Diffuse subaortic stenosis: modified Konno procedures with aortic valve preservation.

The Konno procedure provides adequate relief of diffuse subaortic stenosis but requires aortic valve replacement. This may be questionable in patients without aortic valve lesions. Eleven patients had diffuse subaortic stenosis and normal aortic orifice: tunnel subaortic stenosis (6 patients) or diffuse hypertrophic obstructive cardiomyopathy (5 patients). The mean age was 16 ± 14 years (range: 3 months to 45 years). The mean subaortic gradient was 95 ± 24 mmHg (range: 60 to 150 mmHg). Two patients had previously undergone resection of discrete subaortic stenosis. Modified Konno procedures were used: aortoseptal approach with aortic annulus division in 5 patients, conal enlargement without aortic annulus division in 6 patients. There was one early death (9%, 70% CL = 1%-27%) and no late deaths