Native Pulmonary Valve Research Articles

Staged left ventricular recruitment facilitated by Sano conduit upsizing

Staged left ventricular recruitment facilitated by Sano conduit upsizing

Early post-operative benefits of a pulmonary valve-sparing strategy during Fallot repair

BackgroundPatients undergoing complete repair of tetralogy of Fallot generally have an excellent prognosis. Unfortunately, pulmonary valve reconstruction with a transannular patch is generally required. Resulting pulmonary regurgitation is associated with late right ventricular dysfunction and morbidity. Early pulmonary regurgitation may also be poorly tolerated. This study compares immediate outcomes of non-valved transannular patch repair (NV-TAP) to a valve-sparing (V-Sp) approach. Methods67 patients, with tetralogy of Fallot and severe pulmonary annular hypoplasia underwent complete repair between 2010 and 2018.23 patients had a NV-TAP repair while a V-Sp technique was used in 44 patients. Mortality, length of stay in the intensive care unit and hospital, use of inotropes, duration of mechanical ventilation, use and duration of dialysis, chest drainage duration, reinterventions, and postoperative complications were compared. Immediate outcomes were assessed by biological data and postoperative echocardiography. ResultsICU stay was shorter in the V-Sp group (5 days vs 8 days, p = 0.009). At postoperative day 1, Vasoactive Inotropic Score and mean dosage of adrenaline were significantly lower in the V-Sp group. Duration of inotrope use was significantly shorter. Hospital stay, mechanical ventilation, and chest drainage duration, the incidence and duration of dialysis all showed a trend towards being lower in the V-Sp group. Surgical complications were similar despite longer cardiopulmonary bypass and aortic cross-clamp durations. ConclusionRepair of the native pulmonary valve by a V-Sp technique reduces length of stay in the ICU and the use of inotropic agents in the immediate post-operative period.

Biodegradable Poly-ε-Caprolactone Scaffolds with ECFCs and iMSCs for Tissue-Engineered Heart Valves.

Clinically used heart valve prostheses, despite their progress, are still associated with limitations. Biodegradable poly-ε-caprolactone (PCL) nanofiber scaffolds, as a matrix, were seeded with human endothelial colony-forming cells (ECFCs) and human induced-pluripotent stem cells-derived MSCs (iMSCs) for the generation of tissue-engineered heart valves. Cell adhesion, proliferation, and distribution, as well as the effects of coating PCL nanofibers, were analyzed by fluorescence microscopy and SEM. Mechanical properties of seeded PCL scaffolds were investigated under uniaxial loading. iPSCs were used to differentiate into iMSCs via mesoderm. The obtained iMSCs exhibited a comparable phenotype and surface marker expression to adult human MSCs and were capable of multilineage differentiation. EFCFs and MSCs showed good adhesion and distribution on PCL fibers, forming a closed cell cover. Coating of the fibers resulted in an increased cell number only at an early time point; from day 7 of colonization, there was no difference between cell numbers on coated and uncoated PCL fibers. The mechanical properties of PCL scaffolds under uniaxial loading were compared with native porcine pulmonary valve leaflets. The Young’s modulus and mean elongation at Fmax of unseeded PCL scaffolds were comparable to those of native leaflets (p = ns.). Colonization of PCL scaffolds with human ECFCs or iMSCs did not alter these properties (p = ns.). However, the native heart valves exhibited a maximum tensile stress at a force of 1.2 ± 0.5 N, whereas it was lower in the unseeded PCL scaffolds (0.6 ± 0.0 N, p < 0.05). A closed cell layer on PCL tissues did not change the values of Fmax (ECFCs: 0.6 ± 0.1 N; iMSCs: 0.7 ± 0.1 N). Here, a successful two-phase protocol, based on the timed use of differentiation factors for efficient differentiation of human iPSCs into iMSCs, was developed. Furthermore, we demonstrated the successful colonization of a biodegradable PCL nanofiber matrix with human ECFCs and iMSCs suitable for the generation of tissue-engineered heart valves. A closed cell cover was already evident after 14 days for ECFCs and 21 days for MSCs. The PCL tissue did not show major mechanical differences compared to native heart valves, which was not altered by short-term surface colonization with human cells in the absence of an extracellular matrix.

