A Special Clinical Scenario for Transcatheter Aortic Valve Replacement: "Iatrogenic Double-Outlet" Left Ventricle

A 67-year-old man with a history of chest radiotherapy and severe aortic valve stenosis with calcification of the ascending aortic wall underwent implantation of an apicoaortic conduit from the left ventricular apex to the descending aorta. Eight years later, he presented with progressive exertional dyspnea. Imaging revealed severe native aortic valve insufficiency and calcification, with worsening left ventricular function. We decided to leave the apicoaortic conduit intact and perform transcatheter aortic valve replacement with a balloon-expandable prosthesis. Despite concerns that eliminating the obstruction across the native left ventricular outflow tract might decrease conduit flow and eventually cause graft thrombosis and peripheral embolization, we elected to move forward after a multidisciplinary discussion. The procedure resulted in angiographically and qualitatively similar forward flow across the newly implanted prosthesis and the existing apicoaortic conduit, with no hemodynamic or electrical dysfunction. The patient was discharged from the hospital the next day. At the 1-month follow-up visit, the patient felt well and reported marked functional improvement, with minimal symptoms during moderate to heavy exertion. The stroke volume index across the new bioprosthetic valve was low (13 mL/m2 at 1 mo and 18 mL/m2 at 1 y), suggesting that a substantial amount of blood was still exiting the ventricle through the left ventricle-to-aorta conduit. This report offers some guidance for treating patients with existing apicoaortic conduits and suggests that transcatheter aortic valve replacement is safe and effective if native aortic valve insufficiency develops.