Collateral Circulation and Survival Related to Gradual Occlusion of the Right Coronary Artery in the Pig

Abstract

Studies of survival following ligation and gradual occlusion of the right coronary artery 5 mm. from its ostium have been made in 95 pigs. The pig was selected for the experiments because its coronary artery distribution closely resembles that of the human. Gradual occlusion was produced by constrictors made of a hygroscopic plastic. Survival following gradual occlusion is considered to be due to the development of collateral circulation. Comparisons of survival have been made in untreated animals and in animals treated with an orally administered, long-acting nitrate (pentaerythritol tetranitrate). Increased survival in the animals which received medication is thought to be due to the drug's acting as an aid to collateral circulation.