The national success rate for microvascular free tissue transfer is around 94%. However, in cases of failure, which is most often due to thrombosis in the vascular pedicle, the morbidity can be significant. Microvascular surgeons have used various pharmacologic agents to reduce thrombosis rates; however, none have been ideal. We examined the effects of clopidogrel bisulfate (Plavix), a member of the relatively new class of antiplatelet agents, on the rate of arterial thrombosis in a rat model.
Prospective randomized, blinded.
Tertiary care academic medical center.
Male Sprague-Dawley rats weighing between 350 and 400 g.
Clopidogrel or placebo via gavage. After waiting 2 hours for absorption and activation, the “tuck” model of microvascular anastomosis was performed on both femoral arteries. Arteries were transected after 3 hours and patency was assessed.
Main Outcome Measures
Bleeding time was obtained by determining the time to clot after removal of 2 mm from the tail tip. Vessel patency was assessed after 3 hours in the clopidogrel-treated and control groups.
Of 33 arteries, 19 (58%) in the control group developed complete thrombosis by the end of the period compared with only 6 (19%) of 32 arteries in the group that received clopidogrel. χ2 Analysis revealed this to be significant (P = .001). The mean (SD) bleeding time in the control group was 158 (44) seconds compared with 233 (48) seconds in the clopidogrel group.
Clopidogrel significantly reduced the rate of arterial thrombosis in a rat model of microvascular repair. The average bleeding time in the clopidogrel group was prolonged, suggesting that absorption and activation occurred. These preliminary data suggest a potential role for clopidogrel in select high-risk patients undergoing microvascular free tissue transfer.