Long-term results of surgical repair in patients with congenital subaortic stenosis.

OBJECTIVES: The aim of the study was to analyze the long-term results of congenital subvalvar aortic stenosis (SAS) relief and the risk factors associated with recurrence and reoperations.
METHODS: Between January 1960 and March 2005, 190 patients underwent surgical correction for discrete (n=140) and tunnel (n=50) congenital subaortic stenosis. There were 115 male and 75 female patients ranging in age from 1 week to 36 years (mean age, 8.2+/-4.4 years). Preoperatively, 133 patients were in NYHA functional class I or II, 57 in class III or IV. There were several initial surgical procedures performed in patients with congenital subaortic stenosis: fibrous or fibromuscular subaortic resection, apical aortic conduit insertion, aortic valve replacement with mechanical valve, Ross and/or Konno procedure.
RESULTS: There were 7 early (4%) and 10 late (5%) deaths. Actuarial survival including operative mortality of patients with discrete and tunnel SAS was 94% and 84% at 40 years (P=0.14), respectively. Within 7.1+/-6.2 years a recurrent peak aortic gradient >50 mmHg and moderate to severe aortic insufficiency were found in 50 patients (28%), all of whom had 104 reoperations. At late follow-up, ranging from 6 months to 42 years (mean 9.6+/-7.5 years), the left ventricle-aorta gradient was higher in patients with tunnel versus discrete obstruction (28+/-11 mmHg vs. 13+/-9 mmHg; P=0.01) with a 40-year poor freedom from reoperation (14% vs. 89%; P<0.001).
CONCLUSION: Patients with tunnel SAS and complex multilevel left ventricular outflow tract obstruction required higher reoperation rates. Aortic valve replacement with pulmonary autograft (Ross procedure) performed at our institution resulted in low mortality and morbidity.