Valved Conduit Research Articles

To revascularize or not before transcatheter aortic valve implantation?

Concomitant coronary artery disease (CAD) and aortic stenosis occur in approximately 60-75% of patients referred for surgical or transcatheter aortic valve replacement (TAVR). Current guidelines support simultaneous surgical aortic valve replacement and bypass surgery with a class IIa recommendation, based on observational, non-randomized data. With the inception of TAVR, this strategy has been challenged, as observational studies have not shown significant outcome differences in patients with and without CAD treated with TAVR. Performing percutaneous coronary intervention (PCI) in patients with aortic stenosis is safe, but the indication and timing remain controversial. Complete revascularization before TAVR with low residual Syntax score (<8) may be considered in selected cases with extensive, proximal, and severe CAD to improve outcomes. PCI before TAVR may require less contrast and reduce the risk of acute kidney injury, but uninterrupted dual antiplatelet therapy may increase the risk of bleeding during TAVR. Combined PCI and TAVR can be considered for unstable patients with simple lesions or ostial lesions, with risk of coronary occlusion after deployment of the transcatheter heart valve. PCI after TAVR may be considered in patients who remain symptomatic with significant residual ischemia despite optimal medical therapy. In the near future, it is expected that randomized clinical trials will further clarify the indications and role of revascularization in patients undergoing TAVR. In this article we provide an extensive review on the management of CAD in TAVR candidates, including additional considerations on technical aspects, device selection, and adjunctive pharmacological therapies.

VD11 FROZEN ELEPHANT TRUNK BY USING E-VITA PROSTHESES AND BENTALL PROCEDURE IN A GIANT DESCENDING THORACIC AORTA ANEURYSM

We present the case of a 54-year-old male patient with a 12 cm post-decoarctation aneurysm of the descending thoracic aorta with bicuspid aortic valve stenosis and ventricular septal defect. Right femoral artery and bicaval cannulation were used for Cardiopulmonary bypass. Antegrade cerebral perfusion with moderate hypotermia (25°C) was achieved with the innominate and left carotid artery cannulation. The aortic arch replacement was performed by using Frozen Elephant Trunk technique with a 40 mm E-Vita Open Plus prosthesis and a separated Plexus 4-branches prosthesis. The reimplantation of the left subclavian artery was performed by a 9 mm Gore hybrid vascular graft. A St.Jude 23 mm mechanical valve conduit was used for the Bentall procedure. The ventricular septal defect was closed with direct suture. Cardiopulmonary bypass, aortic cross-clamp and cerebral perfusion times were 258,186 and 109 minutes, respectively. Post-operative course was uneventful and CT scan showed the good result of the procedure.

RF75 SHELHIGH BIOLOGICAL VALVED CONDUIT: 10-YEARS EXPERIENCE FOR AORTIC ROOT REPLACEMENT.

Background: Since 1968 Bentall and DeBono first described the technique for aortic root replacement with the reimplantation of the coronary arteries. This operation has been considered the gold standard in the surgical treatment of the ascending aorta and aortic valve disease. At the end of the 1990 s the Shelhigh No-React biological valved conduit was introduced in Europe for Bentall operation. The aim this study was to report the short and long term follow-up with the Shelhigh conduit. Methods: From 2001 to 2010, 45 patients (mean age 69.6 ± 6.9 years) underwent aortic root replacement with Shelhigh conduit. Endocarditis (2.2%), type A aortic dissection (20%), aneurysm (77.8%) were the most important indications for surgery. End-points were: survival at 1, 5 and 10years, conduit-related major complications and death, freedom from aortic root structural deterioration and reoperation. Results: The median follow-up was 8.9 years (0 to 14.6). The overall hospital mortality rate was 4 patients (8.9 %). The overall estimated survival rates at 1, 5 and 10 years were 86.4 ± 5.2, 81.8 ± 5.8 and 65.9 ± 7.6 respectively. Redo surgery was necessary in 5 cases (11.1 %); in 3 of them (6.7%) there was evidence of false aneurysm. The overall estimated freedom from reoperation at 1, 5 and 10 years was 95.1 ± 3.4, 92.6 ± 4.1 and 92.6 ± 4.1 respectively. Conclusions: In our experience the Shelhigh-NoReact biological valved conduit showed acceptable results. According to the literature, the high rate of aortic root related reoperation (6.7%) and early mortality (8.9%) may be explained by the clinical and demographic features of the studied group.

