Native Pulmonary Valve Research Articles

Intracardiac Echocardiography in Alterra Prestent Constrained by the Native Pulmonary Valve Leaflet.

Intracardiac Echocardiography in Alterra Prestent Constrained by the Native Pulmonary Valve Leaflet.

Characterization of pediatric porcine pulmonary valves as a model for tissue engineered heart valves

Heart valve tissue engineering holds the potential to transform the surgical management of congenital heart defects affecting the pediatric pulmonary valve (PV) by offering a viable valve replacement. While aiming to recapitulate the native valve, the minimum requirement for tissue engineered heart valves (TEHVs) has historically been adequate mechanical function at implantation. However, long-term in situ functionality of TEHVs remains elusive, suggesting that a closer approximation of the native valve is required. The realization of biomimetic engineered pediatric PV is impeded by insufficient characterization of healthy pediatric tissue. In this study, we comprehensively characterized the planar biaxial tensile behaviour, extracellular matrix (ECM) composition and organization, and valvular interstitial cell (VIC) phenotypes of PVs from piglets to provide benchmarks for TEHVs. The piglet PV possessed an anisotropic and non-linear tension-strain profile from which material constants for a predictive constitutive model were derived. The ECM of the piglet PV possessed a trilayer organization populated by collagen, glycosaminoglycans, and elastin. Biochemical quantification of ECM content normalized to wet weight and DNA content of PV tissue revealed homogeneous distribution across sampled regions of the leaflet. Finally, VICs in the piglet PV were primarily quiescent vimentin-expressing fibroblasts, with a small proportion of activated α-smooth muscle actin-expressing myofibroblasts. Overall, piglet PV properties were consistent with those reported anecdotally for pediatric human PVs and distinct from those of adult porcine and human PVs, supporting the utility of the properties determined here to inform the design of tissue engineered pediatric PVs. Statement of significanceHeart valve tissue engineering has the potential to transform treatment for children born with defective pulmonary valves by providing living replacement tissue that can grow with the child. The design of tissue engineered heart valves is best informed by native valve properties, but native pediatric pulmonary valves have not been fully described to date. Here, we provide comprehensive characterization of the planar biaxial tensile behaviour, extracellular matrix composition and organization, and valvular interstitial cell phenotypes of pulmonary valves from piglets as a model for the native human pediatric valve. Together, these findings provide standards that inform engineered heart valve design towards generation of biomimetic pediatric pulmonary valves.

May 2024 Medical Image of the Month: Hereditary Hemorrhagic Telangiectasia in a Patient on Veno-Arterial Extra-Corporeal Membrane Oxygenation

No abstract available. Manuscript truncated after 150 words. A 54-year-old man with a complex cardiac history, including Tetralogy of Fallot requiring Blalock-Taussig shunt in infancy, infundibular patch repair at age 7, and bioprosthetic tricuspid valve replacement at age 52, had ongoing frequent hospitalizations with decompensated right ventricular heart failure secondary to native pulmonary valve mixed stenosis plus regurgitation and left pulmonary artery stenosis. His case was further complicated by his history of hereditary hemorrhagic telangiectasia (HHT) with recurrent epistaxis and recent GI bleeds with multiple angiodysplastic lesions throughout the stomach, duodenum, and descending colon which were previously treated with argon plasma coagulation. The patient was admitted to our hospital in NYHA class IV heart failure receiving a continuous dopamine infusion and aggressive diuresis. Upon admission, a right heart catheterization demonstrated severe pulmonary valve regurgitation, left pulmonary artery stenosis, and systemic hypoxemia suggestive of an intrapulmonary shunt. Admission transthoracic echocardiogram demonstrated normal left ventricular ejection fraction of 55-60%, a …

Long-term outcomes after the arterial switch operation.

