[Modern possibilities for transcatheter pulmonary valve replacement]

The literature review is devoted to transcatheter pulmonary valve replacement. The authors summarize the indications, clinical data and current capabilities of transcatheter pulmonary valve replacement. The authors also overviewed modern valves for transcatheter pulmonary artery replacement. Effectiveness of transcatheter pulmonary valve implantation has been substantiated. Various studies comparing the outcomes of different valve systems for endovascular implantation were analyzed. The authors concluded the prospects for transcatheter pulmonary valve implantation.

Pulmonary Valve Stenosis: From Diagnosis to Current Management Techniques and Future Prospects

Pulmonary stenosis (PS) is mainly a congenital defect that accounts for 7-12% of congenital heart diseases (CHD). It can be isolated or, more frequently, associated with other congenital defects (25-30%) involving anomalies of the pulmonary vascular tree. For the diagnosis of PS an integrated approach with echocardiography, cardiac computed tomography and cardiac magnetic resonance (CMR) is of paramount importance for the planning of the interventional treatment. In recent years, transcatheter approaches for the treatment of PS have increased however, meaning surgery is a possible option for complicated cases with anatomy not suitable for percutaneous treatment. The present review aims to summarize current knowledge regarding diagnosis and treatment of PS.

First experiences with Myval Transcatheter Heart Valve System in the treatment of severe pulmonary regurgitation in native right ventricular outflow tract and conduit dysfunction

The rate of morbidity and mortality related to pulmonary regurgitation and pulmonary stenosis are big concerns after the surgery for CHD. Percutaneous pulmonary valve implantation has been established as a less invasive technique compared to surgery with promising results according to long-term follow-up of the patients. There are only two approved valve options for percutaneous pulmonary valve implantation until now, which are Melody (Medtronic, Minneapolis, Minn, USA) and Sapien (Edwards Lifesciences, Irvine, Ca, USA). Both valves have limitations and do not cover entire patient population. Therefore, the cardiologists need more options to improve outcomes with fewer complications in a such promising area. Herein, we present a case series applying for pulmonary position in conduits and native right ventricular outflow tract of a new transcatheter valve system Myval ® which is designed for transcatheter aortic valve implantation procedures. This is the first patient series in which the use of Myvalv in dysfunctional right ventricular outflow tracts is described, after surgical repair of CHD.

Contrast-free percutaneous pulmonary valve replacement: a safe approach for valve-in-valve procedures

Introduction

Percutaneous pulmonary valve replacement (PPVI) continues to gather pace in pediatric and adult congenital practice. This is fueled by an expanding repertoire of devices, techniques and equipment to suit the heterogenous anatomical landscape of patients with lesions of the right ventricular outflow tract (RVOT). Contrast-induced nephropathy is a real risk for teenagers and adults with congenital heart disease (CHD).

Aim

To present a series of patients who underwent PPVI without formal RVOT angiography and propose case selection criteria for patients who may safely benefit from this approach.

Material and methods

We retrospectively collected PPVI data from the preceding 2 years at our institution identifying patients who had been listed as suitable for consideration for contrast-free PPVI from our multidisciplinary team (MDT) meeting based on predefined criteria. Demographic, clinical, imaging and hemodynamic data were collected. Data were analyzed using SPSS.

Results

Twenty-one patients were identified. All patients had a technically successful implantation with improvements seen in invasive and echocardiographic hemodynamic measurements. 90% of patients had a bio-prosthetic valve (BPV) in situ prior to PPVI. One patient had a complication which may have been recognized earlier with post-intervention RVOT contrast injection.

Conclusions

Zero-contrast PPVI is technically feasible and the suitability criteria for those who might benefit are potentially straightforward. The advent of fusion and 3D imaging in cardiac catheterization laboratories is likely to expand our capacity to perform more procedures with less contrast. Patients with bio-prosthetic valves in the pulmonary position may benefit from contrast-free percutaneous pulmonary valve implantation.

Pulmonary valve replacement following repair of tetralogy of Fallot: comparison of outcomes between bio- and mechanical prostheses

OBJECTIVES

The aims of this study were to evaluate and compare the outcomes after pulmonary valve replacement (PVR) with a mechanical prosthesis (MP) and a bioprosthesis (BP).

