Right Ventricular Outflow Tract Stenosis Research Articles

Transcatheter pulmonary valve replacement after arterial switch operation.

Patients with d-transposition of the great arteries (d-TGA) who have undergone an arterial switch operation (ASO) can develop right ventricular outflow tract (RVOT) dysfunction with pulmonary regurgitation (PR) or stenosis. In these patients, treatment may include transcatheter pulmonary valve replacement (TPVR). Coronary compression is a contraindication occurring in 5% of typical TPVR cases. After ASO, there are various anatomical considerations that can confound TPVR, including potential coronary artery compression. Our goal is to understand feasibility of TPVR in patients following ASO. This was a retrospective multicenter cohort study of patients with RVOT dysfunction after ASO who underwent cardiac catheterization with intention to perform TPVR from 2008 to 2020. Across nine centers, 33 patients met inclusion criteria. TPVR was successful in 22 patients (66%), 19 receiving a Melody valve and 3 a SAPIEN valve. RVOT stenosis in isolation or with PR dictated need for TPVR in nearly all patients. One serious adverse event occurred with valve embolization. After TPVR, the RVOT peak gradient decreased from 43 to 9 mm Hg (p < 0.001); PR was trivial/none in all but one patient, in whom it was mild. Coronary compression prohibiting TPVR occurred in eight patients (24%) and two patients (6%) had severe aortic regurgitation from aortic root deformation precluding TPVR. Seven patients underwent RVOT reintervention a median of 5.3 years post-TPVR. TPVR in patients with d-TGA after ASO is feasible, but in this cohort, coronary compression or aortic root distortion precluded TPVR in one-third of patients. The rate of RVOT reintervention after TPVR was higher in this cohort of ASO patients than in prior studies.

The role of exercise testing in congenital heart disease patients after coronary artery reimplantation

IntroductionThe Ross procedure requires like the arterial switch operation (ASO) coronary artery reimplantation. There is no information on coronary artery stenosis at the site of the reimplantation in Ross patients as has been described for ASO patients. This study assessed therefore the prevalence of positive exercise tests (pETs) suggesting myocardial ischemia in Ross and ASO patients in comparison to tetralogy of Fallot patients (TOF), the latter not undergoing coronary artery reimplantation. The study evaluated further, whether a coronary artery complication was confirmed by a supplementary non- and/or invasive evaluation. MethodsResults of exercise tests, echocardiography, coronary computed tomography (CCT) and coronary angiography (CA) were retrospectively reviewed in 30 Ross, 14 ASO and 30 TOF patients. ResultsExercise capacity did not differ between groups. There was a trend to more frequent pETs in Ross patients (Ross vs. ASO vs. TOF, N, %): 8 (27) vs. 1 (7) vs. 2 (7) p = 0.062. CCT was performed in 30% Ross, 21% ASO, 3% TOF (p = 0.023); CA in 20% Ross, 21% ASO and 13% TOF patients (p = 0.727). None of these investigations revealed a coronary artery stenosis. Patients with pET showed a higher right ventricular outflow tract (RVOT) gradient (44 ± 30 vs. 22 ± 13 mmHg, p = 0.004) and more frequently a severe RVOT stenosis (27 vs. 0%, p < 0.006). ConclusionspETs are rather related to RVOT stenosis than to coronary artery complications after Ross procedure, ASO and TOF repair. The role of exercise testing for detection of myocardial ischemia is limited and should be restricted to evaluation of exercise capacity.

Sağ Ventrikül Çıkış Yolu Darlıklarının Tamirinde Homogreft ve Contegra Greft Kullanılan Hastaların Sağ Kalımının Karşılaştırılması

Giriş ve Amaç: Homogreftler veya ksenogreftler sağ ventrikül çıkış yolu (RVOT) darlıklarının tedavisinde günümüzde en sık kullanılan materyallerdir. Çalışmanın amacı RVOT tamirlerinde homogreft ve Contegra® Greft (ksenogreft) kullanılan hastaların mortalite oranlarını belirlemek ve sağ kalımlarını karşılaştırmaktır. Çalışmanın ikincil amacı ise mortalite için risk faktörlerinin belirlenmesidir.&#x0D; Gereç ve Yöntemler: Çalışmaya üçüncü basamak sağlık kuruluşumuzda son yedi yılda RVOT darlığı nedeniyle homogreft veya Contegra® Greft kullanılarak RVOT rekonstrüksüyonu uygulanan hastalar dahil edilmiştir. Toplam 71 hastanın; 18’ine homogreft (%25,4) ve 53’üne (%74,6) ise Contegra® Greft ile RVOT rekonstrüksüyonu uygulanmıştır. Çalışma için yerel etik kurul izni alınmıştır.&#x0D; Bulgular: RVOT darlığının en sık etiyolojik sebebi Fallot Tetralojisiydi. Contegra® Greft grubunun yaş ortalaması ve kullanılan greft çapları (t test, p

