of the American Medical Association benchmark criteria, and the modified DISCERN instrument.

RESULTS

Ninety-three videos were included for evaluation. Uploader profiles were categorized by continent, with 61.3% from Asia, 35.5% from the United States, 2.2% from Africa, and 1.1% from Australia. When comparing 3 groups as South Korea, United States, and other countries, no significant differences were observed in the technical characteristics of the videos. However, the educational quality and reliability of the videos were higher in those uploaded from South Korea (P < 0.001).When the videos were divided into 2 groups according to their educational quality, significant difference were noted in video duration, loading time, video quality, and reliability (P < 0.001).

CONCLUSIONS

The YouTube videos on unilateral biportal endoscopic spine surgery showed high quality and reliability. However, videos from South Korea were found to have higher educational quality and reliability, while other specifications were similar for all videos. Furthermore, it was determined that videos uploaded more recently and with longer duration were of higher quality.

Unilateral biportal endoscopic discectomy versus microdiscectomy for lumbar disc herniation: a systematic review and meta-analysis

PURPOSE

This study aimed to compare unilateral biportal endoscopic discectomy (UBED) with microdiscectomy (MD) for treating lumbar disk herniation (LDH).

METHODS

A comprehensive literature search was conducted in the Embase, PubMed, Cochrane Library, CNKI, and Web of Science databases from database inception to April 2023 to identify studies comparing UBED and MD for treating LDH. This study evaluated the visual analog scale (VAS) score, Oswestry disability index (ODI), Macnab scores, operation time, estimated blood loss, hospital stay, and complications, estimated blood loss, visual analog scale (VAS) score, Oswestry disability index (ODI), and Macnab scores at various pre- and post-surgery stages. The meta-analysis was performed using RevMan 5.4 software.

RESULTS

The meta-analysis included 9 distinct studies with a total of 1001 patients. The VAS scores for low back pain showed no significant differences between the groups at postoperative 1-3 months (P = 0.09) and final follow-up (P = 0.13); however, the UBED group had lower VAS scores at postoperative 1-3 days (P = 0.02). There were no significant differences in leg pain VAS scores at baseline (P = 0.05), postoperative 1-3 days (P = 0.24), postoperative 1-3 months (P = 0.78), or at the final follow-up (P = 0.43). ODI comparisons revealed no significant differences preoperatively (P = 0.83), at postoperative 1 week (P = 0.47), or postoperative 1-3 months (P = 0.13), and the UBED group demonstrated better ODI at the final follow-up (P = 0.03). The UBED group also exhibited a shorter mean operative time (P = 0.03), significantly shorter hospital stay (P < 0.00001), and less estimated blood loss (P = 0.0002). Complications and modified MacNab scores showed no significant differences between the groups (P = 0.56 and P = 0.05, respectively).

CONCLUSION

The evidence revealed no significant differences in efficacy between UBED and MD for LDH treatment. However, UBED may offer potential benefits such as shorter hospital stays, lower estimated blood loss, and comparable complication rates.

Treatment Concept and Technical Considerations of Biportal Endoscopic Spine Surgery for Lumbar Spinal Stenosis

Decompression is a major component of surgical procedures for degenerative lumbar spinal stenosis (LSS). In addition to sufficient decompression to guarantee the relief of neurological pain, compensating surgical instability after wider laminectomy and foraminotomy and instrumentation with caging and fusion with grafting are performed to secure or restore the foraminal dimension and correct coronal/sagittal imbalance for longer survival of the adjacent segment. Endoscopic spinal surgery (ESS) has been developed under the flag of successful decompression while preserving structural integrity as much as possible with the help of magnification and illumination. ESS provides a technical possibility and feasibility for solving LSS by decompression alone. Recently, many endoscopic trials have been conducted to overcome conventional surgical treatment that requires wider dissection, escape inevitable complications from surgical damage, and compensate for the fusion technique. However, biportal ESS has some technical limitations, including clinical difficulties in accessibility for more moderate to severe stenosis and challenges for complicated conditions with segmental ventral slip, isthmic defect, stenosis combined with foraminal stenosis or foraminal disk rupture, or degenerative segmental scoliosis with disk height collapsing and endplate fatigue fracture. Because decompression alone is a skill for eliminating pathologies, there is no function of preserving degenerative structure or stopping the recurrence of disk degeneration or subsidence. This review of clinical reports investigated the possibility of biportal ESS for treating degenerative lumbar disorders by sufficient decompression and adequate elimination of various pathologies and decreasing technical complications. The results of this study may help develop better innovative spinal surgical techniques in the near future.

Study on early efficacy of UBED and PEID in the treatment of L5/S1 intervertebral disc herniation

INTRODUCTION

This study aimed to compare early efficacy of UBED and PEID in the treatment of L5/S1 IDH.

MATERIAL AND METHODS

Forty-two patients who underwent surgical treatment for L5/S1 IDH were divided into two groups: UBED and PEID. Operation time, complications, VAS/ODI score were recorded. MacNab evaluation was completed one and three months postoperatively.

RESULTS

All patients were successfully operated without infection, nerve injury, or huge hematoma in the spinal canal. There were no significant differences in operation time and hospitalization days between the two groups (p > 0.05). All patients were followed up after the operation and low back/leg pain was significantly reduced. VAS for low back pain, VAS for leg pain, ODI scores in both groups one and three months after the operation were significantly lower than pre-operation (p < 0.05). There were no significant differences between one and three months after the operation in both groups (p > 0.05). There were no significant differences in VAS for low back pain, leg pain, ODI score, and overall efficacy between the two groups one and three months post-operation (p > 0.05).

CONCLUSION

UBED and PEID have very good early efficacy in treating L5/S1 IDH. Because UBED has a wider vision field and more flexible operation, it can be used as a useful complement to PEID.

A case report: Unilateral biportal endoscopic revision for adjacent segmental disease: Case presentations and literature review

RATIONALE

Biportal endoscopic revision surgery for adjacent segmental disease (ASD) after lumbar arthrodesis is seldomly reported. Herein, we present 3 cases of ASD with radiculopathy wherein satisfactory results were obtained using unilateral biportal endoscopic (UBE) decompression.

