Abstract
Background and Clinical Significance: Subvalvular aortic stenosis (SAS) is the second most common form of aortic stenosis after valvular disease and predominantly affects male patients. It is frequently associated with other congenital cardiac anomalies, such as ventricular septal defect, and is rarely diagnosed during infancy. Instead, SAS typically manifests during childhood or adulthood as a progressive left ventricular outflow tract obstruction, leading to left ventricular hypertrophy and, in many cases, aortic regurgitation. Case Presentation: The first patient was a 61-year-old man presenting with progressive dyspnea, in whom echocardiography revealed severe subaortic stenosis and computed tomography demonstrated aneurysmal dilatation of the ascending aorta. Intraoperatively, the aortic valve was found to be dystrophic with mixed stenotic and regurgitant disease; therefore, subaortic membrane resection, mechanical aortic valve replacement, and ascending aortic replacement with a synthetic graft were performed. The second patient was a 31-year-old man with exertional dyspnea and a discrete subaortic membrane associated with mild ascending aortic dilatation. Surgical treatment consisted of complete membrane resection and aortic valve repair, while the ascending aorta was preserved. Both patients had an uneventful postoperative course and were discharged on the fourth postoperative day. At 3-month follow-up, both were asymptomatic, in normal sinus rhythm, and demonstrated satisfactory echocardiographic findings without residual left ventricular outflow tract obstruction. Conclusions: Surgical intervention remains the definitive treatment for subvalvular aortic stenosis when clinically indicated. Concomitant cardiac or aortic pathology should be addressed during the same procedure to optimize outcomes. When performed with meticulous technique and appropriate patient selection, surgical correction is associated with excellent early recovery and favorable mid-term results, although long-term follow-up remains essential due to the risk of recurrence.