MECHANICAL-PROPERTIES OF XENOGENEIC SMALL-INTESTINAL SUBMUCOSA WHEN USED AS AN AORTIC GRAFT IN THE DOG

Small-intestinal submucosa (SIS) has been shown to induce tissue remod eling in vivo when used as a vascular graft. The present study investi gated the physical and mechanical properties of remodeled aortic graft s derived from xenogeneic SIS material. Eight infrarenal aortic grafts were implanted in mongrel dogs. The grafts were explanted at 1 or 2 m onths and tested for compliance and hoop mechanical properties. The mo rphologic changes within the grafts were also characterized. The remod eling process produced graft structures which were significantly stron ger than both the normal artery (P = .012) and the original SIS graft (P = .0001), and the compliance of these structures was one third that of normal artery and similar to the original SIS grafts. The remodele d grafts were >10 times the thickness of the implanted SIS. Immunohist ochemical analysis of remodeled tissues suggest that the SIS material was degraded and resorbed over time. The remodeling process transforme d a material which was physically and mechanically quite different fro m normal aorta into a blood conduit which had the physical and mechani cal properties needed to function in this mammalian arterial system. ( C) 1995 John Wiley and Sons, Inc.