ONLY LIMITED experimental work has been done on the study of chronic aortic insufficiency.1 Methods used in the past in the production of chronic aortic insufficiency include the cautery, hooks, stylets, biopsy forceps, and the like.2-6 However, all these methods were for the most part unpredictable in their immediate or long-term results. Either too severe regurgitation was produced, ending in death of the experimental animal, or the defect in the aortic cusp would heal.
The best results so far in the production of aortic regurgitation have been obtained by Nolan and Muller1 with the method of Roshe and Morrow.7 Their instrument was complicated by the fact that they had to use suction through an airtight cylinder. Through experimentation with various methods, we have developed a new and simpler instrument * which reliably produces a round defect of any desired size in any aortic cusp under direct vision