Functional analysis of cryopreserved veins. Preliminary report.

Abstract

Functional comparisons of cryopreserved and fresh canine vein endothelium, smooth muscle, and connective tissue were performed. Morphometric analysis of saphenous vein endothelium revealed no significant loss of endothelial integrity as a result of cryopreservation. Endothelial cell culture revealed similar numbers of clonogenic intimal cells from cryopreserved and fresh saphenous, cephalic, and jugular veins. Smooth muscle function was assessed by measurement of the isometric force generated by vein rings in response to norepinephrine, serotonin, and potassium chloride. There was no significant difference in the dose responses of cryopreserved and fresh saphenous veins to the reagents tested. Similar results were obtained for the cephalic and jugular vein experiments with norepinephrine. The maximum tensions generated in response to norepinephrine were 52% of fresh control segments. Connective tissue function was assessed by quantitation of 3H-proline incorporation. The results indicate that cryopreserved veins retained approximately 43.5% of values of fresh vein collagen synthesis. Finally, eight cryopreserved cephalic vein autografts were placed as femoral artery grafts and were removed electively after 1 to 8 weeks. All grafts were patent. Both light and electron microscopy demonstrated that the cryopreserved veins remained intact in vivo and that arteriolization occurred as described for fresh autografts in the literature. In conclusion, cryopreserved veins retain much of their cellular and tissue functions on thawing. Transplantation of cryopreserved veins suggests that cryopreservation does not change the sequence of histologic events associated with the use of autologous fresh vein as an arterial substitute.