The aims of this study were to evaluate the 16-year experience with arterial switch operation at Beijing Children's Hospital and to determine early and late mortality and late morbidity, to explore risk factors for late complications and reintervention, and finally to evaluate whether the neoaorticsinotubular junction reconstruction technique reduces late complications of arterial switch operation. The clinical data of 185 patients with transposition of the great arteries who underwent arterial switch operation in Beijing Children's Hospital from January 2006 to January 2022 and 30 patients who underwent modified arterial switch operation with neoaorticsinotubular junction reconstruction technique in Fuwai Hospital during the same period were retrospectively analysed. Propensity score matching was also used to match the neoaorticsinotubular junction reconstruction patients in Fuwai Hospital with 30 non-neoaorticsinotubular junction reconstruction patients in Beijing Children's Hospital. There were 13 early deaths (7.03%) and five late deaths (3.01%). Nineteen patients (11.45%) developed new aortic valve regurgitation and 28 patients (16.87%) developed aortic root dilation. Late right ventricular outflow tract obstruction occurred in 33 patients (19.88%). Late reintervention occurred in 18 cases (10.84%). Multivariate analysis showed that aorto-pulmonary diameter mismatch, previous pulmonary artery banding, and mild moderate or above new aortic valve regurgitation at discharge were independent risk factors for late new aortic valve regurgitation and aortic root dilation. Low surgical weight was an independent risk factor specific to new aortic valve regurgitation, and bicuspid native pulmonary valve was an independent risk factor specific to aortic root dilation. Older surgical age and aortic root dilation were independent risk factors for late right ventricular outflow tract obstruction. Older surgical age, operation before 2014, late right ventricular outflow tract obstruction, and late aortic root dilation were independent risk factors for late intervention. Propensity score matching showed that new aortic valve regurgitation and aortic root dilation were not followed up in the neoaorticsinotubular junction reconstruction group, while seven cases of aortic root dilation and five cases of new aortic valve regurgitation occurred in the non-neoaorticsinotubular junction reconstruction group, respectively, and the differences were statistically significant (P = 0.003; P = 0.015). The increased incidence of new aortic valve regurgitation, aortic root dilation, and right ventricular outflow tract obstruction as children age is a major concern outcome in the future and may mean more late reintervention. neoaorticsinotubular junction reconstruction technique may reduce the incidence of new aortic valve regurgitation and aortic root dilation, and improve the late prognosis of arterial switch operation. Careful follow-up of neo-aortic valve and root function is imperative, especially in patients with aorto-pulmonary diameter mismatch, previous pulmonary artery banding, mild new aortic valve regurgitation at discharge, low surgical weight, and bicuspid native pulmonary valve structures.

Long-term function of a novel autologous transcatheter pulmonary heart valve implant in an adult animal model.

Current heart valve implants entail major disadvantages in the treatment for younger patients or those with congenital heart defects. Evaluation of novel transcatheter pulmonary valve implant made from autologous pericardium with natural crosslinking agent in an in vitro setup and in vivo animal model METHODS: Valves were tested in a pulse duplicator according to ISO-standard 5840. For in vivo studies computer tomography was performed to measure sheep's native pulmonary valve dimensions. Pericardium was harvested by thoracotomy, personalized implants were manufactured and deployed in pulmonary valve position of the same sheep. Every 3 months implant functionality was evaluated by intracardiac echocardiography, intracardiac pressure measurements and cardiac magnetic resonance imaging (cMRI). Implants were explanted for macroscopic and histological examination. In vitro experiments showed compliance with regulatory requirements in terms of valve opening and insufficiency. Five sheep successfully received an autologous valve implant. Two animals had to be euthanized due to trauma sustained in the stable. Long-term valve function was excellent in three out of four animals with median implant cMRI regurgitation fraction of 9% (n = 4) at 3 months, 8% (n = 3) at 6, 8% (n = 3) at 9, 12% (n = 3) at 13, 8% (n = 2) at 17% and 8% (n = 2) at 20.5 months after implantation. Despite good adherence to neighboring tissue and endothelization, histological assessment revealed some signs of degeneration. Transcatheter pulmonary valve implants showed promising function for up to 20.5 months encouraging research to further improve this approach.

An alternative surgical approach for isolated pulmonary valve infective endocarditis secondary to restrictive ventricular septal defect: a case report

BackgroundNative pulmonary valve (PV) infective endocarditis (IE) is a rare condition with an incidence of 1.5–2%. Although medical therapy is the mainstay of treatment, surgical intervention is still indicated in cases that fail to respond to antibiotics. To date, there is lack of consensus about the best surgical approach for isolated native PV IE. While valve repair is sometimes feasible, most of the cases require valve replacement depending on the extent of tissue damage. A stented bioprosthesis can be used when infection is confined to the valve leaflets. However, extension of damage to the pulmonary root or right ventricular outflow tract usually requires debridement and root replacement.Case presentationA 30-year-old lady with a long history of restrictive ventricular septal defect (VSD) presented with fever and shortness of breath shortly after vaginal delivery that was diagnosed as isolated PV IE with pulmonary septic emboli. After 1 week of antibiotic therapy, there was no response with persistent infection and complete valve destruction. Heart team discussion recommended PV replacement using a Freestyle valve along with VSD repair. On follow-up after 1 year, she was doing fine with well-functioning Freestyle valve.ConclusionUnrepaired restrictive VSD can be a predisposing factor for native PV IE. A Freestyle valve in the pulmonary position is a valid option for such cases, with good early outcomes and reasonable durability, particularly when there is extensive tissue infection and homograft is not available. More evidence is still required to evaluate the long-term outcomes of PV Freestyle in cases of IE.

