Transcatheter Pulmonary Valve Replacement With the Melody Valve in Small Diameter Expandable Right Ventricular Outflow Tract Conduits

Transcatheter Pulmonary Valve in Congenital Heart Disease

Over the last 2 decades, experience with transcatheter pulmonary valve replacement (TPVR) has grown significantly and has become an effective and reliable way of treating pulmonary valve regurgitation, right ventricular outflow (RVOT) obstruction, and dysfunctional bioprosthetic valves and conduits. With the introduction of self-expanding valves and prestents, dilated native RVOT can be addressed with the transcatheter approach. In this article, the authors review the current practices, technical challenges, and outcomes of TPVR.

Expanded polytetrafluoroethylene conduits with curved and handsewn bileaflet designs for right ventricular outflow tract reconstruction

OBJECTIVE

This study reviewed the application of curved and bileaflet designs to pulmonary expanded polytetrafluoroethylene conduits with diameters of 10 to 16 mm and characterized this conduit on in vitro experiment, including particle image velocimetry.

METHODS

All patients who received this conduit between 2010 and 2022 were evaluated. Three 16-mm conduits were tested in a circulatory simulator at different cardiac outputs (1.5-3.6 L/minute) and bending angles (130°-150°).

RESULTS

Fifty consecutive patients were included. The median operative body weight was 8.4 kg (range, 2.6-12 kg); 10-, 12-, 14-, and 16-mm conduits were used in 1, 4, 6, and 39 patients, respectively. In 34 patients, the conduit was implanted in a heterotopic position. The overall survival rate was 89% at 8 years with 3 nonvalve-related deaths. There were 10 conduit replacements; 5 16-mm conduits (after 8 years) and 1 12-mm conduit (after 6 years) due to conduit stenosis, and the remaining 4 for reasons other than conduit failure. Freedom from conduit replacement was 89% and 82% at 5 and 8 years, respectively. Linear mixed-effects models with echocardiographic data implied that 16-mm conduits were durable with a peak velocity <3.5 m/second and without moderate/severe regurgitation until the patient's weight reached 25 kg. In experiments, peak transvalvular pressure gradients were 11.5 to 25.5 mm Hg, regurgitant fractions were 8.0% to 14.4%, and peak Reynolds shear stress in midsystolic phase was 29 to 318 Pa.

CONCLUSIONS

Our conduits with curved and bileaflet designs have acceptable clinical durability and proven hydrodynamic profiles, which eliminate valve regurgitation and serve as a reliable bridge to subsequent conduit replacement.

Transcatheter Pulmonary Valve Replacement With Balloon-Expandable Valves: Utilization and Procedural Outcomes From the IMPACT Registry

BACKGROUND

Transcatheter pulmonary valve replacement (TPVR) has expanded and evolved since its initial commercial approval in the United States in 2010.

OBJECTIVES

This study sought to characterize real-world practice, including patient selection, procedural outcomes, complications, and off-label usage.

METHODS

Characteristics and outcomes for patients undergoing balloon-expandable TPVR were collected from the American College of Cardiology National Cardiovascular Data Registry IMPACT (Improving Pediatric and Adult Congenital Treatment) Registry.

RESULTS

Between April 2016 and March 2021, 4,513 TPVR procedures were performed in patients with a median age of 19 years, 57% with a Melody (Medtronic Inc) and 43% with a SAPIEN (Edwards Lifesciences) valve. Most implanting centers performed <10 cases annually. One-third of transcatheter pulmonary valve implants were into homograft conduits, one-third were into bioprosthetic valves (BPVs), 25% were in native or patched right ventricular outflow tracts (RVOTs), and 6% were into Contegra (Medtronic Inc) conduits. Over the course of the study period, SAPIEN valve use grew from ∼25% to 60%, in large part because of implants in patients with a native/patched RVOT. Acute success was achieved in 95% of patients (95.7% in homografts, 96.2% in BPVs, 94.2% in native RVOTs, and 95.4% in Contegra conduits). Major adverse events occurred in 2.4% of procedures, more commonly in patients with a homograft (2.9%) or native RVOT (3.4%) than a prior BPV (1.4%; P = 0.004).

