[Use of aspirin in the primary prevention of vascular thrombi. A comparative study with other anti-aggregant drugs].

We have induced the formation of arterial (carotid) and venous (femoral) thrombi in dogs by means of an intima lesion produced by continuous current. The platelets were labeled with 111In oxine. Groups of 7 mongrel dogs received treatment for 7 days prior to the trial: group I, control; group II, 5 mg/kg body weight/day acetylsalicylic acid; group III, 20 mg/kg body weight/day acetylsalicylic acid; group IV, 15 mg/kg body weight/day triflusal + 5 mg/kg body weight/day dipyridamole; group V, 15 mg/kg body weight/day triflusal; and group VI, 5 mg/kg body weight/day acetylsalicylic acid + 5 mg/kg body weight/day dipyridamole. The only effective treatment for arterial thrombosis prevention was that employed in group II (p less than 0.05). Venous thrombosis was prevented in groups II (p less than 0.01), III (p less than 0.01) and VI (p less than 0.01).