Prophylactic mesh augmentation in midline laparotomy in elective or emergency settings: a systematic review and network meta-analysis of randomized trials

Introduction Incisional hernia (IH) remains a common complication after midline laparotomy. Prophylactic mesh reinforcement reduces IH risk, but the optimal anatomical plane for mesh placement remains uncertain. This systematic review and network meta-analysis (NMA) compared mesh positions for IH prevention while assessing postoperative morbidity. Methods A systematic search of PubMed, Embase, and Cochrane databases identified randomized controlled trials (RCTs) comparing prophylactic mesh reinforcement with suture-only fascial closure after laparotomy. The primary outcome was the IH rate. Secondary outcomes were surgical site infection (SSI), surgical site occurrence (SSO), seroma, and hematoma. Pairwise random-effects meta-analysis and frequentist random-effects NMA were performed using risk ratios (RR) with 95% confidence intervals (CI). Treatments were ranked using P-scores. Results 27 RCTs, including 4327 patients, were analyzed. The control group was suture-only closure (1891 patients). Mesh positions were onlay (38%), retromuscular/preperitoneal (37%), intraperitoneal (18%), and inlay-strip (7%). Overall, prophylactic mesh reinforcement significantly reduced IH compared with suture-only closure (RR 0.41, 95% CI 0.27–0.62). In the NMA, compared with suture-only closure, onlay mesh reinforcement was associated with the largest relative reduction in IH (RR 0.27, 95% CI 0.17–0.45), followed by retromuscular/preperitoneal (RR 0.42, 95% CI 0.27–0.67). Inlay-strip and intraperitoneal meshes were not significantly superior to suture-only closure. Onlay mesh ranked highest for IH prevention (P-score 0.976). Findings were consistent in the elective and emergency subgroup analyses. For SSI, no mesh position significantly increased the risk compared with the suture-only group. For SSO, onlay mesh reinforcement was associated with a significantly increased risk (RR 1.46, 95% CI 1.03–2.06), whereas retromuscular/preperitoneal was not. Similar results were found for seroma. No mesh position significantly increased the risk of hematoma in the NMA analyses. Conclusion Prophylactic mesh reinforcement reduces IH after laparotomy. Both onlay and retromuscular/preperitoneal placement significantly reduced IH. Onlay achieved the highest treatment ranking, without increasing SSI, but at the cost of higher wound morbidity, especially seroma. Further high-quality trials are needed to define the optimal mesh plane, as limited direct evidence between mesh planes precludes firm conclusions of superiority.