Feasibility and Short-Term Outcomes of Percutaneous Transcatheter Pulmonary Valve Replacement in Small (<30 kg) Children With Dysfunctional 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.

Current status of transcatheter intervention for complex right ventricular outflow tract abnormalities

Various transcatheter interventions for the right ventricular outflow tract (RVOT) have been introduced and developed in recent decades. Transcatheter pulmonary valve perforation was first introduced in the 1990s. Radiofrequency wire perforation has been the approach of choice for membranous pulmonary atresia in newborns, with high success rates, although complication rates remain relatively common. Stenting of the RVOT is a novel palliative treatment that may improve hemodynamics in neonatal patients with reduced pulmonary blood flow and RVOT obstruction. Whether this option is superior to other surgical palliative strategies or early primary repair of tetralogy of Fallot remains unclear. Transcatheter pulmonary valve replacement has been one of the biggest innovations in the last two decades. With the success of the Melody and SAPIEN valves, this technique has evolved into the gold standard therapy for RVOT abnormalities with excellent procedural safety and efficacy. Challenges remain in managing the wide heterogeneity of postoperative lesions seen in RVOT, and various technical modifications, such as pre-stenting, valve ring modification, or development of self-expanding systems, have been made. Recent large studies have revealed outcomes comparable to those of surgery, with less morbidity. Further experience and multicenter studies and registries to compare the outcomes of various strategies are necessary, with the ultimate goal of a single-step, minimally invasive approach offering the best longer-term anatomical and physiological results.

Technical recommendations for computed tomography guidance of intervention in the right ventricular outflow tract: Native RVOT, conduits and bioprosthetic valves:: A white paper of the Society of Cardiovascular Computed Tomography (SCCT), Congenital Heart Surgeons' Society (CHSS), and Society for Cardiovascular Angiography & Interventions (SCAI)

This consensus document for the performance of Cardiovascular Computed Tomography (CCT) to guide intervention in the right ventricular outflow tract (RVOT) in patients with congenital disease (CHD) was developed collaboratively by pediatric and adult interventionalists, surgeons and cardiac imagers with expertise specific to this patient subset. The document summarizes definitions of RVOT dysfunction as assessed by multi-modality imaging techniques and reviews existing consensus statements and guideline documents pertaining to indications for intervention. In the context of this background information, recommendations for CCT scan acquisition and a standardized approach for reporting prior to surgical or transcatheter pulmonary valve replacement are proposed and presented. It is the first Imaging for Intervention collaboration for CHD patients and encompasses imaging and reporting recommendations prior to both surgical and percutaneous pulmonary valve replacement.

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.

Technical Recommendations for Computed Tomography Guidance of Intervention in the Right Ventricular Outflow Tract: Native RVOT, Conduits, and Bioprosthetic Valves

This consensus document for the performance of cardiovascular computed tomography (CCT) to guide intervention in the right ventricular outflow tract (RVOT) in patients with congenital heart disease (CHD) was developed collaboratively by pediatric and adult interventionalists, surgeons, and cardiac imagers with expertise specific to this patient subset. The document summarizes definitions of RVOT dysfunction as assessed by multimodality imaging techniques and reviews existing consensus statements and guideline documents pertaining to indications for intervention. In the context of this background information, recommendations for CCT scan acquisition and a standardized approach for reporting prior to surgical or transcatheter pulmonary valve replacement are proposed and presented. It is the first Imaging for Intervention collaboration for CHD patients and encompasses imaging and reporting recommendations prior to both surgical and percutaneous pulmonary valve replacement.

Staged Percutaneous Management of Pulmonary Atresia and Intact Interventricular Septum: Stretching the Limits

Aims

Pulmonary atresia with intact ventricular septum (PA/IVS) can be treated by catheter-based interventions and complemented by various surgical procedures. We aim to determine a long-term treatment strategy to enable patients to be surgery free, depending solely on percutaneous interventions.

