Comparative evaluation of synthetic meshes used for abdominal wall replacement

The lack of adequate fascia for closure of large hernias and traumatic abdominal wall defects has led to a search for suitable fascial substitutes. In this study closure of rabbit abdominal wall defects with knitted polypropylene, knitted polytetrafluoroethylene (PTFE), and molded polyglactin mesh was evaluated for bursting strength, fibrous tissue incorporation, and inflammatory reaction. Full-thickness, inch-square defects in the abdominal walls of rabbits were closed with use of the synthetic meshes, and similar defects in the contralateral abdominal walls were closed with a vascularized flap of external oblique fascia (control flaps). The animals were sacrificed at 3 and 12 weeks, the abdominal walls were removed, and the bursting strength of the grafts and control flaps was determined with a tissue tensometer. Polypropylene and PTFE meshes were similar in bursting strength and not greatly different from controls at 3 and 12 weeks. At 3 weeks polyglactin mesh had a bursting strength comparable to that of control flaps but at 12 weeks was significantly weaker. Fibrous tissue incorporation within the mesh fibers was better with PTFE mesh than with polypropylene mesh. Adequate fibrous tissue incorporation into polyglactin mesh before hydrolysis did not occur, making it an unsatisfactory material for use for permanent abdominal wall replacement.