PATIENT CONCERNS

Case 1 was of a 56-year-old male who presented with a chief complaint of Intermittent claudication since 2-year. Case 2 involved a 78-year-old female who was admitted to the hospital with a chief complaint of radiating pain and weakness in the left leg for at least 1 year. Case 3 was a 67-year-old woman who visited our hospital because of radiating leg pain for 5 months. All the cases had a history of L4 to L5 lumbar interbody fusion surgery.

DIAGNOSES

Computed tomography and magnetic resonance imaging showed the spinal epidural lipomatosis at the L3 to L4 level in case 1, the up-migrated lumbar disc herniation at L3 to L4 level in case 2 and unilateral foraminal stenosis at the L5 to S1 level in case 3.

INTERVENTIONS

Under UBE guidance, the ipsilateral approach was used to treat adjacent lumbar stenosis caused by spinal epidural lipomatosis. The contralateral approach was used to remove the up-migrated herniated disc. The paraspinal approach was applied to decompress the foraminal stenosis.

OUTCOMES

Postoperative parameters were improved clinically, and nerve roots were decompressed radiologically. No complications were developed.

LESSONS

UBE revision surgery showed a favorable clinical and radiological result without complications and may be a safe and effective alternative technique for ASD.

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.

Comparison of Clinical Outcomes and Muscle Invasiveness between Unilateral Biportal Endoscopic Discectomy and Percutaneous Endoscopic Interlaminar Discectomy for Lumbar Disc Herniation at L5/S1 Level

OBJECTIVE

Both unilateral biportal endoscopic discectomy (UBED) and percutaneous endoscopic interlaminar discectomy (PEID) could achieve favorable outcomes for lumbar disc herniation (LDH). There are limited studies comparing the two different methods of endoscopic discectomy. The objective was to comprehensively compare the clinical outcome and muscle invasiveness of UBED and PEID for the treatment of LDH at L5/S1 level with at least 1-year follow-up.

METHODS

The retrospective cohort study enrolled 106 LDH patients of L5/S1 level from January 2018 to December 2020. There were 51 patients who underwent UBED (22 males and 29 females, 43.8 ± 14.2 years old) and 55 patients underwent PEID (28 males and 27 females, 42.3 ± 13.8 years old). Clinical outcomes and surgical invasiveness were compared between the two groups for at least 1 year follow-up. Clinical outcomes included visual analogue scale (VAS) scores, Oswestry Disability Index (ODI), complications, recurrence of LDH, intraoperative anesthesia time, operative time, number of intraoperative fluoroscopies, and postoperative length of stay. Surgical invasiveness was evaluated with serum CPK level and change rate of lean multifidus cross-sectional area (LMCSA). Independent-sample t test and paired sample t test were used to compare continuous data. Chi-square test and Fisher's precision probability tests were used to analyze the categorical data.

RESULTS

Both groups achieved favorable clinical outcomes at the last follow-up, including VAS and ODI (all Ps <0.05). The intraoperative anesthesia time for UBED was longer, but with no difference of operative time. As for intraoperative fluoroscopy times (2.5 vs 2.4), postoperative length of stay (2.1 vs 2.0 days), postoperative complications (5.9% vs 3.6%), there were also no significant difference. The serum CPK level and change rate of LMCSA for UBED was higher than PEID at postoperative 1st day. At the last follow-up, there was no significant difference in the change rate of LMCSA between the two groups (P = 0.096).

CONCLUSIONS

Both UBED and PEID could achieve favorable clinical outcomes for the treatment of L5/S1 LDH. Despite UBED is more invasive, the radiological manifestation of paraspinal muscle invasiveness was equal at last follow-up with at least 1 year. UBED is a safe and innovative alternative choice for treatment of LDH at L5/S1 level.

Modified Unilateral Biportal Endoscopic Lumbar Discectomy Results in Improved Clinical Outcomes

OBJECTIVE

To evaluate and describe the clinical efficacy and safety of a modified unilateral biportal endoscopic lumbar discectomy.

METHODS

From February 2019 to February 2020, patients who met the inclusion criteria were treated using a modified unilateral biportal endoscopic lumbar discectomy. During the operation, the herniated disc was removed and the ligamentum flavum was preserved. Clinical efficacy was assessed via postoperative imaging and follow-up.

RESULTS

A total of 70 patients were followed up for more than 2 years, including 51 males and 19 females, aged 49.4 ± 16.0 years. All operations were completed and no complications were noted. Postoperative lumbar magnetic resonance imaging showed that the decompression of the nerve root was sufficient and the ligamentum flavum was preserved in all patients. Postoperative lumbar CT showed that the caudal lamina and inferior articular process of the cephalad vertebral were partially removed. Lower back and leg pain were significantly relieved after surgery, and the Oswestry Disability Index was significantly improved compared to presurgery measurements (P ＜ 0.01). After 2 years of follow-up, the sensory and muscle strength of nerve roots were significantly recovered (P ＜ 0.01). According to the MacNab score of the patients, 40 cases were defined as "excellent," 26 cases were "good," 2 cases were "fair," and 2 cases were "poor."

CONCLUSIONS

Modified unilateral biportal endoscopic lumbar discectomy can completely remove a lumbar herniated disc; relieve lower back and leg pain; improve lumbar function; reduce the risk of dural tearing, cerebrospinal fluid leakage, and epidural hematoma; and reduce the epidural adhesion and arachnoiditis caused by ligamentum flavum resection.

Comparison of Unilateral Biportal Endoscopic Discectomy with Other Surgical Technics: A Systemic Review of Indications and Outcomes of Unilateral Biportal Endoscopic Discectomy from the Current Literature

OBJECTIVE

Unilateral biportal endoscopic (UBE) spine surgery for spinal diseases has been increasing in popularity because of its favorable outcomes. The goal of this systemic review is to analyze the status of outcomes and complications in lumbar disc herniation during UBE discectomy.

METHODS

A comprehensive search of the PubMed, Embase, Web of Science, and OVID databases published until June 30, 2021, was performed. The outcomes of interest were indications, operative time, blood loss, hospital stay, complications, visual analog scale score, and Oswestry Disability Index.

