Adverse Mid-Term Outcome Following RVOT Reconstruction Using the Contegra Valved Bovine Jugular Vein

Durability of right ventricular conduits in the Ross procedure

BACKGROUND

Right ventricular (RV) conduit availability and degeneration are potential limitations of the Ross procedure. Pulmonary homografts are the gold standard, but their limited availability drives the need for alternatives. The aim of this study was to compare results of different RV conduits.

METHODS

Between 1995 and 2023, 315 consecutive patients (73% males; mean age, 37 ± 12 years) underwent a Ross procedure using a homograft (n = 211), bovine jugular vein (BJV) (n = 34), or xenograft (n = 70) as the RV conduit. The mean follow-up was 5.7 ± 6.7 years and was 96% complete (1631 patient-years).

RESULTS

Twelve patients (homograft, n = 8; BJV. n = 3; xenograft, n = 1) required RV conduit reintervention, including 4 patients within 4 years (all with homografts). Indications for reintervention were degeneration in 8 patients and active endocarditis in 4 patients. Reinterventions included RV conduit replacement (homograft, n = 3; xenograft, n = 1; BJV, n = 2) and transcatheter valve implantation (homograft n = 5; BJV, n = 1). At 15 years, freedom from RV conduit reintervention was 88%, and freedom from reoperation was 93%. Freedom from reintervention at 15 years was similar in the homograft (89%), BJV (89%), and xenograft (100%) groups (P = .812). Progression of mean RV conduit gradient was lowest for the BJV group (1.45 mm Hg/year) and similar in the homograft (2.6 mm Hg/year) and xenograft (2.9 mm Hg/year) groups. Age at <18 years at surgery (hazard ratio [HR], 1.9; P < .001) was a predictive risk factor for reintervention. There was no difference among the RV conduit groups (HR, 1.198; P = .606).

CONCLUSIONS

The incidence of reintervention after 15 years is similar in recipients of homografts, xenografts, and BJV grafts. Interestingly, homografts may fail in the first few years, possibly related to inflammatory phenomena. Thus, the use of xenografts may be an option if homografts are not available.

Novel small-sized ePTFE valves for neonatal RVOT reconstruction: an in-vitro investigation

Small-sized right ventricle to pulmonary artery conduits are hindered by calcification, degeneration, or infective endocarditis and face limited availability. Valved conduits of expanded polytetrafluoroethylene leaflets offer a promising path toward enhanced longevity and performance. This in-vitro study introduces innovative expanded polytetrafluoroethylene valve designs for small-sized conduits.Three bicuspid and three tricuspid expanded polytetrafluoroethylene leaflets designed for size 12 mm were tested using an in-vitro pediatric right-heart mock-up loop and compared with our baseline leaflet design. Polyvinylchloride was used to create a transparent tube for visual access. Regurgitation rates, pressure gradients, effective orifice area under 0.5-3 L/min cardiac outputs, and 100-150beats/min heart rates are measured. Mechanical differences between expanded polytetrafluoroethylene and polyvinylchloride are investigated through biaxial strain tests. In newborn hemodynamic conditions, 0.5-1 L/min cardiac output, bileaflet valves demonstrated regurgitation rates below 20%, and two tricuspid models maintained regurgitation rates below 15% with gradients below 25 mmHg. In infant conditions, 1-3 L/min output, the regurgitation rates of trileaflet models were below 20%, with gradients consistently below 35 mmHg. The fully coapting bileaflet model showed a regurgitation rate of less than 15% and a gradient below 30 mmHg across newborn and infant conditions. A circumferential difference of less than 0.12 mm was detected between expanded polytetrafluoroethylene and polyvinylchloride. Both the fully coapting bileaflet and redundant trileaflet configurations can be integrated in the small conduits. Polyvinylchloride can be an alternative to expanded polytetrafluoroethylene tube graft in in-vitro studies, allowing visual access to assess leaflet kinematics.

Valved Conduits for Right Ventricular Outflow Tract Reconstruction: A Review of Current Technologies and Future Directions

The need for right ventricular outflow tract reconstruction is common and growing in congenital heart surgery given expanding indications for the repair of congenital as well as acquired heart disease. Various valved conduit options currently exist including homografts, xenograft pulmonary valved conduits (Contegra™), and porcine valved conduits. The major limitation for all conduits is implant durability, which requires reoperation. Currently, cryopreserved homografts are often used given their superiority shown in long-term data. Significant limitations remain in the cost and availability of the graft, particularly for smaller sizes. Contegra conduits are available in a variety of sizes. Nonetheless, the data regarding long-term durability are less robust and studies comparing durability with homografts have been conflicting. Additionally, there is concern for increased rates of late endocarditis in this conduit. Porcine valved conduits offer a reliable option but are limited by structural valve degeneration associated with all types of bioprosthetic heart valve replacements. New developments in the field of tissue engineering have produced promising bio-restorative valved conduits that may overcome many of the limitations of previous conduit technologies. These remain in the early stages of clinical testing. This review summarizes the clinical data surrounding the conduits used most commonly in clinical practice today and explores emerging technologies that may bring us closer to developing the ideal conduit.

