We can, but should we?

European Journal of Cardio-Thoracic Surgery, vol. 59, pp. 830–831

Abstract

Previously, surgical pulmonary valve replacement has been the only therapeutic option for right ventricular outflow tract (RVOT) dysfunction. Since 2000, transcatheter pulmonary valve implantation has become an alternative for these patients. Hybrid techniques have been introduced to overcome some limitations of catheter-based techniques due to patient size or the anatomy of RVOT. Breatnach et al. [1] describe their short-term experience with hybrid pulmonary valve (Melody, Medtronic Plc, Dublin, Ireland) insertion in 10 very young children (median age 1.5 years). Diagnoses were pulmonary atresia, ventricular septal defect, major aortopulmonary collaterals (6), tetralogy of Fallot (2), double outlet right ventricle—atrioventricular septal defect (1) and conduit failure after Ross procedure (1). Increased pulmonary artery pressures, distorted pulmonary artery anatomy, conduit failure or right ventricular dysfunction were reported as indications for pulmonary valve replacement. Seven valves were deployed in the native RVOT while 3 were inserted into an existing right ventricle-to-pulmonary artery conduit. Pulmonary valve was inserted using a hybrid approach using a full sternotomy or a subxiphoid incision. Cardiopulmonary bypass (CPB) was utilized in 6 patients. Melody valves were dilated to 15–20 mm, and an extra stent was used in 3 patients. No mortality occurred, 2 patients needed repeat balloon dilatation for postprocedural paravalvular leak, and a new Melody had to be inserted in 1 patient. Endocarditis was observed in 1 patient. When a new technique is introduced there must be a reasonable expectation that the newer method will prove superior to the techniques that are used in current practice. Obvious superiorities of the hybrid approach include less invasiveness, better cosmetics and the avoidance of CPB. Another advantage could be the possibility to increase the valve diameter at a later stage. A newer valve should reasonably be expected to have a higher durability than the valves currently in use. Complication risks should be lower and last but not least the costs involved should not be prohibitive. Furthermore, there must be a clear indication when a novel operation is chosen for. Reasonable expectation is the key issue here. Some expectations are not completely fulfilled while others are doubtful. CPB was used in more than half of the patients, and full sternotomy and subxiphoidal incision were employed in several infants. Lifelong Aspirin is needed while currently used valves can safely do without any anticoagulation. Although less essential, the costs of valved homografts, bovine jugular vein grafts or Hancock valved conduits are substantially lower than those of the Melody valve. Furthermore, it is hard to believe that smaller Melody valves will outperform homografts in terms of durability and event-free functioning [2,3]. A major concern is the potential risk of infection as there are several publications reporting a high incidence of endocarditis associated to the Melody valve [4,5]. We know that a competent pulmonary valve is not always needed. Patients with tetralogy of Fallot can live decades before pulmonary regurgitation leads to symptomatic RV dilatation [6]. Although 6 patients here had pulmonary atresia, ventricular septal defect and major aortopulmonary collaterals, not all the diagnoses in the reported group would typically be in need for pulmonary valve insertion. A transannular patch may have been enough postponing the need for prosthetic valve insertion to a (much) later stage. Once a valve, always a valve says the adagium. The young age of study cohort might be another issue. In a recent multicentre Melody trial, younger age (<13 years) was associated with the higher risk of endocarditis (20% over a 5-year period) and a shorter freedom from reintervention and explant after Melody pulmonary valve insertion [5]. Breatnach et al. are to be complimented for honestly reporting their experience. The hybrid approach has certainly advantages, but its superiority will depend on the type of valve used, on the possibility to completely avoid CPB while the indications for placing a prosthetic valve at such a young age must be properly met. We look forward to the report on longer follow-up with this hybrid approach, but at the same time we express our concern that a reasonable expectation of the technique being superior may not be obtained.

Authors 2

1. Mark Gerard Hazekamp corresponding Aachen Department of Cardiothoracic Surgery

   Leiden University Medical Center

   Affiliation as printed

   Department of Cardiothoracic Surgery, University Hospital Leiden, Leiden, Netherlands

2. Vladimír Soják Aachen Department of Cardiothoracic Surgery

   Leiden University Medical Center

   Affiliation as printed

   Department of Cardiothoracic Surgery, University Hospital Leiden, Leiden, Netherlands