Outcomes of Abdominal Wall Reconstruction with Acellular Dermal Matrix Are Not Affected by Wound Contamination

INTRODUCTION: The optimal choice of mesh for complex abdominal wall reconstruction (AWR) remains controversial, particularly given that surgical site occurrences (SSOs), surgical site infections (SSIs), and hernia recurrences have been shown to increase with increasing degrees of wound contamination. Many surgeons use acellular dermal matrix (ADM) rather than synthetic mesh to minimize SSO following AWR, but studies evaluating this strategy are limited.  We hypothesized that AWRs using ADM result in low rates of SSO and SSI, even with increasing degrees of contamination.

METHODS: We retrospectively reviewed data from consecutive patients with ≥1 year of follow-up who underwent AWR with ADM between 3/2005 and 3/2013 at a single center.  We classified wounds according to the Centers for Disease Control (CDC) guidelines as clean, clean-contaminated, or contaminated and compared outcomes between these CDC classification groups. Primary outcome measures included SSO, 30-day SSI, reoperation, mesh explantation, and hernia recurrence.  Univariate and multivariate logistic regression analysis identified potential associations.

RESULTS: The 359 patients had an average follow-up of 28.1±19.1 months. Three hundred thirty patients had a mesh-reinforced primary fascial coaptation repair, whereas 29 had bridged fascial defect repairs.  Overall rates of complications were low: SSO=24.5%, 30-day SSI=8.4%, reoperation=6.9%, and mesh explantation=1.1%, hernia recurrence=10.0%. Reconstruction of clean wounds (N=171) required fewer reoperations than that of combined clean-contaminated (N=148)/contaminated (N=40) wounds (2.3% vs. 11.2%; p=0.001) and resulted in fewer SSOs (19.9% vs 28.7%, p=0.05). There were no significant differences between clean and clean-contaminated/contaminated cases in 30-day SSI (8.8% vs. 8.0%; p=0.85), hernia recurrence (9.9% vs. 10.1%; p=0.959), and mesh removal (1.2% vs. 1.1%; p=1.00) rates. Independent predictors of SSO included body mass index (BMI) ≥30 kg/m² (OR=3.6; p<0.001), ≥1 co-morbidities (OR=2.5; p=0.008), and defect width ≥15 cm (OR=1.8; p=0.02).  Independent predictors of hernia recurrence included bridged repair (OR=8.7; p<0.001), prior hernia repair (OR=2.1; p=0.03), the use of human (versus xenograft) ADM (OR 2.8; p=0.03), reoperation (OR=3.1; p=0.4), and ADM removal (OR=13.2; p<0.001).   

CONCLUSIONS:  Complex AWRs using ADM demonstrated similar rates of complications between the different CDC wound classifications, in contradistinction to the progressively higher complication rates described in studies of AWR with synthetic mesh. These data support the use of ADM rather than synthetic mesh for complex AWR in the setting of wound contamination.