Medium-Term Results of Balloon Valvuloplasty of Native Pulmonary Valve Stenosis with and without Supravalvular Obstruction in Childhood

Objectives: Factors influencing results of balloon valvuloplasty (BVP) of pulmonary valve stenosis (PS) in children are investigated. Background: BVP has become the standard of care for PS, medium-term results are not uniform and depend on various preconditions. Methods: We analysed the medium-term results of BVP of PS in children in an observational, single centre study. Need for additional procedure was defined as outcome after initial BVP. Results: We included 143 children (83 female) at a median (IQR) age of 2.6 (0.26–9.24) months and body weight of 5 (3.4–8) kg at BVP with a follow–up of 5.04 (1.6–10.2) years. We used balloon size of 10 (9–14) mm and maximal balloon pressure of 4 (3.5–10) atm, resulting in balloon–to–pulmonary annulus ratio of 1.28 (1.2–1.4). Systolic pressure gradient of PS was reduced with BVP (43.5 mmHg vs. 14.0 mmHg, p < 0.001) and confirmed by echocardiography (68.0 mmHg vs. 25.0 mmHg, p < 0.001) day 1 post procedure. Pulmonary BVP with associated supravalvular PS resulted in a relevant reduction of systolic pressure gradient in 23 of 31 patients (74.2%). Early additional procedure was necessary in 14 patients (9.8%) after 0.2 (0.1–0.7) years due to residual PS (n = 13) and infective endocarditis (n = 1). Factors for additional procedures were associated supravalvular PS with a higher residual pressure gradient, but not genetic syndrome. During further follow–up of 5.04 (1.6–10.2) years no further additional procedures were needed. Conclusions: Pulmonary BVP of native pulmonary valve stenosis leads to excellent medium-term results, even in 3 of 4 infants with associated supravalvular obstruction sufficient pressure relief can be obtained.

Tetralogy of Fallot: T-shaped infundibulotomy for pulmonary valve-sparing procedure.

This new and easily reproducible pulmonary valve-sparing technique for the correction of Tetralogy of Fallot is based on a conservative management of the native pulmonary valve to preserve its growth potential. From July 2015 to December 2019, 67 children presenting with a Tetralogy of Fallot were operated consecutively in a single centre using this technique in all cases. A T-shaped infundibulotomy is used to release the anterior pulmonary annulus from any muscular attachment. After myocardial resection and ventricular septal defect closure, an extensive commissurotomy is achieved. Finally, the right ventricular outflow tract remodelling is completed by a shield-shaped bovine patch with an oversized square superior edge, attached directly on the pulmonary valve annulus, with an effect of systolic traction. Sixty patients (89.5%) had a Tetralogy of Fallot repair with preservation of the pulmonary valve. To date, with a median follow-up of 38.2 [14–64] months, no patient has needed a surgical or interventional procedure for pulmonary valve stenosis or regurgitation, with low residual gradients. This procedure could provide a significant increase in native pulmonary valve preservation. Long-term studies are needed to assess pulmonary valve growth and the consequent reduction in surgical or interventional reoperations.

Pulmonary valve infective endocarditis

Background and Objectives:Infective endocarditis (IE) involving the native pulmonary valve (PV) is extremely rare, with no data in Indian literature. The objective of this communication is to describe the clinical and diagnostic characteristics, underlying risk factors, microbiological features, and management of PVIE.Methods:This is a retrospective analysis of 8 cases of PVIE managed in a tertiary care center from 1992 to 2020.Results:PVIE was observed in 8 patients with underlying congenital cardiac malformation (Group A, 6 Patients) and in patients with central venous catheter (Group B, 2 patients). All the patients had prolonged febrile illness accompanied by right heart failure 4 (50%), septic pulmonary emboli 2 (25%), and pulmonary regurgitation 3 (37.5%). Trans-thoracic echocardiography demonstrated the vegetations, whereas computed tomography of chest diagnosed pulmonary emboli in 2 (25%), and pulmonary artery aneurysm in 1 (12.5%) patient. The early mortality was extremely high (5, 62.5%). Delayed diagnosis, fulminant septicemia, and multi-organ failure resulted in unfavorable outcomes.Conclusions:IE of the native PV is a rare and potentially lethal illness. Diagnosis should be considered in any febrile patient with an underlying congenital defect, central venous line, bacteremia, and comorbidities. Multi-modality imaging should be utilized to enhance the diagnostic yield and detect complications promptly.

