Our research hypothesis is that the elements of a normal arterial wall can be reorganized through natural repair processes if the scaffold of a vascular graft is made of a slowly disappearing, biocompatible mesh. The general objective of the project is to explore the feasibility of blood conduits which at the time of implantation display the mechanical strength, suturability and limited thrombogenicity of standard vascular grafts, but lead, after disappearance of a bioresorbable polymer fabric, to the advent of a newly formed vessel wall of appropriate strength and hemocompatibility, without at any time allowing the rupture of the arterial wall. The experience of the first three years of this project has shown that a standard length aortic graft made entirely of bioresorbable materials is indeed feasible and can function effectively in a canine model for at least 24 weeks. At that point, the synthetic fabric has decayed almost completely and newly formed tissue provides the mechanical integrity of the conduit. However the healing process has not yet stabilized and the end point has not been reached. The objectives for the second phase of this project are: a) to optimize yarn coating selection for incorporation into fully bioresorbable vascular grafts; b) to screen bioresorbable polymer fabrics and coatings through subcutaneous implants in mice and dogs in order to assess durability and repair processes; c) to evaluate such prostheses in the infrarenal aortic position in the dog, and to establish the time course of the morphologic and mechanical landmarks of the progressive replacement of the polymer structures by living tissues; d) to extend the histological, chemical and engineering information to the point of complete stabilization of the process; e) and to broaden the concept of bioresorbable scaffolds to confront unmet needs in vascular surgery, such as atrial and vascular patches, small diameter arterial prostheses and venous prostheses.
|Galletti, P M; Aebischer, P; Sasken, H F et al. (1988) Experience with fully bioresorbable aortic grafts in the dog. Surgery 103:231-41|
|Galletti, P M; Trudell, L A; Chiu, T H et al. (1985) Coated bioresorbable mesh as vascular graft material. Trans Am Soc Artif Intern Organs 31:257-63|