Methods and Results

We selected five patients from among a cohort of patients with PA/IVS treated at birth with radiofrequency perforation and dilatation of the pulmonary valve. Patients had reached a pulmonary valve annulus of 20 mm or larger on their biannual echocardiographic follow-up, with right ventricular dilatation. The findings, together with the right ventricular outflow tract and pulmonary arterial tree, were confirmed by multislice computerised tomography. Based on the angiographic size of the pulmonary valve annulus, all patients were successfully implanted with either Melody® or Edwards® pulmonary valves percutaneously, regardless of their small weights and ages. No complications were encountered.

Conclusion

We managed to stretch the age and weight limitations for performing percutaneous pulmonary valve implantation (PPVI): interventions were attempted whenever a pulmonary annulus size of >20 mm was reached, which was rationalised by the prevention of progressive right ventricular outflow tract dilatation and accommodating valves between 24 and 26 mm, which is enough to sustain a normal pulmonary flow in adulthood.

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.

Perventricular Transcatheter Pulmonary Valve Implantation in a Symptomatic 3-Year-Old Child With Repaired Tetralogy of Fallot

In select patients, transcatheter pulmonary valve replacement through a percutaneous approach can be challenging because of complicated anatomy or small patient size. In these patients, especially those weighing <20 kg, hybrid perventricular valve delivery may provide a preferred alternative approach. (Level of Difficulty: Intermediate.)

A geometrically adaptable heart valve replacement

Congenital heart valve disease has life-threatening consequences that warrant early valve replacement; however, the development of a growth-accommodating prosthetic valve has remained elusive. Thousands of children continue to face multiple high-risk open-heart operations to replace valves that they have outgrown. Here, we demonstrate a biomimetic prosthetic valve that is geometrically adaptable to accommodate somatic growth and structural asymmetries within the heart. Inspired by the human venous valve, whose geometry is optimized to preserve functionality across a wide range of constantly varying volume loads and diameters, our balloon-expandable synthetic bileaflet valve analog exhibits similar adaptability to dimensional and shape changes. Benchtop and acute in vivo experiments validated design functionality, and in vivo survival studies in growing sheep demonstrated that mechanical valve expansion accommodated growth. As illustrated in this work, dynamic size adaptability with preservation of unidirectional flow in prosthetic valves thus offers a paradigm shift in the treatment of heart valve disease.

Munich Comparative Study: Prospective Long-Term Outcome of the Transcatheter Melody Valve Versus Surgical Pulmonary Bioprosthesis With Up to 12 Years of Follow-Up

BACKGROUND

Percutaneous pulmonary valve implantation (PPVI) has become an important treatment of right ventricular outflow tract dysfunction. Studies directly comparing the long-term outcome of PPVI with the Melody valve to surgical pulmonary valve replacement (SPVR) are lacking.

METHODS

All patients treated with PPVI with the Melody valve and SPVR between January 2006 and December 2018 in our center were enrolled into a database and investigated with a standard follow-up protocol. The current study compares the outcomes in means of survival, reinterventions, infectious endocarditis, and performance of the valves.

RESULTS

The study included 452 patients, of whom 241 were treated with PPVI with the Melody valve and 211 patients with SPVR with different types of valves. Median follow-up time was 5.4 years (3 months to 12.5 years), and the total observation was 2449 patient-years. Estimated survival after 10 years was 94% in the Melody group and 92% in the SPVR group (P=0.47). There was no difference in the estimated survival free of surgery on the implanted valve at 10 years (Melody, 87%, versus SPVR, 87%; P=0.54) or in the survival with the originally implanted pulmonary valve (Melody group, 80%; SPVR group, 73%; P=0.46) between both groups. The annualized incidence of infective endocarditis was 1.6% in the Melody group and 0.5% in the SPVR group, and the estimated survival free of endocarditis did not differ significantly between groups (Melody group, 82%; SPVR group, 86%; P=0.082). Survival free of valve replacement because of infective endocarditis was comparable between both groups (Melody, 88%; SPVR, 88%; P=0.35).

CONCLUSIONS

PPVI with the Melody valve and SPVR provides similar survival, freedom of reinterventions, and infective endocarditis with or without the need of replacement of the pulmonary valve. Being less invasive, PPVI should be considered a method for treatment for patients with dysfunctional right ventricular outflow tracts.

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.