CONCLUSIONS

This study describes novel population data on the use and procedural outcomes of TPVR with balloon-expandable valves. Over time, there has been increasing use of TPVR to treat regurgitant native RVOT anatomy, with the SAPIEN valve more commonly used for this application.

Outcomes of transcatheter pulmonary SAPIEN 3 valve implantation: an international registry

BACKGROUND AND AIMS

Transcatheter pulmonary valve implantation (TPVI) is indicated to treat right-ventricular outflow tract (RVOT) dysfunction related to congenital heart disease (CHD). Outcomes of TPVI with the SAPIEN 3 valve that are insufficiently documented were investigated in the EUROPULMS3 registry of SAPIEN 3-TPVI.

METHODS

Patient-related, procedural, and follow-up outcome data were retrospectively assessed in this observational cohort from 35 centres in 15 countries.

RESULTS

Data for 840 consecutive patients treated in 2014-2021 at a median age of 29.2 (19.0-41.6) years were obtained. The most common diagnosis was conotruncal defect (70.5%), with a native or patched RVOT in 50.7% of all patients. Valve sizes were 20, 23, 26, and 29 mm in 0.4%, 25.5%, 32.1%, and 42.0% of patients, respectively. Valve implantation was successful in 98.5% [95% confidence interval (CI), 97.4%-99.2%] of patients. Median follow-up was 20.3 (7.1-38.4) months. Eight patients experienced infective endocarditis; 11 required pulmonary valve replacement, with a lower incidence for larger valves (P = .009), and four experienced pulmonary valve thrombosis, including one who died and three who recovered with anticoagulation. Cumulative incidences (95%CI) 1, 3, and 6 years after TPVI were as follows: infective endocarditis, 0.5% (0.0%-1.0%), 0.9% (0.2%-1.6%), and 3.8% (0.0%-8.4%); pulmonary valve replacement, 0.4% (0.0%-0.8%), 1.3% (0.2%-2.4%), and 8.0% (1.2%-14.8%); and pulmonary valve thrombosis, 0.4% (0.0%-0.9%), 0.7% (0.0%-1.3%), and 0.7% (0.0%-1.3%), respectively.

CONCLUSIONS

Outcomes of SAPIEN 3 TPVI were favourable in patients with CHD, half of whom had native or patched RVOTs.

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.

Intravascular Lithotripsy for Severe RVOT Calcification to Optimize Transcatheter Pulmonary Valve Replacement

The presence of severe right ventricular outflow tract calcification may preclude safe and effective transcatheter pulmonary valve replacement in patients with pulmonary allograft stenosis owing to the risk of conduit tear and suboptimal annular expansion. Debulking calcium using intravascular lithotripsy within the right ventricular outflow tract may mitigate this risk and improve valve hemodynamics. (Level of Difficulty: Advanced.).

Long-term outcomes of transcatheter pulmonary valve implantation with melody and SAPIEN valves

BACKGROUND

Transcatheter pulmonary valve implantation (TPVI) is effective for treating right ventricle outflow tract (RVOT) dysfunction. Factors associated with long-term valve durability remain to be investigated.

METHODS

Consecutive patients successfully treated by TPVI with Melody valves (n = 32) and SAPIEN valves (n = 182) between 2008 and 2020 at a single tertiary centre were included prospectively and monitored.

RESULTS

The 214 patients had a median age of 28 years (range, 10-81). The RVOT was a patched native pulmonary artery in 96 (44.8%) patients. Median follow-up was 2.8 years (range, 3 months-11.4 years). Secondary pulmonary valve replacement (sPVR) was performed in 23 cases (10.7%), due to stenosis (n = 22, 95.7%) or severe regurgitation (n = 1, 4.3%), yielding an incidence of 7.6/100 patient-years with melody valves and 1.3/100 patient-years with SAPIEN valves (P = 0.06). The 5- and 10-year sPVR-freedom rates were 78.1% and 50.4% with Melody vs. 94.3% and 82.2% with SAPIEN, respectively (P = 0.06). The incidence of infective endocarditis (IE) was 5.5/100 patient-years with Melody and 0.2/100 patient-years with SAPIEN (P < 0.0001). Factors associated with sPVR by univariate analysis were RV obstruction before TPVI (P = 0.04), transpulmonary maximal velocity > 2.7 m/s after TPVI (p = 0.0005), valve diameter ≤ 22 mm (P < 0.003), IE (P < 0.0001), and age < 25 years at TPVI (P = 0.04). By multivariate analysis adjusted for IE occurrence, transpulmonary maximal velocity remained associated with sPVR.

