Effects of triflusal and acetylsalicylic acid on microthrombi formation in experimental brain ischemia.

Ischemic cerebral infarcts induce hypercoagulation and microthrombosis, thus leading to vessel occlusion and reduction of local cerebral blood flow. Antiaggregant therapy can reduce the formation of microthrombi. We tested the effect of acetylsalicylic acid (ASA) and triflusal (2-acetoxy-4-tri-fluoromethylbenzonic acid) on the formation of microthrombi after middle cerebral artery (MCA) occlusion. Six groups of rats, each consisting of six animals received either ASA or triflusal at dosages of 12.5, 25 or 50 mg/1,000 g b.wt./day. One control group was sham-operated, in another control group MCA occlusion was performed; both groups received no therapy. The number of microthrombi was counted 7 days after MCA occlusion on paraffin sections. The highest number of microthrombi was found in the group with MCAO and without therapy (mean 28 microthrombi/animal). In treated groups a reduction of the number of microthrombi could be stated. The strongest reduction was achieved in the group treated with 12.5 mg triflusal (mean 5.2). No statistic significant difference in the number of microthrombi was found between the groups treated with 12.5 mg triflusal and 50 mg ASA (mean 8.7) compared to sham-operated control animals (mean 4.3, p greater than 0.05). Treatment with 12.5 mg triflusal was superior to 50 mg ASA in preventing microthrombi formation (p less than 0.05). These results indicate, that in experimental brain ischemia the number of microthrombi can be effectively reduced by application of antiaggregatory drugs.