An interventricular membranous septal aneurysm obstructing the right ventricle outflow tract in a five-year-old boy: a case report

BackgroundWhile the aneurysms of the membranous septum (AVS) are rare, the possibility that they lead to obstruction is even rarer. To the best of our knowledge, 11 similar cases have been reported since 1982.Case presentationInitially, the five-year-old boy was evaluated for dyspnoea that had been present since birth. He did not receive any medical treatment until the previous year. At the age of four, the transthoracic echocardiography showed a large aneurysm extending to the right ventricular outflow tract (RVOT) and causing RVOT stenosis. Complete surgical resection of the aneurysmal tissue was performed, and the boy was discharged home in satisfactory condition.ConclusionsAs the occurrence of RVOT obstruction by a membranous ventricular septal aneurysm is very rare, we are reporting the second case in which an aneurysm of the membranous septum dynamically obstructed the RVOT in a child. We are also reviewing all the previously reported similar cases in the literature. Further studies are needed to obtain a more comprehensive understanding of aneurysms of the membranous septum (AVS).

BVES downregulation in non-syndromic tetralogy of fallot is associated with ventricular outflow tract stenosis

BVES is a transmembrane protein, our previous work demonstrated that single nucleotide mutations of BVES in tetralogy of fallot (TOF) patients cause a downregulation of BVES transcription. However, the relationship between BVES and the pathogenesis of TOF has not been determined. Here we reported our research results about the relationship between BVES and the right ventricular outflow tract (RVOT) stenosis. BVES expression was significantly downregulated in most TOF samples compared with controls. The expression of the second heart field (SHF) regulatory network genes, including NKX2.5, GATA4 and HAND2, was also decreased in the TOF samples. In zebrafish, bves knockdown resulted in looping defects and ventricular outflow tract (VOT) stenosis, which was mostly rescued by injecting bves mRNA. bves knockdown in zebrafish also decreased the expression of SHF genes, such as nkx2.5, gata4 and hand2, consistent with the TOF samples` results. The dual-fluorescence reporter system analysis showed that BVES positively regulated the transcriptional activity of GATA4, NKX2.5 and HAND2 promoters. In zebrafish, nkx2.5 mRNA partially rescued VOT stenosis caused by bves knockdown. These results indicate that BVES downregulation may be associated with RVOT stenosis of non-syndromic TOF, and bves is probably involved in the development of VOT in zebrafish.

Use of 65 cm large caliber Dryseal sheaths to facilitate delivery of the Edwards SAPIEN valve to dysfunctional right ventricular outflow tracts.

The Edwards SAPIEN valve and its delivery system may complicate transit through the right heart during transcatheter pulmonary valve replacement (tPVR). We report our early experience using a large diameter, 65 cm delivery sheath to facilitate delivery of the SAPIEN valve to the right ventricular outflow tract (RVOT). Retrospective analysis of all patients from three large congenital heart centers undergoing tPVR with the Edwards SAPIEN valve delivered with the 65 cm Gore Dryseal Sheath. Over a 12 month period, 30 patients (17 female) with median age 17.5 years (range 8-72) underwent attempted tPVR with the SAPIEN valve delivered using the 65 cm Dryseal sheath (20-26Fr). All procedures resulted in successful valve delivery to the target area. Twenty patients had a native RVOT. The most commonly used valve diameter was 29 mm (n = 15) with the majority of cases requiring a 26Fr Dryseal sheath (n = 20). One patient with severe RVOT stenosis underwent prestenting. Median procedure time was 100 min (59-225). No patient had increase in tricuspid valve regurgitation as a consequence of valve delivery. One patient required a synchronous cardioversion for intraprocedural VT and another required ECMO postprocedure due to severe pre-existing left ventricular dysfunction. On median follow-up of 5 months, all patients had mild or less pulmonary regurgitation. Median peak Doppler velocity across the pulmonary valve was 2.2 m/s (1.7-4). There were no clinically relevant complications relating to vascular access. Using 65 cm Dryseal sheaths facilitates delivery of SAPIEN valves in patients with dysfunctional RVOTs.