RESULTS

Seven studies were included in our research. UBE surgery for lumbar stenosis was excluded. A total of 230 patients with lumbar disc herniation were enrolled in the 7 selected studies. The mean operative time was 74.4 minutes, and the mean length of hospital stay was 4.5 days. Mean incidence of complications reported in the 7 articles was 6.2%. UBE showed shorter hospital stays than did microdiscectomy, no significant differences of Oswestry Disability Index or visual analog scale scores, and good recovery rate among other discectomy techniques (microdiscectomy, full endoscopic transforaminal endoscopic lumbar discectomy, and interlaminar endoscopic lumbar discectomy) at 1 month follow-up.

CONCLUSIONS

Even with the small number of studies and reports analyzed, biases were the main limitation of this analysis; overall, the clinical outcomes and complication rates associated with UBE discectomy were relatively good. It is clear that UBE discectomy is a good treatment choice for lumbar disc herniation, but to prevent unique UBE surgery complications, a clear understanding of the surgical procedures and careful efforts to overcome the learning curve are necessary.

The clinical efficacy of biportal endoscopy is comparable to that of uniportal endoscopy via the interlaminar approach for the treatment of L5/S1 lumbar disc herniation

Objective

To compare the clinical outcomes of unilateral biportal endoscopy/biportal endoscopic spinal surgery (UBE/BESS) via the posterior approach with those of interlaminar endoscopic lumbar discectomy (IELD) for the treatment of L5/S1 lumbar disc herniation.

Methods

We collected the clinical data of patients with L5/S1 lumbar disc herniation who had undergone endoscopic surgery at our center from January 2020 to July 2021, and 92 patients were included. They were divided into UBE/BESS (n = 42) and IELD (n = 50) groups. The incision length, operative time (overall operative, extracanal operative, and intracanal decompression times), intraoperative radiation exposure dose, changes in hemoglobin before and after surgery, postoperative hospital stay, visual analog scale (VAS) score for low back pain and leg, and Oswestry disability index (ODI) were statistically analyzed.

Results

One case incurred dural tear in the UBE/BESS group, and one case developed recurrence in the IELD group. Postoperatively, the VAS score and ODI index decreased significantly in both groups (P < 0.01). VAS and ODI scores (preoperative as well as 3 days, 3 months, 6 months, and 12 months after surgery), the overall operative time, and postoperative hospital stay were not significantly different between the two groups (P > 0.05). No statistical difference in intraoperative radiation exposure dose was noted between the two groups (P > 0.05). The surgical incision length was greater in the UBE/BESS group (P < 0.01), and pre- and postoperative hemoglobin changes were more pronounced in the UBE/BESS group (P < 0.01). The UBE/BESS group had a longer extracanal operative time and shorter intracanal decompression time (P < 0.01).

Conclusions

The clinical efficacy of UBE/BESS for L5/S1 lumbar disc herniation is comparable to that of IELD. Intraoperative radiation exposure doses were similar in both techniques. UBE/BESS required more time to identify tissue structures and a larger working space when operating outside the spinal canal; however, the efficiency of nucleus pulposus removal and nerve root release inside the spinal canal superseded that in IELD. Furthermore, the surgical incision in the UBE/BESS technique was longer, with greater actual blood loss during surgery, thus rendering UBE/BESS inferior to the IELD technique in terms of surgical trauma. Nonetheless, no significant difference was noted between the two techniques in the postoperative recovery time of patients.

Risk factors for hidden blood loss in unilateral biportal endoscopic lumbar spine surgery

Background

Unilateral biportal endoscopic (UBE) spine surgery is a minimally invasive procedure for treating lumbar disorders. Hidden blood loss (HBL) is easily ignored by surgeons because blood loss is less visible. However, there are limited studies on HBL in UBE spine surgery. This study aimed to evaluate HBL and its possible risk factors in patients undergoing UBE spine surgery.

Methods

Patients with lumbar disc herniation or lumbar spinal stenosis who underwent unilateral biportal endoscopic surgery between December 2020 and February 2022 at our hospital were retrospectively analyzed. Patient demographics, blood loss-related parameters, and surgical and radiological information were also collected. Pearson or Spearman correlation analysis was conducted to determine the association between clinical characteristics and HBL. Multivariate linear regression analysis was used to determine the independent risk factors for HBL.

Results

Fifty-two patients (17 males and 35 females) were retrospectively enrolled in this study. The mean total blood loss (TBL) volume was 434 ± 212 ml, and the mean HBL volume was 361 ± 217 ml, accounting for 77.9% of the TBL in patients who underwent UBE surgery. Multivariate linear regression analysis revealed that HBL was positively associated with operation time (P = 0.040) and paraspinal muscle thickness at the target level (P = 0.033).

Conclusions

The amount of HBL in patients undergoing UBE surgery should not be neglected. Operation time and paraspinal muscle thickness at the target level may be independent risk factors for HBL.

Global and Current Research Trends of Unilateral Biportal Endoscopy/Biportal Endoscopic Spinal Surgery in the Treatment of Lumbar Degenerative Diseases: A Bibliometric and Visualization Study

The study aimed to make a bibliometric analysis of the current research situation in unilateral biportal endoscopy/biportal endoscopic spinal surgery (UBE/BESS). Research data sets were acquired from the Web of Science database. The study chosed “biportal endoscopic spinal surgery” OR “two portal endoscopic spinal surgery” OR “percutaneous biportal endoscopic decompression” OR “unilateral biportal endoscopy” OR “irrigation endoscopic discectomy” as the search terms. The literature search was limited to articles published before March 5, 2021. We only included original articles and reviews. VOS viewer and Citespace software were used to analyze the data and generate visualization knowledge maps. Annual trend of publications, distribution, H‐index status, co‐authorship status, and research hotspots were analyzed. A total of 74 publications met the requirement. The sum number of citations was 31,204, in which 19,336 were no self‐citations. The average citation of all the papers was 21.84 times. The H‐index of all the publications was 85. South Korea's total number of articles was far higher than that of other countries and regions (61, 82.4%), followed by United Arab Emirates, Egypt, and Peoples Republic of China (three, ranking second, accounting for 12.2% of the total). For the most productive authors, Choi ranked first with 21 articles, Kim ranked second with 16 articles, and Heo ranked third with 12 articles. The journal with the greatest number of publications was World Neurosurgery, with a total of 18 (39.1%) papers. Clinics in Orthopedic Surgery ranked second with six (13.0%) papers. In third place, there were fix articles published by Asian Spine Journal and Neurospine, accounting for 21.8% of the total articles. These top three journals accounted for 73.9% of all the papers. Spondylolisthesis and endoscopic decompression were the research hotspots in recent years. The number of publications has showed an upward trend with a stable rise in recent years. South Korea is the country with the highest productivity, not only in quality, but also in quantity. Barun Hosp and Leon Wiltse Mem Hosphave published most articles. Choi is the most productive author. World Neurosurgery is the most productive journal. Spondylolisthesis and endoscopic decompression are the research hotspots in recent years. Indeed, this study provides new insight into the growth and development of UBE/BESS.