Pediatric RVOT reconstruction with ePTFE trileaflet valved conduits: a dual-center Chinese study

Objective

This study aims to assess the early to mid-term clinical efficacy of expanded polytetrafluoroethylene (ePTFE) trileaflet valved conduits in pediatric right ventricular outflow tract reconstruction for congenital heart disease.

Methods

We conducted a retrospective analysis of pediatric patients who underwent right ventricular outflow tract (RVOT) reconstruction using ePTFE trileaflet valved conduits at two cardiac centers in China, between January 2017 and June 2023. The main assessment criterion was the functionality of the prosthetic pulmonary valve conduit.

Results

A total of 162 pediatric patients were included, with follow-up periods ranging from 0.1 to 5 years post-discharge, and a median follow-up duration of 1 year (interquartile range: 1, 2). Three patients (1.9%) required re-operation due to conduit obstruction. During follow-up, pulmonary valve flow velocities were recorded as <3 m/s in 134 patients (82.7%), between 3 and 4 m/s in 24 patients (14.8%), and >4 m/s in 4 patient (2.5%). Mild pulmonary valve regurgitation was noted in 148 patients (91.4%), and moderate pulmonary valve regurgitation was noted in 14 patients (8.6%), with no instances of more than moderate pulmonary valve regurgitation.

Conclusion

The ePTFE trileaflet valved conduit, known for its accessibility and simplicity in manufacturing, demonstrates favorable early to mid-term clinical outcomes in pediatric RVOT reconstruction.

The Utility of Invengenx® Bovine Patch for Right Ventricular Outflow Tract (RVOT) Reconstruction and Augmentation in the Surgical Management of Tetralogy of Fallot (TOF): A Contemporary Study and Review of the Literature

Background and objective Complex congenital heart diseases (CHDs), such as the tetralogy of Fallot (TOF), often warrant reconstruction and augmentation of the right ventricular outflow tract (RVOT). This procedure requires the use of both synthetic and natural materials. However, finding the ideal material for tissue implants can be challenging. Biological materials often face issues such as tissue degeneration, calcium deposition, antigenicity, rejection, shrinkage, and fibrosis. These issues can lead to complications such as stenosis and insufficiency, potentially requiring early reoperations. In light of this, this study aimed to investigate the effectiveness of the Invengenx® bovine patch for RVOT reconstruction and augmentation. Methods This was a retrospective observational study conducted among eight children who underwent TOF correction cardiac surgery. Their demographic and clinical characteristics, intraoperative findings, and postoperative follow-up results at six months were collected from the hospital patient database. Results There were no deaths or complications in this study. We observed a significant reduction in the gradient across the pulmonary valve and the outflow tract at six months post-procedure. The analysis demonstrated that the Invengenx® bovine patch was successful and did not lead to any complications. Conclusions This study demonstrates the safety and efficacy of this engineered bovine pericardial patch (Invengenx®) as a cardiovascular substitute for surgical repair of both simple and more complex congenital cardiac defects.

Bovine jugular vein conduit replacement after homograft degeneration in patients with tetralogy of Fallot: The results of re-redo cases

Background

This study aims to present our experience and results in terms of reconstruction with bovine jugular vein conduit in re-redo patients who developed severe homograft degeneration with pulmonary homograft valve replacement.

Methods

Between May 2018 and May 2021, a total of 10 re-redo patients (4 males, 6 females; mean age: 16.5±3.0 years; range, 12 to 21 years) who underwent bovine jugular vein conduit replacement due to homograft degeneration were retrospectively analyzed. The clinical, pre-, intra-, and postoperative data of the patients were recorded.

Results

The mean age of the second operation (homograft replacement) was 8.5±3.8 (range, 4 to 14) years in the patients who underwent homograft replacement. No postoperative mortality was observed. When the pre- and postoperative findings were compared, the right ventricular outflow tract gradient, the degree of pulmonary and tricuspid regurgitation, and right ventricular dilatation were regressed (p<0.05). A significant improvement in the New York Heart Association functional class was observed in all patients after surgery.

Conclusion

After tetralogy of Fallot corrective surgery, repetitive surgical interventions are inevitable due to pulmonary valve deterioration. Therefore, a bovine jugular vein conduit may be a good alternative for conduit preference after pulmonary homograft failure in re-redo cases.

Biological Scaffolds for Congenital Heart Disease

Congenital heart disease (CHD) is the most predominant birth defect and can require several invasive surgeries throughout childhood. The absence of materials with growth and remodelling potential is a limitation of currently used prosthetics in cardiovascular surgery, as well as their susceptibility to calcification. The field of tissue engineering has emerged as a regenerative medicine approach aiming to develop durable scaffolds possessing the ability to grow and remodel upon implantation into the defective hearts of babies and children with CHD. Though tissue engineering has produced several synthetic scaffolds, most of them failed to be successfully translated in this life-endangering clinical scenario, and currently, biological scaffolds are the most extensively used. This review aims to thoroughly summarise the existing biological scaffolds for the treatment of paediatric CHD, categorised as homografts and xenografts, and present the preclinical and clinical studies. Fixation as well as techniques of decellularisation will be reported, highlighting the importance of these approaches for the successful implantation of biological scaffolds that avoid prosthetic rejection. Additionally, cardiac scaffolds for paediatric CHD can be implanted as acellular prostheses, or recellularised before implantation, and cellularisation techniques will be extensively discussed.