Pulmonary valve reconstruction by allograft replacement of underdeveloped anterior leaflet in case of late combined pulmonary restenosis after early primary repair.

IntroductionThe native pulmonary valve (PV) reconstruction is an attractive alternative to a replacement but is challenging due to the systematic underdevelopment of the valve structures in congenital heart diseases. The partial replacement of underdeveloped parts of the valve and saving of well-developed may have advantages versus replacing the whole valve in terms of durability and patient outgrowth of the prosthesis.Case presentationThis report describes a case of the PV reconstruction by allograft replacement of an underdeveloped anterior leaflet in an adolescent patient who previously corrected pulmonary stenosis during the first year of her life. The normal anatomy of the right and left leaflets was revealed. The rudimental anterior leaflet determined the annular restenosis. The monocusp with the related supporting aortic wall was sewn instead of the anterior leaflet. The Z-score of the pulmonary annulus changed from minus 3, 9 before to +0.8 after the procedure. The excellent function of the PV was observed in 1-year follow-up.DiscussionValve deterioration over time will have a less negative impact on the function when it occurs in a limited area. The annular dilatation becomes unlikely if the annulus predominantly consists of natural tissues. The procedural effectiveness allows the transcatheter valve-in-valve therapy in case of late dysfunction. The expected feature of the procedure described is that the growth of the PV remains possible.ConclusionIf allograft replacement of the PV is scheduled and allograft is available, the partial replacement may be superior to replacement of the whole valve in terms of durability and patient outgrowth of the prosthesis.

Native Bicuspid Pulmonary Valve in D-Loop Transposition of the Great Arteries: Outcomes of the Neo-Aortic Valve Function and Root Dilation After Arterial Switch Operation.

BackgroundNeo‐aortic root dilation and neo‐aortic regurgitation (AR) are common after arterial switch operation for D‐loop transposition of the great arteries. We sought to evaluate these outcomes in patients with bicuspid native pulmonary valve (BNPV).Methods and ResultsA retrospective analysis of patients with transposition of the great arteries undergoing arterial switch operation at Boston Children's Hospital from 1989 to 2018 matched BNPV patients 1:3 with patients with tricuspid native pulmonary valve by year of arterial switch operation. Kaplan–Meier analyses with log‐rank test compared groups for time to first neo‐aortic valve reoperation, occurrence of ≥moderate AR, and neo‐aortic root dilation (root z score ≥4). A total of 83 patients with BNPV were matched with 217 patients with tricuspid native pulmonary valve. Patients with BNPV more often had ventricular septal defects (73% versus 43%; P<0.001). Hospital length of stay (11 versus 10 days) and 30‐day surgical mortality (3.6% versus 2.8%) were similar. During median 11 years follow‐up, neo‐aortic valve reoperation occurred in 4 patients with BNPV (6.0%) versus 6 patients with tricuspid native pulmonary valve (2.8%), with no significant difference in time to reoperation. More BNPV had AR at discharge (4.9% versus 0%; P=0.014) and during follow‐up (13.4% versus 4.3%; hazard ratio [HR], 3.9; P=0.004), with shorter time to first occurrence of AR; this remained significant after adjusting for ventricular septal defects. Similarly, neo‐aortic root dilation was more common in BNPV (45% versus 38%; HR, 1.64; P=0.026) with shorter time to first occurrence.ConclusionsWhile patients with BNPV have similar short‐term arterial switch operation outcomes, AR and neo‐aortic root dilation occur more frequently and earlier compared with patients with tricuspid native pulmonary valve. Further long‐term studies are needed to determine whether this results in greater need for neo‐aortic valve reoperation.

