Morphologic study of small intestinal submucosa as a body wall repair device

BACKGROUND: The extracellular matrix (ECM) derived from porcine small intestinal submucosa (SIS) has been used as a constructive scaffold for tissue repair in both preclinical animal studies and human clinical trials. Quantitative characterization of the host tissue response to this xenogeneic scaffold material has been lacking. MATERIALS AND METHODS: The morphologic response to a multilaminate form of the SIS-ECM was evaluated in a chronic, 2-year study of body wall repair in two separate species: the dog and the rat. Morphologic response to the SIS-ECM was compared to that for three other commonly used bioscaffold materials including Marlex mesh, Dexon, and Perigard. Quantitative measurements were made of tissue consistency, polymorphonuclear cell response, mononuclear cell response, tissue organization, and vascularity at five time points after surgical implantation: 1 week, 1, 3, and 6 months, and 2 years. RESULTS: All bioscaffold materials functioned well as a repair device for large ventral abdominal wall defects created in these two animal models. The SIS-ECM bioscaffold showed a greater number of polymorphonuclear leukocytes at the 1-week time point and a greater degree of graft site tissue organization after 3 months compared to the other three scaffold materials. There was no evidence for local infection or other detrimental local pathology to any of the graft materials at any time point. CONCLUSIONS: Like Marlex, Dexon, and Perigard, the SIS-ECM is an effective bioscaffold for long-term repair of body wall defects. Unlike the other scaffold materials, the resorbable SIS-ECM scaffold was replaced by well-organized host tissues including differentiated skeletal muscle.