METHODS

From 2004 through 2017, a total of 131 patients, who had already been repaired for tetralogy or Fallot or its variants, underwent their first PVR with an MP or a BP. Outcomes of interests were prosthesis failure (stenosis >3.5 m/s, regurgitation >mild or infective endocarditis) and reintervention.

RESULTS

The median age at PVR was 19 years. BP and MP were used in 88 (67.2%) and 43 (32.8%) patients, respectively. The median follow-up duration was 7.4 years, and the 10-year survival rate was 96.4%. Risk factors for prosthesis failure were smaller body surface area [hazard ratio (HR) 0.23 per 1 m2, P = 0.047] and smaller prosthesis size (HR 0.73 per 1 mm, P = 0.039). Risk factors for prosthesis reintervention were smaller body surface area (HR 0.11 per 1 m2, P = 0.011) and prosthesis size (HR 0.67 per 1 mm, P = 0.044). Probability of prosthesis failure and reintervention at 10 years were 24.6% (19.5% in BP vs 34.8% in MP, P = 0.34) and 7.8% (5.6% in BP vs 11.9% in MP, P = 0.079), respectively. Anticoagulation-related major thromboembolic events were observed in 4 patients receiving an MP.

CONCLUSIONS

MP might not be superior to BP in terms of prosthesis failure or reintervention. MP should be carefully considered for highly selected patients in the era of transcatheter PVR.

Percutaneous Pulmonary Valve Implantation: Current Status and Future Perspectives

Patients with congenital heart disease (CHD) with right ventricle outflow tract (RVOT) dysfunction need sequential pulmonary valve replacements throughout their life in the majority of cases. Since their introduction in 2000, the number of percutaneous pulmonary valve implantations (PPVI) has grown and reached over 10,000 procedures worldwide. Overall, PPVI has been proven safe and effective, but some anatomical variations can limit procedural success. This review discusses the current status and future perspectives of the procedure.

Impact of Percutaneous Pulmonary Valve Implantation on the Timing of Reintervention for Right Ventricular Outflow Tract Dysfunction

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect. Early surgical repair has dramatically improved the outcome of this condition. However, despite the success of contemporary approaches with early complete repair, these are far from being curative and late complications are frequent. The most common complication is right ventricle outflow tract (RVOT) dysfunction, affecting most patients in the form of pulmonary regurgitation, pulmonary stenosis, or both, and can lead to development of symptoms of exercise intolerance, arrhythmias, and sudden cardiac death. Optimal timing of restoration of RVOT functionality in asymptomatic patients with RVOT dysfunction after TOF repair is still a matter of debate. Percutaneous pulmonary valve implantation, introduced almost 2 decades ago, has become a major game-changer in the treatment of RVOT dysfunction. In this article we review the pathophysiology, the current indications, and treatment options for RVOT dysfunction in patients after TOF repair with a focus on the role of percutaneous pulmonary valve implantation in the therapeutic approach to these patients.

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 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.

Infective Endocarditis Risk After Percutaneous Pulmonary Valve Implantation With the Melody and Sapien Valves

OBJECTIVES

This study compared the risk of infective endocarditis (IE) after percutaneous pulmonary valve implantation (PPVI) with the Sapien and Melody valves.

BACKGROUND

The incidence of IE after PPVI is estimated at 3% per year with the Melody valve. The Sapien valve is a more recently marketed valve used for PPVI.

METHODS

We retrospectively included consecutive patients who underwent PPVI at a single center between 2008 and 2016. IE was diagnosed using the modified DUKE criteria.

