Experimental study of cryopreserved allogeneic transfer of vessel: preliminary report

It has long been known that the antigenicity of tissues is depressed when they are kept at a very low temperature. In this study, Lewis rats and Brown Norway (B.N.) rats were used because these species are significantly dissimilar at the major histocompatibility complex (MHC) Femoral arteries were harvested from Lewis rats, frozen while lowering the temperature in a stepwise fashion to -70 degrees C. After three weeks of cryogenic storage, the arteries were transplanted into Lewis and B.N. rats. At various times from the first to the twelfth week after surgery, grafted vessels were observed, and pathological and electron microscopic studies were carried out. The vessels were found to be in good condition at the end of the 12 week observation period. These results strongly suggest that prolonged cryopreservation of vessels makes allotransplantation without immunosuppression possible.