Current development of bovine jugular vein conduit for right ventricular outflow tract reconstruction

Right ventricular outflow tract (RVOT) reconstruction is a common surgical method to treat congenital cardiac lesions, and bovine jugular vein conduit (BJVC) has become a prevalent candidate of prosthetic material for this procedure since 1999. Although many clinical studies have shown encouraging results on BJVCs, complications such as stenosis, aneurysmal dilatation, valve insufficiency, and infective endocarditis revealed in other clinical outcomes still remain problematic. This review describes the underlying mechanisms causing respective complications, and summarizes the current technological development that may address those causative factors. Novel crosslinking agents, decellularization techniques, conduit coatings, and physical reinforcement materials have improved the performances of BJVCs. The authors expect that the breakthroughs in the clinical application of BJVC may come from new genetic research findings and advanced characterization apparatuses and bioreactors, and are optimistic that the BJVC will in the future provide sophisticated therapies for next-generation RVOT reconstruction.

Early multicenter experience of Melody valve implantation in India

Background

Transcatheter valves provide a safe and effective alternative to surgery for treating dysfunctional right ventricular outflow tracts (RVOTs). We present our early multicenter experience of percutaneous pulmonary valve implantation (PPVI) using Melody valve (Medtronic Inc., Minneapolis, MN).

Methods

Patients with stenosed conduits or degenerated bioprosthetic valves in RVOT with combined stenosis and regurgitation were evaluated for suitability of Melody valve implantation. After undergoing an initial structured training, PPVI using Melody transcatheter pulmonary valve (TPV) was guided by an approved proctor. Conduits were serially dilated and prestented with careful coronary interrogation, and bioprosthetic valves were dilated with high-pressure balloons. Clinical and echocardiographic follow-up was performed at 6 monthly intervals.

Results

Fifteen patients (three females) aged 23.1 ± 9.5 years in NYHA Class II-III underwent Melody TPV implantation in four Indian centers. The underlying anatomy comprised surgically implanted bioprosthetic valves for pulmonary regurgitation (n= 5), conduit repair for pulmonary atresia (n = 4), Rastelli repair (n = 3), truncus (n = 1), and Ross procedure (n = 2). Twelve patients had more than one previous surgery. Doppler gradient decreased from 74.2 ± 21.5 mmHg to 10.2 ± 4.5 mmHg after the PPVI. At a median follow-up of 14 months (1-39 months), all the patients were in NYHA Class I with echocardiographic gradients of 8 ± 5.7 mmHg with no evidence of pulmonary regurgitation. There were no major procedural adverse events or deaths.

Conclusions

Our early experience shows encouraging results of the PPVI program in India with proctored case selection and meticulous planning. It also confirms the safety and efficacy of Melody TPV for treating dysfunctional RVOT in postoperative patients.

Mid-term outcomes of Contegra implantation for the reconstruction of the right ventricular outflow tract to proximal branch pulmonary arteries: Japan multicentre study

OBJECTIVES

To reveal the mid-term outcomes of Contegra implantation for the reconstruction of the right ventricular outflow tract to proximal branch pulmonary arteries in a multicentre study.

METHODS

Between April 2013 and December 2019, 178 Contegra conduits were implanted at 5 Japanese institutes. The median age and body weight at operation were 16 months (25th-75th percentile: 8-32) and 8.3 kg (6.4-10.6). Sixteen patients were neonates (9.0%). Selected conduit sizes were 12 mm in 28 patients (15.7%), 14 mm in 67 patients (37.6%), 16 mm in 66 patients (37.1%), 18 mm in 5 patients (2.8%) and <12 mm in 12 patients (6.7%). Fifty-six grafts (31.4%) were ring supported. Proximal branch pulmonary arteries were concomitantly augmented in 85 patients (47.5%). Follow-up was completed in all patients and the median follow-up period was 3.1 years (1.3-5.1).

RESULTS

The overall, conduit explantation-free and conduit infection-free survival rates at 5 years were 91.3%, 71.0% and 83.7%, respectively. Infection (P = 0.009) and common arterial trunk (P = 0.024) were risk factors for explantation. Conduit durability was shorter in smaller one (P < 0.001). Catheter interventions (for conduit to proximal branch pulmonary artery)-free survival rates at 5 years was 52.9%; however, need for catheter interventions was not a risk factor for conduit explantation.

CONCLUSIONS

Mid-term outcomes of reconstruction of the right ventricular outflow tract to the proximal branch pulmonary arteries with Contegra were acceptable. The need for explantation over time was higher in smaller conduits. Conduit infection was a strong risk factor for conduit explantation. Frequently and repeated catheter interventions effectively extended the conduit durability.

