Abdominoperineal Resection in Prone Versus Supine Position: A Systematic Review and Meta-Analysis

Background: Abdominal perineal resection (APR) remains the gold standard for lower rectal cancer involving the anal sphincter. However, the optimal patient position remains unclear. While lithotomy or Lloyd-Davies are commonly used, APR and extra-levator abdominal perineal excision (ELAPE) in a prone jackknife position have been linked to better oncological outcomes. Methods: We searched PubMed, Embase, the Central Register of Clinical Trials, and Web of Science for randomized controlled trials (RCTs) and observational studies published up to February 2024. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using a random-effects model. Heterogeneity was assessed using I-2 statistics. Statistical analysis was performed with R Software version 4.4.1. Results: Two RCTs and 26 observational studies, including 4529 patients, were analyzed. Among them, 2249 (49.7%) underwent APR or ELAPE in the prone position and 2280 (50.3%) in the supine position. The prone position was associated with reduced surgical specimen perforation (5.3% versus 9.4%; OR: 0.44; 95% CI: 0.39-0.78; P < .001), lower positive circumferential resection margins (CRMs) rates (9.8% versus 14.3%; OR: 0.69; 95% CI: 0.53-0.89; P < .001), and decreased intraoperative bleeding (mean difference: -63.7 mL; 95% CI: -104.5, -22.8; P < .01). No significant differences were observed in operative time, urinary retention, urinary injury, wound infections, perineal dehiscence, Clavien-Dindo >= 3, reoperation, local recurrence, distal recurrence, or overall survival. Conclusion: The prone position during APR is associated with reduced specimen perforation, lower positive CRM rates, and less intraoperative bleeding without significant differences in other clinical outcomes.