Comparative analysis of surgical and percutaneous pulmonary valve implants over a 20-year period.

Since percutaneous pulmonary valve implantation (PPVI) was introduced to prolong the lifetime of surgically placed right ventricular to pulmonary artery conduits, valve technology has evolved and the indications for PPVI expanded to native and larger right ventricular outflow tracts. We explore how indications, patient populations and outcomes compare to surgical pulmonary valve replacement (PVR). This is a retrospective cohort study of PPVI and PVR procedures between 1998 and 2020 at a single UK centre. One hundred and twenty-eight patients underwent PPVI and 365 patients PVR. Primary outcome measures were survival, infective endocarditis and reintervention. The most common indication for PVR was replacement of the native pulmonary valve for pulmonary regurgitation whereas PPVI was more commonly used to treat pulmonary stenosis in a previously placed bioprosthetic conduit or valve. Treatment indications for PPVI expanded over the study to include the native right ventricular outflow tract. Survival was similar for PPVI and PVR (92% PPVI and 96.8% PVR at 5 years; 85.8% PPVI and 95.1% PVR at 10 years). Preprocedural New York Heart Association class 3 and 4 was the most important predictor of poor outcome. Annualized infective endocarditis rate was significantly higher for the Melody PPVI (0.024 vs 0.0024/person/year for PVR, P < 0.05). Both groups showed significant symptomatic improvement postprocedure with remodelling of ventricular volumes and improvement in cardiac output. Long-term follow-up for PVR showed half of patients will need replacement at 10-15 years post-index procedure. An increasing number of patients requiring PVR can now be treated percutaneously. A lifetime strategy for re-valving should be considered at the first valve implant.

The Ross procedure in children: a systematic review.

The Ross procedure involves autograft transplantation of the native pulmonary valve into the aortic position and reconstruction of the right ventricular outflow tract (RVOT) with a homograft. The operation offers the advantages of a native valve with excellent hemodynamic performance, the avoidance of anticoagulation, and growth potential. Conversely, the operation is technically demanding and imposes the risk of turning single-valve disease into double-valve disease. This systematic review reports outcomes of pediatric patients undergoing the Ross procedure. An electronic search identified studies reporting outcomes on pediatric patients (mean age <18 years, max age <21 years) undergoing the Ross procedure. Long-term outcomes, including early mortality, late mortality, sudden unexpected unexplained death, reoperation due to failure of the pulmonary autograft or RVOT reconstruction, thromboembolic events, bleeding events, and endocarditis-related complications, were evaluated. Upon review of 2,035 publications, 30 studies and 3,156 pediatric patients were included. Patients had a median age of 9.5 years and median follow-up period of 5.7 years. Early mortality rates varied from 0.0 to 17.0% and were increased in the neonatal population. Late mortality rates were much lower (0.04-1.83%/year). Reoperation due to pulmonary autograft failure occurred at rates of 0.37-2.81%/year and reoperation due to RVOT reconstruction failure was required at rates of 0.34-4.76%/year. Thromboembolic, bleeding, and endocarditis events were reported to occur at rates of 0.00-0.58, 0.00-0.39, and 0.00-1.68%/year, respectively. The Ross operation offers a durable aortic valve replacement (AVR) option in the pediatric population that offers favorable survival, excellent hemodynamics, growth potential, decreased risk of complications, and avoidance of anticoagulation. Larger multi-institutional registries focusing on pediatric patients are necessary to provide more robust evidence to further support use of the Ross procedure in this population.

Bicuspid Aortic Valve in Infants, Children, and Adolescents: A Review for Primary Care Providers.