Biofabrication in Congenital Cardiac Surgery: A Plea from the Operating Theatre, Promise from Science

Despite significant advances in numerous fields of biofabrication, clinical application of biomaterials combined with bioactive molecules and/or cells largely remains a promise in an individualized patient settings. Three-dimensional (3D) printing and bioprinting evolved as promising techniques used for tissue-engineering, so that several kinds of tissue can now be printed in layers or as defined structures for replacement and/or reconstruction in regenerative medicine and surgery. Besides technological, practical, ethical and legal challenges to solve, there is also a gap between the research labs and the patients' bedside. Congenital and pediatric cardiac surgery mostly deal with reconstructive patient-scenarios when defects are closed, various segments of the heart are connected, valves are implanted. Currently available biomaterials lack the potential of growth and conduits, valves derange over time surrendering patients to reoperations. Availability of viable, growing biomaterials could cancel reoperations that could entail significant public health benefit and improved quality-of-life. Congenital cardiac surgery is uniquely suited for closing the gap in translational research, rapid application of new techniques, and collaboration between interdisciplinary teams. This article provides a succinct review of the state-of-the art clinical practice and biofabrication strategies used in congenital and pediatric cardiac surgery, and highlights the need and avenues for translational research and collaboration.

Expanded Polytetrafluoroethylene Conduits With Bulging Sinuses and a Fan-Shaped Valve in Right Ventricular Outflow Tract Reconstruction

We developed a handmade expanded polytetrafluoroethylene (ePTFE) pulmonary valvular conduit (PVC) with bulging sinuses and a fan-shaped ePTFE valve for right ventricular outflow tract (RVOT) reconstruction. We aimed to investigate the results of this device in this multicenter study. From 2001 to 2020, 1776 patients underwent RVOT reconstruction using ePTFE PVCs at 65 institutions in Japan. The median age and body weight were 4.1 years (range, 3 days to 67.1 years) and 13.3 (range, 1.8-91.3) kg, respectively. The median PVC size was 18 (range, 8-24) mm. The median Z-value of the ePTFE PVC was 1.1 (range, -3.8 to 5.0). The ePTFE PVC conditions were investigated by cardiac echocardiography and catheterization. The median follow-up period was 3.3 years (range, 0 day to 16.2 years). There were only 9 cases (0.5%) with PVC-related unknown deaths. Reintervention was performed in 283 patients (15.9%), and 190 patients (10.7%) required explantation. Freedom from reintervention and explantation at 5/10 years were 86.7/61.5% and 93.0/69.1%, respectively. At the latest echocardiography, PVC regurgitation grade was better than mild in 88.4% patients. The average peak RVOT gradient was 15.7 ± 15.9 mm Hg at the latest cardiac catheterization. ePTFE PVC infection was detected in only 8 patients (0.5%). Relative stenosis due to somatic growth was the most common cause of PVC explantation. The performance of ePTFE in terms of durability, valvular performance, and the resistance against infection is considerable and may replace conventional prosthetic materials. Further improvement of the ePTFE membrane is essential to prevent valvular dysfunction.

Surgery for Truncus Arteriosus: Contemporary Practice

Surgery for truncus arteriosus has an early mortality of 3% to 20%, with a long-term survival of approximately 75% at 20 years. Nowadays, truncus arteriosus repair is mostly done in the neonatal period together with a single-staged repair of concomitant cardiovascular anomalies. There are many challenging subgroups of patients with truncus arteriosus, including those with clinically significant truncal valve insufficiency, an interrupted aortic arch, or a coronary artery anomaly. In fact, truncal valve competency appears to be the most important factor influencing the outcomes after truncus arteriosus repair. The use of a conduit during truncus arteriosus repair invariably requires reoperation on the right ventricular outflow tract. Through improvements in perioperative techniques over time, many children are now living well into adulthood after repair of truncus arteriosus, albeit with a high rate of reoperation. Despite this, the long-term outcomes of truncus arteriosus repair are good, with many patients being asymptomatic and with a quality of life comparable to the general population.

Diepoxy- Versus Glutaraldehyde-Treated Xenografts: Outcomes of Right Ventricular Outflow Tract Reconstruction in Children

BACKGROUND

Xenografts used for right ventricular outflow tract (RVOT) reconstruction are typically treated with glutaraldehyde. However, potential benefit of epoxy treatment was demonstrated in experimental studies. We aimed to compare diepoxy-treated bovine pericardial valved conduits (DE-PVCs) and glutaraldehyde-treated bovine pericardial valved conduits (GA-PVCs) for RVOT reconstruction in pediatric patients.

METHODS

Between 2002 and 2017, 117 patients underwent RVOT reconstruction with PVC in single center: DE-PVC group, n = 39; and GA-PVC group, n = 78. After performing propensity score analysis (1:1) for the entire sample, 29 patients from the DE-PVC group were matched with 29 patients from the GA-PVC group.

RESULTS

There were no conduit-related deaths. In the DE-PVC group, the freedom from conduit failure was 90.9% at four years and 54.3% at eight years postoperatively. In the GA-PVC group, it was 46.3% and 33.1%, respectively. The difference was significant (P = .037). Conduit failure was typically caused by stenosis in both groups. In the DE-PVC group, the main cause of stenosis was xenograft calcification (27.6%); while in the GA-PVC group, it was mostly due to neointimal proliferation (25.0%) and, less often, calcification (14.3%). Conduit thrombosis was the cause of replacement in 6.9% of patients from the GA-PVC group.

CONCLUSIONS

Diepoxy-treated bovine pericardial valved conduit is a suitable alternative to GA-PVC for RVOT reconstruction in pediatric patients. Diepoxy-treated bovine pericardial valved conduits may be less prone to conduit failure and more resistant to neointimal proliferation and conduit thrombosis than GA-PVCs.

