Imaging for Preintervention Planning Transcatheter Pulmonary Valve Therapy

In contrast to the 50 000+ transcatheter aortic valve replacements to date since 2002, PPVI has enjoyed a more gradual, but nonetheless measured success. Dynamic RVOT characteristics pose greater technical challenges, and preimplantation 3D imaging can be considered the mandatory gold standard for safe patient selection for PPVI. Currently available percutaneous valve sizes remain the rate-limiting step to increasing the number of patients eligible for PPVI, but characterization of RV morphology may also play an important role for designing new devices. Finally, a patient-specific approach (preimplantation 4D imaging, hybrid FEM, and 3D physical prototyping) can be used to improve safety and accuracy in selection of borderline cases. Preimplantation modeling and prototyping is vital to assess morphological suitability with 3D imaging for reintervention to predict stent fracture risk to generate patient-specific physical models in dilated RVOTs and to measure RV function and structure for accurate serial follow-up. The practicalities of designing a clinical service to deliver the above benefits require a truly multidisciplinary team approach involving surgeons, imagers, interventional cardiologists, and engineers incorporating a multimodality imaging protocol and integrated software and manufacturing tools. Despite the promise of this integrated approach, patients and their caregivers need to understand that although percutaneous therapies prolong conduit life span and delay future surgical procedures, stent fracture and redo interventions remain a real possibility. © 2013 American Heart Association, Inc.