RESULTS

PPVI was performed in 79 patients (Melody valve, 40.5%; Sapien valve, 59.5%). Median age was 24.9 years (range 18.1 to 34.6). IE occurred in 8 patients (10.1%) at a median of 1.8 years (minimum: 1.0; maximum: 5.6) after surgery. Causative organisms were methicillin-sensitive Staphylococcus aureus (n = 3), Staphylococcus epidermidis (n = 1), Streptococcus mitis (n = 1), Aerococcus viridans (n = 1), Corynebacterium striatum (n = 1), and Haemophilus influenzae (n = 1). All 8 cases occurred after Melody PPVI (25.0% vs. 0.0%). The incidence of IE was 5.7% (95% confidence interval: 2.9% to 11.4%) per person-year after Melody PPVI. The Kaplan-Meier cumulative incidence of IE with Melody PPVI was 24.0% (95% confidence interval: 12.2% to 43.9%) after 4 years and 30.1% (95% confidence interval: 15.8% to 52.5%) after 6 years, compared with 0.0% with the Sapien PPVI after 4 years (p < 0.04 by log-rank test). There was a trend toward a higher incidence of IE in the first 20 patients with Melody PPVI (who received prophylactic antibiotics during the procedure only) and in patients who had percutaneous interventions, dental care, or noncardiac surgery after PPVI.

CONCLUSIONS

IE after PPVI may be less common with the Sapien compared with the Melody valve.

The effect of balloon valvuloplasty for bioprosthetic valve stenosis at pulmonary positions

BACKGROUND

Balloon dilatation of a bioprosthetic valve in the pulmonary position could be performed to delay valve replacement. We proposed to identify the long-term effectiveness of such a procedure.

METHODS

We reviewed the medical records of 49 patients who underwent balloon valvuloplasty between January 2000 and December 2015. The primary goal was to determine the time interval until the following surgical or catheter intervention.

RESULTS

The mean age at bioprosthetic valve insertion was 5.7 years old, and the mean age for ballooning was 11.7 years. The mean interval after pulmonary valve replacement was 71.6 months. The mean ratio of balloon size to valve size was 0.94. The pressure gradient through the pulmonary valve after balloon valvuloplasty was significantly improved (55.3 ± 18.5 mm Hg vs 33.8 ± 21.5 mm Hg, P < .001). There were no significant changes in pulmonary regurgitation and no serious adverse events. Patients had a mean freedom from re-intervention of 30.6 months after balloon valvuloplasty. The interval of freedom from re-intervention was affected only by the pressure gradient before balloon valvuloplasty and the patient age at insertion. The mean interval to re-intervention in patients with pressure gradients less than 48.5 mm Hg before ballooning was 46.0 months, which was significantly longer than for those with a higher gradient (18.7 months).

CONCLUSION

The effectiveness of this process may depend on the pressure gradient before ballooning and the patient age at valve insertion. It is possible that earlier valvuloplasty at pressure gradient not over 48.5mm Hg may have a benefit to delaying re-operation.

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.

Percutaneous management of failed bioprosthetic pulmonary valves in patients with congenital heart defects

AIMS

We reviewed our center experience in the field of transcatheter pulmonary valve-in-valve implantation (TPViV), that is emerging as a treatment option for patients with pulmonary bioprosthetic valve (BPV) dysfunction.

METHODS

Between April 2008 and September 2015, a total of six patients with congenital heart disease (four men) underwent TPViV due to stenosis of preexisting BPV. Four patients received a Melody Medtronic Transcatheter Pulmonary Valve and two an Edward Sapien Valve.

RESULTS

No procedural-related complications occurred. After valve implantation, right ventricular systolic pressure (RVSP, 80.5 ± 25.3-41.2 ± 8.35 mmHg, P < 0.05), right ventricular outflow tract (RVOT) gradient (55.3 ± 23.4-10.6 ± 3.8 mmHg, P < 0.05), and RVSP-to-aortic pressure (0.75 ± 0.21-0.38 ± 0.21, P = 0.01) fell significantly. Echocardiograms at follow-up revealed a significant reduction in estimated RVSP (88.7 ± 22-21.7 ± 4.7 mmHg, P < 0.05), in RVOT (76.2 ± 17.9-25.7 ± 6.1 mmHg, P = 0.005), and in mean RVOT (40.7 ± 9.9-15.5 ± 4.8 mmHg, P < 0.05) gradients. Cardiac magnetic resonance showed no significant change in biventricular dimensions and function. Symptomatic patients reported improvement of symptoms, although cardiopulmonary exercise did not show any significant differences.