Native pulmonary valve massive endocarditis in a drug-addicted patients with Covid-19 pneumonia: a case report

BackgroundPulmonary valve (PV) infective endocarditis is a rare pathology. Association between acute endocarditis and Covid pneumonia is equally poorly investigated.Case presentationWe present the case of a 50-year-old male active drug-abuser admitted for native PV endocarditis with huge and mobile vegetations and a concomitant interstitial SARS-Cov2 pneumonia. Surgical timing was carefully evaluated, and the patient was first treated with Remdesivir to prevent ARDS evolution. After 5 days he underwent PV replacement with bioprosthesis via patch enlargement of RVOT and a tricuspid valve De-Vega annuloplasty. The postoperative course was uneventful with complete resolution of sepsis and viremia.ConclusionsThe association between infective endocarditis and Covid pneumonia is emerging in the recent months. The reorganization in cardiac surgery hub centers resulted in an increase of urgencies referral, with consequent relative observation of some pathologies (i.e., endocarditis). The widespread administration of antibiotics and corticosteroids during the first phase of the pandemic could have contributed to the development of a moderate immunodepression of the general population and, during the pandemic, patients have been reluctant to access to hospital care, and this diagnostic delay could contribute to misdiagnosis or late presentation. We believe that in the present case, the strategy of immediate viral and respiratory stabilization, followed by a timely surgical procedure, allowed an excellent outcome in a very complicated situation.

Systematic Analysis of PTFE Monocusp Leaflet Design in a Patient-Based 3D in-Vitro Model of Tetralogy of Fallot.

Pulmonary valve (PV) monocusp reconstruction in transannular patch (TAP) right ventricular outflow tract (RVOT) repair for Tetralogy of Fallot has variable clinical outcomes across different surgical approaches. The study purpose was to systematically evaluate how monocusp leaflet design parameters affect valve function in-vitro. A 3D-printed, disease-specific RVOT model was tested under three infant physiological conditions. Monocusps were sewn into models with the native main pulmonary artery (MPA) forming backwalls that constituted 40% and 50% of the reconstructed circumference for z-score zero PV annulus and MPA diameters (native PV z-score - 3.52 and - 2.99 for BSA 0.32m2). Various leaflet free edge lengths (FEL) (relative to backwall), positions (relative to PV STJ), and scallop depths were investigated across both models. Pressure gradient, regurgitation, and coaptation were analyzed with descriptive statistics and regression models. Increasing FEL beyond 100% of the MPA backwall decreased gradient but mildly increased regurgitation to a peak of 25%. Positioning the free edge 2mm past the STJ mildly increased gradient for each FEL without significantly changing regurgitation compared to STJ placement. Scalloping leaflets trivially affected performance. Pre-folding leaflets improved mobility and slightly reduced gradient. Balancing gradient, regurgitation, and oversizing for growth, a set of leaflet designs have been selected for pre-clinical evaluation. Designs with leaflet widths 140-160% in the 40% backwall model (110-120% in the 50% backwall), positioned at or 2mm past the STJ, demonstrated the best results. The next stage of ex-vivo testing will additionally consider native RVOT distensibility, native leaflet interactions, and TAP characteristics.

