SURGEONS have been interested in mitral stenosis, experimentally, for more than half a century.1 Logically, this interest first became manifest as an attempt to produce stenosis of the mitral valve in the experimental animal. If the disease could be reproduced in animals, the relative merits of various surgical technics for the relief of the sequelae of mitral stenosis could more easily be determined. On the basis of information so gained, proper application to this disease in human beings might be made without resort to trial and error in clinical cases. Such application could be perfectly valid, even though the disease as it occurs naturally in human beings, a cicatricial stenosis consequent upon healing of an infectious granuloma, and that obtained in the animal have a different mechanism of production.
The primary aim of corrective surgical treatment is the relief of the dynamic disturbances of circulation caused by the valvular