Comparative Analysis of Onlay versus Sublay Mesh Repair for Ventral Hernia: A Prospective Randomized Study

Background: Ventral hernia repair remains a common surgical procedure withongoing debate regarding optimal mesh placement. This study aimed to compare theoutcomes of onlay versus sublay mesh repair techniques for ventral hernia.Methods: A prospective randomized controlled trial was conducted at a tertiary carecenter between January 2023 and December 2024. Adult patients with ventral hernia(fascial defect size 3-15 cm) were randomized to either onlay (n=153) or sublay(n=155) mesh repair. Primary outcome was hernia recurrence at 12 months. Secondaryoutcomes included perioperative parameters, complications, patient-reported outcomes,and cost-effectiveness.Results: Baseline characteristics were comparable between groups. The sublaytechnique was associated with longer operative time (105.6±22.4 vs. 78.3±18.7minutes, p<0.001) and greater blood loss (110 vs. 75 mL, p<0.001). However, seromaformation (7.7% vs. 24.2%, p<0.001), surgical site infection (5.8% vs. 13.7%,p=0.018), and hernia recurrence at 12 months (3.9% vs. 11.1%, p=0.017) weresignificantly lower in the sublay group. Multivariate analysis identified onlay repair asan independent predictor of recurrence (aOR=3.18, 95%CI:1.18-8.57, p=0.022). Patientsatisfaction (8.2±1.3 vs. 7.4±1.6, p<0.001) and physical component summary of SF-36(49.7±7.8 vs. 46.3±8.2, p<0.001) were significantly better in the sublay group.Conclusion: Despite requiring longer operative time and higher resource utilization,sublay mesh repair for ventral hernia demonstrates superior outcomes in terms ofreduced seroma formation, surgical site infection, and recurrence rates, along withbetter patient satisfaction and quality of life. These findings support the preferential useof the sublay technique, particularly in high-risk patients.