Efficacy and safety of unilateral biportal endoscopy compared with microscopic decompression in the treatment of lumbar spinal stenosis: A protocol for systematic review and meta-analysis

OBJECTIVE

Systematic evaluation of the efficacy and safety of unilateral biportal endoscopic decompression in the treatment of lumbar spinal stenosis.

METHODS

We conducted a systematic literature search and compared the randomized controlled trials (RCTs) and retrospective studies of unilateral biportal endoscopy (UBE) and microscopic decompression (MD) in the treatment of lumbar spinal stenosis from several databases.

RESULTS

Seven studies were included. The results of meta-analysis showed that the operation time of UBE was shorter than that of MD. [SMD = -0.443, 95% CI (-0.717, -0.169), P  = .002]. Compared with MD, the patients' back pain was slighter on the 1st day, 1-2 months and 6 months after UBE. During the long-term follow-up, there was no significant difference in back pain between MD and UBE [SMD = -0.519, 95% CI (-0.934, -0.104), P  = .014]. There was no significant difference in lower limb visual analogue score (VAS) score between UBE decompression and MD [SMD = -0.105, 95% CI (-0.356, 0.146), P  = .412]. The results of meta-analysis showed that the C-reactive protein (CRP) level of UBE was lower than that of MD [weighted mean difference = -1.437, 95% CI (-2.347, -0.527), P  = .002]. There was no significant difference in other clinical effects between the 2 groups.

CONCLUSION

The operation time of UBE was shorter than that of MD, and it was superior to micro decompression in early back VAS score, lower limb VAS score and early postoperative CRP level. There was no statistical difference between UBE and MD in other outcomes.

Efficacy and Complications of Unilateral Biportal Endoscopic Spinal Surgery for Lumbar Spinal Stenosis: A Meta-Analysis and Systematic Review

OBJECTIVE

As an emerging minimally invasive endoscopic technique, unilateral biportal endoscopic spinal surgery (UBESS) has the advantages of flexibility, a wide and clear field of view, and less soft tissue damage. However, the clinical evidence is insufficient and controversy exists regarding UBESS for the treatment of lumbar spinal stenosis (LSS). In the present meta-analysis, we investigated the clinical efficacy and complications of UBESS for the treatment of LSS.

METHODS

The PubMed, Embase, Web of Science, and Cochrane Library databases were searched through to June 1, 2021 to identify all reported studies on UBESS for LSS. Only English-language studies with original reported data from ≥30 cases were considered for inclusion. The patient demographics, operative time, hospital stay, complications, visual analog scale (VAS) score, Oswestry disability index, and Macnab criteria were extracted. Quality assessment was performed using the Cochrane collaboration tool for randomized controlled trials and the Newcastle-Ottawa scale for retrospective studies. A meta-analysis was performed using a random or fixed effect model according to the heterogeneity.

RESULTS

Thirteen studies with 586 patients and 607 operation levels were included. The mean single-level operative time, hospital stay, and follow-up duration were 61.10 minutes, 2.32 days, and 14.7 months, respectively. At the final follow-up visit, the mean VAS score for leg pain had decreased from 7.23 preoperatively to 1.83 postoperatively, the mean VAS score for back pain had decreased from 6.30 to 1.95, and the mean Oswestry disability index had significantly improved from 56.99 to 17.83. The average satisfied outcome (excellent or good using the Macnab criteria) was 86%. The overall complication rate was 5%, and the most common complication was a dural tear, with an incidence of 2%, followed by epidural hematoma with an incidence of 1%. The remaining complications were nerve root injury, inadequate decompression, and postoperative headache.

CONCLUSIONS

From the available clinical results and experience from reported studies, UBESS for LSS is a feasible and effective approach and a worthwhile choice for clinicians. However, the complications associated with the procedure should also be seriously considered.

Dural Injury in Unilateral Biportal Endoscopic Spinal Surgery

STUDY DESIGN

Retrospective study.

OBJECTIVES

Unilateral biportal endoscopic surgery (UBES) is a popular surgical method used to treat degenerative spinal diseases because of its merits, such as reduced tissue damage and outstanding visual capacity. However, dural injury is the most common complication of UBES with an incidence rate of 1.9% to 5.8%. The purpose of this study was to analyze the pattern of dural injury during UBES and to report the clinical course.

METHODS

We retrospectively reviewed the medical and radiographic records of surgically treated patients who underwent UBES at a single institute between January 2018 and December 2019.

RESULTS

Fifty-three patients, representing 67 segments, underwent UBES. Seven dural injuries occurred, and the incidence rate was 13.2%. Among 16 far lateral approaches, 2 dural injuries of the exiting roots occurred and were treated with fibrin sealant reinforcement. Among 51 median approaches, dural injury occurred at the thecal sac (n = 3) and traversing root (n = 2). A dural injury of the shoulder of the traversing root was treated with a fibrin sealant; however, a defect in the thecal sac required a revision for reconstruction. The other 2 thecal sac injuries were directly repaired via microscopic surgery.

CONCLUSIONS

Dural injury during UBES can occur because of the various anatomical features of the meningo-vertebral ligaments. Direct repair of the central dural defect should be considered under microscopic vision. A linear tear in the lateral dura or root can be controlled with a simple patchy reinforcement under endoscopic vision.

