Evaluation of subvalvular aortic stenosis in children: a 16-year single-center experience

Subvalvular aortic stenosis accounts for 1-2 % of all congenital heart disease and for 8-20 % of cases of left-ventricular outflow tract (LVOT) obstruction in children. Recurrence of subaortic stenosis (SAS) is not uncommon after surgical management. This study was performed to investigate the clinical and surgical outcomes and to estimate the predictability of recurrences of SAS. Seventy-nine patients age 3-21 years with SAS between 1994 and 2010 were reviewed. Fifty-one patients had discrete SAS, whereas the remaining 15 patients had fibromuscular ridge-type SAS. Mean follow-up time without surgery was 22 months (range of 1-94). Forty-one patients with a diagnosis of SAS underwent surgery. Recurrence rates were 22.7 % (15 patients), and these patients developed SAS at a mean of 4.7 years follow-up. We performed second surgical membrane resection in only 1 patient. The risk of recurrence of SAS was only linked to higher preoperative LVOT gradient. Twenty-three patients had no aortic regurgitation (AR) at preoperative echocardiography. Of these, 39.1 % had trivial, 8.7 % had mild, and 8.7 % had moderate AR after surgery; there was no significant AR. We conclude that surgical intervention was required most of the time in patients with SAS, and surgical outcomes was excellent even if there were associated cardiac defects. The risk of recurrences was higher, especially in patients with higher initial LVOT gradients, although a second surgery was rarely necessary in these patients.