CONCLUSIONS

TPVI is effective for treating RVOT dysfunction. Incidence of sPVR is higher in patients with residual RV obstruction or IE. IE add a substantial risk of TPVI graft failure and is mainly linked to the Melody valve.

SOCIAL MEDIA ABSTRACT

Transcatheter pulmonary valve implantation is effective for treating right ventricular outflow tract dysfunction in patients with congenital heart diseases. Incidence of secondary valve replacement is higher in patients with residual obstruction or infective endocarditis.

Is there a role for endovascular stent implantation in the management of postoperative right ventricular outflow tract obstruction in the era of transcatheter valve implantation?

BACKGROUND

The optimal management pathway for the dysfunctional right ventricular outflow tract (RVOT) is uncertain. We evaluated the long-term outcomes and clinical impact of stent implantation for obstructed RVOTs in an era of rapidly progressing transcatheter pulmonary valve technology.

METHODS

Retrospective review of 151 children with a biventricular repair who underwent stenting of obstructed RVOT between 1991 and 2017.

RESULTS

RVOT stenting resulted in significant changes in peak right ventricle (RV)-to-pulmonary artery (PA) gradient (39.4 ± 17.1-14.9 ± 8.3; p < 0.001) and RV-to-aortic pressure ratio (0.78 ± 0.22-0.49 ± 0.13; p < 0.001). Subsequent percutaneous reinterventions in 51 children to palliate recurrent stenosis were similarly effective. Ninety-nine (66%) children reached the primary outcome of subsequent pulmonary valve replacement (PVR). Freedom from PVR from the time of stent implantation was 91%, 51%, and 23% at 1, 5, and 10 years, respectively. Small balloon diameters for stent deployment were associated with shorter freedom from PVR. When additional children without stent palliation (with RV-to-PA conduits) were added to the stent cohort (total 506 children), the multistate analysis showed the longest freedom from PVR in those with stent palliation and subsequent catheter reintervention. Pulmonary regurgitation was well-tolerated clinically. Indexed RV dimensions and function estimated by echocardiography remained stable at last follow up or before primary outcome.

CONCLUSION

Prolongation of conduit longevity with stent implant remains an important strategy to allow for somatic growth to optimize the risk-benefit profile for subsequent surgical or transcatheter pulmonary valve replacement performed at an older age.

Conduits for Right Ventricular Outflow Tract Reconstruction in Infants and Young Children

Purpose of Review: Right ventricular outflow tract (RVOT) reconstruction remains a challenge due to the lack of an ideal conduit. Data and experience are accumulating with each passing day. Therefore, it is necessary to review this topic from time to time. This is a 2021 update review focused on the history, evolution, and current situation of small-sized conduits (≤ 16 mm) for RVOT reconstruction in infants and young children.

Recent Findings: Currently, the available small-sized (≤16 mm) conduits can meet most clinical needs. Homograft is still a reliable choice for infants and young children validated by a half-century clinical experience. As an alternative material, bovine jugular vein conduit (BJVC) has at least comparable durability with that of homograft. The performance of expanded polytetrafluoroethylene (ePTFE) is amazing in RVOT position according to limited published data. The past century has witnessed much progress in the materials for RVOT reconstruction. However, lack of growth potential is the dilemma for small-sized conduits. Tissue-engineering based on cell-free scaffolds is the most promising technology to obtain the ideal conduit.

Summary: No conduit has proved to have lifelong durability in RVOT position. We are far from the ideal, but we are not in a state of emergency. In-depth clinical research as well as innovation in material science are needed to help improve the durability of the conduits used in infants and young children.

Edwards SAPIEN XT transcatheter pulmonary valve implantation: 5-year follow-up in a French Registry

OBJECTIVES

This study sought to investigate patient intermediate-term outcomes after transcatheter pulmonary valve replacement (TPVR) with Edwards SAPIEN valve.

BACKGROUND

The Edwards SAPIEN valve, initially designed for percutaneous aortic valve replacement, has been approved for TPVR in patients with dysfunctional right ventricular outflow tracts (RVOT), but only short-term follow-up has been reported.