Abstract 17910: Is Implantation of a Larger Edwards Sapien Transcatheter Pulmonary Valve Associated With Early Valve Failure? A Different Type of Patient-Prosthesis Mismatch

Introduction: Transcatheter pulmonary valve replacement (TPVR) is an alternative option to address failing native and bioprosthetic pulmonary valves (BPV). TPVR has expanded to implantation in native right ventricular outflow tracts (nRVOT) and progressively smaller patients. We aim to define the relationship between valve-to-patient size ratio and early development of pulmonary insufficiency (PI). Methods: This single-center retrospective cohort study identified patients who underwent TPVR with a Sapien valve between 2014 and 2021. We collected demographic, anatomic, and pre- and post-TPVR echo data. Echo data were collected at four post-TPVR time points: prior to discharge, short-term (1-9 months), mid-term (9-18 months), and most recent study. The primary outcome was development of moderate or severe PI by mid-term follow-up. Valve size-to-body surface area (BSA) ratio was evaluated for correlation with the development of moderate or severe PI. Results: The cohort consisted of 187 patients; 79 (42.2%) underwent TPVR within the nRVOT (Table). Compared to patients with TPVR in a conduit or BPV, patients with a nRVOT were younger, had lower weight, and lower BSA. Moderate or severe PI post-TPVR was more common in patients in the nRVOT group (P-value < 0.001), occurring in 9 (11.5%) by mid-term follow-up, compared to 2 (1.9%) in a conduit or BPV. In the subset of patients with TPVR within the nRVOT, the development of moderate or severe PI was associated with a larger valve size-BSA ratio (OR=1.13, 95% CI: 1.03, 1.26, P-value=0.012). Conclusions: Development of moderate or severe PI following TPVR with a Sapien valve was rare in this cohort. Patients receiving a Sapien TPVR within the nRVOT with a large valve size-to-BSA ratio were more likely to develop early PI. The increased risk of early valve failure in these patients should inform counseling regarding expected longevity of the valve and may guide valve choice as more transcatheter valve options become available.

Abstract 15472: The IRIS™ Valve: A Growth Accommodating Transcatheter Pulmonary Valve for Pediatric Patients

Introduction: It is estimated that at least 1 million children are living with a congenital heart defect (CHD) in the U.S. Most of these patients are born with some degree of right ventricular outflow tract (RVOT) abnormalities that at some point require pulmonary valve replacement to mitigate the detrimental effects of pulmonary valve regurgitation (PVR) on the right ventricle (RV). Due to their size, available solutions, e.g., the Melody™ valve (Medtronic Inc., Minneapolis, MN) cannot be implanted in small children under 20 Kg. Those must wait until they grow to a suitable weight to receive the valve, which may lead to RV dysfunction. Hypothesis: To mitiagte the detrminental effects to the RV, the IRIS™ valve is implantable at 12 mm with a 12-Fr delivery catheter. As the valve annulus grows, the valve would be balloon expanded up to 20 mm. Methods: The IRIS™ valve has been designed according to origami concepts such that its three leaflets would retain a fully-coapted form as it is expanded to a larger size. Here we report our methods and results of implantation in 9-17Kg Yucatan pigs. Results: The IRIS™ valve is made of thin porcine pericardial leaflets sewn into a laser-cut stainless-steel stent. The stented valve is covered with an ePTFE skirt to mitigate paravalvular leak. The IRIS™ valve is fully crimped over a 12-Fr delivery catheter for transfemoral implantation. We have successfully implanted the valve at the native pulmonary valve position with minimal regurgitation in three pigs ranging from 9 to 17kg with varying pulmonary annulus sizes. Conclusions: The IRIS™ transcatheter pulmonary valve has been successfully developed according to proprietary origami concepts. Using the 12Fr delivery catheter, the smallest delivery profile reported, we successfully implanted the IRIS™ valve within the pulmonary annulus of mini pigs with encouraging results.

New insights into the hemodynamics of pulmonary homograft patients under stress echocardiography: The contribution of pressure recovery.

The importance of pulmonary artery pressure recovery (PR) in patients with Ross procedures in whom a homograft substitutes the resected pulmonary valve, is unknown. The aim of the study was to evaluate the occurrence and extent of PR in the pulmonary artery in 65 asymptomatic patients with pulmonary homograft after Ross surgery during rest and exercise. Stress echocardiography was performed in 65 pulmonary homograft patients and 31 controls with native pulmonary valves up to 75W. Right ventricular systolic pressure (RVSP), transvalvular flow, mean pressure gradient (Pmean ), valve resistance, and RV stroke work were determined in the exercise (max. 75W) and recovery phases in increments of 25W each. Pulmonary homografts demonstrated significantly elevated Pmean compared to controls at all stages. When considering pressure recovery (absolute and relative PR at rest 3.8±1.8mm Hg, 42.6±7.2%, respectively) and transvalvular energy loss (EL; at rest 4.5±4.3mm Hg) the homograft hemodynamics reached the level of controls. In a subgroup of patients with tricuspid regurgitation, resting RVSP was the same in homograft patients and controls (21.3±6.1 vs. 20.4±6.3, p=.62), despite significant different Pmax values. Ross patients with pulmonary homograft showed systematically increased hemodynamic parameters compared to normal pulmonary valves. These differences were abolished when PR was considered for homograft patients. The equality of RVSP values at rest in both groups shows non-invasive evidence for PR in the pulmonary system after homograft implantation. Therefore, PR appears to be an important measure in calculating the actual hemodynamics in pulmonary homografts.

