[Organic subaortic stenosis. Surgical indications, surgical technic, late results]

Between 1966 and 1979 60 patients underwent resection of organic subaortic stenosis at the National Heart Hospital. There was a male:female ratio of 40:20 and an age range of 4 to 56 years (mean 18 years). 22 patients (36.7%) had a single or multiple additional cardiac abnormalities including left ventricular outflow tract obstruction (12 cases), right ventricular outflow tract obstruction (3 cases), ventricular septal defect (6 cases), patent ductus arteriosus (5 cases), aortic coarctation (1 case), congenital mitral stenosis (1 case) and mitral atresia associated with a single ventricle (1 case). Isolated resection of the organic sub-aortic with myotomy and wedge resection was performed in 47 patients and Cooley technique in 2 patients. Total aortic root replacement with a homograft valve was necessary in 4 patients and the 22 patients additional cardiac abnormalities received concomitant surgery. There was one early death (2.6%) amongst the 38 patients with isolated organic sub-aortic stenosis and no late deaths. There were 3 early deaths (13.7%) amongst the 22 patients with additional cardiac abnormalities and one late sudden death after 14 months. There were 7 non-fatal complications: a myocardial infarction, AV block and pacemaker insertion; three mild aortic regurgitations; one mild mitral regurgitation; an arrhythmia due to Wolf Parkinson White syndrome; and an aortic and mitral valve replacement after 9 years. 43 other patients have been followed for 1 to 14 years and are symptom free. Left bundle branch block is present in two of them. Resection of organic sub-aortic stenosis with myotomy and wedge resection is a safe technique and offers an excellent prognosis for this group of congenitally compromised patients.