Remodeling of an acellular collagen graft into a physiologically responsive neovessel

Surgical treatment of vascular disease has become common, creating the need for a readily available, small-diameter vascular graft. However, the use o f synthetic materials is limited to grafts larger than 5-6 mm because of th e frequency of occlusion observed with smaller-diameter prosthetics. An alt ernative to synthetic materials would be a biomaterial that could be used i n the design of a tissue-engineered graft. We demonstrate that a small-diam eter (4 mm) graft constructed from a collagen biomaterial derived from the submucosa of the small intestine and type I bovine collagen has the potenti al to integrate into the host tissue and provide a scaffold for remodeling into a functional blood vessel. The results obtained using a rabbit arteria l bypass model have shown excellent hemostasis and patency. Furthermore, wi thin three months after implantation, the collagen grafts were remodeled in to cellularized vessels that exhibited physiological activity in response t o vasoactive agents.