Perhaps one of the most significant consequences of the fascinating research now being carried out relating to the survival of transplanted tissue may be the discovery of the long-sought blood vessel substitute with the ideal qualities of flexibility, inertia, ability to retain shape, and ease of handling, as enumerated by the Committee for The Study of Vascular Prostheses of the Society for Vascular Surgery.1 Deaths have occurred from uncontrollable hemorrhage through prosthetic interstices, and it is often difficult to compensate for the disparate diameters of prosthetic and host vessel. The use of homografts for vascular replacements has been sharply curtailed because of growing numbers of late catastrophies, due to degeneration and thrombosis.2,3
The observations of Medawar,4 in 1943, that the sloughing of serial skin grafts from one person to another was accelerated in direct proportion to the frequency and size of grafting, thus establishing the responsibility of