Valve-Sparing Root Replacement Provides Excellent Midterm Outcomes for Bicuspid Valve Aortopathy

Standard therapy for aortic root dilation in the setting of bicuspid aortic valves remains use of a composite valve conduit. The long-term durability of valve-sparing root replacement (VSRR) in bicuspid aortopathy is presently unclear. In this study, the midterm results of performing VSRR in the setting of a bicuspid valve was analyzed. A single institutional database identified 280 patients who underwent VSRR from 2005 to 2016. Outcomes were analyzed in 60 consecutive patients undergoing a VSRR in the setting of a bicuspid aortic valve with aortic insufficiency (AI). Patients were followed prospectively and had annual echocardiograms. The average age in this series was 42 ± 11 years. Eighty percent were men and 33% had New York Heart Association class III to IV symptoms. More than 2+ AI was present in 42% of patients preoperatively. The incidence of operative death, stroke, and renal failure was 0%. Mean follow-up was 39 ± 30 months. At latest follow-up, 62% of patients had zero AI and 87% of patients had <1+ AI. At 5 years, freedom from >2+ AI was 97% and freedom from AVR was 96%. Preoperative AI was not found to be a significant risk factor for postoperative >2+ AI (p= 0.61) or AVR (p= 0.61). VSRR can be safely and effectively performed in young patients with bicuspid valve anatomy regardless of degree of preoperative AI. Valve function is durable and the incidence of valve-related complications is low. VSRR is an attractive and potentially superior option to conventional root replacement in appropriately selected patients with bicuspid aortopathy.

Fever within 48 h after Melody implantation is a risk factor of late infective endocarditis

Fever following pulmonary valve implantation is known but its frequency and impact have been poorly described. The aim of this study was to analyze clinical and biological parameters of inflammation just after the Melody valve implantation, and to see if early onset of inflammation can predict the risk of late infective endocarditis (IE). We performed a retrospective study on patients with Melody valve implanted for dysfunctional RVOT in our unit between January 2008 and December 2016. All clinical and biological inflammatory parameters following Melody implantation were recorded. In total, 198 patients were included (median age = 22.8 [Q1–Q3: 15.4–31.5] years). Before the procedure, the RVOT statute of patients was: 74 (37.4%) pulmonary valved conduits, 57 (28.8%) natives (with or without valve), 50 (25.2%) homografts, and 17 (8.6%) valveless conduits. Within 48 h post procedure, 58 patients (29.3%) had fever [T > 37.9 °C] and 140 patients (70.7%) had no fever, 98 patients (49.5%) had a CRP >5 mg/L, and 61 patients (30.8%) had white blood cells (WBC) >10G/L. Fifty-five patients received large spectral antibiotic regimen waiting for results of blood culture. No patients were found to have early IE and antibiotics were stopped after a median duration of 2 [1–2] days. Length of stay was longer in patients with fever compared to those without fever ( P < 0.001). The median follow-up was 3.3 [1.3–5.3] years. Twenty-one patients developed IE (10.6%), with a median at 1.8 [0.3–3.5] years. At 5 years, freedom from IE was 87.2%. Fever within 48 h post procedure was a significative risk factor (HR = 6.1, IC95%[2.5–15.1], P < 0.001). At 5 years, freedom from IE was 88.5% for patients without fever and 67.7% patients with fever within 48 h post-procedure ( P < 0.001). Elevated post-procedural WBC ( P = 0.62), CRP level ( P = 0.90), and initial RVOT statute of patients ( P = 0.70) were not a risk factor for IE. Patients with fever within 48 hours after Melody valve implantation are at particular risk of IE in their life. The reasons might be related to a specific genetic profile. Further studies are needed to understand the causes behind.