Outcomes of truncus arteriosus repair with bovine jugular vein conduit

Background

In this study, we aimed to evaluate the outcomes of truncus arteriosus repair in patients undergoing Rastelli type truncus arteriosus.

Methods

A total of 13 patients (7 males, 6 females; median age 37 days; range, 16 to 60 days) underwent repair of truncus arteriosus using Contegra conduits between January 2011 and March 2 017. P reoperative d iagnosis w as t runcus a rteriosus type 1 (Edwards-Collett) in eight, type 2 in three, type 3 in one, and type 4 in one patient. Contegra conduits used for operations were 14 mm (n=5), 12 mm (n=7), and 16 mm (n=1).

Results

Early death was seen in two patients (15.4%). The median intensive care and hospital stays were 10 (range, 6 to 14) and 20 (range, 14 to 41) days, respectively. The median follow-up was 36 (range, 2 to 66) months. In four patients (31%), the conduit sizes severely increased during follow-up and reached 23 mm in two patients and 20 mm in one patient, and 18 mm in the other patient. Three patients had moderate distal conduit stenosis. Moderate pulmonary insufficiency was detected in four patients and severe pulmonary insufficiency in one patient. Two patients had moderate truncal valve insufficiency and one patient had moderate residual ventricular septal defect. None of the patients needed reoperation.

Conclusion

Contegra conduit is a good alternative for repair of truncus arteriosus in infants; however close follow-up is necessary, as distal conduit stenosis and conduit dilatation may develop.

Right ventricular outflow tract obstruction: a quest for ideal management

Management of right ventricular outflow tract obstruction has undergone much change over the last century. Techniques described in the literature include anatomical repairs and the use of various patches, conduits, and innovative grafts. However, many of these approaches require reoperations or catheter-based interventions, leading to increased morbidity, mortality, and cost. The search for the ideal long-lasting conduit continues and there are new techniques on the horizon, using genetic engineering and nanotechnology. This review discusses the evolution of various techniques for repair of right ventricular outflow tract obstruction, past and current conduits, as well as ongoing research.

Outcomes of Right Ventricular Outflow Tract Reconstruction for Children with Persistent Truncus Arteriosus: A 10-Year Single-Center Experience

The purpose of this report is to assess the mid- and long-term outcomes of right ventricular outflow tract (RVOT) reconstruction for children with persistent truncus arteriosus. Between September 2006 and 2016, 105 patients with persistent truncus arteriosus (PTA) received surgical treatment at Shanghai Children's Medical Center. Direct right ventricle-pulmonary artery anastomosis (pulmonary artery pull-down) was performed in 51 patients; a left auricle or pericardial conduit was inserted between the RVOT and pulmonary artery as a connection in 17 patients; heterograft (bovine jugular vein or Gore-tex) conduits and homograft conduits were used in 30 and 7 cases, respectively, to connect the distal pulmonary and right ventricle outflow tract; and pulmonary valve reconstruction was performed in 38 patients using a Gore-tex monocusp. There were six in-hospital deaths and one delayed death 5 months after operation. After a mean follow-up of 55.8 ± 16.5 months (6-113 months), 19 patients underwent reoperation (3 with pulmonary patch enlargement, 14 with conduit replacement and 2 with aortic valve replacement) 10-89 months after the first operation, with 1 hospital death. The actuarial survival rates were 94.2, 93.3 and 93.3% at 1, 5 and 10 years, respectively. Freedom from reoperation was 98.0, 87.8 and 82.7% at 1, 5 and 10 years, respectively. The follow-up variables included echocardiography, chest radiography, cardiac CT and cardiac function. At the last examination, most of the patients exhibited an improvement of New York Heart Association functional class from III or IV preoperatively to I or II at follow-up. Surgical treatment for PTA has an acceptable survival rate and satisfactory outcomes. Most patients exhibited an improvement in cardiac function during follow-up. Aortic arch deformity, truncal valvular regurgitation and long cardiopulmonary bypass time were regarded as risk factors for hospital mortality. Autologous tissue has a lower reoperation rate and better growth potential than extracardiac conduits. A monocusp valve effectively reduces pulmonary regurgitation in the early postoperative stage.

Pulmonary valve replacement after right ventricular outflow tract reconstruction with homograft vs Contegra®: a case control comparison of mortality and morbidity

Background

Repair of congenital heart defects involving the right ventricular outflow tract may require the implantation of a right ventricle to pulmonary artery conduit. This conduit is likely to be replaced during childhood. This study compares the operative outcomes of the replacement procedure of Contegra® and homografts in pulmonary position.

Methods

From 1999 to 2016, 82 children underwent 87 right ventricle to pulmonary artery conduit replacements (60 Contegra® and 27 homografts). Demographics, operative and clinical data were obtained through a retrospective review of the medical records. The two groups were matched for comparison using propensity score matching. All the procedures were performed by the same team of surgeons.