Clinical Outcomes of Biportal Endoscopic Interlaminar Decompression with Oblique Lumbar Interbody Fusion (OLIF): Comparative Analysis with TLIF

Oblique lumbar interbody fusion (OLIF) improves the spinal canal, with favorable clinical outcomes. However, it may not be useful for treating concurrent, severe central canal stenosis (SCCS). Therefore, we added biportal endoscopic spinal surgery (BESS) after OLIF, evaluated the combined procedure for one-segment fusion with clinical outcomes, and compared it to open conventional TLIF. Patients were divided into two groups: Group A underwent BESS with OLIF, and Group B were treated via TLIF. The length of hospital stay (LOS), follow-up period, operative time, estimated blood loss (EBL), fusion segment, complications, and clinical outcomes were evaluated. Clinical outcomes were measured using Visual Analog Scale (VAS) scores, Oswestry Disability Index (ODI) scores, and the modified Macnab criteria. All the clinical parameters improved significantly after the operation in Group A. The only significant between-group difference was that the EBL was significantly lower in Group A. At the final follow-up, no clinical parameter differed significantly between the groups. No complications developed in either group. We suggest that our combination technique is a useful, alternative, minimally invasive procedure for the treatment of one-segment lumbar SCCS associated with foraminal stenosis or segmental instability.

Percutaneous Endoscopic Lumbar Discectomy for Lumbar Disc Herniation Using an Endoscopic Staining: A Technical Note

Symptomatic lumbar disc herniation (LDH) is widely treated using percutaneous endoscopic lumbar discectomy (PELD). In the present PELD surgery, performing decompression under endoscope still takes a long time to explore the rupture site of annulus fibrosus, resulting in prolonged operation time and over-invasion of the undegenerated annulus fibrosus. A wide range of intraoperative exploration also induces an iatrogenic injury of the normal annulus fibrosus, even aggravating intervertebral disc degeneration, which may lead to early postoperative recurrence in severe case. Hence, it is important to seek a precise decompression in PELD surgery. Under this kind of realization, more spinal surgeons possibly choose a disc staining before performing decompression. However, the classical disc staining technique still has its shortcomings. First of all, an appropriate dose of staining cannot be accurately mastered, even induces unqualified staining effect. Second, the duration of surgery and the times of fluoroscopy will be increased. Finally, what surgeons see under the endoscope is the staining result but not the staining process. Hence, this is accomplished more effectively by designing procedures that perform fully visible disc staining under spinal endoscope. There is no specific research to discuss the technique note of endoscopic staining in PELD surgery. We have come up with a new original technology of endoscopic staining with methylene blue injection in PELD for treatment of LDH.

Clinical outcome of biportal endoscopic revisional lumbar discectomy for recurrent lumbar disc herniation

BACKGROUND

Although literature provides evidence regarding the superiority of surgery over conservative treatment in patients with lumbar disc herniation, recurrent lumbar disc herniation (RLDH) was the indication for reoperation in 62% of the cases. The major problem with revisional lumbar discectomy (RLD) is that the epidural scar tissue is not clearly isolated from the boundaries of the dura matter and nerve roots; therefore, unintended durotomy and nerve root injury may occur. The biportal endoscopic (BE) technique is a newly emerging minimally invasive spine surgical modality. However, clinical evidence regarding BE-RLD remains limited. We aimed to compare the clinical outcomes after performing open microscopic (OM)-RLD and BE-RLD to evaluate the feasibility of BE-RLD.

METHODS

This retrospective study included 36 patients who were diagnosed with RLDH and underwent OM-RLD and BE-RLD. RLDH is defined as the presence of herniated disc material at the level previously operated upon in patients who have experienced a pain-free phase for more than 6 months. BE-RLD was performed as follows: two independent surgical ports were made inside the medial pedicular line of the target segment and on the intact upper and lower laminas. Peeling off the soft tissue from the vertebral lamina helps to easily identify the traversing nerve root and the recurrent disc material without dealing with the fibrotic scar tissue. Clinical outcomes were obtained using a visual analog scale (VAS) and the modified Macnab criteria before and at 2 days, 2 and 6 weeks, and 3, 6, and 12 months after surgery.

RESULTS

The data of 20 and 16 patients who underwent OM-RLD and BE-RLD, respectively, were evaluated. The demographic and perioperative data were comparable between the groups. During the year following the surgery, in the BE-RLD group, the VAS scores at each point were significantly improved over the baseline and remained improved up to 2 weeks after surgery (p < 0.05); however, no statistical difference between the two groups was observed after 6 weeks of surgery (p > 0.05). According to the modified Macnab criteria on the follow-up, the excellent or good satisfaction rates reported at 2 weeks, 6 weeks, 6 months, and 12 months after surgery were 81.25%, 81.25%, 75%, and 81.25%, respectively, in the BE-RLD group, and 50%, 75%, 75%, and 80%, respectively, in the OM-RLD group.

CONCLUSION

BE-RLD yielded similar outcomes to OM-RLD, including pain improvement, functional improvement, and patient satisfaction, at 1 year after surgery. However, faster pain relief, earlier functional recovery, and better patient satisfaction were observed when applying BE-LRD.

TRIAL REGISTRATION

Retrospectively registered.

Safety Evaluation of Biportal Endoscopic Lumbar Discectomy: Assessment of Cervical Epidural Pressure During Surgery

STUDY DESIGN

A prospective study.

OBJECTIVE

To evaluate the change in cervical epidural pressure (CEP) during biportal endoscopic lumbar discectomy (BELD).

SUMMARY OF BACKGROUND DATA

In percutaneous uniportal endoscopic lumbar discectomy, irrigation fluid (IF) introduced into the spinal canal during surgery can compress the thecal sac, and act as a potential risk for neurological complications by disturbing cerebrospinal fluid (CSF) circulation and increasing intracranial pressure.

METHODS

Thirty consecutive patients, who underwent BELD, which was performed under automated pump system, an infusion pressure of 30 mmHg were enrolled. The change in CEP on C7-T1 level was measured. CEP was measured in each of the five phases of the procedure (1st phase-making surgical portals; 2nd phase-creating a workspace; 3rd phase-performing neural decompression and discectomy; 4th phase-factitious increase of pressure by clogging the outflow; 5th phase-dismission from fluid irrigation system). Neurological complications and independent risk factors were evaluated.

RESULTS

In the final 27 patients, changes in CEP during surgery were similar. The baseline CEP was 14.8 ± 2.8 mmHg, and the mean CEP in the 3rd phase 18.8 ± 5.1 mmHg was not significantly higher. In the 4th phase, however, the CEPs rose with linear correlation as the pressure increased. In the 5th phase, the elevated CEP returned to baseline in 2.5 ± 5.6 minutes. No patient had neurological complications. No statistically significant risk factors were observed.

