A case of a quadricuspid aortic valve identified preoperatively using transthoracic echocardiography.

Quadricuspid aortic valve is an extremely rare congenital heart anomaly that often causes valve incompetence, requiring surgical intervention. Care must be taken to avoid surgical complications in patients with quadricuspid aortic valve; thus, preoperative diagnosis is important. A 76-year-old man presented with exertional dyspnea due to aortic regurgitation. Transthoracic and transesophageal echocardiography revealed severe aortic regurgitation caused by quadricuspid aortic valve. To avoid interference with the cardiac conduction system, we performed aortic valve replacement using an ingenious technique, in which pledgeted sutures on the accessory leaflet were placed from outside the sinus of Valsalva to above the aortic annulus. The patient recovered uneventfully and was discharged from the hospital without any complications. While preoperative diagnosis of quadricuspid aortic valve is considered difficult, we identified it preoperatively using transthoracic echocardiography; we were, thus, able to properly prepare for complete atrioventricular block.