METHODS

From 2011 to 2016, 62 patients undergoing successful TPVR using the SAPIEN XT valve were consecutively included into the study. Primary efficacy and safety endpoints were defined as freedom from valve-reintervention and freedom from infective endocarditis at last follow-up, respectively.

RESULTS

The primary efficacy outcome was met for 87.1% patients after a mean follow-up of 4.6 ± 1.8 years, corresponding to a freedom of reintervention at 5 years of 89% (95% CI 74.8-95.6%). Reinterventions were exclusively due to recurrent obstruction, no significant valvular regurgitation was observed. One case of infective endocarditis was reported, corresponding to a rate of 0.35% per patient-year (95% CI 0.01-2.00%). At 5 years, freedom from infective endocarditis was 98.4% (95% CI 89.1-99.8%). Six patients died or were transplanted due to advanced cardiac failure, without relationship with TPVR. In univariate analysis, reintervention was associated with young age, a smaller tube-graft, a higher pulmonary valve gradient after the procedure and a ratio of largest implanted stent diameter to invasive balloon conduit diameter over 1.35.

CONCLUSIONS

This study documents the mid-term safety and efficacy of the Edwards SAPIEN XT valve in patients with dysfunctional RVOT, and identifies a patient profile associated with an uncertain benefit-risk balance.

Time-related risk of pulmonary conduit re-replacement: a Congenital Heart Surgeons' Society Study

BACKGROUND

Patients receiving a right ventricle-to-pulmonary artery conduit in infancy will require successive procedures or replacements, each with variable longevity. We sought to identify factors associated with time-related risk of a subsequent surgical replacement (PC3) or transcatheter pulmonary valve insertion (TPVI) after a second surgically-placed PC (PC2).

METHODS

From 2002 to 2016, 630 patients from 29 Congenital Heart Surgeons' Society member institutions survived to discharge after initial valved PC insertion (PC1) at age < 2 years. Of those, 355 had undergone surgical replacement (PC2) of that initial conduit. Competing risk methodology and multiphase parametric hazard analyses were used to identify factors associated with time-related risk of PC3 or TPVI.

RESULTS

Of 355 PC2 patients (median follow-up of 5.3 years), 65 underwent PC3 and 41 TPVI. Factors at PC2 associated with increased time-related risk of PC3 were smaller PC2 Z score (Hazard Ratio [HR] 1.6, p<0.001), concomitant aortic valve intervention (HR 7.6, p=0.009), aortic allograft (HR 2.2, p=0.008), younger age (HR 1.4, p<0.001), and larger Z score of PC1 (HR 1.2, p=0.04). Factors at PC2 associated with increased time-related risk of TPVI were aortic allograft (HR: 3.3, p=0.006), porcine unstented conduit (HR 4.7, p<0.001), and older age (HR 2.3, p=0.01).

CONCLUSIONS

Aortic allograft as PC2 was associated with increased time-related risk of both PC3 and TPVI. Surgeons may reduce risk of these subsequent procedures by not selecting an aortic homograft at PC2, and by oversizing the conduit when anatomically feasible.

Transcatheter pulmonic valve implantation: Techniques, current roles, and future implications

Right ventricular outflow tract (RVOT) obstruction is present in a variety of congenital heart disease states including tetralogy of Fallot, pulmonary atresia/stenosis and other conotruncal abnormalities etc. After surgical repair, these patients develop RVOT residual abnormalities of pulmonic stenosis and/or insufficiency of their native outflow tract or right ventricle to pulmonary artery conduit. There are also sequelae of other surgeries like the Ross operation for aortic valve disease that lead to right ventricle to pulmonary artery conduit dysfunction. Surgical pulmonic valve replacement (SPVR) has been the mainstay for these patients and is considered standard of care. Transcatheter pulmonic valve implantation (TPVI) was first reported in 2000 and has made strides as a comparable alternative to SPVR, being approved in the United States in 2010. We provide a comprehensive review in this space–indications for TPVI, detailed procedural facets and up-to-date review of the literature regarding outcomes of TPVI. TPVI has been shown to have favorable medium-term outcomes free of re-interventions especially after the adoption of the practice of pre-stenting the RVOT. Procedural mortality and complications are uncommon. With more experience, recognition of risk of dreaded outcomes like coronary compression has improved. Also, conduit rupture is increasingly being managed with transcatheter tools. Questions over endocarditis risk still prevail in the TPVI population. Head-to-head comparisons to SPVR are still limited but available data suggests equivalence. We also discuss newer valve technologies that have limited data currently and may have more applicability for treatment of native dysfunctional RVOT substrates.