Mid-Term Outcomes Following Percutaneous Pulmonary Valve Implantation Using the "Folded Melody Valve" Technique

Background:

The folded valve is a manual shortening of the Melody device, which has been validated as a valuable therapeutic option for the management of dysfunctional right ventricular outflow tracts needing a short valved stent. In this article, we aimed to evaluate, in a multicenter cohort, the mid-term outcomes of patients in whom a percutaneous pulmonary valve implantation was performed using the folded valve technique.

Methods:

A 2012 to 2018 retrospective multicenter study was performed in 7 European institutions. All patients who benefit from percutaneous pulmonary valve implantation with a folded Melody valve were included.

Results:

A total of 49 patients (median age, 19 years [range 4–56], 63% male) were included. The primary percutaneous pulmonary valve implantation indication was right ventricular outflow tract stenosis (n=19; 39%), patched native right ventricular outflow tracts were the most common substrate (n=15; 31%). The folded technique was mostly used in short right ventricular outflow tracts (n=28; 57%). Procedural success was 100%. After a median follow-up of 28 months (range, 4–80), folded Melody valve function was comparable to the immediate postimplantation period (mean transvalvular peak velocity=2.6±0.6 versus 2.4±0.6 m/s, P>0.1; only 2 patients had mild pulmonary regurgitation). Incidence rate of valve-related reinterventions was 2.1% per person per year (95% CI, 0.1%–3.9%). The probability of survival without valve-related reinterventions at 36 months was 90% (95% CI, 76%–100%).

Conclusions:

The folded Melody valve is a safe technique with favorable mid-term outcomes up to 6.5 years after implantation, comparable with the usual Melody valve implantation procedure. Complications and reinterventions rates were low, making this technique relevant in selected 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.

Transcatheter pulmonary valve implantation in 100 patients: a 10-year single-center experience

Introduction

Transcatheter pulmonary valve implantation (TPVI) is a non-surgical method of treatment for patients with right ventricular outflow tract (RVOT) dysfunction after surgical repair of congenital heart defects (CHD).

Aim

To evaluate the long-term results of TPVI performed in a single center.

Material and methods: Over 10 years, TPVI was performed in 100 patients (mean age: 26.4 ±8.1 years), using Melody Medtronic or Sapien Edwards valves.

Results

The initial success rate of TPVI was 93%. In 7 cases (5 urgent), a switch to surgical intervention was necessary due to periprocedural complications (all patients survived). Following TPVI, none of the 93 patients had severe pulmonary regurgitation. The pulmonary gradient decreased from 49.0 ±37.8 before to 27.6 ±14.9 mm Hg directly after TPVI (p < 0.0001). Right ventricular end-diastolic volume decreased, while NYHA class and pVO₂ uptake significantly improved in 1 year after TPVI. Freedom from reintervention was 100% in 1 year. Freedom from serious adverse events was 86% in mean 5.5 years of observation. The main reason for reintervention was infective endocarditis (IE) (1.6% patients/year). Increased risk of IE was associated with severe PS before valve implantation and the suboptimal result of TPVI. The incidence of IE seems to be lower in patients treated permanently with antiplatelet therapy (1.8% vs. 0.9% patients/year, NS).

Conclusions

TPVI is a safe and effective method of treatment in patients with RVOT dysfunction after surgical correction of CHD. To achieve a good outcome, precise patient selection and rigorous IE prevention are necessary.

Pulmonary regurgitation after repaired tetralogy of Fallot: surgical versus percutaneous treatment

Pulmonary regurgitation is the most important sequellae after correction of Tetralogy of Fallot and has a considerable impact over the right ventricle. Surgery has demonstrated low early mortality after pulmonary valve replacement and good long-term outcomes, remaining nowadays the gold standard treatment of pulmonary regurgitation in rTOF patients. Nevertheless, transcatheter pulmonary valve implantation has emerged as a new, safe and efficient alternative to surgical valve replacement. In this review article, we try to evaluate and compare both techniques to find out which is the best therapeutic option in this patients.

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.

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

OBJECTIVES

This study sought to evaluate the safety, feasibility, and outcomes of transcatheter pulmonary valve replacement (TPVR) in conduits ≤16 mm in diameter.