Physician-Modified Endograft-Facilitated Transcatheter Pulmonary Valve Replacement in Large Right Ventricular Outflow Tract.

Transcatheter pulmonary valve replacement (TPVR) in patients with a congenital or acquired abnormality resulting in enlarged right ventricular outflow tract (RVOT) is challenging and may preclude treatment with dedicated devices. We describe a technique using a physician-modified endograft to facilitate TPVR. Six patients underwent physician-modified endograft-facilitated TPVR for severe symptomatic pulmonary insufficiency with enlarged RVOT. The fenestration was created in a commercially available endograft before implantation, which was then deployed from the dominant branch pulmonary artery into the RVOT, with the fenestration aligned with the ostium of the nondominant pulmonary artery. A covered stent was placed through the fenestration into the nondominant branch pulmonary artery, and a transcatheter heart valve was deployed within the endograft at the level of the original pulmonary valve. Four patients had tetralogy of Fallot, 1 had pulmonary atresia, and 1 had rheumatic valve disease. The RVOT/main pulmonary artery was severely enlarged (diameter, 44.2 [43.5-50.6] mm). All patients had reduced right ventricular (RV) function and dilated RVs (RV end-diastolic volume, 314 [235-316] mL). Successful endograft, covered stent, and transcatheter heart valve deployment were achieved in all cases without stent/valve embolization, vascular complications, or bleeding complications. At 30 days, 1 patient had mild pulmonary insufficiency, while others had none. The RV size measured by echocardiography was significantly reduced after TPVR (RV area, 34.4 [baseline] versus 29.0 [pre-discharge] versus 25.3 [30 days] cm2; P=0.03). During median follow-up of 221.5 (range, 29-652) days, there were no deaths or need for pulmonary valve reintervention. One patient developed severe tricuspid regurgitation due to entrapment of the anterior tricuspid leaflet by the endograft. The patient underwent successful tricuspid replacement and resection of the offending endograft with preservation of the pulmonary valve prosthesis. Simple fenestration of an off-the-shelf endograft and associated covered stent placement through the fenestration allows TPVR for patients with dysfunctional native or patch-repaired pulmonary valves and RVOT enlargement.

Case report: right sided endocarditis in pediatric patient after surgical treatment of tetralogy Fallot

Right-side endocarditis is a well-defined clinical entity, rarer than left-side endocarditis. Infective endocarditis in children has multiple challenges. A history of congenital heart disease is the most common risk factor, although other emerging predisposing conditions have important relevance. We report the clinical presentation, diagnosis and management in a pediatric patient with isolated native pulmonary valve endocarditis one year after surgical treatment of Tetralogy Fallot.

Isolated native pulmonary valve endocarditis

Isolated native pulmonary valve endocarditis

From Scan to Simulation-A Novel Workflow for Developing Bioinspired Heart Valves.

Current heart valve replacements lack durability and prolonged performance, especially in pediatric patients. In part, these problems may be attributed to the materials chosen for these constructs, but another important contributing factor is the design of the valve, as this dictates hemodynamic performance and impacts leaflet stresses which may accelerate structural valve deterioration. Most current era bioprosthetic valves adhere to a fundamental design where flat leaflets are supported by commissural posts, secured to a sewing ring. This overall design strategy is effective, but functionality and durability can be improved by incorporating features of the native valve geometry. This paper presents a novel workflow for developing and analyzing bio-inspired valve designs computationally. The leaflet curvature was defined using a mathematical equation whose parameters were derived from the three-dimensional model of a native sheep pulmonary valve obtained via microcomputed tomography. Finite element analysis was used to screen the various valve designs proposed in this study by assessing the effect of leaflet thickness, Young's modulus, and height/curvature on snap-through (where leaflets bend against their original curvature), geometric orifice area (GOA) and the stress in the leaflets. This workflow demonstrated benefits for valve designs with leaflet thicknesses between 0.1 and 0.3 mm, Young's moduli less than 50 MPa, and elongated leaflets with higher curvatures. The proposed workflow brings substantial efficiency gains at the design stage, minimizing manufacturing and animal testing during iterative improvements, and offers a bridge between in vitro and more complex in silico studies in the future.

