Imaging for preintervention planning: transcatheter pulmonary valve therapy

For many congenital heart defects treated in infancy (eg, tetralogy of Fallot, transposition of the great arteries, double outlet right ventricle), long-term right ventricular outflow tract (RVOT) dysfunction, in the form of pulmonary stenosis and regurgitation, is a common finding as patients become older (older children, adolescents, and adults). This dysfunction can lead to right ventricular (RV) dilatation, progressive dyspnea, arrhythmia, and sudden cardiac death.1,2 Patients are often treated with RV to pulmonary artery (PA) conduits or homograft, which have a finite lifespan and may require replacement every decade or sooner, with pulmonary valve replacement at open-heart surgery.3,4 Medical management has a limited role,5 and although conduit/homograft stenosis can be managed percutaneously with balloon dilatation and bare metal stent insertion6 to prolong conduit/homograft life, this has the inevitable consequence of inducing free pulmonary regurgitation. During the last decade, however, percutaneous pulmonary valve implantation (PPVI) has been developed to provide a minimally invasive, transcatheter-based approach to prolong conduit/homograft life by treating stenosis and regurgitation without the need for open-heart surgery, thereby reducing procedural risks, hospital stay, and the time it takes to return to normal daily activities. Since the first, pioneering human PPVI in 2000 by Bonhoeffer et al,7 the technique has gained acceptance, with >4000 procedures performed to date. Several studies have now demonstrated the short-term efficacy of PPVI8–13 and defined the potential complications of the procedure, including device migration and fractures,14 coronary compression,15 and infective endocarditis. Sustained relief from stenosis and regurgitation has also been demonstrated in the medium term, with freedom from reoperation of 93%, 86%, 84%, and 70% at 10, 30, 50, and 70 months, respectively, with similar freedom from redo interventions 95%, 87%, 73%, and 73% at the same intervals. Survival at …