Procedural technique for hybrid pulmonary valve replacement in infants and small children

OBJECTIVES

Hybrid approach to pulmonary valve replacement (PVR) in the paediatric population has been reported, although data in infants and small children are limited. Several strategies are now possible. The aim of this study is to review our hybrid PVR strategy in a complex patient cohort, outlining a variety of approaches employed in our centre.

METHODS

We performed a retrospective review of infants and small children who underwent hybrid PVR between May 2017 and April 2019 in a single tertiary cardiology centre. Medical records were reviewed to ascertain demographic, clinical and outcome data.

RESULTS

Ten patients with a median (interquartile range) age of 1.5 years (1.1-1.9) and weight of 8.8 kg (8-10.6) were managed with hybrid pulmonary valve insertion. Eight patients had perventricular approach (4 sternotomy and 4 subxiphoid) and 2 patients had surgically sutured valve. Six patients underwent cardiopulmonary bypass for associated lesions. Three had insertion of the valve into conduits and 7 were deployed into native right ventricular outflow tracts. The pulmonary valve was successfully inserted in all 10 patients with no mortality. Postprocedural complications included paravalvar leak in 2 patients, suspected endocarditis in 1 patient who developed early valve regurgitation and wound infection in 1 patient.

CONCLUSIONS

Several approaches to hybrid PVR may be employed in small children with a high success rate. Follow-up studies are required to evaluate longer term durability of these approaches compared to standard surgical replacement.

Preclinical study of a self-expanding pulmonary valve for the treatment of pulmonary valve disease

In the past decade, balloon-expandable percutaneous pulmonary valves have been developed and applied in clinical practice. However, all the existing products of pulmonary artery interventional valves in the market have a straight structure design, and they require a preset support frame and balloon expansion. This shape design of the valve limits the application range. In addition, the age of the population with pulmonary artery disease is generally low, and the existing products cannot meet the needs of anti-calcification properties and valve material durability. In this study, through optimization of the support frame and leaflet design, a self-expanding pulmonary valve product with a double bell-shaped frame was designed to improve the match of the valve and the implantation site. A loading and deployment study showed that the biomaterial of the valve was not damaged after being compressed. Pulsatile flow and fatigue in vitro tests showed that the fabricated pulmonary valve met the hydrodynamic requirements after 2 × 10⁸ accelerated fatigue cycles. The safety and efficacy of the pulmonary valve product were demonstrated in studies of pulmonary valve implantation in 11 pigs. Angiography and echocardiography showed that the pulmonary valves were implanted in a good position, and they had normal closure and acceptable valvular regurgitation. The 180 days' implantation results showed that the calcium content was 0.31-1.39 mg/g in the anti-calcification treatment group, which was significantly lower than that in the control valve without anti-calcification treatment (16.69 mg/g). Our new interventional pulmonary valve product was ready for clinical trials and product registration.

Prevention and management of endocarditis after transcatheter pulmonary valve replacement: current status and future prospects

Introduction: Transcatheter pulmonary valve replacement (TPVR) has become an important tool in the management of congenital heart disease with abnormalities of the right ventricular outflow tract. Endocarditis is one of the most serious adverse long-term outcomes and among the leading causes of death in patients with congenital heart disease and after (TPVR).Areas covered: This review discusses the current state knowledge about the risk factors for and outcomes of endocarditis after transcatheter pulmonary valve replacement in patients with congenital and acquired heart disease. It also addresses practical measures for mitigating endocarditis risk, as well as diagnosing and managing endocarditis when it does occur.Expert opinion: With increasing understanding of the risk factors for and management and outcomes of endocarditis in patients who have undergone TPVR, we continue to learn how to utilize TPVR most effectively in this complex population of patients.

Rationale and feasibility of transcatheter pulmonary valve implantation in small conduits with the Edwards Sapien valves

BACKGROUND

Conduit dilatation above 110% and TPVI in conduits <16 mm is not recommended. However, if we want to reach normal values for RVOT diameters and diminish reintervention rates, pushing these boundaries is essential.