1. Talha Niaz, MBBS* 2. Jonathan N. Johnson, MD*,† 3. Frank Cetta, MD*,† 4. Timothy M. Olson, MD*,† 5. Donald J. Hagler, MD*,† 1. *Division of Pediatric Cardiology, Department of Pediatric and Adolescent Medicine, and 2. †Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN * Abbreviations: AHA : : American Heart Association BAV : : bicuspid aortic valve TTE : : transthoracic echocardiography Bicuspid aortic valve is the most common congenital heart defect in children, adolescents, and adults. Primary care providers play an important role in screening, referral, and follow-up of these patients and should be aware of the family screening guidelines, sports participation recommendations, and periodic follow-up requirements for adequate surveillance of the complications that arise from bicuspid aortic valve. After reading this article, readers should be able to: 1. Describe the epidemiology and anatomy of bicuspid aortic valve (BAV). 2. Understand the clinical presentation and diagnosis of BAV in infants, children, and adolescents. 3. Identify the various complications of BAV disease. 4. Discuss the management and follow-up requirements for BAV. 5. Analyze the family screening and sports participation guidelines for patients with BAV. Bicuspid aortic valve (BAV) is the most common congenital heart defect in children, adolescents, and adults. (1) It is a heterogeneous disease that affects both the aortic valve and the aorta. It can lead to many complications, including aortic valve stenosis, regurgitation, or endocarditis. (2)(3) It also can lead to dilation of the aorta, predisposing individuals to a significantly higher risk of aortic aneurysm and dissection. (4) Although most individuals with BAV present with these long-term complications during adulthood, a considerable number of patients may also present during childhood and adolescence with early-onset disease; that may require interventions in up to 12% to 15% of the patients. (5)(6) Therefore, patients with BAV require lifelong follow-up and surveillance. BAV has multiple implications in terms of sports participation and family screening, making it an important subject for primary care providers. This article reviews the anatomy, genetics, presentation, diagnosis, …

In Vitro Assessment of Right Ventricular Outflow Tract Anatomy and Valve Orientation Effects on Bioprosthetic Pulmonary Valve Hemodynamics.

The congenital heart defect Tetralogy of Fallot (ToF) affects 1 in 2500 newborns annually in the US and typically requires surgical repair of the right ventricular outflow tract (RVOT) early in life, with variations in surgical technique leading to large disparities in RVOT anatomy among patients. Subsequently, often in adolescence or early adulthood, patients usually require surgical placement of a xenograft or allograft pulmonary valve prosthesis. Valve longevity is highly variable for reasons that remain poorly understood. This work aims to assess the performance of bioprosthetic pulmonary valves in vitro using two 3D printed geometries: an idealized case based on healthy subjects aged 11 to 13 years and a diseased case with a 150% dilation in vessel diameter downstream of the valve. Each geometry was studied with two valve orientations: one with a valve leaflet opening posterior, which is the native pulmonary valve position, and one with a valve leaflet opening anterior. Full three-dimensional, three-component, phase-averaged velocity fields were obtained in the physiological models using 4D flow MRI. Flow features, particularly vortex formation and reversed flow regions, differed significantly between the RVOT geometries and valve orientations. Pronounced asymmetry in streamwise velocity was present in all cases, while the diseased geometry produced additional asymmetry in radial flows. Quantitative integral metrics demonstrated increased secondary flow strength and recirculation in the rotated orientation for the diseased geometry. The compound effects of geometry and orientation on bioprosthetic valve hemodynamics illustrated in this study could have a crucial impact on long-term valve performance.

Evolving Techniques for the Achievement of Optimal Long-Term Results After Tetralogy of Fallot Repair.

Several techniques designed to improve long-term results after repair of tetralogy of Fallot are described. We have recently embarked on a program focused on preserving the native pulmonary valve. Here, combined techniques are described in detail, including intraoperative pulmonary valve balloon dilatation, pulmonary valve reconstruction by delamination and resuspension of the leaflets, and pulmonary valve annulus augmentation. As with any other complex congenital heart disease, senior surgeons should select teaching cases, starting from the less severe side of the spectrum.