Outcomes after common arterial trunk repair in children

The persisting controversy on the repair of the right outflow tract in common arterial trunk led us to analyze the outcomes of children operated at our institution. We identified 153 children diagnosed with CAT between 2000 and 2017. Six patients died before first surgery and were excluded. Types of CAT were classified according to the modified Van Praagh classification. We included 147 patients: CAT A1 ( n = 89, 60.6%), CAT A2 ( n = 32, 21.7%), CAT A3 ( n = 8, 5.4%), and CAT A4 ( n = 18, 12.3%). The mean follow-up was 10 ± 4.4 years. Seventeen patients (11.6%) died after surgery. Mean survival was 88.2% at 5 years. Survival of CAT A4 was significantly lower than for other types (65% at 5 years; P < 0.01). In multivariate analysis, quadricuspid truncal valve anatomy ( P = 0.02, HR = 3.15, 95%CI [1.1961 to 8.3066]) and bovine xenograft valve conduit for the right ventricle outflow tract (RVOT) repair ( P = 0.04, HR = 2.34 [0.8584 to 6.4221]) were the two risk factors for mortality. Seventy-nine patients (53.7%) needed reintervention (surgery or percutaneous). Freedom from reintervention at 5 years was 51.7%. The risk for reintervention was similar in different types of CATs ( P = 0.65). The vast majority of reinterventions were done in the RVOT (96.2%). In univariate analysis, the use of bovine xenografts valve conduit ( P = 0.047, HR = 1.62 [1.12 to 2.51]) and porcine xenografts ( P < 0.01, HR = 2.46 [1.54 to 3.92]) were associated with a higher risk of reinterventions, while autologous connections of the pulmonary artery with the left atrial appendage or pericardial patch were associated with a reduced risk ( P < 0.0001, HR = 0.25 [0.1267 to 0.4779]) ( Fig. 1 ). The anatomical type of CAT did not influence the risk for reintervention after repair. Autologous reconstruction of the pulmonary artery with autologous tissue limits the risk for reintervention on the RVOT during childhood.

Long-term clinical outcome and echocardiographic function of homografts in the right ventricular outflow tract†.

Although homografts are often the preferred valve conduits for right ventricular outflow tract (RVOT) reconstruction, data on long-term homograft-related outcomes, durability and impact on quality of life (QoL) are scarce. The aim of this study was therefore to describe the long-term homograft function, clinical outcomes and QoL after RVOT reconstruction. We performed a single-centre retrospective analysis of all consecutive patients who underwent RVOT reconstruction with a homograft. Multiple subsequent allografts in the same patients were regarded as separate subjects. Valve-related events were analysed by Kaplan-Meier and Life Table methods. Serial echocardiographic measurements were analysed with mixed effects models. In addition, QoL was repeatedly assessed and compared with a matched general population. In total, 701 consecutive homografts were implanted in 604 patients [59.6% males, mean age at operation 19.5 ± 15.2 (standard deviation)]. Hospital mortality was 3.3%. After 25 years follow-up, survival and freedom from valve replacement were 84 ± 4% and 56 ± 6%, respectively. Freedom from valve replacement after 15 years for patients under 1 year of age was 28 ± 14% years, for those between 1 and 18 years, 59 ± 8%, and for those older than 18 years, 82 ± 5%. The peak gradient increased predominantly in the first postoperative decade in infants and paediatric patients from 19 to 54 mmHg. In adults, the average gradient increased from 9 to 31 mmHg after 14 years. Compared to a gender- and age-matched Dutch population, patients reported lower vitality and general health but less bodily pain. Patients, in whom QoL was repeatedly assessed, reported lower scores on physical functioning and vitality after a 5-year follow-up period. However, we found no differences in any of the subscales in patients who underwent valve replacement during the 5-year interval. Homografts are a durable valve alternative for RVOT reconstruction; in particular, adults show extensive freedom from valve replacement and report QoL comparable with healthy subjects. An online interactive application form created by our institution can be used to assess patient outcome after RVOT reconstruction with a homograft for different patient profiles.

The function of the modified novel 0.1 mm polytetrafluoroethylene hand-made valved conduit through the hydrodynamic test in vitro

