INTRODUCING A SELECTIVELY BIODEGRADABLE FILAMENT WOUND ARTERIAL PROSTHESIS - A SHORT-TERM IMPLANTATION STUDY

This article introduces a new compliant and selectively biodegradable filament wound vascular graft and reports the findings of a short-term implantation study. A basic feature of filament winding is its ability to tailor and better control the mechanical properties of the prosthesis, so that a closer match with the anisotropic properties of native arteries is achieved. The elastomeric vascular grafts comprise poly(ether urethane urea) fibers (Lycra) embedded in a two-component matrix consisting of poly(ether urethane) (Pellethane) and a highly flexible poly(ethylene glycol)/poly(lactic acid) biodegradable segmented copolymer (PELA). Typical tensile modulus values fall in the few megapascals (MPa) range, this being comparable to that of natural arteries. The wound graft exhibits excellent handling and suturability characteristics as well as enhanced burst strength. Furthermore, due to its biodegradable constituent, the prosthesis combines minimal intraoperative blood loss and high healing porosity. The graft displays initially negligible in vitro water permeation, which increases gradually with time. In this short-term study, the prostheses were implanted in the canine carotid, and their biological performance was compared to that of expanded Gore-Tex. The luminal surface of the wound grafts was coated with a thin layer of pseudointima, strongly adhered to the prosthesis surface. Contrasting with the very stiff Gore-Tex grafts, the filament wound prostheses retained their high compliance, being highly pulsatile upon explantation. Histological studies fully corroborated these findings, underscoring the healing properties of these new filament wound vascular prostheses.