ANALYSIS OF SUTURING TECHNIQUES IN THE MICROVASCULAR ANASTOMOSIS OF VESSELS OF UNEQUAL DIAMETER

A rat model has been devised to study the determinants of microvascula r anastomotic patency in the setting of diameter discrepancy. Isogenei c interposition grafts of rat inferior vena cava were used to repair a femoral artery defect (diameter ratio 4.5:1). Three methods for compe nsating for diameter discrepancy were studied. The anastomoses were ex plored on postoperative days 3, 7, and 14. By 2 weeks, tapered grafts were shown to result in higher patency rates (p < 0.05) compared with nontapered and spatulated grafts. Hemodynamic, histological, and scann ing electron microscopic analysis suggested that turbulence caused by large velocity gradients predisposes to thrombosis. This animal model was shown to be sensitive to experimental hemodynamic alterations and may be useful in elucidating the effect of technical or pharmacologica l manipulations on patency in the setting of vessel diameter discrepan cy.