CONCLUSION

TPViV is an effective and well tolerated treatment for BPV dysfunction, improving freedom from surgical reintervention. Long-term studies will redefine the management of dysfunctional RVOT, either native or surrogate.

Will catheter interventions replace surgery for valve abnormalities?

PURPOSE OF REVIEW

Catheter-based valve technologies have evolved rapidly over the last decade. Transcatheter aortic valve replacement (TAVR) has become a routine procedure in high-risk adult patients with calcific aortic stenosis. In patients with congenital heart disease (CHD), transcatheter pulmonary valve replacement represents a transformative technology for right ventricular outflow tract dysfunction with the potential to expand to other indications. This review aims to summarize the current state-of-the-art for transcatheter valve replacement (TVR) in CHD; the expanding indications for TVR; and the technological obstacles to optimizing TVR.

RECENT FINDINGS

Multiple case series have demonstrated that TVR with the Melody transcatheter pulmonary valve in properly selected patients is safe, effective, and durable in short-term follow-up. The Sapien transcatheter heart valve represents an alternative device with similar safety and efficacy in limited studies. Innovative use of current valves has demonstrated the flexibility of TVR, while highlighting the need for devices to address the broad range of postoperative anatomies either with a single device or with strategies to prepare the outflow tract for subsequent device deployment.

SUMMARY

The potential of TVR has not been fully realized, but holds promise in treatment of CHD.

Echocardiographic guidance for diagnostic and therapeutic percutaneous procedures

Echocardiographic guidance has an important role in percutaneous cardiovascular procedures and vascular access. The advantages include real time imaging, portability, and availability, which make it an effective imaging modality. This article will review the role of echocardiographic guidance for diagnostic and therapeutic percutaneous procedures, specifically, transvenous and transarterial access, pericardiocentesis, endomyocardial biopsy, transcatheter pulmonary valve replacement, pulmonary valve repair, transcatheter aortic valve implantation, and percutaneous mitral valve repair. We will address the ways in which echocardiographic guidance provides these procedures with detailed information on anatomy, adjacent structures, and intraprocedural instrument position, thus resulting in improvement in procedural efficacy, safety and patient outcomes.

Infective endocarditis after transcatheter pulmonary valve replacement using the Melody valve: combined results of 3 prospective North American and European studies

BACKGROUND

Transcatheter (percutaneous) pulmonary valve (TPV) replacement has emerged as a viable therapy for right ventricular outflow tract conduit dysfunction. Little is known about the incidence, clinical course, and outcome of infective endocarditis (IE) after TPV implant. We reviewed combined data from 3 ongoing prospective multicenter trials to evaluate the experience with IE among patients undergoing TPV replacement using the Melody valve.

METHODS AND RESULTS

Any clinical episode reported by investigators as IE with documented positive blood cultures and fever, regardless of TPV involvement, was considered IE. Cases were classified as TPV-related if there was evidence of vegetations on or new dysfunction of the TPV. The 3 trials included 311 patients followed for 687.1 patient-years (median, 2.5 years). Sixteen patients were diagnosed with IE 50 days to 4.7 years after TPV implant (median, 1.3 years), including 6 who met criteria for TPV-related IE: 3 with vegetations, 2 with TPV dysfunction, and 1 with both. The annualized rate of a first episode of IE was 2.4% per patient-year and of TPV-related IE was 0.88% per patient-year. Freedom from TPV-related IE was 97±1% 4 years after implant. All patients were treated with intravenous antibiotics, 4 had the valve explanted, and 2 received a second TPV. There was 1 sepsis-related death, 1 patient died of sudden hemoptysis, and 2 patients developed recurrent IE.

CONCLUSIONS

Bacterial endocarditis has occurred in all 3 prospective multicenter studies of the Melody valve in North America and Europe. Most cases did not involve the TPV and responded to antibiotics. More data are necessary to understand risk factors in this population.

