The prevention of mitral restenosis represents one of the most significant problems in mitral valve surgery today.1,4 This study of 66 patients in which recurrent mitral stenosis was proved by operation or autopsy was undertaken to delineate the cause of this distressing occurrence.
The case records of these 66 patients were particularly closely studied from the point of view of the valve findings (calcium, thrombi, etc.) and the rapidity of restenosis. All these patients were operated upon on each occasion by the same surgeon (C.P.B.) by a closed technique. An additional 60 patients were excluded who had initial operations elsewhere. This series ends in August, 1959, when we began routine open operations for mitral stenosis.
In Table 1 is shown age grouping by decades of the various patients who were reoperated upon. The autopsy cases are excluded. The age of the average patient at his first operation roughly corresponds