Objective 0.1 mm polytetrafluoroethylene (PTFE) has been comfirmed to be better biocompatibable comparing to the bovine pericardium. The study aims to explore the appropriate hand sewed way for the 0.1 mm PTFE conduit and to assess the function through the hydrodynamic test in vitro. Methods The modified novel 0.1 mm PTFE hand-made valved conduit was tested with different size of 0.1 mm PTFE patch under TH-2200 machine in vitro. The 19 mm valved conduits were divided group A and B according to different width and lenth of 0.1 mm PTFE patch, comparing to the traditional bioprosthetic valve as group A0 and B0 relatively. In group A, the circumference of the conduit (π×d) mm was defined as the lenth of PTFE patch while (0.65×d+ 0.74) (mm) or (0.84×d) (mm) as width differently (group A1, group A2). In group B, the appropriate width was defined as the width of PTFE patch while π×d (mm) or (1.2π×d) (mm) as length differently (group B1, group B2). Then 14mm, 16mm and 22 mm valved conduits were made with the appropriate width and length from perious study to get tested as well as 19 mm conduits. Results Under the flow of 2, 3, 4, 5L/min, Gradiant pressure (ΔP) in group A1 and A2 was a little bit higher than A0. But there is no significant difference on effective orifice area (EOA) among A1, A2 and A0. The regurgitation fraction (RF) of group A2 is less than A1, but still more than A0 which showed (0.84×d) (mm) width was better than (0.65×d+ 0.74) (mm). There was no significant difference on ΔP and EOA between B1 and B2. But RF of B2 was much lower than B1, even better than B0, which showed (1.2π×d) (mm) length was better than (π×d) (mm) length. The 14, 16, 19 and 22 mm valved conduits made with (0.84×d) (mm) width and (1.2π×d) (mm) also showed low ΔP and few regurgitation. Conclusion Modified novel 0.1 mm PTFE hand-made valved conduits play a satisfying role on anti-regurgitation with the (0.84×d) (mm) width and (1.2π×d) (mm) length PTFE patch. Key words: Expanded polytetrafluoroethylene; In vitro; Handmade; Valve function

In Vitro Hemodynamic Evaluation of Right Ventricle-Pulmonary Artery Continuity Reconstruction Through a Trileaflet Expanded Polytetrafluoroethylene Valved Conduit.

Percutaneous pulmonary valve implantation is a technique to treat narrowed pulmonary valves or leaky pulmonary valves in congenital heart disease. This technique provides a promising strategy to reduce surgical risk. In clinical cases, due to stent size restrictions, commercial valve stents are sometimes unsuitable for children or certain patients. Hence, handmade pulmonary valved conduits prove useful because a customized size can be obtained for valve replacement. We propose a meta-learning-based intelligent model to train an estimator (including two sub-estimators) to determine optimal trileaflet parameters for customized trileaflet valve reconstruction. The purpose of this study was to investigate the hemodynamic and functional consequences of the novel design by employing a mock circulation system. We recorded the diastolic valve leakage and calculated the pulmonary regurgitation, regurgitation fraction, and ejection efficiency in a pulsatile setting. The prosthetic leaflet behavior was assessed using an endoscope camera and the pressure drops through valves were measured. All the in vitro parameters indicated that the expanded polytetrafluoroethylene (ePTFE) valved conduits were not inferior to commercial mechanical or tissue valve conduits and could decrease the regurgitation volume and increase the efficiency. Compatible early clinical outcomes were also identified between ePTFE valved conduits and other valved conduits used for right ventricular outflow tract reconstruction. The ePTFE valved conduits could be implanted in relatively small patients. An in vitro experimental study provided evidence that a handmade ePTFE valved conduit could be an attractive alternative to other commercialized valved conduits used for right ventricle-pulmonary artery continuity reconstruction.

Single stage repair for aortic root aneurysm in a patient with coexisting coarctation incorporating the Cabrol technique: a case report

BackgroundA 44 year old man who presented with a history of chest pain and dyspnoea was found to have an aneurysm of the aortic root, aortic valve insufficiency, and coarctation of the aorta.Case presentationThe patient underwent a single stage procedure to treat the aortic root, valve and coarctation with a composite valved conduit and extra-anatomic bypass of the coarctation. The modified Cabrol technique was necessary to attach the coronary buttons due to grossly abnormal anatomy. The patient made a remarkable recovery and was discharged on the 8th post-operative day.ConclusionThis case report highlights the feasibility and efficacy of performing a single stage procedure on complex coarctation with associated cardiac defects. To the best of our knowledge, this is the first report of the modified Cabrol technique being used in this particular setting.

Pulmonary Valve Regurgitation: Neither Interventional Nor Surgery Fits All.

