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 (uniand 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.