Abdominal aorta transplantation after programmed cryopreservation.

AIM

To study the morphologic and cellular immunologic changes after homologous transplantation of the abdominal aorta in rats after programmed cryopreservation (-196 degrees).

METHODS

Abdominal aorta was harvested from anesthetized Spraque Dawley (SD) rats for cryopreservation (group B) or immediate implantation (group A). The survival rates and apoptotic rates of aortic endothelial cells (ECs) were examined. The patency rates, histology and cellular immunologic changes of the abdominal aorta were examined on days 1, 3, 7, 14, 30, 60 after transplantation respectively.

RESULTS

The survival rate of ECs after programmed cryopreservation was 90.1+/-1.79%, about 3.4% lower than that of uncryopreservation (93.5+/-1.96%). The apoptotic rates of ECs was increased after cryopreservation (7.15% vs 4.86%, P<0.05). The patency rate of group B was significantly higher than that of group A (91.6+/-12.9% vs 62.5+/-26.2%, P<0.01). CD4/CD8 ratio, TCR alpha beta and CD11b/CD18 ratio of group B were significantly lower than those of group A (P<0.05). Revivification of the cryopreserved abdominal aorta showed normal adventitia and intact smooth muscle cells.

CONCLUSION

Cryopreservation can reduce homologous abdominal aortic antigenecity. Even if without administration of immunosuppressive agents, it is still feasible to implement homologous artery grafting in rats.