Introduction: PV implantation is indicated for severe PV regurgitation after surgery for congenital heart defects, but debates accompany the following issues: timing of PV implantation; choice of the approach, percutaneous interventional vs. surgical PV implantation, and choice of the most suitable valve.Timing of pulmonary valve implantation: The presence of symptoms is class I evidence indication for PV implantation. In asymptomatic patients indication is agreed for any of the following criteria: PV regurgitation > 20%, indexed end-diastolic right ventricular volume > 120–150 ml/m2 BSA, and indexed end-systolic right ventricular volume > 80–90 ml/m2 BSA.Choice of the approach: percutaneous interventional vs. surgical: The choice of the approach depends upon the morphology and the size of the right ventricular outflow tract, the morphology and the size of the pulmonary arteries, the presence of residual intra-cardiac defects and the presence of extremely dilated right ventricle.Choice of the most suitable valve for surgical implantation: Biological valves are first choice in most of the reported studies. A relatively large size of the biological prosthesis presents the advantage of avoiding a right ventricular outflow tract obstruction, and also of allowing for future percutaneous valve-in-valve implantation. Alternatively, biological valved conduits can be implanted between the right ventricle and pulmonary artery, particularly when a reconstruction of the main pulmonary artery and/or its branches is required.Hybrid options: combination of interventional and surgical: Many progresses extended the implantation of a PV with combined hybrid interventional and surgical approaches. Major efforts have been made to overcome the current limits of percutaneous PV implantation, namely the excessive size of a dilated right ventricular outflow tract and the absence of a cylindrical geometry of the right ventricular outflow tract as a suitable landing for a percutaneous PV implantation.Conclusion: Despite tremendous progress obtained with modern technologies, and the endless fantasy of researchers trying to explore new forms of treatment, it is too early to say that either the interventional or the surgical approach to implant a PV can fit all patients with good long-term results.

Biological solutions to aortic root replacement: valve-sparing versus bioprosthetic conduit.

Composite valve graft implantation described by Bentall and De Bono is a well-documented technique of aortic root replacement used for a large spectrum of pathologic conditions involving the aortic valve and the ascending aorta. While mechanical valves were initially used, biological prostheses were later introduced in order to avoid long-term anticoagulation and its related complications. The increasing age of patients who undergo aortic root surgery, and data supporting the use of a biological aortic valve in the younger population, have significantly increased the need for a composite biological valved conduit. However, parallel to the increased use of biological valve in the context of a Bentall operation, aortic valve-sparing (AVS) operation have also been performed in a growing number of patients. Sarsam and David described the remodeling and the reimplantation procedures more than 25 years ago with the aim of sparing otherwise normal aortic valves in the presence of a root aneurysm. Important achievements in this discipline have occurred over the past decade including development and refinement of valve preserving aortic root replacement techniques, development of a classification system for aortic insufficiency, surgical approaches to cusp disease with different cusp anatomy. Both procedures can now provide excellent root reconstruction and adequate clinical results in terms of late valve durability. The AVS technique offers several advantages over the Bentall procedure, such as no need for oral anticoagulation and lifestyle adjustments. AVS operations have become established alternatives to Bentall procedures for patients with aortic root pathology. However, data comparing the safety and durability of these approaches are lacking.

Aortic valve bypass surgery in severe aortic valve stenosis: Insights from cardiac and brain magnetic resonance imaging

ObjectiveTo investigate and describe the distribution of aortic and cerebral blood flow (CBF) in patients with severe valvular aortic stenosis (AS) before and after aortic valve bypass (AVB) surgery. MethodsWe enrolled 10 consecutive patients who underwent AVB surgery for severe AS. Cardiovascular magnetic resonance imaging (CMR) and brain magnetic resonance imaging were performed as baseline before surgery and twice after surgery. Quantitative flow measurements were obtained using 1.5-T magnetic resonance imaging (MRI) scanner phase-contrast images of the ascending aorta, descending thoracic aorta (3 cm proximally and distally from the conduit-to-aorta anastomosis), and ventricular outflow portion of the conduit. The evaluation of CBF was performed using 3.0-T MRI scanner arterial spin labeling (ASL) through sequences acquired at the gray matter, dorsal default-mode network, and sensorimotor levels. ResultsConduit flow, expressed as the percentage of total antegrade flow through the conduit, was 63.5 ± 8% and 67.8 ± 7% on early and mid-term postoperative CMR, respectively (P < .05). Retrograde perfusion from the level of the conduit insertion in the descending thoracic aorta toward the aortic arch accounted for 6.9% of total cardiac output and 11% of total conduit flow. We did not observe any significant reduction in left ventricular stroke volume at postoperative evaluation compared with preoperative evaluation (P = .435). No differences were observed between preoperative and postoperative CBF at the gray matter, dorsal default-mode network, and sensorimotor levels (P = .394). ConclusionsAfter AVB surgery in patients with severe AS, cardiac output is split between the native left ventricular outflow tract and the apico-aortic bypass, with two-thirds of the total antegrade flow passing through the latter and one-third passing through the former. In our experience, CBF assessment confirms that the flow redistribution does not jeopardize cerebral blood supply.