CONCLUSION

In BELD, which is performed to allow continuous lavage with infusion pressure set to 30 mmHg, CEP does not increase beyond the physiological range. Therefore, BELD may be considered as a potentially safe technique.

LEVEL OF EVIDENCE

4.

Biportal endoscopic discectomy for high-grade migrated lumbar disc herniation

OBJECTIVE

Although endoscopic procedures for lumbar disc herniation have improved greatly and offer many advantages, the indications are limited mostly to nonmigrated or low-grade migrated disc herniation. Endoscopic application in migrated disc herniation cases is still challenging and technically demanding. The goal in this study was to determine the feasibility of biportal endoscopic discectomy for removal of high-grade migrated disc herniation.

METHODS

A retrospective review was performed in 262 patients who had undergone biportal endoscopic discectomy after the diagnosis of lumbar herniated disc. According to preoperative MRI findings, disc herniation was classified into 5 zones based on the direction and distance from the disc space. Patients were divided into 2 groups-a high-grade migration group and a low-grade migration group. Clinical outcomes were evaluated using the Oswestry Disability Index (ODI), visual analog scale (VAS), and modified Macnab criteria, and those outcomes and operation time were compared between the 2 groups.

RESULTS

There were 10 patients with "high-grade up," 8 with "low-grade up," 98 with disc-level, 102 with "low-grade down," and 44 with "high-grade down" herniation, thereby yielding 54 patients in the high-grade group and 208 in the low-grade group. Demographic data for the 2 groups showed no significant difference. There was no significant difference between the 2 groups in ODI, VAS, and modified Macnab criteria. Operation time between the 2 groups was not significantly different (60.74 vs 65.63 minutes, p > 0.05).

CONCLUSIONS

Biportal endoscopic discectomy can be effective for high-grade migrated lumbar disc herniation with no prolonged operation time and satisfactory clinical outcomes.

Risk Factors and Options of Management for an Incidental Dural Tear in Biportal Endoscopic Spine Surgery

Study Design

Here we perform a retrospective analysis regarding an incidental dural tear (IDT) during biportal endoscopic spinal surgery (BESS).

Purpose

This study investigates the causes of IDT specifically related to technical procedures of BESS with the aim of lowering its risk during training.

Overview of Literature

The incidence of dural tear is reported 0.5%–18% in open spinal surgery and 1.7%–4.3% during endoscopic spinal surgery. Because conversion to open surgery for direct repair could become necessary during endoscopic spinal surgery, prevention of this complication is essential.

Methods

We have retrospectively studied IDTs by four surgeons during 1 or 2 years after starting BESS for lumbar degenerative diseases and analyzed the locations, sizes, and specific endoscopic conditions specific to each.

Results

Twenty-five cases (1.6%) of IDTs among 1,551 cases of BESS occurred; 13 cases (52%) of these were within the first 6 months. The locations were dorsal midline in 12 cases, ipsilateral side in 11 cases, and contralateral side in two cases. The tear sizes were <10 mm in 20 cases and ≥10 mm in five cases. IDT commonly occurred due to injury of central dural folding during flavectomy under turbid surgical fields due to small bleeds under water. Twenty cases with IDTs of <10 mm were treated well with the patch technique. Among five cases of ≥10 mm, three underwent open repair within a few days, and two of these which failed to conservative management required a delayed revision operation due to pseudomeningocele. No cases progressed to surgical site infection or infectious spondylitis.

Conclusions

IDTs of <10 mm can be successfully treated with the patch technique. To prevent IDT during the early learning period, maintaining clear visibility by securing fluent saline outflow and meticulous hemostasis of small bleeding from exposed cancellous bone and epidural vessels is essential with caution not to injure the central dural folding during midline flavectomy.

Residual leg numbness after endoscopic discectomy treatment of lumbar disc herniation

Background

Transforaminal endoscopic discectomy was popular in the treatment of lumbar disc herniation. Previous study focuses on the leg pain of disc herniation, and little study concern the residual leg numbness after surgery. The purposes of this study were to evaluate the clinical outcomes of transforaminal endoscopic discectomy in the treatment of lumbar disc herniation with leg pain and numbness.

Methods

Patients with one level lumbar disc herniation who had transforaminal endoscopic lumbar discectomy from June 2016 to July 2019 were categorized into two groups according to the leg numbness. 293 patients initially fulfilled the study criteria, and 27 patients were lost to follow-up. Of the remaining 266 patients available for analysis, 81 cases with leg numbness and pain (A group), and 185 cases with leg pain (B). Endoscopic transforaminal lumbar discectomy was performed, and the clinical outcomes of blood loss, operation times, hospital stay days, pain (Visual Analog Scale, VAS-pain), numbness (VAS-numbness), functional disability (Oswestry Disability Index, ODI), and the disk height and intervertebral foramen height were recorded.

Results

All patients with pain and numbness pre-operation in group A, complain of leg numbness during or just after walking or standing not diminished after surgery in group A, and no one complain numbness after surgery in group B. The pain index and ODI score were better than preoperational in all patients (P < 0.01), and no significant difference between two groups (P > 0.05). The postoperative disk and foramen height were no significant difference compare to preoperative in all patients (P > 0.05), and no significant difference between two groups (P > 0.05). The leg numbness symptoms last longer in central disc herniation patients (10.4 ± 2.2 months) than in paracentral (6.3 ± 2.1 months) and foraminal disc herniation patients (5.6 ± 2.3 months) after surgery (P < 0.01).

Conclusions

Based on the results of this study, transforaminal endoscopic lumbar discectomy was effective and safe procedures in the treatment of disc herniation with leg pain and numbness. The leg numbness symptoms last longer in central disc herniation patients than in paracentral and foraminal disc herniation patients after surgery.

