The antithrombotic effects of ticlopidine and aspirin in a microvascular thrombogenic model

In the effort to reduce a persistently significant failure rate in free tissue transfers and digital replantations, the efficacy of two oral platelet inhibitors, aspirin and ticlopidine, was examined using the arterial inversion graft, a known microvascular thrombogenic model. Forty male New Zealand White rabbits were used to create eighty 5-mm inversion grafts. Four groups were blindly given perioperative oral drug therapy: ticlopidine, aspirin, both, or neither (control). Vessel patency was evaluated at 1 hour and 1 week after surgery. The patency rate for the control group was 20 percent at 1 hour and 5 percent at 1 week. The drug-treated patency rates at 1 hour and 1 week, respectively, were 45 percent (p = 0.046) and 15 percent for ticlopidine, 35 percent and 10 percent for aspirin, and 45 percent (p = 0.046) and 20 percent for the combination therapy. This study shows that ticlopidine alone or in combination with aspirin significantly increases the 1-hour patency rates in a reliable thrombosis model, but it fails to show a significant increase in the final patency rates by either drug administered alone or in combination. The benefit in clinical microvascular surgery of either aspirin or ticlopidine is not determined by this study.