Indications for Pulmonary Valve Replacement in Repaired Tetralogy of Fallot

Until Blalock and Taussig developed the first palliative systemic-to-pulmonary shunt operation in 1945,1 tetralogy of Fallot (TOF) was a nearly uniformly lethal congenital cardiac anomaly. In the 5 decades since Lillehei and his colleagues at the University of Minnesota reported the first successful intracardiac repair in 1955,2 early mortality has decreased markedly from 50% to <2%.2–4 In the modern surgical era, most infants with TOF survive the initial surgical repair and reach adulthood. More recently, the excellent results in the pediatric age group have led the field to shift its attention to late sequelae of repaired TOF in the rapidly growing population of adult patients, including the increasing rates of morbidity and mortality. Article see p 1861 Despite many advances in surgical repair during the past 6 decades, the majority of TOF patients continue to experience residual hemodynamic and electrophysiological abnormalities.5,6 To effectively relieve the obstructed right ventricular outflow tract (RVOT), the surgeon must often disrupt the integrity of the pulmonary valve, which results in pulmonary regurgitation. The ensuing chronic right ventricular (RV) volume overload and akinesis or dyskinesis of the RVOT wall, along with conduction delay from the nearly universal right bundle-branch block, initiate a cascade of pathophysiological abnormalities that lead to RV dilatation and ultimately dysfunction.7 Left ventricular dysfunction, arrhythmias, exercise intolerance, heart failure symptoms, and death may follow.8 Residual intracardiac shunts, tricuspid regurgitation, RVOT or pulmonary artery stenosis, impaired diastolic properties, atrial enlargement, RV hypertension, intraventricular and interventricular dyssynchrony, and diffuse myocardial fibrosis are some of the factors that might accelerate the adverse cardiac remodeling and lead to worse clinical outcomes. Indeed, the adverse remodeling that leads to electromechanical cardiomyopathy manifests in increasing rates of morbidity and mortality beginning during the third decade of life.9 Pulmonary …

Percutaneous Balloon Dilation of Carpentier-Edwards Porcine-Valved Right Ventricle-to-Pulmonary Artery Conduits

Right ventricular outflow tract (RVOT) conduit stenosis remains a significant problem for patients with right ventricle-to-pulmonary artery (RV-to-PA) conduits placed as palliation for congenital heart disease. Previous reports on balloon dilation of RVOT conduits all describe small series with varying levels of success during limited follow-up evaluation. This study reviewed all patients with RV-to-PA conduits who underwent percutaneous balloon dilation for conduit stenosis at the authors' institution from 2000 to 2011. Patients with Carpentier-Edwards (CE) model 4300 porcine-valved conduits (Edwards Lifesciences Corp., Irvine, CA) (n = 19) were compared with patients who had all other types of conduits (n = 19). Successful balloon angioplasty was defined as a 20 % decrease in the RV-to-PA gradient, a 20 % decrease in the ratio of the RV systolic-to-aortic systolic pressure, or both. Balloon dilation was successful for 57.9 % of the patients with CE conduits and for 31.6 % of patients with other types of conduits (p = 0.10, Chi square test). Logistic regression analysis showed that balloon dilation was significantly more likely to be successful with CE valves than with other types (odds ratio [OR], 6.59; 95 % confidence interval [CI], 1.22-35.49). In a continuous series of patients with stenotic RV-to-PA conduits, the CE porcine-valved conduit was more amenable to percutaneous balloon dilation than other types of RV-to-PA conduits at the midterm follow-up evaluation. This has important ramifications in terms of valve selection for patients with congenital heart disease who will require surgical reintervention for RVOT stenosis.