Melody valve implant within failed bioprosthetic valves in the pulmonary position: a multicenter experience

BACKGROUND

Transcatheter pulmonary valve implantation using the Melody valve has emerged as an important therapy for the treatment of postoperative right ventricular outflow tract dysfunction. Melody-in-bioprosthetic valves (BPV) is currently considered an off-label indication. We review the combined experience with transcatheter pulmonary valve implantation within BPVs from 8 centers in the United States and discuss technical aspects of the Melody-in-BPV procedure.

METHODS AND RESULTS

A total of 104 patients underwent Melody-in-BPV in the pulmonary position at 8 US centers from April 2007 to January 2012. Ten different types of BPVs were intervened on, with Melody valve implantation at the intended site in all patients. Following Melody valve implant, the peak right ventricle-to-pulmonary artery gradient decreased from 38.7 ± 16.3 to 10.9 ± 6.7 mm Hg (P<0.001), and the right ventricular systolic pressure fell from 71.6 ± 21.7 to 46.7 ± 15.9 mm Hg (P<0.001). There was no serious procedural morbidity, and no deaths related to the catheterization or implant. At a median follow-up of 12 months (1-46 months), no patients had more than mild regurgitation, and 4 had a mean right ventricular outflow tract gradient ≥30 mm Hg. During follow-up, there were 2 stent fractures, 3 cases of endocarditis (2 managed with surgical explant), and 2 deaths that were unrelated to the Melody valve.

CONCLUSIONS

Transcatheter pulmonary valve implantation using the Melody valve within BPVs can be accomplished with a high rate of success, low procedure-related morbidity and mortality, and excellent short-term results. The findings of this preliminary multicenter experience suggest that the Melody valve is an effective transcatheter treatment option for failed BPVs.

State-of-the-art percutaneous pulmonary valve therapy

Transcatheter pulmonary valve replacement is one of the most exciting recent developments in the treatment of patients with congenital heart disease and is being used to treat both stenotic and regurgitant valves within previously placed surgical conduits. Although limited somewhat by both patients and available valve sizes, ongoing attempts are being made to extend this technology to native right ventricular outflow tracts. If achieved, this will represent a significant advancement in attempts to prevent morbidity and mortality secondary to the chronic effects of right ventricular volume loading. This review deals with the development, current status and future endeavors of this approach.

Transcatheter pulmonary valve replacement

Transcatheter pulmonary valve replacement (tPVR) has evolved into a viable alternative to surgical conduit or bioprosthetic valve replacement. This procedure has paved the way for a more advanced approach to congenital and structural interventional cardiology. Although many successes have been noted, there are still a number of challenges with this procedure, including large delivery systems, the need for a conduit or a bioprosthetic valve as a landing zone for the valve, optimal timing of the procedure to prevent right ventricular failure, arrhythmias, and possible death. Research is ongoing to broaden the use of this technology when treating patients with dilated right ventricular outflow tracts, and early experience with a self-expanding valve model has been reported. Affordability is an important factor that must be considered especially in developing nations. The aim of this review is to emphasize the advancement of tPVR, the benefits and challenges of valve implantation, the current state, and the future innovations associated with this approach.

Percutaneous implantation of the Edwards SAPIEN(™) pulmonic valve: initial results in the first 22 patients

BACKGROUND

Percutaneous pulmonary valve implantation (PPVI) was introduced in 2000 as an interventional procedure for the treatment of right ventricular outflow tract (RVOT) dysfunction. The new Edwards SAPIEN(™) pulmonic valve has reached CE certification at the end of 2010 thus offering an attractive alternative with extended sizes (23 and 26 mm) to the conventional Melody(®) valve (sizes 18, 20 and 22 mm).

PATIENTS

Over a 1-year period, PPVI using the Edwards SAPIEN(™) pulmonic valve was performed in 22 patients using a standardized procedure. Primary diagnosis was tetralogy of Fallot (n = 11), pulmonary atresia (n = 2), Truncus arteriosus (n = 3), TGA/PS-Rastelli (n = 1), Ross surgery (n = 2), double outlet right ventricle (n = 2) and absent pulmonary valve syndrome (n = 1). The character of the RVOT for PPVI was transannular patch (n = 4), bioprosthesis (n = 2), homograft (n = 5) and Contegra(®) conduit (n = 11). The leading hemodynamic problem consisted of a pulmonary stenosis (PS) (n = 2), pulmonary regurgitation (PR) (n = 11) and a combined PS/PR lesion (n = 9).