BACKGROUND

The Melody valve (Medtronic, Minneapolis, Minnesota) is approved for the treatment of dysfunctional right ventricular outflow tract (RVOT) conduits ≥16 mm in diameter at the time of implant. Limited data are available regarding the use of this device in smaller conduits.

METHODS

The study retrospectively evaluated patients from 9 centers who underwent percutaneous TPVR into a conduit that was ≤16 mm in diameter at the time of implant, and reported procedural characteristics and outcomes.

RESULTS

A total of 140 patients were included and 117 patients (78%; median age and weight 11 years of age and 35 kg, respectively) underwent successful TPVR. The median original conduit diameter was 15 (range: 9 to 16) mm, and the median narrowest conduit diameter was 11 (range: 4 to 23) mm. Conduits were enlarged to a median diameter of 19 mm (29% larger than the implanted diameter), with no difference between conduits. There was significant hemodynamic improvement post-implant, with a residual peak RVOT pressure gradient of 7 mm Hg (p < 0.001) and no significant pulmonary regurgitation. During a median follow-up of 2.0 years, freedom from RVOT reintervention was 97% and 89% at 2 and 4 years, respectively, and there were no deaths and 5 cases of endocarditis (incidence rate 2.0% per patient-year).

CONCLUSIONS

In this preliminary experience, TPVR with the Melody valve into expandable small diameter conduits was feasible and safe, with favorable early and long-term procedural and hemodynamic outcomes.

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.

Transcatheter Pulmonary Valve Replacement: Current State of Art

PURPOSE OF REVIEW

The past couple of decades have brought tremendous advances to the field of pediatric and adult congenital heart disease (CHD). Percutaneous valve interventions are now a cornerstone of not just the congenital cardiologist treating patients with congenital heart disease, but also-and numerically more importantly-for adult interventional cardiologists treating patients with acquired heart valve disease. 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 right ventricular outflow tract (RVOT) dysfunction. This review aims to summarize (1) the current state of the art for tPVR, (2) the expanding indications, and (3) the technological obstacles to optimizing tPVR.

RECENT FINDINGS

Since its introduction in 2000, more than ten thousands tPVR procedures have been performed worldwide. Although the indications for tPVR have been adapted earlier from those accepted for surgical intervention, they remain incompletely defined. The new imaging modalities give better assessment of cardiac anatomy and function and determine candidacy for the procedure. The procedure has been shown to be feasible and safe when performed in patients who received pulmonary conduit and or bioprosthetic valves between the right ventricle and the pulmonary artery. Fewer selected patients post trans-annular patch repair for tetralogy of Fallot may also be candidates for this technology. Size restrictions of the currently available valves limit deployment in the majority of patients post trans-annular patch repair. Newer valves and techniques are being developed that may help such patients. Refinements and further developments of this procedure hold promise for the extension of this technology to other patient populations.

PPVI in children under 20 kilograms: A quid pro quo?

Percutaneous PV implantation can be achieved in very small children (<20 kg) The clinic impact appears beneficial in the early term Studies to determine whether this treatment pathway will preserve RV function and translate to better survival needs investigation.

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.

Is mesocardia with left-sided caval vein draining to coronary sinus a contraindication for a percutaneous pulmonary valve implantation? A case description

Introduction Although the right jugular vein approach for percutaneous pulmonary valve implantation is well described, there are no reports that describe a percutaneous pulmonary valve implantation through a left superior caval vein to coronary sinus pathway. Case A 14-year-old female with tetralogy of Fallot, mesocardia, left superior caval vein draining into the coronary sinus, and hemiazygos continuation of the inferior caval vein underwent ventricular septal defect closure, with homograft insertion from the right ventricle to the pulmonary artery, patch augmentation of the left pulmonary artery, and creation of an atrial communication. Thereafter followed numerous catheterisations and interventions with stent implantation for stenosis of the left pulmonary artery and the homograft, as did device closure of the atrial communication. When she was a 12-year-old, the indications for a percutaneous pulmonary valve implantation were fulfilled and she underwent implantation of a 22 mm Melody® valve through the left superior caval vein. The extra-stiff exchange wire was pre-formed into a "U-spiral"-type configuration, according to the underlying anatomy, in order to provide a smooth route for the delivery of stents, to create the landing zone, and for the implantation of the Melody "ensemble". The procedure was performed under deep sedation according to our standard protocol. The duration of the procedure was 172 min and the radiation time was 24.9 min.