Abstract 14744: Native Bicuspid Pulmonary Valve in D-loop Transposition of the Great Arteries: Outcomes of the Neo-aortic Valve Function and Root Dilation After Arterial Switch Operation

Introduction: Neo-aortic root dilation (ARD) is common after arterial switch operation (ASO) for D-loop transposition of the great arteries (TGA). We sought to compare short and long-term outcomes for bicuspid native pulmonary valve (BNPV) patients to those with normal trileaflet variants (TNPV). Methods: A retrospective cohort of TGA patients undergoing ASO at Boston Children’s Hospital from 1989-2018 was analyzed, matching BNPV patients 1:3 with TNPV patients by year of ASO; those with &gt;mild subpulmonary stenosis or complex TGA were excluded. Categorical and continuous variables were compared using Fisher’s exact and Wilcoxon rank sum tests, respectively. Kaplan-Meier analyses with log-rank test compared groups for time to first reoperation on the neo-aortic valve, first occurrence of ≥moderate neo-aortic regurgitation (AR), and ARD defined as root z-score ≥4. Hazard ratios were estimated based on the Cox proportional hazards model. Results: A total of 83 BNPV patients were matched with 217 TNPV. BNPV patients were more likely to have a VSD (75% vs 44%, p &lt;0.001). Early surgical outcomes including hospital LOS (11 vs 10 days) and 30-day mortality (3.6% vs 2.8%) were similar. During median 10 years follow-up, neo-aortic valve reoperation occurred in 4 BNPV (6%) vs 6 TNPV (3%) patients, with no statistically significant difference in time to reoperation. More BNPV patients had AR at discharge (4.9% vs 0%, p=0.014) and during follow-up (13.4% vs 4.3%, HR 3.9, p=0.004), with shorter time to first occurrence of AR (Figure 1A); this remained significant after adjusting for presence of VSD. Similarly, ARD was more common in BNPV (45% vs 37%, HR 1.64, p=0.02) with shorter time to first occurrence (Figure 1B). Conclusions: While patients with BNPV have similar short-term ASO outcomes, AR and ARD occur more frequently and earlier compared with TNPV patients. Further long-term studies are needed to determine whether this results in greater need for neo-aortic valve reoperation.

En Block Rotation of the Outflow Tracts: Intermediate Follow-up After 15 Years of Experience

The en bloc rotation of the outflow tracts is a surgical option for anatomic repair of transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction with preserved growth potential in all tubular structures and the option for keeping the native pulmonary valve. The aim of this study was to analyze our 15-year experience with this operation. A retrospective single-center study including 27 consecutive patients, who underwent the en bloc rotation between 2003 and 2019, was performed. Median age at operation was 103 days (interquartile range [IQR], 17-117 days), and median body weight was 5.2 kg (IQR, 3.66-8.4 kg). Six patients had undergone 1 to 4 previous operations. In 18 patients (66.7%), the pulmonary valve could be preserved, and in 9 patients (33.3%) a transannular patch was performed. Median follow-up was 5.7 years (IQR, 1.6-9.0 years). One patient died of chronic left ventricular failure during the hospital stay. Two more died after discharge: 1 of aspiration after a cerebral hemorrhage and 1 of sudden death. Five other patients required reoperations or had reinterventions: 1 ventricular septal defect closure, 1 aortic valve repair, 1 patch plasty, 2 dilatations of supravalvular pulmonary stenosis, and 1 stent into a left pulmonary artery. During the follow-up period, no gradient in the left ventricular outflow tract was found, and postoperative growth of the pulmonary valve was shown. The en bloc rotation allows an anatomic correction of the complex transposition with growth potential in all tubular structures. Reoperations or reinterventions on the pulmonary valve or on the left ventricular outflow tract have not been necessary to date.