Results

No statistically significant difference was observed between the two groups when considering the operative data for anesthesia, surgery, cardiopulmonary bypass and aortic clamping durations. A peroperative complication rate of 13.47% and 15.36% in Contegra® and homograft replacement groups respectively (p value = 0.758) was observed. There was no difference regarding the blood loss and fluid input. No statistically significant difference was observed between the two groups for the post-operative morbidity. We considered the Pediatric Risk of Mortality (PRISM) score, the day of extubation, the day of withdrawal of inotropic drugs, the length of the intensive care unit stay and the length of hospital stay. The overall mortality is 2.3% but there is no statistically significant difference between the two groups.

Conclusion

Right ventricle to pulmonary artery conduit replacement procedure can be achieved with a low surgical morbidity or mortality, not influenced by the type of conduit that is replaced. Therefore, the choice between homograft or Contegra® for right ventricle to pulmonary artery reconstruction should not be influenced by the future surgical risk during the replacement procedure.

Trial registration

NCT03048071. Registered 9 February 2017 (retrospectively registered).

Application of a Simplified Hand-Sewn Trileaflet Valved Conduit in Right Ventricular Outflow Tract Reconstruction as an Alternative for Bovine Jugular Vein Graft: Single-Center Experience

The Bovine jugular vein (BJV) graft for right ventricular outflow tract reconstruction (RVOT) is limited applied due to possible graft failure. In this study, we reported the clinical application of simplified hand-sewn trileaflet valved conduit as an alternative for BJV graft. We retrospectively included 68 patients underwent 76 conduits implantation including 22 new simplified hand-sewn trileaflet valved conduits (Group A) and 54 BJV grafts (Group B). For patients in Group A, a hand-sewn trileaflet valved conduit with valves made of autologous pericardium or expanded polytetrafluoroethylene was applied. Baseline, perioperative, and outcomes were analyzed. No early mortality or perioperative complication occurred in Group A, while 2 patients died and 16 patients suffered from conduits failure due to conduits stenosis (n = 11), stenosis plus regurgitation (n = 3), and regurgitation alone (n = 2) in Group B. Freedom from BJV grafts failure within 1, 3, 5, and 7 years was 98.0%, 88.2%, 83.6% and 83.6% in Group A, and 98.0%, 85.8%, 76.8% and 62.1% in Group B. Endocarditis occurred in 9 patients in Group B, but not in Group A. Subsequent analysis showed that endocarditis is the only significant predictor of BJV grafts failure (odds ratio: 6.202, 95% confidence intervals 1.237∼31.108). The novel simplified hand-sewn trileaflet valved conduits seems to be associated with lower incidences of perioperative complication, graft failure, and early-phase mortality, as compared with conventional BJV grafts.

A Case Report of Contegra Conduit Dissection With Subsequent Heart Failure

The surgical palliation of several congenital heart defects requires the use of a conduit, particularly between the right ventricle and the pulmonary artery. Contegra, a valved bovine vein conduit, is a conduit frequently used. Pseudoaneurysms, aneurysms, and dissections have seldom been reported with Contegra conduits but are potential complications associated with these conduits. We report a new case of Contegra dissection.

First Melody(®) valve implantations in Africa

Congenital heart lesions involving the right ventricular outflow tract (RVOT) are a common problem in paediatric cardiology. These patients need multiple surgical interventions in the form of valved conduits over a lifetime. Surgical re-valvulation was the standard treatment option until the introduction of percutaneous pulmonary valves over a decade ago. These valves can be used to prolong the lifespan of conduits and reduce the number of re-operations. The Melody(®) valve (Medtronic, Minneapolis, MN, USA) was introduced as the first dedicated percutaneous pulmonary valve. Percutaneous pulmonary valves can be implanted successfully and have the advantage of short hospitalisations. We describe the first three Melody(®) valve implantations in Africa.

Analysis of flow dynamics in right ventricular outflow tract

BACKGROUND

The mechanism behind early graft failure after right ventricular outflow tract (RVOT) reconstruction is not fully understood. Our aim was to establish a three-dimensional computational fluid dynamics (CFD) model of RVOT to investigate the hemodynamic conditions that may trigger the development of intimal hyperplasia and arteriosclerosis.

METHODS

Pressure, flow, and diameter at the RVOT, pulmonary artery (PA), bifurcation of the PA, and left and right PAs were measured in 10 normal pigs with a mean weight of 24.8 ± 0.78 kg. Data obtained from the experimental scenario were used for CFD simulation of pressure, flow, and shear stress profile from the RVOT to the left and right PAs.

RESULTS

Using experimental data, a CFD model was obtained for 2.0 and 2.5-L/min pulsatile inflow profiles. In both velocity profiles, time and space averaged in the low-shear stress profile range from 0-6.0 Pa at the pulmonary trunk, its bifurcation, and at the openings of both PAs. These low-shear stress areas were accompanied to high-pressure regions 14.0-20.0 mm Hg (1866.2-2666 Pa). Flow analysis revealed a turbulent flow at the PA bifurcation and ostia of both PAs.

CONCLUSIONS

Identified local low-shear stress, high pressure, and turbulent flow correspond to a well-defined trigger pattern for the development of intimal hyperplasia and arteriosclerosis. As such, this real-time three-dimensional CFD model may in the future serve as a tool for the planning of RVOT reconstruction, its analysis, and prediction of outcome.