Bentall procedure after previous aortic valve or complete root replacement: Usefulness of self-assembled aortic valve conduit

ObjectivesThe aim of this study was to evaluate surgical results of complete aortic root replacement using self-assembled valve composite graft in the setting of destroyed aortic annulus after previous valve replacement. MethodsAortic root pathology being addressed by complete root replacement was combined with partial or complete absence of annular tissue in 112 consecutive patients. Eighty-eight had undergone a previous replacement of the aortic valve and 24 had undergone root replacement with a valved conduit. Altogether, 31 patients (27.7%) presented with acute endocarditis, which was the indication for surgery in 75% of patients with prior root replacement. In all patients, the root replacement or re-replacement was performed with a self-assembled valved conduit using mechanical (n = 74) or, in patients with an advanced age, biological (n = 38) valve prostheses. ResultsIn-hospital mortality was 11.6%, including a 30-day mortality of 6.3%. Resternotomy for bleeding was necessary in 5.4% of patients and about one-quarter did not need any blood transfusion. Estimated survival at 1, 5, and 10 years was 84.8% ± 3.4%, 75.7% ± 4.3%, and 57.1% ± 6.5%, respectively. Freedom from any valve-related events at 10 years was 86.2% ± 4.1%. During the follow-up time (mean, 63 ± 47 months), there was only 1 reoperation necessary 9 years after surgery (replacement of deteriorated biological valve prosthesis within the vascular tube leaving the conduit untouched). ConclusionsA self-assembled composite graft allows safe proximal fixation of the conduit in patients with destroyed aortic annulus, resulting in sufficient proximal anastomosis and a very low incidence of aorta-related reoperations.

In search of the best xenogeneic material for a paediatric conduit: an analysis of clinical data.

In this study, we aimed to determine the incidence of reintervention and calcification of xenografts in paediatric patients who underwent placement of the right ventricle-to-pulmonary artery valved conduits. We retrospectively analysed clinical data of paediatric patients (1 day-18 years) who underwent right ventricular outflow tract reconstruction using xenograft from 2000 to 2016 at a single centre. A total of 301 patients underwent the placement of 337 xenografts, including glutaraldehyde-treated bovine jugular vein (n = 171, 50.7%), glutaraldehyde-treated bovine pericardial valved conduit (n = 75, 22.3%), diepoxy-treated porcine aortic conduit (n = 58, 17.2%) and diepoxy-treated bovine pericardial valved conduit (DE-PVC) (n = 33, 9.8%). There were 284 (84.3%) primary implantations and 53 (15.7%) reimplantations. The median follow-up was 4.2 years (range 1.5 months-14.5 years). The multivariate regression analysis did not reveal statistically significant associations of the first reintervention with the type of xenograft (P = 0.78). At reintervention, calcification of the wall and/or cusps was the main cause of conduit dysfunction in 66.4% of cases. On the basis of the multivariate Cox regression analysis, xenograft types were significant predictors of reintervention caused by conduit calcification (P = 0.012). The diepoxy-treated porcine aortic conduit group had the risk of calcification 3 times higher than the glutaraldehyde-treated bovine jugular vein group (P < 0.001).The glutaraldehyde-treated bovine pericardial valved conduit and diepoxy-treated bovine pericardial valved conduit groups had the risk of calcification comparable with the glutaraldehyde-treated bovine jugular vein group in multivariate proportional hazards model (P = 0.36 and P = 0.59, respectively). We have not revealed significant difference in the freedom from first reintervention among types of conduit. Calcification leading to the conduit dysfunction was present in all groups; however, diepoxy-treated porcine aortic conduits demonstrated suboptimal results in terms of calcification at follow-up.