Infective endocarditis in a child caused by Cardiobacterium hominis after right ventricular outflow tract reconstruction using an expanded tetrafluoroethylene conduit

Cardiobacterium hominis, a member of the HACEK group of organisms, is a rare cause of endocarditis. We report a case of infective endocarditis caused by C. hominis in a male child who had undergone right ventricular outflow tract (RVOT) reconstruction using an expanded polytetrafluoroethylene conduit for tetralogy of Fallot with pulmonary atresia. Two days before admission, the patient suffered from exertional shortness of breath. Right ventricular hypertension was confirmed and RVOT stenosis was suspected based on the echocardiography findings. A CT scan revealed vegetation above the cusp of the conduit. An emergency operation was performed to avoid a pulmonary embolism due to large friable vegetation. C. hominis was cultured from the blood and the vegetation, prompting a diagnosis of prosthetic valve endocarditis. The patient was discharged after a 6-week course of intravenous ceftriaxone therapy.

Right Ventricular Outflow Tract Stenting in a Low Birth Weight Infant Born With Tetralogy of Fallot and Prostaglandin E1 Dependency

Surgical skill and strategy for the correction of tetralogy of Fallot (TOF) have improved and resulted in satisfactory outcomes. However, prematurity and low birth weight continue to remain risk factors for poor outcomes. We present a case of a 2,150 g neonate born with TOF, in whom palliation was achieved with right ventricular outflow tract (RVOT) stenting. Seventy-seven days after the procedure, stenosis of RVOT below the stent was identified. At that time his body weight was 4.9 kg and total corrective surgery was deemed feasible. Eight months following surgical repair, the patient remained well without medical intervention. RVOT stenting may be a viable interim procedure while waiting for a low birth weight neonate born with TOF and prostaglandin E1 dependency to reach optimal weight to undergo corrective surgery.

315 One-stage percutaneous Melody pulmonary valve implantation: a single-center experience in 21 consecutive patients

Right ventricular outflow tract (RVOT) reconstruction in infancy or childhood leads to lifetime iterative surgery for pulmonary stenosis or regurgitation. Transcatheter pulmonary valve implantation (TPVI) was developed with the aim to reduce the number of reoperations and operative-related morbidity. From 12/2008 to 03/2010, 21 patients were referred to Marie-Lannelongue Hospital for TPVI. Mean age was 24 yrs (11.5–55 yrs), mean weight was 60 kg (20–85 kg). Most of them had a Tetralogy of Fallot variant (n = 12) and 70% had 3 or more previous surgery. RVOT stenosis was predominant in 90% of patients. RVOT reconstruction techniques were: valved conduit (n = 12), non-valved conduit (n = 1), homograft (n = 6), RVOT patch (n = 2). RVOT balloon inflation test was performed only if cardiac CT scan showed coronary arteries located next to the RVOT. Two patients were excluded, 1 because an aorto-pulmonary fistula after Ross operation, and 1 with previous arterial switch because of compression of the reimplanted left coronary artery at RVOT balloon inflation test. Initial stenting and TPVI were performed during the same procedure in 18/19. There was immediate significant decrease in right ventricular systolic pressure (mean 88.6 to 52.2 mmHg), mean RVOT gradient (mean 43.7 to 22 mmHg) and pulmonary regurgitation (grade 2 or more before, none after). One patient with a 16 mm homograft had significant residual stenosis (mean RVOT gradient 45 mmHg) after Melody implantation. All patients were discharged within 2 days. At a mean follow-up of 9.3 months (1 to 24 months) all patients are alive and well and neither Melody valve dysfunction nor stent fracture or migration was noticed. Percutaneous pulmonary valve implantation is a safe alternative to surgery. Our experience suggests that patients with RVOT conduit < 18 mm and those with previous arterial switch operation should be referred to surgery without considering transcatheter procedure.

