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.