Long-term outcomes of expanded polytetrafluoroethylene conduits with bulging sinuses and a fan-shaped valve in right ventricular outflow tract reconstruction

ObjectiveVarious types of conduits are available for right ventricular outflow tract (RVOT) reconstruction. We have developed an expanded polytetrafluoroethylene (ePTFE) conduit with bulging sinuses and a fan-shaped ePTFE valve. This study summarized the results of a multicenter study evaluating the valved ePTFE conduit. MethodsThe valve functions of 902 patients (median age, 3.9 years; median weight, 12.6 kg) who underwent RVOT reconstruction using valved ePTFE conduits (9 different sizes, 8-24 mm in diameter) at 65 hospitals between 2001 and 2015 were retrospectively investigated. Median follow-up time was 5.5 years. The valve functions were assessed using echocardiography, cardiac catheterization, and magnetic resonance angiography. ResultsThere were no deaths related to the ePTFE conduit. The peak RVOT gradient was 16.5 ± 13.1 mm Hg, and pulmonary insufficiency graded better than mild was 95.9% at the latest follow-up. Conduit replacement was performed in 55 patients, and in only 3 patients because of conduit infection. Freedom from intervention at 5 years and 10 years was 92.3% and 76.1%, respectively, with small conduits (8-16 mm in diameter) and 99.6% and 95.1%, respectively, with large conduits (18-24 mm in diameter). ConclusionsThe long-term outcomes of the ePTFE conduit with a fan-shaped valve and bulging sinuses appear clinically satisfactory. We believe that the longevity of small-sized conduits can yield sufficient time to exchange them to larger-sized conduits without any loss of their valve functions. Regarding longevity and resistance to infections, this ePTFE valved conduit can be one of the best ways to reconstruct the RVOT.

Handmade Trileaflet Valve Design and Validation for Pulmonary Valved Conduit Reconstruction Using Taguchi Method and Cascade Correlation Machine Learning Model

Pulmonary valve diseases in children and adults include different degrees of stenosis, regurgitation, or congenital defects. Valve repair or replacement surgery is used to treat valvular dysfunction and to improve regurgitations flow for pulmonary valve pathologies. Handmade trileaflet valve designs with different ranges of diameters have been used for pulmonary valved conduit reconstruction among children or adult patients with available conditions. In this paper, we propose a multiple regression model as a cascade-correlation-network-based estimator to determine optimal trileaflet parameters, including width, length, and upper/lower curved structures, for trileaflet valve reconstruction. The diameter of the main pulmonary artery is determined via computed tomography pulmonary angiography, and a trileaflet valve template is rapidly sketched. The actual valve is constructed using an expanded polytetrafluoroethylene material. Using an experimental pulmonary circulation loop system, design parameters and valve efficacy can be validated by the Taguchi method through calculation of signal-to-noise ratios. Experimental results indicate that in contrast to commercial valve stents, the handmade trileaflet valve exhibits good performance and is a valuable option in treatment of severe pulmonary regurgitation.

Customized Handmade Pulmonary Valved Conduit Reconstruction for Children and Adult Patients Using Meta-Learning Based Intelligent Model

Percutaneous pulmonary valve implantation is an improved technique that is used to treat narrowed pulmonary valves or leaky pulmonary valves in patients with congenital heart disease. This technique represents a promising strategy to reduce surgical risk and operation. In clinical cases, commercial valve stents are sometimes not available for children or special subjects due to restrictions in stent size. Hence, the handmade pulmonary valved conduit provides a strategy to design stents with customized size for valve replacement. In this paper, we propose a meta-learning-based intelligent model to train an estimator (including two sub-estimators) to determine optimal trileaflet parameters for customized trileaflet valve reconstruction. This estimation model overcomes the problem of empirical parameter determination. The meta-learning model possesses learning-to-optimization capability for training generalized regression neural network by particle swarm optimization algorithm. Through incremental training patterns, this scheme can gradually enhance optimization to provide refined parameters for customized designs that can be applicable to individuals of all age groups. The customized handmade pulmonary valved conduit was validated by assessing the regurgitation fraction and the heart pump efficiency using an experimental cardiopulmonary circulation loop system.

Carcinoid Heart Disease: A Simple Pulmonary Valve Solution

Purpose: The carcinoid valve disease process affects the tricuspid and pulmonary valves, with the development of right-sided heart failure. The definitive management of this is surgical replacement of the affected valves. The size and shape of the BioIntegral porcine pericardial valve conduit is an ideal conduit for use in the pulmonary position.

Fresh Pericardial Valved Conduit for Reconstruction of Right Ventricular Outflow Tract in Tetralogy of Fallot with Pulmonary Stenosis or Pulmonary Atresia: Early Results

Objective: To study early results of handmade fresh (autologous/homologous) pericardial valved conduit in achieving right ventricle to pulmonary artery continuity.