Experimental evaluation of four biologic prostheses for ventral hernia repair

To evaluate two bioprostheses derived from bovine pericardium, one cross-linked (Peri-Guard®) and the other non-cross-linked (Veritas®), and to compare them with Alloderm® and Permacol® for abdominal wall repair. The four prostheses were tested in acute and chronic hernia models. Prostheses were either sutured to the edge of the abdominal wall defect (inlay) or secured as an underlay with surgical tacks. Evaluation at 3 and 6 months included adhesion formation, defect area size and thickness, tensile strength, and histology. Mean adhesion coverage area ranged from 25 to 31%. The two cross-linked materials, Permacol and Peri-Guard, showed greater tensile strength. Significant defect contraction followed repair with Veritas, whereas Alloderm stretched. All prostheses had cellular ingrowth and neovascularization by 3 months. No significant differences were found in prosthesis to abdominal wall breaking strength. Operative site infection occurred in six animals (5 Peri-Guard, 1 Veritas), and overlying skin ulceration in six others (6 Peri-Guard). Permacol provided a strong and durable repair for up to six months. Peri-Guard was equally strong but prone to infection and to skin ulceration. With time, Veritas and Alloderm lost tensile strength associated with marked thinning and with hernia-like bulging in the case of Alloderm.