Impact of right ventricular outflow tract size and substrate on outcomes of percutaneous pulmonary valve implantation

Over-expansion of right ventricle to pulmonary artery conduits during transcatheter pulmonary valve placement

OBJECTIVES

To determine the safety and feasibility of over-expansion of right ventricle to pulmonary artery conduits during transcatheter pulmonary valve placement.

BACKGROUND

Transcatheter pulmonary valve placement is an alternative to surgical pulmonary valve replacement. Traditionally, it was thought to be unsafe to expand a conduit to >110% of its original size.

METHODS

This retrospective cohort study from two centers includes patients with right ventricle to pulmonary artery conduits with attempted transcatheter pulmonary valve placement from 2010 to 2017. Demographic, procedural, echocardiographic and follow-up data, and complications were evaluated in control and overdilation (to >110% original conduit size) groups.

RESULTS

One hundred and seventy-two patients (51 overdilation and 121 control) had attempted transcatheter pulmonary valve placement (98% successful). The overdilation group was younger (11.2 versus 16.7 years, p < 0.001) with smaller conduits (15 versus 22 mm, p < 0.001); however, the final valve size was not significantly different (19.7 versus 20.2 mm, p = 0.2). Baseline peak echocardiographic gradient was no different (51.8 versus 55.6 mmHg, p = 0.3). Procedural complications were more frequent in overdilation (18%) than control (7%) groups (most successfully addressed during the procedure). One patient from each group required urgent surgical intervention, with no procedural mortality. Follow-up echocardiographic peak gradients were similar (24.1 versus 26 mmHg, p = 0.5).

CONCLUSIONS

Over-expansion of right ventricle to pulmonary artery conduits during transcatheter pulmonary valve placement can be performed successfully. Procedural complications are more frequent with conduit overdilation, but there was no difference in the rate of life-threatening complications. There was no difference in valve function at most recent follow-up, and no difference in rate of reintervention. The long-term outcomes of transcatheter pulmonary valve placement with conduit over-expansion requires further study.

Percutaneous pulmonary valve implantation: what have we learned over the years?

Percutaneous pulmonary valve implantation has been widely accepted as an alternative to surgery in selected patients with right ventricular outflow tract (RVOT) dysfunction. This totally new field of our specialty pushed centres to rethink overall strategies on how to treat RVOT dysfunction. In this review, we will focus on challenges related to patient selection, and discuss innovative procedural techniques developed over the years to enlarge the number of candidates for the technique.

Transcatheter pulmonary valve implantation: will it replace surgical pulmonary valve replacement?

INTRODUCTION

Right ventricular outflow tract (RVOT) dysfunction is a common hemodynamic challenge for adults with congenital heart disease (ACHD), including patients with repaired tetralogy of Fallot (TOF), truncus arteriosus (TA), and those who have undergone the Ross procedure for congenital aortic stenosis and the Rastelli repair for transposition of great vessels. Pulmonary valve replacement (PVR) has become one of the most common procedures performed for ACHD patients. Areas covered: Given the advances in transcatheter technology, we conducted a detailed review of the available studies addressing the indications for PVR, historical background, evolving technology, procedural aspects, and the future direction, with an emphasis on ACHD patients. Expert commentary: Transcatheter pulmonary valve implantation (TPVI) is widely accepted as an alternative to surgery to address RVOT dysfunction. However, current technology may not be able to adequately address a subset of patients with complex RVOT morphology. As the technology continues to evolve, new percutaneous valves will allow practitioners to apply the transcatheter approach in such patients. We expect that with the advancement in transcatheter technology, novel devices will be added to the TPVI armamentarium, making the transcatheter approach a feasible alternative for the majority of patients with RVOT dysfunction in the near future.

Percutaneous pulmonary valve implantation for reconstruction of a patch-repaired right ventricular outflow tract

Percutaneous pulmonary valve implantation (PPVI) is nowadays an accepted treatment option to repair post-surgical conduit dysfunction of the right ventricular outflow tract (RVOT). In addition, many patients need a pulmonary valve to reconstruct a hemodynamically incompetent native or conduit free outflow tract. Based on our experience with percutaneous stent-valve placement in a cohort of 125 patients, we report here transvenous reconstruction of a conduit-free, patch repaired outflow tract by utilizing balloon-expandable stent-valves in 23 patients with a median age of 22 years (5-60 years). In 20 patients, the step-by-step procedure was performed uneventful with the aimed success. Severe RVOT dysfunction in term of a clinical relevant regurgitation could be changed to mild, as it was confirmed by follow-up color Doppler echocardiography. In a 5-year-old girl a Melody® valve was placed as a surgical-interventional hybrid approach. In one patient, the procedure was complicated by stent embolization during preparation of the RVOT for stent-valve implantation. Reposition of the embolized stent was nevertheless successful for finishing percutaneous valve-implantation. In one patient, surgical approach became necessary because of the inability to advance the balloon-mounted stent-valve through a pre-stented RVOT. Considering the current available balloon-expandable stent-valves, transvenous pulmonary valve implantation is feasible to treat even an incompetent conduit-free RVOT. However, preparation of the RVOT by pre-stenting, in most patients with more than two stents in telescope technique remains challenging. Reconstruction of RVOT by the current available valves is promising only for a carefully selected group of patients.

Contained rupture of patched right ventricular outflow tracts during balloon sizing for percutaneous pulmonary valve implantation

Transcatheter pulmonary valves are being used off-label to treat pulmonary insufficiency in patched right ventricular outflow tracts (RVOTs). We describe the first reported cases of patched RVOT rupture, during balloon sizing for percutaneous pulmonary valve implantation, in two patients with tetralogy of Fallot status post repair. Both RVOTs were too large for subsequent catheter-based intervention. The ruptures remained stable over time, and both patients were managed conservatively with follow-up imaging.