The Use of Adhesion Barriers in Abdominopelvic Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: The efficacy and safety of adhesion barriers in preventing postoperative adhesions remain uncertain. This systematic review and meta-analysis aimed to evaluate the effectiveness and safety of adhesion barriers in reducing postoperative adhesions following abdominopelvic surgery. Methods: CENTRAL, EMBASE and MEDLINE were searched from inception to January 15, 2025 for parallel-arm randomized controlled trials (RCTs) comparing adhesion barriers with controls in patients undergoing abdominopelvic surgery. Case series, case reports, reviews, animal studies, observational studies and studies involving patients with pre-existing adhesions were excluded. Results: Thirty-six RCTs involving 6729 patients were included. Adhesion barriers significantly reduced the incidence of postoperative adhesions on second-look assessment compared with controls (21 RCTs, n = 2351; OR 0.37, 95% CI 0.30–0.45, p < 0.00001; I2 = 51%; certainty of evidence: moderate). Subgroup analyses demonstrated significant reductions in postoperative adhesions in both general surgery (9 studies, n = 1162; OR 0.38, 95% CI 0.27–0.53, p < 0.00001; I2 = 27%) and obstetrics and gynecology (12 studies, n = 1189; OR 0.36, 95% CI 0.27–0.47, p < 0.00001; I2 = 62%). Pooled analysis demonstrated no significant differences between the adhesion barrier and control groups in the incidence of anastomotic leakage (9 RCTs, n = 1541), abscess formation (6 RCTs, n = 1182), wound infection (11 RCTs, n = 1084), time between initial surgery and second surgery (10 RCTs, n = 874), intraoperative blood loss (15 RCTs, n = 5327) and adhesion severity (11 RCTs, n = 756). Adhesion barriers were associated with a modest reduction in post-operative small bowel obstruction (12 RCTs, n = 4917; OR 0.81, 95% CI 0.66 to 0.99, p = 0.04; I2 = 38%), but were associated with a significantly longer duration of the index operation (18 RCTs, n = 5868; MD 18.66, 95% CI 11.25 to 26.06, p < 0.00001; I2 = 99%). Conclusions: Adhesion barriers reduced adhesions at second-look assessment in a meta-analysis of pooling eight heterogeneous agent classes and procedures against an inconsistently scored surrogate outcome. Thus, evidence remains insufficient to recommend routine use or to define which patients, procedures, or risk levels warrant its use. Until adequately powered, agent-specific trials with standardized scoring and patient-centered endpoints exist, adhesion-barrier use should remain an individual clinical decision, not standard care. PROSPERO registration: CRD42024595564.