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 non-randomized studies comparing endoscopic versus microscopic decompression was conducted, in accordance with 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 non-randomized trials respectively. Quality of the overall body of evidence was appraised using the GRADE system. Results A total of 19 primary references comprising 1997 patients and 2132 spinal levels were included. Endoscopic decompression was associated with significantly reduced intraoperative blood-loss (WMD = -33.29 mLs, 95% CI: -51.80 to -14.78, p = 0.0032), shorter duration of hospital stay (WMD = -1.79 days, 95% CI: -2.63 to 0.95, p = 0.001), rates of incidental durotomy (RR = 0.63, 95% CI: 0.43 to 0.91, p = 0.0184) and surgical site infections (RR = 0.23, 95% CI: 0.10 to - 0.51, p = 0.001), and a non-significant 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.