METHODS

Analysis of subsequent patients who underwent TPVI with Edwards Sapien valves in conduits ≤16 mm between 2010 and 2020.

RESULTS

In n = 33 cases median age was 13 years (5-20 y) and median weight 47 kg (15-91 kg). Preexisting RVOT grafts were n = 28 Contegra® conduits and n = 5 homografts (12 mm n = 15; 14 mm n = 11; 16 mm n = 7). Implanted were the Sapien (n = 8), Sapien XT (n = 10) and Sapien 3 valve (n = 15) with 20 mm (n = 4), 23 mm (n = 19), 26 mm (n = 9) and 29 mm (n = 1). Mean minimal RVOT diameter after TPVI was 22,7 ± 2,3 mm (18-30 mm) which is 150% of the mean minimal RVOT diameter before TPVI (15,1 ± 4,3 mm). Covered stents were used in n = 10 cases. Contained conduit rupture occurred in n = 7 cases (21%). Residual RVOT gradients of 5,7 ± 4,9 mmHg (0-18 mmHg) showed adequate RV unloading.

CONCLUSION

TPVI could be performed successfully in all patients. Dilatation above 150% and a valve/conduit diameter ratio up to 2,4 were well tolerated. There was a considerable amount of conduit rupture but all were confined without further need for intervention or surgery.

Experience and Outcomes of Surgically Implanted Melody Valve in the Pulmonary Position

BACKGROUND

Multiple congenital cardiac malformations require pulmonary valve replacement and/or right ventricular outflow (RVOT) reconstruction. Pulmonary valve replacement remains challenging in children owing to the limited growth potential of prosthetic valves. We evaluated outcomes in patients undergoing surgical implantation of a Melody valve in the RVOT.

METHODS

Data were retrospectively collected for 23 patients undergoing surgical Melody valve implantation at Boston Children's Hospital between 2009 and 2019. We assessed postoperative valve function, reintervention rates, and mortality.

RESULTS

Median age was 1.7 years (range, 2 months to 6 years); 12 patients were aged greater than 2 years (52%). Diagnosis was tetralogy of Fallot in 15 patients (65%); 15 had a prior RVOT operation (65%). The Melody valve was dilated before surgery to a median diameter of 14 mm (range, 10-20 mm). No patients had acute pulmonary regurgitation. One required transcatheter RVOT reintervention before discharge. Median follow-up was 3.7 years (range, 0.02-8.7 years) with moderate or greater pulmonary regurgitation in 2 patients. Catheter-based interventions (mean, 0.83 ± 1.07/patient) occurred at a median of 1 year (range, 16 days to 5.4 years) and included valve expansion for somatic growth (n = 10) and subsequent valve-in-valve replacement (n = 3). Three patients (13%) required surgical valve explant or replacement at a median of 1.0 year (range, 0.6-3.7 years) for Melody-specific indications. One-, 3-, and 5-year freedom from Melody-driven reoperation was 90%, 90%, and 83%, respectively.

CONCLUSIONS

The Melody valve can be surgically implanted in the RVOT of young patients with acceptable early results. These valves can be successfully dilated through transcatheter reintervention to accommodate growth.

Transcatheter pulmonary valve replacement in pediatric patients

INTRODUCTION

Right ventricular outflow tract (RVOT) dysfunction is common among individuals with congenital heart disease (CHD). Surgical intervention often carries prohibitive risks due to the need for sequential pulmonary valve (PV) replacements throughout their life in the majority of cases. Transcatheter pulmonary valve replacement (tPVR) is one of the most exciting recent developments in the treatment of CHD and has evolved to become an attractive alternative to surgery in patients with RVOT dysfunction.

AREAS COVERED

In this review, we examine the pathophysiology of RVOT dysfunction, indications for tPVR, and the procedural aspect. Advancements in clinical application and valve technology will also be covered.

EXPERT OPINION

tPVR is widely accepted as an alternative to surgery to address RVOT dysfunction, but still significant numbers of patients with complex RVOT morphology deemed not suitable for tPVR. As the technology continues to evolve, new percutaneous valves will allow such complex RVOT patient to benefit from tPVR.