Spinal epidural abscess successfully treated with biportal endoscopic spinal surgery

Surgical decompression and antibiotic therapy are the treatments of choice for patients with spinal epidural abscess (SEA). Surgical treatment included decompression, evacuation of abscess, and debridement. Recently, minimal invasive surgery has been introduced more widely, and biportal endoscopic spinal surgery have shown satisfactory clinical outcomes compared with traditional open surgery. The purpose of this study was to evaluate the efficacy of biportal endoscopic spinal surgery for the treatment of SEA .From January 2016 to June 2017, 13 patients who underwent biportal endoscopic spinal surgery under the diagnosis of SEA were retrospectively enrolled in this study. The surgical indications of the enrolled patients included SEA with or without early stage spondylodiscitis who had neurological symptoms. Periopertaive data and clinical outcomes were assessed by regular serologic testing, imaging studies, physical examination, visual analog scale, Oswestry Disability Index and modified Macnab criteria.Offending pathogens were identified in seven (54%) of 13 biopsy specimens. Appropriate intravenous antibiotics for the identified pathogens isolated from infected tissue biopsy cultures were administrated to patients for at least 30 days. All patients reported satisfactory relief of pain and neurological symptoms after surgery. No surgery-related complications and recurrences were found after 2 years follow up.Biportal endoscopic spinal surgery may be an effective alternative to traditional open surgical decompression for the treatment of SEA.

Current techniques of endoscopic decompression in spine surgery

Endoscopic spine surgery has become a practical, minimally invasive technique for decompression in patients with spinal disc herniation or stenosis. This review aimed to summarize the current techniques of endoscopic decompression technique in spine surgery and to discuss the benefits, limitations, and future perspectives of this minimally invasive technique. Endoscopic spine decompression surgery can be categorized according to the endoscopic property: percutaneous endoscopic (full-endoscopic), microendoscopic, and biportal endoscopic. It can also be classified based on the approach: transforaminal, interlaminar, anterior, posterior, and caudal approaches. Theoretically, each technique can be applied in the lumbar, cervical, and thoracic spine. The various endoscopic spine surgery techniques should be appropriately conducted according to the disease entities, level, and zone of pathologies. Although the current level of evidence is relatively low and the relevance of the technique is controversial, recent clinical results and the critical concept are promising. Development in optics, instruments, and approach will improve its safety and reduce technical complexity. In the meantime, high-quality clinical studies, including randomized trials and meta-analyses, are due for publication. Eventually, endoscopic spine surgery is expected to become the golden standard for spinal surgery.

Is biportal technique/endoscopic spinal surgery satisfactory for lumbar spinal stenosis patients?: A prospective randomized comparative study

BACKGROUND

Lumbar decompressive surgery is a standard surgical technique for lumbar spinal stenosis. Many new surgical techniques have been introduced, ranging from open surgery to minimally invasive procedures. Minimally invasive surgical techniques are preferred because patients experience less postoperative pain and shorter hospital stays. However, the success rate of minimally invasive techniques have been controversial. The object of this study was to assess the feasibility of spinal decompression using biportal technique/endoscopic surgery compared with microscopic surgery.

METHODS

Seventy lumbar spinal stenosis patients undergoing laminectomy were included in this study. A number table was used to randomize the patients into two groups: a biportal technique/endoscopic surgery group (BG-36) and a microscopic surgery group (OG-34). One surgeon performed either biportal technique/endoscopic decompression or microscopic decompression using a tubular retractor, depending on the group to which the patient was randomized. Perioperative data and clinical outcomes at postoperative 6 months were collected and analyzed.

RESULTS

The demographic data and level of surgery were comparable between the two groups. A shorter operation time (36 ± 11 vs 54 ± 9 min), less hemovac drain output (25.5 ± 15.8 vs 53.2 ± 32.1 ml), less opioid usage (2.3 ± 0.6 vs 6.5 ± 2.5 T) and shorter hospital stay (1.2 ± 0.3 vs 3.5 ± 0.8 days) were shown in BG. The BG experienced no significant differences in clinical outcomes compared with OG. Favorable clinical outcomes were shown at 6 months after surgery in both groups.

CONCLUSION

Lumbar decompressive surgery using biportal technique/endoscopy showed favorable clinical outcomes, less pain and a shorter hospital stay compared to microscopic surgery in patients with lumbar spinal stenosis.

A Novel Biportal Full Endoscopy Technique for Lumbar Lateral Recess Stenosis: Technical Report

Full endoscopy spine surgery is one of the minimally invasive procedures for lumbar spine disease and is especially popular in East Asia. As for the interlaminar approach, lumbar recess stenosis can be manipulated through a uniportal bigger diameter working channel spinal endoscope or a smaller one, or a biportal arthroscope. Each kind of procedure has its advantages and shortcomings. Here, a novel experience in biportal interlaminar approach for lumbar recess stenosis is presented. A smaller uniportal spinal endoscope is adopted for biportal procedures rather than the arthroscope. Briefly, 2 spinal endoscope working tubes are placed onto the interlaminar window of the target segment. Both of the 2 working tubes can serve as either a viewing or working channel, which means that more flexible visual fields and instrument manipulation can be used during the procedures. Bigger surgical instruments can be used directly through one working tube, and the visual field can be provided by the spinal endoscope in the other working tube. Smaller surgical instruments can be used at the same time through the working channel of the endoscope. The 2 working tubes can change their roles according to the surgeon's needs. This paper will describe the surgical technique and perioperative management.

Efficacy of Biportal Endoscopic Spine Surgery for Lumbar Spinal Stenosis

Background

Biportal endoscopic spine surgery (BESS) is a recent addition to minimally invasive spine surgery treatments. It boasts excellent magnification and fine discrimination of neural structures. Selective decompression with preservation of facet joints for structural stability is also feasible owing to access to the spinal canal and foramen deeper inside. This study has a purpose to investigate clinical benefits of BESS for spinal stenosis in comparison to the other common surgical treatments such as microscopic decompression-only (DO) and fusion and instrumentation (FI).

Methods

From December 2013 to March 2015, 30 cases of DO, 48 cases of FI, and 66 consecutive cases of BESS for lumbar spinal stenosis (LSS) were enrolled to evaluate the relative clinical efficacy of BESS. Visual analog scale (VAS) for back pain and leg pain, postoperative hemoglobin, C-reactive protein (CRP) changes, transfusion, and postoperative complications were examined.

