First Report of an Acute, Obstructive Thrombosis of a Melody Valve Used for Transcatheter Pulmonary Replacement.

Transcatheter pulmonary valve (TPV) replacement is an effective therapy of right ventricular outflow tract conduit dysfunction. Acute complications after TPV implantation include infective endocarditis, stent fracture, and device dislocation. We present a novel, life-threatening complication: an acute, noninfectious TPV thrombosis. Within 24 hours after implantation of a Melody system (Medtronic, Inc, Minneapolis, MN), the patient developed an acute TPV thrombosis characterized by severe TPV stenosis on echocardiography and contrast filling defects on computed tomography pulmonary angiography images. Genetic testing revealed heterozygous prothrombin G20210A polymorphism and homozygous 4G/4G polymorphism of the plasminogen-activator-inhibitor. The patient recovered after surgical valve replacement with a pulmonary homograft.