The successful transplantation of blood vessels in animals, reported by Carrel2 and Klotz10 (1910, 1925), along with the publications of Gross and co-workers* (1948) on the preservation and clinical utilization of homografts in man, has stimulated the present-day interest in human arterial implants. As a result, many investigators,† owing to the new techniques for the procurement and preservation of blood vessels, are evaluating the reactions which occur after implantation in the host. This is a natural result of the increasing demand for grafts to correct surgically the many congenital or acquired vascular abnormalities which only a short while ago were without treatment.
A sufficiently long period of time is necessary to evaluate experimental or clinical results. It seems therefore important to continue research on the fate of any type of transplant for long periods in an attempt to correlate functional results with histologica findings. Since the experimental work