Outcomes after ROSS procedure with pulmonary autograft reinforcement using reimplantation technique

Pulmonary autograft reinforcement to prevent dilatation and subsequent neo-aortic valve regurgitation was reported. However, the late functional outcome of the native pulmonary valve inside a rigid Dacron conduit requires to be documented. We aimed to assess the results of modified Ross procedure associated with autograft reinforcement reimplantation technique. Outcomes of 61 consecutive patients who underwent Ross procedure with reinforcement between 2009 and 2021 were analyzed. Majority of cases has presented with mono or bicuspid aortic valve ( n = 52; 85%), predominant aortic valve regurgitation ( n = 47; 77%) and dilatation (> 30 mm) of the ascending aorta ( n = 33; 54%). Forty-seven patients (77%) had prior aortic valve procedure including 38 surgical repair (62%) and 9 balloon dilatation (15%). Pulmonary autograft was reimplanted in a Dacron conduit of a median diameter = 25.6 mm (ranges: 20–30) using Tirone David's valve sparing aortic root replacement technique. No death occurred. Median age at procedure was 16.8 years (range: 6–38). Two patients (3%) required early neo-Aortic root revision, one other was reoperated later on resulting in neo-aortic valve replacement in 3 (4.9% IC 95% [0.34%; 12.7%]) because of respectively infective endocarditis, left ventricular false aneurysm and leaflet perforation. Six patients required right ventricular outflow conduit replacement including one percutaneous replacement. At mean 66 ± 50.5 months postoperatively, the survival rate with freedom from reintervention was 83% [71.9; 93.5] and the deterioration of the initial neo-Aortic valve function (regurgitation or stenosis) was not observed ( Fig. 1 ). Autograft reinforcement by means of reimplantation technique allowed to extend the indications for Ross procedure to all patients requiring Aortic valve replacement and prevented neo-Aortic root dilatation. Failures were early and rare, and late controls confirmed the stability of the neo-aortic valve function in follow-up.

Anterior and Posterior Pulmonary Cusp Augmentation in the Repair of Tetralogy of Fallot.

In this retrospective study, we compared the results from 2 pulmonary valve augmentation techniques in patients undergoing surgical repair of tetralogy of Fallot. Between 2015 and 2018, 18 patients had anterior pulmonary valve repair at our institution, and 26 patients had both anterior and posterior pulmonary valve repair. Patients ranged from 6 months to 30 years of age. The median follow-up period was 8 months in the anterior augmentation group and 5 months in the anterior and posterior augmentation group. Postoperative echocardiograms indicated that only 2 patients (11%) in the anterior augmentation group had moderate or severe pulmonary insufficiency, compared with no patients in the anterior and posterior augmentation group. At follow-up, pulmonary insufficiency was seen in 3 patients (17%) in the anterior augmentation group and no patients in the anterior and posterior augmentation group. Reconstruction of the native pulmonary valve accompanied by pulmonary cusp augmentation can decrease or even circumvent postoperative pulmonary insufficiency. Both anterior augmentation and anterior and posterior augmentation techniques are easily applied; however, we believe that the anterior and posterior augmentation technique is superior in terms of early postoperative and follow-up pulmonary insufficiency outcomes.

Incidence and risk factors for late complications after the arterial switch operation.

