SUCCESSFUL SMALL-DIAMETER ARTERIAL GRAFTING USING CRYOPRESERVED ALLOGRAFT ARTERIES

Intimal hyperplasia (IH) limits the long-term success of veins as arte rial grafts. IH occurs in veins partly as an adaptive process to arter ial pressure conditions. The authors have previously reported early su ccess with cryopreserved (CP) saphenous veins as aortocoronary bypass grafts, and they have hypothesized that CP arterial segments were alre ady structurally adapted for arterial conditions. Six femoral arterial segments were harvested from three adult donor dogs, and cryopreserve d. The segments were thawed and implanted into six recipient dogs, in end-to-end fashion, as interpositional grafts in the femoral artery. A similar length of native femoral artery was removed from the implant site and grafted in the contralateral femoral artery of the same anima l to serve as native autograft-matched controls. Grafts were harvested bilaterally after 2 (n = 3) and 4 weeks (n = 3), perfusion fixed (80 mmHg, 15 min), and analyzed histologically. All grafts were patent at harvest, and flows distal to the grafted segments were not significant ly different between grafts within an animal either at implant or subs equent harvest. Although CP arterial grafts still showed slight but si gnificant dilation compared with native autograft, the dilation was mu ch less than seen previously with either CP or native venous segments. No evidence of inflammation or IH was seen in CP arterial grafts. The absence of early IH or inflammation suggests that CP small diameter a rteries may perform better than many currently available allograft tis sues and synthetic prosthetics.