Current status of right ventricular outflow tract reconstruction: complete translation of a review article originally published in Kyobu Geka 2014;67:65-77

Right ventricular outflow tract (RVOT) reconstruction is becoming more prevalent as the number of adult patients who require repeated surgery long after definitive repair of congenital heart defects during childhood has increased. Early primary repair and annulus-preserving surgery have been the two current strategies of RVOT reconstruction from the viewpoint of timing and indications for surgical intervention; however, the long-term outcomes of both procedures remain unknown. Although various materials have been used for pulmonary valve replacement during RVOT reconstruction, deficient durability due primarily to immunological rejection frequently arises, particularly when implanted into young patients. A multicenter study in Japan showed that the clinical outcomes of expanded polytetrafluoroethylene (ePTFE) valved patches/conduits that we developed and manufactured comprised an excellent alternative material for RVOT reconstruction. Such enhanced outcomes might have partly been attributable to the biocompatibility and low antigenicity of ePTFE, and also to the fluid dynamic properties arising from the structural characteristics of a bulging sinus and a fan-shaped valve. However, numerous issues concerning RVOT reconstruction, such as indications for and the timing of definitive repair, as well as the choice of materials for pulmonary valve replacement, must be resolved to achieve better patient prognoses and quality of life. This review describes recent surgical strategies and outstanding issues associated with RVOT reconstruction.

MR and CT imaging of pulmonary valved conduits in children and adolescents: normal appearance and complications

BACKGROUND

The Contegra® is a conduit made from the bovine jugular vein and then interposed between the right ventricle and the pulmonary artery. It is used for cardiac malformations in the reconstruction of right ventricular outflow tract.

OBJECTIVE

To describe both normal and pathological appearances of the Contegra® in radiological imaging, to describe imaging of complications and to define the role of CT and MRI in postoperative follow-up.

MATERIALS AND METHODS

Forty-three examinations of 24 patients (17 boys and 7 girls; mean age: 10.8 years old) with Contegra® conduits were reviewed. Anatomical description and measurements of the conduits were performed. Pathological items examined included stenosis, dilatation, plicature or twist, thrombus or vegetations, calcifications and valvular regurgitation. Findings were correlated to the echographic gradient through the conduit when available.

RESULTS

CT and MR work-up showed Contegra® stenosis (n = 12), dilatation (n = 9) and plicature or twist (n = 7). CT displayed thrombus or vegetations in the Contegra® in three clinically infected patients. Calcifications of the conduit were present at CT in 12 patients and valvular regurgitation in three patients. The comparison between CT and/or MR results showed a good correlation between the echographic gradient and the presence of stenosis in the Contegra®.

CONCLUSION

CT and MR bring additional information about permeability and postoperative anatomy especially when echocardiography is inconclusive. Both techniques depict the normal appearance of the conduit, and allow comparison and precise evaluation of changes in the postoperative follow-up.

In search of a pediatric cardiac surgeon’s ‘Holy Grail’: the ideal pulmonary conduit

The limited lifespan of all currently available conduits leads to repeat operations and interventional procedures in many children. Each reoperation entails considerable risk to life, expenditure and compromised quality of life as the conduit degenerates. The ideal conduit should be available freely, inexpensive, require no anticoagulation, be resistant to infection, free from thromboembolism, have no gradients or regurgitation and have unlimited durability. This review explores various options as surgeons and researchers endeavor to develop the ideal conduit--which will fulfill all of the above-mentioned criteria. Various currently available conduits are analyzed. Special emphasis is given to tissue-engineered valves and percutaneous valve implantations.

Chronic pulmonary valve insufficiency after repaired Tetralogy of Fallot: diagnostics, reoperations and reconstruction possibilities

Complete correction of Tetralogy of Fallot, the most common cyanotic congenital heart defect, has now become routine. However, late residual lesions, primarily chronic pulmonary valve insufficiency, may have a negative impact on right-ventricular function, leading to the need for reoperation to insert a competent valve at the right-ventricular outflow. The diagnostic modalities pertaining to the failing right ventricle, the timing for eventual reintervention and the various surgical reconstruction possibilities of the right-ventricular outflow tract are still controversial and evolving, and are reviewed with a brief overview on current trends and future outlooks.

Evaluation of a tissue-engineered bovine pericardial patch in paediatric patients with congenital cardiac anomalies: initial experience with the ADAPT-treated CardioCel(R) patch

OBJECTIVES

This study evaluated the safety, efficacy and clinical performance of the tissue-engineered ADAPT® bovine pericardial patch (ABPP) in paediatric patients with a range of congenital cardiac anomalies.

METHODS

In this single-centre, prospective, non-randomized clinical study, paediatric patients underwent surgery for insertion of the ABPP. Primary efficacy measures included early (<30 day) morbidity; incidence of device-related complications; haemodynamic performance derived from echocardiography assessment at 6- and 12-month follow-up and magnetic resonance imaging findings in 10 randomly selected patients at 12 months. Secondary measures included device-handling characteristics; shape and sizing characteristics and perioperative implant complications. The Aristotle complexity scoring system was used to score the complexity level of all surgical procedures. Patients completing the 12-month study were eligible to enter a long-term evaluation study.