Percutaneous Pulmonary Valve Implantation in the Young: 2-Year Follow-Up

The aim of this study was to investigate physiological and clinical consequences of percutaneous pulmonary valve implantation (PPVI) in patients with chronic right ventricular outflow tract (RVOT) obstruction and volume overload. The PPVI is a nonsurgical technique to address RVOT conduit dysfunction. Twenty-eight adolescents (median age 14.9 years; age range 10.9 to 19 years) underwent PPVI due to RVOT stenosis and/or pulmonary regurgitation (PR). Before and after PPVI echocardiographic and magnetic resonance imaging, cardiopulmonary exercise tests were obtained. The RVOT gradient (p < 0.001) and right ventricular (RV) systolic pressure decreased (p < 0.001), acutely. Magnetic resonance imaging (median 6 months) documented reduction in RV end-diastolic (149 +/- 49 ml/m(2) vs. 114 +/- 35 ml/m(2), p < 0.005) volume, increases in left ventricular (LV) end-diastolic (p < 0.007) volume and cardiac output (RV: p < 0.04 and LV: p < 0.02), and reduced PR fraction (24 +/- 10% to 7 +/- 7%, p < 0.0001). Symptoms, aerobic exercise performance (maximal oxygen consumption: p < 0.0001) and ventilatory response to carbon dioxide production (p < 0.003) improved. After 24 months, echocardiography demonstrated the RV/systemic-pressure ratio, and RVOT peak pressure gradient reductions persisted, and PR was absent in 93% (n = 12 of 13) of the cohort. Freedom from surgery was 91%, 83%, and 83%, and freedom from transcatheter reintervention was 91%, 80%, and 80%, at 12, 24, and 36 months, respectively. There were no acute device-related complications, with stent fractures noted in 10.8%. Percutaneous pulmonary valve implantation is feasible and safe in the young with dysfunctional RVOT conduits. An improvement in symptoms, hemodynamic status, and objective findings of exercise performance occurs. Early follow-up demonstrates persistent improvement in ventricular parameters, PR, and objective exercise capacity.

Current Strategy of Repair of Tetralogy of Fallot in Children and Adults: Emphasis on a New Technique to Create a Monocusp‐Patch for Reconstruction of the Right Ventricular Outflow Tract

In older children (>four years) and adults the strategy of repair of tetralogy of Fallot (TOF) should have a low rate of transannular patch to avoid pulmonary insufficiency (PI), and in addition, we developed a new method of reconstruction of the right ventricular outflow tract (RVOT) to reduce PI. From 2001 through 2005, 74 patients (50 male, 24 female; mean age of 13.6 +/- 0.8 years, ranging from four to 34 years) with TOF (67) or double outlet RV (DORV)-type-TOF (seven) underwent complete repair. The resection of RVOT stenosis +/- pulmonary valvotomy was principally through RA. A new two-patch technique to create a folded mono-cusp valve by using autologous pericardium was applied since August 2004. The repair was through RA in 52 patients and through RA + RVOT/PA in 22 patients (18/4). TAPR was performed in 17 patients (23%, eight non-valved and nine valved). The aortic cross-clamp time was 130.1 +/- 6.8 min in TAPR group and 85.8 +/- 4.6 min in non-TAPR group (p < 0.0001). The operative mortality was 4.0% (3/74) in all and 2.9% (2/67) in TOF patients (due to low output, uncontrollable bleeding, and repeated bleeding from the pulmonary collateral vessels late) and was similar in TAPR or non-TAPR. The valved patch-repaired patients had mild PI and good RV function postoperatively up to eight to 12 months. Repair of TOF in older children/adults should include low rate of TAPR of RVOT. If indicated, the new folded monocusp-patch technique is recommended. It is an effective and simple way to markedly reduce postoperative PI with no additional cost.

Right ventricular outflow tract reconstruction using a Goretex membrane monocusp valve in infant animals.

We examined the feasibility of using a polytetrafluoroethylene membrane (goretex) valve and transannular patch (TAP) for right ventricular outflow tract (RVOT) reconstruction in growing animal models. Eleven infant goats (Group A) and 12 infant sheep (Group B) underwent RVOT reconstruction under cardiopulmonary bypass. In Group A, a monocusp valve was constructed of goretex, and the RVOT was roofed over utilizing a TAP of bovine pericardium. In Group B, both a monocusp valve and a TAP were constructed of goretex. Animals were sacrificed at 6 or 12 postoperative months. Two goats in Group A died at 9 days and 4 months postoperatively due to RVOT obstruction caused by thrombus formation. Seven goats in Group A and 11 in Group B showed no pressure gradient across the valve. All animals in Group B revealed mild to moderate valvular insufficiency, but no ventricular deterioration. In contrast to the bovine pericardium, which showed a prominent fibroinflammatory reaction with calcified areas causing TAP shrinkage and RVOT stenosis, there was minimal calcification and inflammatory reaction directed against the goretex valve and TAP. We conclude that goretex can be used as a material from which to create both a monocusp valve and TAP for long-term RVOT reconstruction.