Surgical treatment of subaortic stenosis: A seventeen-year experience

Objective: The aim of the study was to analyze the long-term results of sub aortic stenosis relief and the risk factors associated with recurrence and reoperation. Methods: One hundred sixty patients with subaortic stenosis un derwent biventricular repair. Before the operation the mean left ventricle- aorta gradient was 80 +/- 35 mm Hg, 57 patients had aortic regurgitation, a nd 34 were in New York Heart Association functional class III or IV. Median age at repair was 10 years. For discrete subaortic stenosis (n = 120), 39 patients underwent isolated membranectomy, 67 underwent membranectomy with associated septal myotomy, and 14 underwent septal myectomy, Tunnel subaort ic stenosis (n = 34) was treated by myotomy in 10 cases, myectomy in 12, se ptoplasty in 7, Konno procedure in 3, and apical conduit in 2, Aortic valve replacement was performed in 6 cases, mitral valve replacement in 2 cases, and mitral valvuloplasty in 4 cases. Results: There were 5 early (3.1%) an d 4 late (4.4%) deaths. Within 3.6 +/- 3.3 years a recurrent gradient great er than 30 mm Hg was found in 42 patients (27%), 20 of whom had 26 reoperat ions. According to multivariable Cox regression analysis survival was influ enced by hypoplastic aortic anulus (P = .01) and mitral stenosis (P = .048) ; recurrence and reoperation were influenced by coarctation and immediate p ostoperative left ventricular outflow tract gradients. At a median follow-u p of 13.3 years, mean left ventricle-aorta gradient was 20 +/- 13 mm Hg. Re lief of the subaortic stenosis improved the degree of aortic regurgitation in 86% of patients with preoperative aortic regurgitation, Actuarial surviv al and freedom from reoperation rates at 15 years were 94% +/- 1.3% and 85% +/- 6%, respectively. Conclusion: Although surgical treatment provides goo d results, recurrence and reoperation are significantly influenced by previ ous coarctation repair and by the quality of initial relief of subaortic st enosis.