[Fixed subaortic stenosis in childhood. The surgical correction of 28 cases]

Between January 1976 and December 1989, 28 patients with fixed subaortic stenosis underwent surgical correction. Twenty-one were male and seven female. The mean age when surgery was performed was 7.4 years (range 14 months to 14 years). Angiography was not done in 8 patients (28.5%). Fourteen had a subaortic stenosis due to a fibrous shelf and the other 14 to a fibromuscular one. Fifteen had associated anomalies, seven aortic stenosis, three aortic regurgitation and four mitral disturbances. Three surgical procedures were carried out: resection in 16 patients (57.1%), resection and myotomy in ten (35.7%), and resection with myectomy in two (7.1%). In 5 patients a residual stenosis was detected, one of whom required repeated surgery, and 2 other patients developed recidive of the stenosis (both required repeated surgery). Prosthetic valves (five aortic and one mitral) were inserted in 6 patients (21.4%). One of these required an aortic valve conduct. Pacemaker was placed in other 4 patients (two with prosthesis). No patient died and 20 (71.4%) are normal, nowadays, with a mean follow-up of 5.5 years. We conclude that fixed subaortic stenosis is a serious disease which requires correction at the time of diagnosis, independently of gradient. The type of surgical procedure influences in recidive. The older patients with the fibromuscular type and associated anomalies are candidates for a prosthetic valve.