RESULTS

In 21/22 patients, PPVI was performed successfully (10 × 23 and 11 × 26 mm). There were 9 female and 13 male patients; the mean age was 21.7 years (range 6-83 years), the mean length was 162 cm (range 111-181 cm) and the weight 56.5 kg (range 20-91 kg). Invasive data showed a decrease of RV-systolic pressure from 61.2 mmHg (± 23.1) to 41.2 mmHg (± 8.6) and reduction of RV-PA gradient from 37.3 mmHg (± 23.2) to 6.9 mmHg (± 5.3). The PA-systolic pressure increased from 25.8 mmHg (± 8.6) to 33.9 mmHg (± 9.3) as did the PA diastolic pressure (from 6.0 mmHg (± 5.6) to 14.6 mmHg (± 4.3). There was a substantial reduction of pulmonary regurgitation from before (none/trivial n = 0, mild n = 2, mode rate n = 9, severe n = 11) to after PPVI (none/trivial n = 20, mild n = 1). During the short-term follow-up of 5.7 months there was no change in the immediate results.

CONCLUSION

PPVI using the Edwards SAPIEN(™) pulmonic valve can be performed safely in a wide range of patients with various diagnoses and underlying pathology of the RVOT and enables the restoration of an adult-size RVOT diameter. Although the immediate and short-term results seem promising, the long-term effects and safety have to be assessed in further clinical follow-up studies.

Transcatheter valve-in-valve implantation for failing bioprosthetic valves

Transcatheter valve implantation is becoming an alternative to conventional surgical valve replacement in patients at high surgical risk. While experience and acceptance with transcatheter techniques increased rapidly, transcatheter valve implantation within failing bioprostheses has emerged as a new concept (valve-in-valve implantation). Currently, the majority of prostheses implanted in patients are bioprosthetic valves that are expected to degenerate over time. Valve-in-valve implantation provides great utility in high-operative-risk patients since the mortality risk for reoperation can be significantly higher than for first-time isolated valve replacement. Although two current devices are CE Mark approved in Europe for implantation within native valves, off-label clinical implementation of valve-in-valve have been described in numerous case reports. In this article, we provide an overview of transcatheter valve implantation in failing bioprostheses with an emphasis on the aortic position.

Injectable living marrow stromal cell-based autologous tissue engineered heart valves: first experiences with a one-step intervention in primates

AIMS

A living heart valve with regeneration capacity based on autologous cells and minimally invasive implantation technology would represent a substantial improvement upon contemporary heart valve prostheses. This study investigates the feasibility of injectable, marrow stromal cell-based, autologous, living tissue engineered heart valves (TEHV) generated and implanted in a one-step intervention in non-human primates.

METHODS AND RESULTS

Trileaflet heart valves were fabricated from non-woven biodegradable synthetic composite scaffolds and integrated into self-expanding nitinol stents. During the same intervention autologous bone marrow-derived mononuclear cells were harvested, seeded onto the scaffold matrix, and implanted transapically as pulmonary valve replacements into non-human primates (n = 6). The transapical implantations were successful in all animals and the overall procedure time from cell harvest to TEHV implantation was 118 ± 17 min. In vivo functionality assessed by echocardiography revealed preserved valvular structures and adequate functionality up to 4 weeks post implantation. Substantial cellular remodelling and in-growth into the scaffold materials resulted in layered, endothelialized tissues as visualized by histology and immunohistochemistry. Biomechanical analysis showed non-linear stress-strain curves of the leaflets, indicating replacement of the initial biodegradable matrix by living tissue.

CONCLUSION

Here, we provide a novel concept demonstrating that heart valve tissue engineering based on a minimally invasive technique for both cell harvest and valve delivery as a one-step intervention is feasible in non-human primates. This innovative approach may overcome the limitations of contemporary surgical and interventional bioprosthetic heart valve prostheses.