Sublay versus underlay in open ventral hernia repair

Background The ideal location for mesh placement in open ventral hernia repair (OVHR) remains under debate. Current trends lean toward underlay or sublay repair. We hypothesize that in patients undergoing OVHR, sublay versus underlay placement of mesh results in fewer surgical site infections (SSIs) and recurrences. Materials and methods A multi-institution database of all OVHRs performed from 2010 to 2011 was accessed. Patients with mesh placed in the sublay or underlay position and at least 1 mo of follow-up were included. Primary outcome was SSI. Secondary outcome was hernia recurrence. Multivariate analysis was performed using logistic regression for SSI and Cox regression for recurrence. Subgroup analysis of elective, midline ventral incisional hernias was also performed. Results Of 447 patients, 139 (31.1%) had a sublay repair. The unadjusted analysis showed no difference in SSI and lower recurrence using sublay compared with underlay. On multivariate analysis, there was no difference in SSI using sublay compared with underlay (odds ratio 1.5, 95% confidence interval [CI] 0.8-2.8). Recurrence was less common with sublay (hazard ratio 0.4, 95% CI 0.2-0.8). On subgroup analysis of elective, midline incisional hernias only (n = 247), there were more SSIs with sublay compared with underlay repair (28.0% versus 15.1%, P = 0.018); however, there was no difference in major SSI (sublay 9.3% versus underlay 5.8%, P = 0.315). There were fewer recurrences using sublay repair compared with underlay repair (10.7% versus 25.0%, P = 0.010). Conclusions In this multi-center, risk-adjusted study, sublay repair was associated with fewer recurrences than underlay repair and no difference in SSI. Randomized controlled trials are warranted to validate these findings.