Transcatheter Aortic Valve Dislocation into the Left Ventricle Caused by the Watermelon Effect

Transcatheter aortic valve implantation (TAVI) is a well-established method for treating severe aortic stenosis. Prosthetic valve dislocation immediately after deployment is a rare and feared complication. We present a case of a patient with severe, symptomatic aortic stenosis who was admitted for TAVI. During balloon inflation the valve (Edwards SAPIEN XT) dislocated into the left ventricle as a result of the watermelon effect caused by a narrow, severely calcified sino-tubular junction. A second valve of the same type and size was immediately implanted in a suboptimal position in order to reduce severe aortic regurgitation. This facilitated the use of veno-arterial extracorporeal membrane oxygenation support (V-A ECMO). The patient was thereafter stabilized and transferred for urgent surgery, where both prosthetic valves were removed. The aortic valve was replaced with an additional reconstruction of the ascending aorta.