An incidentally detected giant membranous interventricular septal aneurysm secondary to previous surgery for subaortic valvular stenosis.

Ventricular septal aneurysms are rare clinical entities and their certain prevalence and clinical significance are not well known. Most of them are thought to develop during or after the closure process of the accompanying ventricular septal defects. Although a majority of the patients are typically asymptomatic, the potential risks should also be kept in mind. We present a case of a membranous interventricular septal aneurysm that developed after surgery for subaortic valvular stenosis. The points that make our case worth reporting are development of the aneurysm after aortic surgery and lack of a concomitant ventricular septal defect. On the basis of the existence of an aortic valve surgery history and reports that do not mention any ventricular septal defect and ventricular septal aneurysm when she was operated, we suggest that the aneurysmatic formation in the membranous portion of the interventricular septum developed due to valve surgery in the postoperative wound healing period.