Comment on: Comparative analysis of biologic versus synthetic mesh outcomes in contaminated hernia repairs

We read with great interest the article by Majumder et al.1 The authors performed a multicenter, retrospective review of 126 patients undergoing prosthetic sublay abdominal wall reconstruction (AWR) in cleancontaminated/ contaminated field. They concluded that the use of polypropylene or polyester mesh resulted in a significantly lower wound morbidity and more durable outcomes compared with a similar cohort patients in whom non–cross-linked porcine acellular dermal matrix (PADM) was used. Surgical site infections (SSIs) and recurrence (mean follow-up >12 months, <22 months) were less frequent in the synthetic group (12.3% and 8.9%, respectively) than in the biologic group (31.9% and 26.3%, respectively), with one incidence of partial mesh explantation in each group. At the end of the study, the authors challenged the advantage of biologics in patients at risk of wound infection. According to our experience with biologics, the results of complex AWR were different. Between 2005 and 2014, 49 patients underwent elective AWR using biologic mesh in our tertiary referral center for complex hernias. Patient demographics, comorbidities, risk infection, according to the modifiedWorking Ventral Hernia Group,2 and hernia characteristics did not significantly differ from Majumder’s review. All patients underwent sublay repair using PADM processed with 2 different cross-linking agents, group A (hexamethylene diisocyanate: 36 implants) and group B (carbodiimide: 13 implants), with posterior component separation when necessary. Patients were collected in a database and submitted to clinical exam and computed tomography scan every year. Our SSI rate was 19%, taking into account group A only. No implant needed to be removed, including one case with early sigmoid perforation, which was conservatively treated with success. In June 2016, the database analysis of group A showed an overall recurrence rate of 2.8%, with a medium follow-up >5 years (17– 132 months). Group A proved that the putative advantages of biologics were true. Outcomes of group B were instead less favorable (SSI 31%, recurrence 23%). These results, along with those of Majumder’s non–cross-linked PADM series, confirm that all biologics are not equal.3 The authors assert that the operative technique and mesh site of the implant play a primary role. We completely agree and add that these are especially important when using biologics. 4 Selection of the proper implant is also crucial. The choice of a cross-linked, proper-sized PADM represented the key factor of our success. In fact, no implant was removed due to infection, and the long-term recurrence rate was significantly lower than that achieved by Majumder, both in the biologic and the synthetic group. Results of prospective, randomized trials comparing monofilament synthetic meshes with biologics in sublay AWR are needed before advocating the purported advantages of biologic implants in contaminated AWRs. Which biologic should be proposed for this study? On the basis of our experience, we suggest the proper one from the cross-linked meshes family.