Unruptured congenital sinus of Valsalva aneurysm causing right ventricular outflow tract obstruction associated with hidden ventricular septal defect: a case report

BACKGROUND: Sinus of Valsalva aneurysms are rare congenital lesions. Unruptured aneurysms are often silent, but when they are large, they can cause symptoms by compressing nearby structures. This case is notable because an unruptured aneurysm from the right sinus produced severe right ventricular outflow tract obstruction and concealed a ventricular septal defect that was not detected on preoperative imaging. CASE PRESENTATION: A 45-year-old man with a remote history of congenital heart disease and no follow-up presented with three weeks of progressive shortness of breath, which was consistent with New York Heart Association classes II to III. He was stable but had signs of right-sided heart failure, including elevated jugular venous pressure and bilateral leg edema. Transthoracic echocardiography revealed a large saccular aneurysm arising from the right sinus of Valsalva and protruding into the right ventricle with severe right ventricular outflow tract obstruction and a peak systolic gradient of 80 mmHg. Transesophageal echocardiography confirmed the aneurysm and obstruction; an agitated saline study did not demonstrate intracardiac shunting. Cardiac computed tomography confirmed the aneurysm anatomy and vascular dilation, and coronary angiography showed normal coronary arteries. The patient underwent surgical repair with excision of the large aneurysmal sac, closure of an intraoperatively discovered ventricular septal defect using a pericardial patch, and valve-sparing aortic root reimplantation with a tube graft and aortic valve repair. He was discharged five days after surgery without complications. At one month, echocardiography revealed preserved left ventricular function, relief of outflow obstruction, no residual shunt, decreased pulmonary artery dilation, and mild residual aortic regurgitation. CONCLUSIONS: A large unruptured sinus of Valsalva aneurysm can cause severe right ventricular outflow tract obstruction and can mask an associated ventricular septal defect despite negative shunt assessment. Surgeons and imagers should anticipate occult associated defects when planning repair.