Synthetic versus Biologic Mesh for Complex Open Ventral Hernia Repair: A Pilot Randomized Controlled Trial.

Background: Many surgeons utilize biologic mesh for elective complex ventral hernia repair (VHR; large hernias, contaminated fields, or patients with comorbid conditions). However, no randomized controlled trials (RCTs) have compared biologic and synthetic mesh. We hypothesize biologic mesh would result in fewer major complications at one-year post-operative compared with synthetic mesh. Patients and
Methods: We performed a single-center, pilot RCT. All eligible patients undergoing complex, open VHR were randomly assigned to receive biologic or synthetic mesh placed in the retromuscular position. Primary outcome was major complications, namely, a composite of mesh infection, recurrence, or re-operation at one-year post-operative. Secondary outcomes included surgical site infections (SSI), seromas, hematomas, wound dehiscence, re-admissions, and Clavien-Dindo complication grade. Outcomes were assessed using Fisher exact test and Bayesian generalized linear models.
Results: Of 87 patients, 44 were randomly assigned to biologic mesh and 43 to synthetic mesh. Most cases were wound class 2-4 (68%) and 75% had a hernia width >4 cm. Most patients were obese (70%) and had an American Society of Anesthesiogists (ASA) score of 3-4 (53%). Compared with patients in the synthetic mesh group, patients in the biologic mesh group had a higher percentage of: major complications at one-year post-operative (42.4% vs. 21.6%; relative risk [RR] = 1.96 [95% confidence interval {CI} = 0.94-4.08]; number needed to harm = 4.8; p = 0.071); SSI (15.9% vs. 9.3%; RR = 1.71 [95% CI = 0.54-5.42]; p = 0.362); wound dehiscence (25.0% vs. 14.0%; RR = 1.79 [95% CI = 0.73-4.41]; p = 0.205); and re-admissions (22.7% vs 9.3%; RR = 2.44 [95% CI = 0.83-7.20]; p = 0.105). Bayesian analysis demonstrated that compared with synthetic mesh, biologic mesh had a 95% probability of increased risk of major complications at one-year post-operative. No clear evidence of a difference was found on seromas, hematomas, or Clavien-Dindo complication grade. Conclusions: In elective complex open VHR, biologic mesh demonstrated no benefit compared with synthetic mesh in one-year outcomes. Moreover, Bayesian analysis suggests that biologic mesh may have an increased probability of major complications.