The surgical treatment of fixed subaortic stenosis: A clinical experience in Japan

We report herein the results of a retrospective study conducted on ten cons ecutive Japanese patients who underwent successful surgical relief of fixed subaortic stenosis between 1972 and 1994 at ages ranging from 8 months to 21 Sears, and followed for 3.6 gears and 26 years, Associated cardiovascula r defects were present in six patients, two had a history of infective endo carditis, a discrete fibrous ring was found in nine patients, and a redunda nt abnormal sheet was found in one. A stenotic structure was removed in nin e patients and incised in one, while myotomy was additionally performed in one, There were no early complications or deaths. Cardiac catheterization r evealed a significant decrease in the peak systolic pressure gradient from 84 +/- 22 mmHg preoperatively to 32 +/- 22 mmHg postoperatively (P = 0,0017 ), Reoperation of an aortic valve replacement with or without valvular annu lus enlargement was required in four patients because of a small annulus wi th aortic insufficiency or infective endocarditis. Infective endocarditis w as a major cause of late mortality (n = 1) and morbidity (n = 1), but the r emaining eight patients have been asymptomatic, Thus, although this lesion is relatively rare in Japan, the typical discrete type may be more common t han previously believed. While a relief operation is associated with low ea rly mortality, the palliative aspect regarding pathology of the aortic valv e should not be underestimated, including poor growth of the valve annulus, deterioration of aortic insufficiency, and infective endocarditis, The mos t appropriate operative procedure for reoperation remains to be evolved.