Anatomic Risk Factors for Reintervention After Arterial Switch Operation for Taussig-Bing Anomaly

This study aimed to determine the factors related to reintervention, especially for pulmonary stenosis (PS), in patients with Taussig-Bing anomaly (TBA) after the arterial switch operation. This retrospective study included 34 patients with TBA who underwent the arterial switch operation between 1993 and 2018. Preoperative anatomic and physiologic differences and long-term outcomes were determined using a case-matched control with transposition of the great arteries with ventricular septal defect and TBA with an anterior and rightward aorta. At arterial switch operation, median age was 43 days (range, 16 to 102) and median body weight was 3.6 kg (range, 2.8 to 3.8 kg). Aortic arch obstruction and coronary anomalies were present in 64% and 41% of patients, respectively. The hospital mortality rate was 11%, including one cardiac death, and the late mortality rate was 2.9%. Furthermore, 41% patients underwent 26 reinterventions for PS. Patients undergoing PS-related reintervention had a significantly larger native pulmonary artery to aortic annulus size ratio than patients not receiving reintervention (1.69 vs 1.41, P= .02). This ratio was the only predictor of PS-related reintervention; it was significantly higher in the TBA group than in the transposition of great arteries/ventricular septal defect group. The PS-related reintervention was required more in the TBA group than in the transposition of great arteries/ventricular septal defect group. Regardless of complex coronary anatomy and associated anomalies, early and late survival were acceptable. Postoperative PS was strongly associated with having a larger native pulmonary valve, suggesting that an optimal surgical reconstruction was required for achieving an appropriate aortopulmonary anatomic relationship during the arterial switch operation.

P641 Severe pulmonary steno-insufficiency due to metastatic carcinoid tumor in a 57 years old patient treated with MTPV implantation: first experience

Abstract Funding Acknowledgements none Background Right side heart valve involvement is a well known phenomenon in metastatic carcinoid disease. In recent times bioprosthetic valves have been widely used for replacement of stenotic and regurgitant native heart valves. Melody Transcatheter Pulmonary Valve (MTPV, Medtronic, Minneapolis, MN, USA) has been approved for treatment of native pulmonary valves as well as failing biological prostheses and conduits. We present the first case to our knowledge of severe native pulmonary valve steno-insufficiency due to metastatic carcinoid syndrome treated with MTPV implantation. Case report A 57-year-old woman is known since 2007 for metastatic carcinoid syndrome treated with surgical resection followed by chemotherapy (tamoxifene, everolimus) and radiotherapy. For 2 years she has been known for tricuspid and pulmonary involvement, which aggravated progressively, leading to symptomatic right heart failure. She was therefore submitted for multimodality imaging evaluation (see picture) and right heart catheterization. Transthoracic echocardiogram, cardiac MRI and right heart catheterization confirmed severe pulmonary valve steno-insufficiency. Cardiopulmonary exercise testing revealed a severe limitation of aerobic exercise capacity (VO2 max 14.4 ml/min/kg). After heart team discussion it was decided to treat the patient in a 2 step approach, initially with implantation of a Melody valve in pulmonary position and subsequently with surgical repair of the tricuspid valve. Pulmonary valve was treated by placement of a 39 x 25 mm ANDRA stent and subsequent implantation of a 22 mm Melody valve. Before stenting, coronary angiography with simultaneous balloon inflation in RVOT was performed to exclude coronary artery compression. During the procedure the patient developed hypotension, which was treated effectively with Octeotride. Post-operative echocardiogram showed a significant reduction in pulmonary valve gradient and no significant residual regurgitation. Conclusions We treated effectively severe pulmonary steno-insufficiency due to metastatic carcinoid tumor with MTPV implantation. No complications occurred. Multimodality imaging is fundamental for patients selection and preoperative planning of prosthetic valve dimensions. Abstract P641 Figure. Multimodality imaging of PV

Bovine jugular vein conduit versus pulmonary homograft in the Ross operation.

