Biologic Versus Synthetic Mesh in Ventral Hernia Repair: Are We There Yet? A Trial Sequential Analysis and Fragility Index of Randomized Clinical Trials

Introduction: Ventral hernia repair (VHR) is one of the most frequently performed surgical procedures. However, the selection of the most appropriate mesh type remains a subject of considerable debate. Moreover, the current body of evidence regarding the choice of mesh for VHR in contaminated fields remains insufficient. Given these limitations, this study aims to systematically evaluate and analyze existing data on the comparative efficacy and safety of biologic versus synthetic mesh in VHR. Materials and Methods: A comprehensive online search was conducted across databases (PubMed/MEDLINE, EMBASE, Web of Science, and Cochrane Library) from January 2000 until January 2025. Randomized controlled trials (RCTs) exclusively comparing biologic and synthetic mesh in patients undergoing VHR were included, with no restrictions on language. The primary outcomes were surgical site occurrence (SSO), surgical site infection (SSI), reoperation, and hernia recurrence. Secondary outcomes included hematoma and seroma formation, operative time (OT), and length of stay (LOS). Trial sequential analysis (TSA) was performed using TSA Software 0.9.5.10 Beta (Copenhagen Trial Unit, Center for Clinical Interventional Research), and the Fragility Index (FI) and Reverse Fragility Index (RFI) were calculated using R Statistical Software (v4.1.2; R Core Team 2021). Results: A total of 762 studies were screened, of which 16 were fully reviewed. Four RCTs including 758 patients were analyzed in the TSA; 48% of patients had Wound Classification II–IV, and 83.4% underwent open procedures. Only OT reached the required information size (RIS), providing conclusive evidence favoring synthetic mesh. For all other outcomes—including SSO, SSI, reoperation, hernia recurrence, seroma, hematoma, and LOS—the RIS was not reached, reflecting underpowered evidence. Fragility and reverse fragility analyses revealed highly unstable results across most studies, with FI values of 0 in nearly all nonsignificant outcomes and RFI ranging from 1 to 11. Conclusions: Biologic and synthetic mesh demonstrated comparable results in VHR across multiple clinical parameters. However, the TSA indicated that only OT reached the RIS, providing conclusive evidence favoring synthetic mesh by demonstrating a significantly shorter duration of surgery. For all other outcomes, the analysis suggests that current evidence remains inconclusive regarding the superiority of either mesh type.