Experience with fully bioresorbable aortic grafts in the dog.

Reorganization of the arterial wall through natural processes on the resorption of a totally bioresorbable graft was investigated in dogs with Vicryl prostheses coated with two different blends of bioresorbable polyesters capable of slowing down considerably the disintegration of a Vicryl fabric in vivo. The prostheses (8 to 9 mm in internal diameter, 8 to 10 cm long) were implanted in the infrarenal aortic position for up to 24 weeks. All 18 animals implanted with coated prostheses survived, whereas one animal implanted with an uncoated Vicryl prosthesis died because of early rupture of the graft. Patent tubular conduits were present in 14 animals at the time of retrieval. On resorption of the synthetic polymers, the tissue layers that formed on both sides of the prosthetic material either fused or remained separated, depending on the polymer used as a retardant coating. We conclude that polymer composition influences the repair process and that a fully resorbable vascular graft can function effectively in a canine model, provided that tissue organization is sufficiently advanced by the time the prosthesis has lost its mechanical integrity. Further studies are needed to document the performance of the newly formed blood conduit over extended periods, in hypertensive subjects, and when presented with a bacterial challenge.