Right Ventricular Outflow Tract Reintervention in the Transcatheter Era: Outcomes and Cost Analysis

Surgical pulmonary valve insertion (SPVI) for re-entry right ventricular outflow tract intervention (RVOTI) remains an established and reproducible approach. Fast-track in patients undergoing RVOTI of the comprehensive valve program targets early ICU and hospital discharge (Hd). Feasibility study for outcome and cost analysis was undertaken. Between January 2015 and December 2016, 34 patients underwent re-entry RVOTI. Seventeen had SPVI and 17 transcatheter PVI (TPVI). Surgical perioperative fast-track protocol was used. Echocardiographic evaluation preoperatively (TTE-1), after RVOTI (TTE-2), at hospital discharge (TTE-3), and follow-up (TTE-4) were obtained. Cost Analysis included procedural and hospital costs. Mean follow-up period was 11.3 ± 6.9 months. All patients were extubated prior to ICU arrival. Mean age was 8.5 ± 7.8 for SPVI [vs 28.5 ± 8.6 years for TPVI] (p < 0.05). There was no hospital mortality or 30-day readmission for SPVI (versus 1 for TPVI).Mean hospital length of stay (LOS) was 4.1 ± 1.1 days for SPVI [vs 1.1 ± 0.7 days for TPVI] (p < 0.05). Number of prior sternal re-entry had no influence on outcome. RV systolic pressure referenced to LVSP (rRVSP, %) and diastolic dimension (RVEDDi, z score) showed sustainable improvement (TTE-2, TTE-3, TTE-4) in both groups compared to TTE-1 (p < 0.05). Mean total hospital cost was $5475.86 ± 2503.91 lower after SPVI (p = 0.09), 21.7% procedural cost reduction. Patients undergoing RVOTI can be safely stratified, based on a customized concept, towards SPVI or TPVI. Standardized strategy can advocate a fast-track path. SPVI is associated with comparable mid-term outcomes to TPVI although SPVI is delivered in younger patients. Despite longer LOS SPVI is associated with reduced hospital cost. Multisite studies might help determine suitability for each strategy on cost containment/quality of life basis.

Implantation of the Melody transcatheter pulmonary valve PB1016 in patients with dysfunctional right ventricular outflow tract conduits

OBJECTIVES

This study describes procedural and 1-year outcomes of the 16 mm Melody PB1016 valve in patients with dysfunctional RVOT conduits.

BACKGROUND

The Melody PB1016 is a standard Melody valve produced from a 16 mm bovine jugular vein and is intended for deployment up to 20 mm.

METHODS

This is a prospective, non-randomized, multicenter study of the procedural and short-term outcomes of Melody PB1016 TPV replacement within dysfunctional RVOT conduits. Data from eight centers were included in the analysis.

RESULTS

During the study period, 39 patients underwent attempted Melody TPVR. Of the 39 patients, 30 underwent successful Melody TPVR. The majority of patients underwent placement of one or more stents prior to TPVR. There was a significant reduction in peak conduit pressure gradient following TPVR (38 mmHg vs. 11 mmHg, P < 0.001). There were three cases of confined conduit tears successfully treated with covered stents or the valve itself. Repeat catheterization was performed in one patient for early re-obstruction that was successfully treated with balloon valvuloplasty. At recent follow-up, there were no cases of more than mild valve regurgitation and the mean pulmonary valve gradient by echocardiogram remained reduced relative to pre-TPVR implant measurements (33.5 mmHg vs. 15.2 mmHg). There were no cases of valve stent fracture or endocarditis reported at the 1-year follow-up.

CONCLUSIONS

Our analysis of TPVR with the PB1016 valve in RVOT conduits showed it to be safe and effective and can be performed in a wide range of conduit sizes with preserved valve function. ClinicalTrials.gov Identifier: NCT02347189.

Transcatheter pulmonary valve replacement: evolving indications and application

The introduction of transcatheter therapy for valvular heart disease has changed the spectrum of care of patients with a variety of cardiovascular conditions. Transcatheter valve placement has become established as a method of treating pathologic regurgitation or stenosis of the pulmonary valve, right ventricular outflow tract or a right ventricle to pulmonary artery conduit. In this review, we examine the pathophysiology of and indications for transcatheter pulmonary valve replacement along with procedural complications. Advancements in clinical application and valve technology will also be covered.