The effects of thrombus, thrombectomy end thrombolysis on endothelial function

Objective: this study ws undertaken to examine and compare the effects of t hrombus, thrombectomy, and thrombolysis on endothelial function as measured by endothelium-dependent vasorelaxation (EDR). Methods: adult, male New Zealand white rabbits underwent ligation of the le ft common iliac to femoral artery to induce thrombosis and were then random ly assigned to one of five groups, n = 6 in each. Group A consisted of liga tion and thrombosis for 4h. Group B underwent similar ligation for 4h, but without intraluminal thrombus present. Following 4h of ligation and thrombo sis, Group C underwent thrombectomy while group D was treated with urokinas e (UK), 4000 U/min for 30 min. Group E underwent UK infusion alone. The rig ht external iliac artery served as control vessel in each group. All arteri es were removed and endothelial function was determined by measuring EDR. Results: the presence of thrombus reduced EDR by 50% (group A) compared to control. Vessels with interrupted flow, but not exposed to thrombus, retain ed normal EDR (group B). Thrombectomy decreased EDR significantly (group C) compared to thrombolysis (group D) and control. UK did not significantly a lter EDR (groups D, E). Conclusions: in the absence of thrombus. Thrombectomy appeared to cause a f urther additive insult to the endothelium. In contrast, thrombolysis with U K preserved residual endothelial function. These data suggest that it is im portant to differentiate the effects of thrombus on endothelium from effect s due to thrombectomy or thrombolysis when evaluating treatment modalities for arterial thrombosis.