RESULTS

Between April 2008 and September 2009, the ABPP was used in 30 paediatric patients. In the 30-day postoperative period, no graft-related morbidity was observed. In total, there were 5 deaths (2 in the 30-day postoperative period and 3 within the first 6 postoperative months). All deaths were deemed due to comorbid non-graft-related events. Echocardiography assessment at 6 and 12 months revealed intact anatomical and haemodynamically stable repairs without any visible calcification of the patch. Magnetic resonance imaging assessment in 10 patients at 12 months revealed no signs of calcification. Fisher's exact test demonstrated that patients undergoing more complex, higher risk surgical repairs (Aristotle complexity score >8) were significantly more likely to die (P = 0.0055, 58% survival compared with 100% survival for less complex surgical repairs). In 19 patients, echocardiographic data were available at 18-36 months with no evidence of device calcification, infection, thromboembolic events or device failure.

CONCLUSIONS

This study demonstrates the safety and efficacy of this engineered bovine pericardial patch as a cardiovascular substitute for surgical repair of both simple and more complex congenital cardiac defects.

"V-PLASTY": a novel technique to reconstruct pulmonary valvular and annular stenosis in patients with right ventricular outflow tract obstruction

BACKGROUND

The goal of repair of right ventricular outflow tract obstruction with or without Tetralogy of Fallot (TOF) is to eliminate valvular and/or subvalvular obstruction. However, this operation has a high risk of late complication of pulmonary insufficiency. In this study, we aimed to present early period results of our new technique that we call "V-Plasty" developed to prevent pulmonary insufficiency after pulmonary valve reconstruction in selected patients.

METHODS

Between January 2006 and January 2010, we performed V-plasty for pulmonary valve reconstruction in 10 patients. Eight patients (5 males, 3 females) had TOF and 2 patients (1 male, 1 female) had atrial septal defect concomitant with pulmonary valve stenosis. Patient selection for V-plasty reconstruction was made due to the pulmonary valve anatomy and degree of stenosis. The mean follow-up time was 55.7 ± 16.2 months (ranging from 32 to 80 months).

RESULTS

Functional capacity of the patients improved immediately after the surgery. There were no mortality and re-operation in follow-up period. Patients were followed up with echocardiography one week after the operation, at 1st, 6th, 12th months and annually. There was no pulmonary insufficiency.

CONCLUSIONS

Operative correction of the pulmonary outflow tract obstruction with or without TOF, frequently requires transannular enlargement because of the infundibular and/or annular-valvular obstruction. This conventional technique is usually a reason for late pulmonary insufficiency. In our study, we have not seen pulmonary insufficiency in early term follow-up period. Our early term results are encouraging, but long term follow-up results are needed with large case series.

The Contegra conduit: Late outcomes in right ventricular outflow tract reconstruction

OBJECTIVES

To report the clinical outcomes (early death, late death, and rate of reintervention) and performance of the Contegra conduit as a right ventricle outflow tract implant and to determine the risk factors for early reintervention.

METHODS

Forty-nine Contegra conduits were implanted between January 2002 and June 2009. Data collection was retrospective. The mean age and follow-up duration of Contegra recipients was 3.5 ± 4.6 years and 4.2 ± 2.0 years, respectively.

RESULTS

There were three deaths (two early, one late), giving a survival rate of 93.9%. The rate of conduit-related reintervention was 19.6% and was most often due to distal conduit stenosis. Age at implantation of <3 months, receipt of a conduit of 12-16 mm diameter, and a diagnosis of truncus arteriosus were each significant contributors to the rate of reintervention.

CONCLUSION

The Contegra is a cost-effective and readily available solution. However, there is a limited range of larger calibers, which means that the homograft conduit (>22 mm) remains the first choice of implant in older children. The rates of reintervention are significantly higher with a diagnosis of truncus arteriosus, age at implantation of <3 months, and implantation of conduits sized 12-16 mm.

Long-term follow-up of persistent truncus arteriosus: Kuwait experience

OBJECTIVE

To evaluate the long-term results of patients in Kuwait who were operated for persistent truncus arteriosus (PTA).

SUBJECTS AND METHODS

The following data were collected for retrospective analysis from 24 medical records of consecutive patients with PTA in Kuwait between August 1993 and August 2009: demographics, morphology, management and outcome. Major associated abnormalities included interrupted aortic arch in 1 patient and abnormal coronary artery anatomy in 2.

RESULTS

Of the 24 patients, 16 underwent total intracardiac repair. The age at operation ranged from 15 days to 5 years (mean 166.19 ± 438.63 days) and weight ranged from 2.5 to 15 kg (mean 4.3 ± 3.01 kg). The right ventricle to pulmonary artery continuity was established with aortic homograft in 11, pulmonary homograft in 4 and by implantation of a Contegra conduit in 1 patient. Four patients had moderate truncal valve regurgitation requiring concomitant truncal valve repair. After a mean follow-up period of 81.81 ± 61.58 months (range 3-166) there was no death. Eight of the 16 (50%) patients underwent redo homograft operations. One patient who had concomitant truncal valve repair subsequently underwent aortic valve replacement.

CONCLUSION

The data showed that complete repair of PTA in the neonatal and early infancy period was the treatment with the best potential for survival. The homograft remained one of the conduits of choice to establish continuity between the right ventricle and the pulmonary artery in spite of the high incidence of conduit redo operations.