The purpose of this study was to evaluate our institution's 16-year arterial switch operation (ASO)experience and to determine early and late mortality and late morbidity, as well as the need for reoperation and catheter intervention, and finally, to explore risk factors for late complications and reintervention. The clinical data of 185 transposition of the great arteries (TGA)patients who received ASO treatment in our center from January 2006 to January 2022 were continuously included for retrospective study. There were 13 early deaths (7.03%), 5 late deaths (3.01%), and 6 lost to follow-up. The median follow-up time for the 166 hospitalized survivors was 88.5 (2190) months. Moderate or above new aortic valve regurgitation (NAR;in this article, NAR represents moderate or greater reflux unless otherwise specified) occurred in 19 cases (11.45%), and aortic root dilation (ARD) occurred in 28 cases (16.87%). Late right ventricular outflow tract obstruction (RVOTO) occurred in 33 cases (19.88%). There were 18 patients (10.84%) who underwent late re-intervention, and the most common indication for intervention was RVOTO, followed by recurrent aortic coarctation in patients undergoing concurrent arch repair and NAR or ARD. Receiver operating characteristicsanalysis found that NAR had the strongest predictive power for ARD, followed by RVOTO, followed by bicuspid native pulmonary valve (BPV), and aorto-pulmonary diameter mismatch (APDMM) was the weakest. Multivariate analysis showed that APDMM, previous pulmonary artery banding (PAB), and mild NAR at discharge were independent risk factors for late NAR and ARD. Low surgical weight was an independent risk factor specific to NAR, and BPV was an independent risk factor specific to ARD. Older surgical age and ARD were independent risk factors for late RVOTO. Older surgical age, operation before 2014, late RVOTO, and late ARD were independent risk factors for late intervention. No reintervention events for coronary dysfunction were found in the late stage, but one patient occurred myocardial infarction due to coronary embolism after reoperation. Early and late survival rates after ASO in TGA patients have been remarkably improved in recent decades. Increased rates of NAR, ARD, recurrent coarctation of the aorta, and RVOTO as children age are major future outcomes of concern and may imply more late reinterventions. Careful follow-up of neo-aortic valve and root function is imperative, especially in patients with APDMM, previous PAB, mild NAR at discharge, low surgical weight, and BPV structures.

Transcatheter Pulmonary Valve Replacement from Autologous Pericardium with a Self-Expandable Nitinol Stent in an Adult Sheep Model.

Transcatheter pulmonary valve replacement has been established as a viable alternative approach for patients suffering from right ventricular outflow tract or bioprosthetic valve dysfunction, with excellent early and late clinical outcomes. However, clinical challenges such as stented heart valve deterioration, coronary occlusion, endocarditis, and other complications must be addressed for lifetime application, particularly in pediatric patients. To facilitate the development of a lifelong solution for patients, transcatheter autologous pulmonary valve replacement was performed in an adult sheep model. The autologous pericardium was harvested from the sheep via left anterolateral minithoracotomy under general anesthesia with ventilation. The pericardium was placed on a 3D shaping heart valve model for non-toxic cross-linking for 2 days and 21 h. Intracardiac echocardiography (ICE) and angiography were performed to assess the position, morphology, function, and dimensions of the native pulmonary valve (NPV). After trimming, the crosslinked pericardium was sewn onto a self-expandable Nitinol stent and crimped into a self-designed delivery system. The autologous pulmonary valve (APV) was implanted at the NPV position via left jugular vein catheterization. ICE and angiography were repeated to evaluate the position, morphology, function, and dimensions of the APV. An APV was successfully implanted insheep J. In this paper, sheep J was selected to obtain representative results. A 30 mm APV with a Nitinol stent was accurately implanted at the NPV position without any significant hemodynamic change. There was no paravalvular leak, no new pulmonary valve insufficiency, or stented pulmonary valve migration. This study demonstrated the feasibility and safety, in a long-time follow-up, of developing an APV for implantation at the NPV position with a self-expandable Nitinol stent via jugular vein catheterization in an adult sheep model.

Unexpected isolated native pulmonary valve endocarditis; really benign as thought?

Isolated pulmonary valve endocarditis is extremely rare, accounting for <2% of cases. Major predisposing factors are intravenous drug use, implanted cardiac devices, congenital heart diseases, and central venous catheters. Most patients respond well to appropriate antibiotherapy. We report a case with an isolated native pulmonary valve endocarditis due to methicillin-resistant staphylococcus-aureus infection which developed after a tooth abscess in a previously healthy non-drug user young male. After one week antibiotherapy, surgery was required due to acute severe pulmonary insufficiency and right heart-failure. After the operation, he had a multi-organ failure despite veno-arterial extracorporeal membrane oxygenation, antibiotherapy, and other supportive treatments, therefore the case concluded with mortality. Our case showed that pulmonary valve endocarditis may occur in patients without risk factors in case of portal of entry for bacteremia and it may carry worse prognosis than previously known. Virulence of the microorganism and vegetation size are the major predictors of prognosis. Pulmonary valve endocarditis should be kept in mind even in patients without any known risk factors.