Smooth Muscle Function in Short- and Long-term Stored Cryopreserved Veins

There is considerable interest in banking of allograft veins for vascular recon struction procedures in patients for whom there are no suitable autologous or prosthetic vessels available. A major obstacle to vein banking has been posed by the lack of long-term storage studies and by a prior report indicating that veins deteriorated rapidly during liquid nitrogen storage. This study was, there fore, initiated to determine the effects of long-term liquid nitrogen storage on tissue viability. Viability was assessed by measurement of smooth muscle func tion in fresh, short-term (one to twenty-eight days), and long-term (> two years) cryopreserved canine saphenous veins. There were no significant differences in the median effective doses of norepinephrine, serotonin, and KCL for genera tion of isometric force by vein rings from short- and long-term stored groups. Similarly, the maximum forces generated by long-term-stored cryopreserved veins in response to each reagent were the same as in short-term-stored veins. These results demonstrate that vein viability is maintained in cryopreserved banked veins.