CONCLUSION

On the basis of this unique experience, percutaneous pulmonary valve implantation is safe and feasible even in patients with unusual anatomy. Crucial is the "U-spiral" shaped configuration of the guide wire.

Percutaneous pulmonary valve implantation in small conduits: A multicenter experience

BACKGROUND

Guidelines allow percutaneous pulmonary valve implantation (PPVI) in conduits above 16mm diameter. Balloon dilatation of a conduit to a diameter>110% of the original implant size is also not recommended. We analyzed patients undergoing PPVI in such conditions.

METHODS AND RESULTS

Nine patients (May 2008-July 2016) from 8 institutions underwent PPVI in conduits <16mm diameter. Five patients with 16-18mm conduit diameter underwent PPVI after over-expansion of the conduit>110%. Mean age and weight of the 14 patients was 12.1 (7.7 to 16) years and 44.9 (19 to 83) kg. Median conduit diameter at PPVI was 12 (10 to 17) mm. Median systolic right ventricular pressure was 70 (40 to 94) mmHg. Procedure was successful in all cases. A confined conduit rupture occurred in 7 patients (50%) and was treated with covered stent in 6. One patient experienced dislocation of 2 pulmonary artery stents that were parked distally. The post-implantation median systolic right ventricular pressure was 36 (28 to 51) mmHg. A fistula between right-ventricle outflow and aorta was found in one patient, secondary to undiagnosed conduit rupture. This was closed surgically. After a median follow-up of 20.16 (6.95 to 103.61) months, all the patients are asymptomatic with no significant RVOT stenosis.

CONCLUSIONS

PPVI is feasible in small conduits but rate of ruptures is high. Although such ruptures remain contained and can be managed with covered stents in our experience, careful selection of patients and high level of expertise are necessary. More studies are needed to better assess the risk of PPVI in this population.

Comparison of valvar and right ventricular function following transcatheter and surgical pulmonary valve replacement

OBJECTIVE

Trans-catheter (TC) pulmonary valve replacement (PVR) has become common practice for patients with right ventricular outflow tract obstruction (RVOTO) and/or pulmonic insufficiency (PI). Our aim was to compare PVR and right ventricular (RV) function of patients who received TC vs surgical PVR.

DESIGN

Retrospective review of echocardiograms obtained at three time points: before, immediately after PVR, and most recent.

PATIENTS

Sixty-two patients (median age 19 years, median follow-up 25 months) following TC (N = 32) or surgical (N = 30) PVR at Yale-New Haven Hospital were included.

OUTCOME MEASURES

Pulmonary valve and right ventricular function before, immediately after, and most recently after PVR.

RESULTS

At baseline, the TC group had predominant RVOTO (74% vs 10%, P < .001), and moderate-severe PI was less common (61% vs 100%, P < .001). Immediate post-procedural PVR function was good throughout. At last follow-up, the TC group had preserved valve function, but the surgical group did not (moderate RVOTO: 6% vs 41%, P < .001; >mild PI: 0% vs 24%, P = .003). Patients younger than 17 years at surgical PVR had the highest risk of developing PVR dysfunction, while PVR function in follow-up was similar in adults. Looking at RV size and function, both groups had a decline in RV size following PVR. However, while RV function remained stable in the TC group, there was a transient postoperative decline in the surgical group.

CONCLUSIONS

TC PVR in patients age <17 years is associated with better PVR function in follow-up compared to surgical valves. There was a transient decline in RV function following surgical but not TC PVR. TC PVR should therefore be the first choice in children who are considered for PVR, whenever possible.

Pediatrics Spanish Registry of Percutaneous Melody Pulmonary Valve Implantation in Patients Younger Than 18 Years

INTRODUCTION AND OBJECTIVES

A decade has passed since the first Spanish percutaneous pulmonary Melody valve implant (PPVI) in March 2007. Our objective was to analyze its results in terms of valvular function and possible mid-term follow-up complications.

