Abstract
In the protracted search for segmental arterial replacements, the ideal substitute still remains autogenous artery. However, since obvious, severe limitations on their harvesting and use exist, the autogenous vein has become the practical bypass material of choice.’ Because even vein is occasionally not available in suitable diameter or length, or for other reasons cannot be used, surgeons have either employed substitutes derived from polymer chemistry2-4 or used homologous5 or modified heterologous6 blood vessels. While plastic prostheses can satisfy some needs as large vessel substitutes, they usually fail when employed as bypasses around obstructed smaller arteries. This paper will attempt a historical review of experiences to date in the development of prostheses of biologic origin, with a review of past rationales and of production techniques based on those rationales, nales.