Transcatheter pulmonary valve replacement

Philipp Bonhoeffer
Chief of Cardiology, Director of the Catheterisation Laboratory,
Great Ormond Street Hospital for Children NHS TrustProfessor of Cardiology, Institute of Child Health
London, UK

Until recently, definitive treatment of heart valve disease has required surgical repair. Whilst balloon valvuloplasty has been available only for the treatment for stenotic pulmonary and aortic valves in congenital lesions, recent advances in stent and balloon technology have led to an extension in indications to those with patients with acquired stenotic or even regurgitant disease.
　Transcatheter pulmonary valve replacement represented the first human experience of this concept, with over 800 cases performed worldwide and an overall mortality of <5% with a maximal follow-up of over 8 years. There is an increasing number of patients treated with the current device. The patients who have been treated with this novel technique typically have residual pulmonary regurgitation or stenosis in right ventricular to pulmonary artery conduits, following earlier repair of congenital heart defects. The application of this approach is presently restricted to RVOT morphologies, measuring <22mm, since the device needs to be anchored safely to prevent device dislodgement.
　In our own experience with > 220 patients, early results show an improvement in symptoms, exercise capacity and biventricular performance following valve implantation. Major procedural complications included valve dislodgement (2 cases), homograft rupture (3 cases), coronary artery compression (1 case), right pulmonary artery obstruction (1 case), and perforation of the left pulmonary artery (n=1). During follow-up, stent fractures have been documented in around 20% of patients and mostly were incidental. In the event of associated obstruction, implantation of a second device within the first proved to be effective to further prolong conduit lifespan. Although follow-up is limited to 7 years, the durability of the valve appears good and mean freedom from explantation is currently 68.5 months.