METHODS

Spanish retrospective descriptive multicenter analysis of Melody PPVI in patients < 18 years from the first implant in March 2007 until January 1, 2016.

RESULTS

Nine centers were recruited with a total of 81 PPVI in 77 pediatric patients, whose median age and weight were 13.3 years (interquartile range [IQR], 9.9-15.4) and 46kg (IQR, 27-63). The predominant cardiac malformation was tetralogy of Fallot (n = 27). Most of the valves were implanted on conduits, especially bovine xenografts (n = 31). The incidence of intraprocedure and acute complications was 6% and 8%, respectively (there were no periprocedural deaths). The median follow-up time was 2.4 years (IQR, 1.1-4.9). Infective endocarditis (IE) was diagnosed in 4 patients (5.6%), of which 3 required surgical valve explant. During follow-up, the EI-related mortality rate was 1.3%. At 5 years of follow-up, 80% ± 6.9% and 83% ± 6.1% of the patients were free from reintervention and pulmonary valve replacement.

CONCLUSIONS

Melody PPVI was safe and effective in pediatric patients with good short- and mid-term follow-up hemodynamic results. The incidence of IE during follow-up was relatively low but was still the main complication.

Transcatheter Pulmonary Valve Implantation: A Comprehensive Systematic Review and Meta-Analyses of Observational Studies

BACKGROUND

Transcatheter pulmonary valve implantation is approved for the treatment of dysfunctional right ventricle to pulmonary artery conduits. However, the literature is limited because of a small patient population, and it does not reflect changing procedural practice patterns over the last decade.

METHODS AND RESULTS

A comprehensive search of Medline and Scopus databases from inception through August 31, 2016 was conducted using predefined criteria. We included studies reporting transcatheter pulmonary valve implantation in at least 5 patients with a follow-up duration of 6 months or more. In 19 eligible studies, 1044 patients underwent transcatheter pulmonary valve implantation with a pooled follow-up of 2271 person-years. Procedural success rate was 96.2% (95% confidence intervals [CI], 94.6-97.4) with a conduit rupture rate of 4.1% (95% CI, 2.5-6.8) and coronary complication rate of 1.3% (95% CI, 0.7-2.3). Incidence of reintervention was 4.4 per 100 person-years overall (95% CI, 3.0-5.9) with a marked reduction in studies reporting ≥75% prestenting (2.9 per 100 person-years [95% CI, 1.5-4.3] versus 6.5/100 person-years [95% CI, 4.6-8.5]; P<0.01). Pooled endocarditis rate was 1.4 per 100 person-years (95% CI, 0.9-2.0).

CONCLUSIONS

Our study provides favorable updated estimates of procedural and follow-up outcomes after transcatheter pulmonary valve implantation. Widespread adoption of prestenting has improved longer-term outcomes in these patients.

Post-market surveillance to detect adverse events associated with Melody® valve implantation

OBJECTIVE

The aim of this study was to describe previously unrecognised or under-recognised adverse events associated with Melody® valve implantation.

BACKGROUND

In rare diseases and conditions, it is typically not feasible to conduct large-scale safety trials before drug or device approval. Therefore, post-market surveillance mechanisms are necessary to detect rare but potentially serious adverse events.

METHODS

We reviewed the United States Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database and conducted a structured literature review to evaluate adverse events associated with on- and off-label Melody® valve implantation. Adverse events were compared with those described in the prospective Investigational Device Exemption and Post-Market Approval Melody® transcatheter pulmonary valve trials.

RESULTS

We identified 631 adverse events associated with "on-label" Melody® valve implants and 84 adverse events associated with "off-label" implants. The most frequent "on-label" adverse events were similar to those described in the prospective trials including stent fracture (n=210) and endocarditis (n=104). Previously unrecognised or under-recognised adverse events included stent fragment embolisation (n=5), device erosion (n=4), immediate post-implant severe valvar insufficiency (n=2), and late coronary compression (n=2 cases at 5 days and 3 months after implantation). Under-recognised adverse events associated with off-label implantation included early valve failure due to insufficiency when implanted in the tricuspid position (n=7) and embolisation with percutaneous implantation in the mitral position (n=5).