The Ross procedure involves using the native pulmonary valve for aortic valve replacement then replacing the pulmonary valve with an allograft or xenograft. We aimed to compare our age-matched experience with the bovine jugular vein conduit and the pulmonary homograft for pulmonary valve replacement during the Ross procedure in children. Between 1998 and 2016, 15 patients <18 years of age underwent a Ross procedure using the bovine jugular vein conduit (Ross-Bovine Jugular Vein Conduit) at our institution. These patients were age-matched with 15 patients who had the Ross operation with a standard pulmonary homograft for right ventricular outflow tract reconstruction (Ross-Pulmonary Homograft). Paper and electronic medical records were retrospectively reviewed. The median age of the Ross-Bovine Jugular Vein Conduit and Ross-Pulmonary Homograft patients were 4.8 years (interquartile range 1.1-6.6) and 3.3 years (interquartile 1.2-7.6), respectively (p = 0.6). The median follow-up time for the Ross-Bovine Jugular Vein Conduit and Ross-Pulmonary Homograft groups were 1.7 years (interquartile range 0.5-4.9) and 6.8 years (interquartile range 1.9-13.4), respectively (p = 0.03). Overall, 5-year survival, freedom from redo aortic valve replacement, and freedom from pulmonary valve replacement were similar between groups. The bovine jugular vein conduit and pulmonary homograft have favourable mid-term durability when used for right ventricular outflow tract reconstruction for the Ross operation. The bovine jugular vein conduit may be a suitable replacement for appropriately sized patients undergoing a Ross aortic valve replacement, though longer follow-up is needed.

Subclinical thrombus formation in bioprosthetic pulmonary valve conduits

ObjectivesBioprosthetic pulmonary valve conduits have been reported with an increased risk of endocarditis. Thrombus formation is considered as source of these serious and life-threatening infections. We reviewed a series of explanted valved pulmonary conduits for histological evidence for thrombus formation. Materials and methodsExplanted bioprosthetic pulmonary valves were fixed in formalin and embedded in paraffin or in methylmethacrylate. Standard staining as well as immunohistochemical staining techniques were applied. Native pulmonary valves of German domestic pigs served as controls. Results47 valved pulmonary conduits (Hancock n = 23, Homograft n = 7, Contegra n = 7, Melody n = 7, other n = 3) were analyzed histologically. Average time of implantation had been 63 months (6 to 342 months). Indications for explantation included significant obstruction (n = 45), regurgitation (n = 7), and/or endocarditis (n = 6). In 44/47 (93%) specimen, we found accumulation of thrombotic material at the basis of the semilunar valve sinus to a variable degree. 11 patients had been treated with antiplatelet agents, 2 had received anticoagulants at the time of explantation. There was no suspicion of thrombus formation clinically or echocardiographically prior to explantation in any of the patients.Control porcine pulmonary valves (n = 5) did not show any evidence of accumulation of thrombotic material. ConclusionsIn a large series of explanted valved pulmonary conduits, formation of subclinical, mostly non-infectious thrombotic material was an almost ubiquitous finding. We speculate that high incidence of endocarditis in bioprosthetic valves may in part be explained by thrombus apposition at the basis of conduit valve sinus.

Toward predictive modeling of catheter-based pulmonary valve replacement into native right ventricular outflow tracts.

Pulmonary insufficiency is a consequence of transannular patch repair in Tetralogy of Fallot (ToF) leading to late morbidity and mortality. Transcatheter native outflow tract pulmonary valve replacement has become a reality. However, predicting a secure, atraumatic implantation of a catheter-based device remains a significant challenge due to the complex and dynamic nature of the right ventricular outflow tract (RVOT). We sought to quantify the differences in compression and volume for actual implants, and those predicted by pre-implant modeling. We used custom software to interactively place virtual transcatheter pulmonary valves (TPVs) into RVOT models created from pre-implant and post Harmony valve implant CT scans of 5 ovine surgical models of TOF to quantify and visualize device volume and compression. Virtual device placement visually mimicked actual device placement and allowed for quantification of device volume and radius. On average, simulated proximal and distal device volumes and compression did not vary statistically throughout the cardiac cycle (P = 0.11) but assessment was limited by small sample size. In comparison to actual implants, there was no significant pairwise difference in the proximal third of the device (P > 0.80), but the simulated distal device volume was significantly underestimated relative to actual device implant volume (P = 0.06). This study demonstrates that pre-implant modeling which assumes a rigid vessel wall may not accurately predict the degree of distal RVOT expansion following actual device placement. We suggest the potential for virtual modeling of TPVR to be a useful adjunct to procedural planning, but further development is needed.