The effect of a simple preservation method on immediate and late patency rates of autogenous microvenous grafts

The subject of this study was assessing in vivo a simple short-term preservation method of autogenous microvenous grafts. Forty-five autogenous vein grafts in rats were divided into groups of five and preserved in lactated Ringer's solution at 4 degrees C for 0, 1, 2, 3, 5, 8, 10, 12, and 14 days. After a designated preservation period, the veins were implanted as autografts into defects created in the animal's femoral arteries, while a small portion of each vein was processed for histologic examination. The patency was assessed immediately, at 1 week, and at 5 to 6 weeks following grafting, at which time the patent grafts were biopsied. Preserving the grafts for up to 2 days had no effect on their patency rate, which remained 100 percent, and no histologic changes were noted in the veins preserved for this period. However, longer preservation resulted in gradual necrotic changes in the veins, which were reflected in lower patencies of the grafts. The histology of the preserved veins and of the patent vein grafts 5 to 6 weeks following grafting is discussed. The model developed in this study can be used as a benchmark for further preservation studies using more sophisticated methods.