This study was performed to describe the extraforaminal approach of biportal endoscopic spinal surgery (BESS) as a new endoscopic technique for transforaminal decompression and discectomy and to demonstrate the clinical outcomes of this new procedure for the first time. Twenty-one patients (27 segments) who underwent the extraforaminal approach of BESS between March 2015 and April 2016 were enrolled according to the inclusion and exclusion criteria. The operative time (minutes/level) and complications after the procedure were recorded. The visual analog scale (VAS) score was checked to assess the degree of radicular leg pain preoperatively and at the time of the last follow-up. The modified Macnab criteria were used to examine the clinical outcomes at the time of the last follow-up. The mean duration of the follow-up period was 14.8 months (minimum duration 12 months). The mean operative time was 96.7 minutes for one level. The mean VAS score for radicular leg pain dropped from a preoperative score of 7.5 ± 0.9 to a final follow-up score of 2.5 ± 1.2 (p < 0.001). The final outcome according to the modified Macnab criteria was excellent in 5 patients (23.8%), good in 12 (57.2%), fair in 4 (19.0%), and poor in 0. Therefore, excellent or good results (a satisfied outcome) were obtained in 80.9% of the patients. Complications were limited to one dural tear (4.8%). The authors found that the extraforaminal approach of BESS was a feasible and advantageous endoscopic technique for the treatment of foraminal lesions, including stenosis and disc herniation. They suggest that this technique represents a useful, alternative, minimally invasive method that can be used to treat lumbar foraminal stenosis and disc herniation.

Biportal endoscopic spinal surgery (BESS) with interbody fusion is a relatively novel minimally invasive technique that was developed to reduce soft tissue trauma and intraoperative blood loss and shorten recovery time while achieving comparable clinical outcomes for lumbar degenerative diseases. Despite the growing interest in BESS, a comprehensive analysis of its effectiveness, complication rates, and long-term outcomes remains lacking. This systematic review evaluated the clinical outcomes, surgical efficacy, and complication rates of BESS with interbody fusion for lumbar degenerative diseases. Recent literature on endoscopic lumbar interbody fusion was included to expand the scope and gain new perspectives, thereby, providing a comparative analysis that highlighted the advantages, limitations, and emerging trends in minimally invasive spine surgery. This review synthesized current evidence to guide future research and clinical applications. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and using a combination of MeSH (Medical Subject Headings) terms and relevant keywords, PubMed/Medline and Scopus databases were systematically searched for studies published between January 2000 and September 2024. The studies were assessed using the ROBINS-I (Risk of Bias in Nonrandomized Studies of Interventions) tool to determine the risk of bias. From the 12 studies that provided clinical evidence, the data extracted were patient demographics; operative time; blood loss; clinical outcomes, such as Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) scores and fusion rates; and complications. The mean operative time ranged from 98 to 206 minutes, with fusion rates between 70% and 95%. Most studies reported significant improvements in VAS scores for back and leg pain and ODI scores. Complications, including dural tears (2.9%–6.4%) and hematomas (1.4%–4.3%), were infrequent but notable. BESS with interbody fusion demonstrated excellent clinical outcomes, high fusion rates, and few complications. Although these results are promising, more randomized controlled trials and long-term studies are required to confirm the broader applicability, particularly in more complex or multilevel spinal pathologies.

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.

Objective: This study aimed to evaluate the clinical and radiological outcomes of unilateral laminotomy for bilateral decompression (ULBD) using biportal endoscopic spinal surgery (BESS) in patients with central canal stenosis, with and without low-grade degenerative lumbar spondylolisthesis (DLS).Methods: A retrospective observational study was conducted on 170 patients who underwent BESS-ULBD between 2015 and 2018, with at least 2 years of follow-up. Patients were categorized into 2 groups: group A (68 patients) with central stenosis and low-grade DLS and group B (102 patients) with central stenosis alone. Clinical outcomes were assessed using the visual analogue scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and Modified MacNab criteria. Radiological assessments included sagittal translation measurements on dynamic flexion-extension radiographs.Results: Both groups significantly improved clinical outcomes at the final follow-up (p<0.05). Group A’s mean VAS scores improved from 3.8±2.4 to 1.9±2.0 for back pain and from 6.4±1.8 to 2.3±2.0 for leg pain. In group B, back pain improved from 3.9±2.5 to 1.7±1.9, and leg pain from 6.6±2.0 to 2.2±2.2. ODI scores also improved significantly in both groups. Radiological evaluation showed no significant changes in sagittal translation postoperatively, indicating preserved spinal stability. Both groups had comparable clinical outcomes, with no major complications reported.Conclusion: BESS-ULBD is a safe and effective minimally invasive option for managing central canal stenosis, with or without low-grade DLS. This technique provides substantial symptom relief, preserves spinal stability, and presents a promising alternative to more invasive fusion procedures in carefully selected patients.

Ahn JS, et al. Asian Spine J. 2015 Dec;9(6):863-868. http://dx.doi.org/10.4184/asj.2015.9.6.863