Effect of aspirin on experimentally induced arterial thrombosis during the healing phase

Twenty dogs were treated with either acetylsalicylic acid or a lactose placebo for 5.5 ± 2.3 days before surgical or chemical injury to the carotid and femoral arteries and for the following 34.5 days. Only the laboratory diener had knowledge of the random table used to select type of treatment until after all determinations had been completed. Following sacrifice the arteries were classified for the presence of intimal proliferation, defects in the internal elastica, presence of organized thrombi and the percentage of recanalization, and the presence of fresh thrombi and the percentage of occlusion. Thrombi were present in 8% of the arteries of dogs treated with acetylsalicylic acid and in 36% of those treated with placebo. This difference is significant (P<0.01). The degree of intimal proliferation and defects in the internal elastica were not significantly different between the two groups. We conclude that in dogs acetylsalicylic acid therapy during the healing phase following arterial injury protects against thrombosis and does not retard the healing process.

Cerebral blood flow, metabolism and mean arterial pressure changes following unilateral internal carotid endarterectomy: cerebral ischemia and elevated systemic arterial pressure

Cerebral blood flow and metabolism studies were performed on 13 patients before and after unilateral carotid endarterectomy for severe atheromatous occlusive disease. Mean brachial arterial pressure was monitored during these studies. Postoperative studies compared to a control group revealed a rise in cerebral blood flow and a fall in mean arterial pressure and cerebral vascular resistance. The clinically recorded blood pressure in the study group compared to closely matched control patients with cerebral vascular disease showed a similar but not significant difference. Ten patients studied following ligation of a common carotid artery had a small but significant increase in mean systemic arterial pressure. These results suggest a relationship between systemic arterial pressure and cerebral ischemia. Some possibilities for this relationship are discussed.