CONCLUSION

Post-market passive surveillance does not demonstrate a high frequency of previously unrecognised serious adverse events with "on-label" Melody® valve implantation. Further study is needed to evaluate safety of "off-label" uses.

Perventricular Implantation of Melody Valve in Child With Pulmonary Hypertension After a Potts Shunt

The Potts operation is a surgical option for the treatment of children with suprasystemic pulmonary arterial hypertension (PAH). Its positive hemodynamic effect may be obliterated by pulmonary valvar insufficiency. We describe a case in which the Potts shunt was followed by perventricular Melody valve implantation in the pulmonary position in a 12-kg child with a previously repaired truncus arteriosus communis (TAC) in whom PAH developed. The combined approach using both procedures significantly improved functional capacity and led to spectacular reverse remodeling of the right ventricle seen at 2-year follow-up. Elimination of significant pulmonary insufficiency is crucial in achieving the hemodynamic benefits of a Potts shunt in patients with pulmonary hypertension.

Popular Hybrid Congenital Heart Procedures without Cardiopulmonary Bypass

As surgical and catheter interventions advance, patients with congenital heart disease are now offered alternative treatment options that cater to their individual needs. Furthermore, collaboration between interventional cardiologists and cardiac surgeons have led to the development of hybrid procedures, using the best techniques of each respective field to treat these complex cardiac entities from initial treatment in the pediatric patient to repeat intervention in the adult. We present a review of the increased popularity and trend in hybrid procedures in congenital heart disease without the use of cardiopulmonary bypass.

Initial Experience with Elective Perventricular Melody Valve Placement in Small Patients

Perventricular Melody valve placement has been described as a bailout approach or alternative RVOT approach in patients >30 kg. We present three patients <20 kg and two patients with limited venous access, where we electively performed the perventricular approach. Retrospective analysis of patients <30 kg and vascular access limitation undergoing elective hybrid pulmonary valve replacement were reviewed. The subcostal approach was performed without sternotomy with the sheath introduced through the diaphragmatic surface of the right ventricle. Diagnoses included tetralogy of Fallot (n = 3) and truncus arteriosus (n = 2). Mean weight was 16.2 kg (range 4.7-28.1 kg). Four patients had RV-PA conduits (size: 14-21 mm), and the fifth patient had a transannular patch. All patients met criteria for surgical valve replacement. Technical success was 100%. In two patients with absent pulmonary valve, the stent migrated during advancement of the delivery sheath. These stents were anchored in the distal main pulmonary artery (n = 1) or branch pulmonary artery (n = 1) without sequela. Tricuspid valve chordal injury occurred in one patient, where transesophageal echocardiogram (TEE) was not utilized. No patient required conversion to cardiopulmonary bypass. One patient with absent pulmonary valve died on follow-up as a consequence of severe airway compromise. Our initial experience demonstrates that the perventricular valve can be placed safely in small-sized patients. Advancement of the melody ensemble may be difficult and may cause stent migration. We conclude that the technique is feasible in small-sized patients and that prevention of complications includes placement of the stent at the time of the valve and TEE assistance in reducing tricuspid valve injury.

Patient outcomes after transcatheter and surgical pulmonary valve replacement for pulmonary regurgitation in patients with repaired tetralogy of Fallot: A quasi-meta-analysis

BACKGROUND

Individuals with repaired tetralogy of Fallot develop pulmonary regurgitation that may cause symptoms (dyspnea, chest pain, palpitations, fatigue, presyncope, and syncope), impair functional capacity, and may affect health-related quality of life. Surgical pulmonary valve replacement is the gold standard of treatment although transcatheter pulmonary valve replacement is becoming more common. Patients want to know whether less invasive options are as good.

AIMS

This analysis aimed to examine the differences in surgical versus transcatheter pulmonary valve replacement effects in terms of physiological/biological variables, symptoms, functional status and health-related quality of life.

METHODS

This quasi-meta-analysis included 85 surgical and 47 transcatheter pulmonary valve replacement studies published between 1995-2016.