Results

All the patients were followed up until 6 months, and 98 patients (86.7%) for 2 years. At the 6-month follow-up, VAS for back pain improved from 6.8 to 2.8, 6.8 to 3.2, and 6.8 to 2.8 (p = 0.078) for BESS, DO, and FI, respectively; VAS for leg pain improved from 6.3 to 2.2, 7.0 to 2.5, and 7.2 to 2.5 (p = 0.291), respectively. Two cases in the BESS group underwent additional foraminal decompression, but no fusion surgery was performed. Postoperative hemoglobin changes for BESS, DO, and FI were -2.5, -2.4, and -1.3 mL, respectively. The BESS group had no transfusion cases, whereas 10 cases (33.3%) in DO and 41 cases (85.4%) in FI had transfusion (p = 0.000). CRP changes for BESS, DO, and FI were 0.32, 6.53, and 6.00, respectively, at day 2 postoperatively (p = 0.000); the complication rate for each group was 8.6% (two dural tears and one root injury), 6.7% (two dural tears), and 8.3% (two dural tears and two wound infections), respectively.

Conclusions

BESS for LSS showed clinical results not inferior to those of the other open surgery methods in the short-term. Stable hemodynamic changes with no need for blood transfusion and minimal changes in CRP were thought to cause less injury to the back muscles with minimal bleeding. Foraminal stenosis decompression should be simultaneously conducted with central decompression to avoid an additional surgery.

Surgical Treatment of Extra-Foraminal Gas Containing Pseudocyst Compressing L5 Nerve Root by Using Unilateral Biportal Endosopy: A Case Report

BACKGOUND

Most gaseous lumbar pseudocysts have been previously reported to be located in the spinal canal and successfully treated by several therapeutic methods. By comparison, a gas containing pseudocyst in lumbar extra-foraminal area is very rare. Here, the authors report a case of symptomatic gas containing cyst located in lumbar foramen. It was successfully treated with unilateral biportal endoscopic (UBE) surgery.

CASE DESCRIPTION

a 75-year-old man presented with severe left leg pain and tingling sensation refractory to conservative treatment that aggravated with weight bearing and position change. Computed tomography and magnetic resonance imaging showed a gas containing cyst compressing the left L5 nerve root ganglion in the foramina area at L5-S1 level. Gaseous extra-foraminal pseudocyst was successfully removed by UBE surgery via para-spinal approach. Vivid and clear endoscopic operative imaging of pseudocyst in detail was obtained during operation. The patient's symptom was significantly improved after the operation.

CONCLUSIONS

Gas containing pseudocyst in lumbar foraminal area is not common. Combined use of pre-operative MRI and CT can help diagnose gaseous pseudocyst and differentiate other pathologies. UBE technique which provides good operative visualization and delicate operative manipulation is a less invasive therapeutic method to treat foraminal gas containing pseudocyst.

Unilateral Biportal Endoscopic Spinal Surgery Using a 30° Arthroscope for L5-S1 Foraminal Decompression

Foraminal decompression using a minimally invasive technique to preserve facet joint stability and function without fusion reportedly improves the radicular symptoms in approximately 80% of patients and is considered one of the good surgical treatment choices for lumbar foraminal or extraforaminal stenosis. However, proper decompression was not possible because of the inability to access the foramen at the L5–S1 level due to prominence of the iliac crest. To overcome this challenge, endoscopy-based minimally invasive spine surgery has recently gained attention. Here, we report the technical skills required in unilateral extraforaminal biportal endoscopic spinal surgery using a 30° arthroscope to enable foraminal decompression at the L5–S1 level. Two 0.8-cm portals were created 2 cm lateral from the lateral border of the pedicles at the L5–S1 level. After sufficient working space was made, half of the superior articular process (SAP) in the hypertrophied facet joint was removed using a high-speed burr and a 5-mm wide osteotome, whereas the remaining inside part of the SAP was removed using a Kerrison punch and pituitary punch. The foraminal ligamentum flavum should be removed to inspect the conditions of the L5 exiting root and disc. Removing of the extruded disc could decompress the L5 root. The extraforaminal approach using a 30° arthroscope is considered a minimally invasive alternative technique for decompressing foraminal stenosis at the L5–S1 level that preserves facet stability and provides symptomatic relief.

Clinical and Radiological Outcomes of Foraminal Decompression Using Unilateral Biportal Endoscopic Spine Surgery for Lumbar Foraminal Stenosis

Background

Since open Wiltse approach allows limited visualization for foraminal stenosis leading to an incomplete decompression, we report the short-term clinical and radiological results of unilateral biportal endoscopic foraminal decompression using 0° or 30° endoscopy with better visualization.

Methods

We examined 31 patients that underwent surgery for neurological symptoms due to lumbar foraminal stenosis which was refractory to 6 weeks of conservative treatment. All 31 patients underwent unilateral biportal endoscopic far-lateral decompression (UBEFLD). One portal was used for viewing purpose, and the other was for surgical instruments. Unilateral foraminotomy was performed under guidance of 0° or 30° endoscopy. Clinical outcomes were analyzed using the modified Macnab criteria, Oswestry disability index, and visual analogue scale. Plain radiographs obtained preoperatively and 1 year postoperatively were compared to analyze the intervertebral angle (IVA), dynamic IVA, percentage of slip, dynamic percentage of slip (gap between the percentage of slip on flexion and extension views), slip angle, disc height index (DHI), and foraminal height index (FHI).

Results

The IVA significantly increased from 6.24° ± 4.27° to 6.96° ± 3.58° at 1 year postoperatively (p = 0.306). The dynamic IVA slightly decreased from 6.27° ± 3.12° to 6.04° ± 2.41°, but the difference was not statistically significant (p = 0.375). The percentage of slip was 3.41% ± 5.24% preoperatively and 6.01% ± 1.43% at 1-year follow-up (p = 0.227), showing no significant difference. The preoperative dynamic percentage of slip was 2.90% ± 3.37%; at 1 year postoperatively, it was 3.13% ± 4.11% (p = 0.720), showing no significant difference. The DHI changed from 34.78% ± 9.54% preoperatively to 35.05% ± 8.83% postoperatively, which was not statistically significant (p = 0.837). In addition, the FHI slightly decreased from 55.15% ± 9.45% preoperatively to 54.56% ± 9.86% postoperatively, but the results were not statistically significant (p = 0.705).

Conclusions

UBEFLD using endoscopy showed a satisfactory clinical outcome after 1-year follow-up and did not induce postoperative segmental spinal instability. It could be a feasible alternative to conventional open decompression or fusion surgery for lumbar foraminal stenosis.