PurposeThis study evaluated functional outcomes and safety after endoscopic and open bilateral carpal tunnel syndrome release in opposite hands of the same patients through a meta-analysis of randomized controlled trial data.Materials and MethodsRandomized controlled trials involving bothmethods in opposite hands of patients with bilateral carpal tunnel syndrome were identified via a systematic review of PUBMED and EMBASE.ResultsRelative risks (RRs) and 95% confidence intervals (CIs) from five randomized controlled trials involving 142 patients with bilateral carpal tunnel syndrome were calculated using fixed- or random-effect methods, with a length of follow-up from 24 to 52weeks after surgery. Compared with open release, endoscopic carpal tunnel release was associated with significantly better Boston Carpal Tunnel Questionnaire functional status scores (mean difference [MD]=0.13, 95% confidence interval [CI] [0.02-0.25]; P=0.02), but not symptom severity scores (RR=0.06, 95% CI [-0.15 to 0.04]; P=0.25). Endoscopic release required a longer operative time, but the procedures did not differ significantly in visual analog scale pain scores (MD=0.02, 95% CI [-0.08 to 0.11]; P=0.75), handgrip strength (MD=0.17, 95% CI [-2.03 to 2.37]; P=0.88), digital sensibility static two-point discrimination (MD=0.34, 95% CI [-0.03 to 0.70]; P=0.07), or complication rates (MD=0.01, 95% CI [-0.02 to 0.05], P=0.47).ConclusionFrom intraindividual evidence, endoscopic release promoted better recovery of daily life functions than open release, but required a longer operative time. The procedures provided similar symptom relief and hand strength and sensibility recovery, and were safe for patients with carpal tunnel syndrome.