RESULTS

In terms of physiological/biological variables, both surgical and transcatheter pulmonary valve replacement improved pulmonary regurgitation and systolic and diastolic right ventricular volume indices but not heart function. In the left heart, only surgical pulmonary valve replacement improved heart function. Only transcatheter pulmonary valve replacement improved left ventricular end-diastolic indices and neither improved endsystolic indices. Only surgery has been demonstrated to decrease QRS duration but there is little evidence of arrhythmia reduction. Symptom change is poorly documented. Functional class improves but exercise capacity generally does not. Some aspects of health-related quality of life improve with surgery and in one small transcatheter pulmonary valve replacement study.

CONCLUSION

Transcatheter and surgical pulmonary valve replacement compare favorably for heart remodeling. Exercise capacity does not change with either technique. Health-related quality of life improves after surgical pulmonary valve replacement. There are numerous gaps in documentation of changes in arrhythmias and symptoms.

Factors associated with the internal jugular venous approach for Melody™ Transcatheter Pulmonary Valve implantation

BACKGROUND

Transcatheter pulmonary valve implantation is usually performed from a femoral venous - transfemoral - approach, but this may not be the optimal vascular access option in some patients. This study aimed to determine which group of patients might benefit from an internal jugular - transjugular - approach for transcatheter pulmonary valve implantation.

METHODS

This multicentre retrospective study included all patients who underwent attempted transcatheter pulmonary valve placement in the right ventricular outflow tract between April 2010 and June 2012 at two large congenital heart centres. Patients were divided into two groups based on venous access site - transfemoral or transjugular. Patient characteristics, procedural outcomes, and complications were compared between groups.

RESULTS

Of 81 patients meeting the inclusion criteria (median age 16.4 years), the transjugular approach was used in 14 patients (17%). The transjugular group was younger (median age 11.9 versus 17.3 years), had lower body surface area (mean 1.33 versus 1.61 m2), more often had moderate or greater tricuspid regurgitation (29% versus 7%), and had a higher ratio of right ventricle-to-systemic systolic pressure (mean 82.4 versus 64.7). Patients requiring a transjugular approach after an unsuccessful transfemoral approach had longer fluoroscopic times and procedure duration.

CONCLUSIONS

The transjugular approach for transcatheter pulmonary valve implantation is used infrequently but is more often used in younger and smaller patients. Technical limitations from a transfemoral approach may be anticipated if there is moderate or greater tricuspid regurgitation or higher right ventricular pressures. In these patients, a transjugular approach should be considered early.

Hybrid interventional procedures in congenital heart disease

The evolution of congenital cardiac surgery has seen significant innovative advances in collaborative efforts between congenital cardiac surgeons and interventionalists to provide the least invasive intervention with the greatest hemodynamic benefit for patients with congenital heart disease. This review looks at how this collaborative approach has evolved and is being applied to treat a number of congenital conditions across the age ranges.

Prestenting for prevention of melody valve stent fractures: A systematic review and meta-analysis

INTRODUCTION

The role of right ventricular outflow tract (RVOT) prestenting in the prevention of Melody valve stent fractures (SFs) is not well defined. We aimed to perform a systematic review and meta-analysis comparing the incidence of SF in Melody valve transcatheter pulmonary implants with and without prestenting.

METHODS

PubMed, EMBASE, and Cochrane Central were searched for studies that reported the incidence of SF in Melody valve transcatheter pulmonary implants stratified by the presence or absence of RVOT prestenting. Subgroup analyses were performed for (1) SF associated with a loss of stent integrity and (2) SF requiring reintervention.

RESULTS

Five studies and 360 patients were included, of whom 207 (57.5%) received prestenting. Follow-up ranged from 15 to 30 months. SF were significantly reduced in the prestenting group (16.7%) when compared to no prestenting (33.5%) (odds-ratio [OR] 0.39; 95%CI 0.22-0.69). Patients who received prestenting also had a lower incidence of (1) SF associated with loss of stent integrity (OR 0.16; 95%CI 0.05-0.48) and (2) SF requiring reintervention (OR 0.15; 95%CI 0.02-0.91).

CONCLUSION

Our findings suggest that stenting of the RVOT prior to Melody valve implantation is associated with a reduction in the incidence of SF and fracture-related reinterventions.