Current Experience with Percutaneous Pulmonary Valve Implantation Johannes Nordmeyer, Louise Coats, MRCP, and Philipp Bonhoeffer, MD Transcatheter valve replacement has recently been introduced into clinical practice and has the potential to transform the management of valvular heart disease. To date, the largest human experience exists with percutaneous pulmonary valve implantation in patients with repaired congenital heart disease who require re-intervention to the right ventricular outflow tract. The application of this approach, however, is presently restricted to certain right ventricular outflow tract morphologies, because the device needs to be anchored safely to prevent device dislodgement. Early results of percutaneous pulmonary valve implantation show lower morbidity than surgery and significant early symptomatic improve- ment. In the future, the challenge will be to extend percutaneous pulmonary valve implan- tation to all patients with a clinical indication to delay or avoid repeat open-heart surgery. Semin Thorac Cardiovasc Surg 18:122-125 © 2006 Elsevier Inc. All rights reserved. KEYWORDS percutaneous valve replacement, pulmonary valve, congenital heart disease, catheterization A cquired dysfunction of the pulmonary valve in the adult population is rare, whereas dysfunction of the right ventric- ular outflow tract (RVOT) can be commonly found in patients with repaired congenital heart disease. Conventionally, these patients now undergo repeat heart surgery in an attempt to restore pulmonary valvar competency and to protect from right ventricular dysfunction and arrhythmia. Unfortunately, various factors limit the longevity of biological valves and patients may require several reoperations during a lifetime. These factors in- clude aneurysmal dilation, degeneration, calcification, and lack of growth. 1-3 In 2000, a valved stent was implanted for the first time percutaneously into a degenerated right ventricular (RV) to pulmonary artery (PA) prosthetic conduit of a 12-year-old boy. 4 This intervention has now been performed in over 120 patients with repaired congenital heart disease (age 7 to 59 years), with the initial series recently reported, 5 and has the potential to reduce reoperations for this patient group. Procedure Valved Stent The device is composed of a bovine jugular venous valve su- tured to a balloon-expandable platinum iridium stent (Numed, Hopkinton, NY, Fig. 1A). It is mounted on a specially designed delivery system with a balloon-in-balloon catheter (Numed, Fig. 1B) available in diameters of 18 to 22 mm. 6 The valved stent is delivered to the RVOT via the venous circulation, usually from a femoral approach, under general anesthesia with the guidance of biplane angiography (Fig. 2). Indications There are clinical and morphological criteria that are applied to judge the suitability for percutaneous pulmonary valve implantation (PPVI). At our institution, every potential can- didate for PPVI undergoes echocardiography, magnetic res- onance imaging (MRI), electrocardiogram, and cardiopulmo- nary exercise testing to assess ventricular function and RVOT morphology. Clinical indications for PPVI mirror the conventional cri- teria for surgical re-intervention and include pulmonary re- gurgitation with increasing right ventricular size, substantial tricuspid regurgitation, arrhythmia, and/or impairment in exercise capacity or RVOT obstruction with right ventricular pressures greater than 2/3 systemic. The timing of re-inter- vention remains subject to debate as some investigators have found that right ventricular dysfunction may not be recover- able. 7 Typically, this concern has had to be balanced against the limited longevity of biological valves and the need for reoperation in the future. The percutaneous approach now offers a less invasive treatment, without the need for cardio- pulmonary bypass, which may potentially shift the indica- tions toward earlier intervention. The Cardiac Unit, Institute of Child Health and Great Ormond Street Hospital for Children, London, United Kingdom. This work was supported in part by the British Heart Foundation. Address reprint requests to Dr. Johannes Nordmeyer, Cardiothoracic Unit, Great Ormond Street Hospital for Children, Great Ormond Street, London WC1N 3JH, UK. E-mail: NordmJ@gosh.nhs.uk 122 1043-0679/06/$-see front matter © 2006 Elsevier Inc. All rights reserved. doi:10.1053/j.semtcvs.2006.07.006