Fate of Right Ventricle to Pulmonary Artery Conduits After Complete Repair of Pulmonary Atresia and Major Aortopulmonary Collaterals

Anatomic Position and Durability of Polytetrafluoroethylene Conduit ≥18 mm: Single-Center Experience

BACKGROUND

Conduit longevity after right ventricular outflow tract (RVOT) reconstruction is determined by the interaction of different factors. We evaluated the relationship between conduit anatomic position and long-term durability among ≥18 mm polytetrafluoroethylene (PTFE) conduits.

METHODS

A single-institution RVOT reconstructions using a PTFE conduit ≥18 mm were identified. Catheter-based interventions or the need for conduit replacement were comparatively assessed between orthotopic vs heterotopic conduit position. Time to the first reintervention, censored by death, was compared between the groups.

RESULTS

A total of 102 conduits were implanted in 99 patients, with a median age of 13.2 years (interquartile range [IQR] 8.9-17.8 years), median weight of 47 kg (IQR, 29-67 kg), and body surface area of 1.4 m² (IQR, 1-1.7 m²). Overall, 50.9% (n = 52) of conduits were placed in an orthotopic position after the Ross procedure in congenital aortic valve abnormalities (80% [n = 36]). Tetrology of Fallot in 39% (n = 18), followed by truncus arteriosus with 33% (n = 15), were the most common in the heterotopic position. Trileaflet configuration was similar (67% vs 69%; P = .32) between the groups. Survival free from reintervention was 91% (95% CI, 79-97) and 88% (95% CI, 71-95) in the orthotopic and the heterotopic group, respectively, at 5 years, without differences in the Kaplan Meier curves (log-rank >.05).

CONCLUSIONS

RVOT reconstruction with PTFE conduits ≥ 8 mm showed >90% conduit survival free from replacement in our cohort at 5 years. The anatomic position of the PTFE conduit does not seem to impact intermediate durability.

Staged correction of pulmonary atresia, ventricular septal defect, and collateral arteries

Objectives

Pulmonary atresia (PA) with ventricular septal defect (VSD) and systemic‐pulmonary collateral arteries (SPCAs) presents with variable anatomy with regard to the pulmonary vasculature, requiring personalized surgical treatment. A protocol consisting of staged unifocalization and correction was employed.

Methods

Since 1989, 39 consecutive patients were included (median age at first operation 13 months). In selected cases, a central aorto‐pulmonary shunt was performed as the first procedure. Unifocalization procedures were performed through a lateral thoracotomy. Correction consisted of shunt takedown, VSD closure, and interposition of an allograft between the right ventricle and the reconstructed pulmonary artery. Echocardiographic data were obtained postoperatively and at interval follow‐up.

Results

In 39 patients 66 unifocalization procedures were performed. Early mortality was 5%. Seven patients were considered not suitable for correction, of which four have since died. One patient is awaiting further correction. A correction was performed successfully in 28 patients. Operative mortality was 3% and late mortality was 11%. Median follow‐up after the correction was 19 years. Eleven patients required homograft replacement. Freedom from conduit replacement was 88%, 73%, and 60% at 5, 10, and 15 years respectively. Right ventricular function was reasonable or good in 75% of patients. All but one patient were in NYHA Class I or II.

Conclusions

After complete unifocalization 30/37 patients (81%) were considered correctable. The staged approach of PA, VSD, and SPCAs results in adequate correction and good functional capacity. RV function after correction remains reasonable or good in the majority of patients.

Homograft durability after correction of pulmonary atresia and ventricular septal defect with or without systemic pulmonary collateral arteries

Background

Pulmonary atresia and ventricular septal defect (PA-VSD), with or without systemic pulmonary collateral arteries (SPCAs), represents a complex anatomic and surgical spectrum of congenital heart disease. Currently, there is limited evidence on homograft durability after complete correction, which potentially could be affected by anatomic differences in pulmonary vasculature.

Methods

This retrospective single-center study included all 69 consecutive PA-VSD patients (46 with SPCAs, 23 without SPCAs) operated on between 1978 and 2018. The primary interest was in homograft durability after complete repair. Longitudinal echocardiographic homograft function and right ventricular systolic pressure were analyzed with linear mixed-effects models.

Results

The median duration of follow-up was 20 years. Of the 46 patients with SPCAs, 37 (80.4%) underwent biventricular correction at a median age of 2.7 years (interquartile range [IQR], 1.8-6.3 years). Two patients are currently awaiting unifocalization and correction. All 23 patients without SPCAs underwent successful complete correction at a median age of 1.6 years (IQR, 1.1-3.6 years). Freedom from any reintervention after 20 years was 15%. When a homograft was used during correction, freedom from homograft replacement after 20 years was comparable in the 2 groups (P = .925), at 32 ± 11% in the SPCA group and 32 ± 13% in the non-SPCA group. Indications for homograft replacement were isolated stenosis (n = 7; 46.7%), isolated regurgitation (n = 3; 20.0%), and mixed stenosis and regurgitation (n = 5; 33.3%) in the SPCA group and isolated stenosis (n = 8; 88.9%) and stenosis and regurgitation (n = 1; 11.1%) in the non-SPCA group. Peak homograft gradient was significantly (P = .0003) higher in patients without SPCA, with a comparable rate of progression in the 2 groups. However, the prevalence of severe pulmonary regurgitation (PR) was higher in patients with SPCAs, estimated at 35% at 10 years, compared with 15% in patients without SPCAs.

Conclusions

Homografts used for right ventricular outflow tract reconstruction in patients with PA-VSD, either with or without SPCAs, have similar limited durability. Repeated reintervention is common, and careful follow-up with attention to severe PR is warranted.

Conduits for Right Ventricular Outflow Tract Reconstruction in Infants and Young Children

Purpose of Review: Right ventricular outflow tract (RVOT) reconstruction remains a challenge due to the lack of an ideal conduit. Data and experience are accumulating with each passing day. Therefore, it is necessary to review this topic from time to time. This is a 2021 update review focused on the history, evolution, and current situation of small-sized conduits (≤ 16 mm) for RVOT reconstruction in infants and young children.

Recent Findings: Currently, the available small-sized (≤16 mm) conduits can meet most clinical needs. Homograft is still a reliable choice for infants and young children validated by a half-century clinical experience. As an alternative material, bovine jugular vein conduit (BJVC) has at least comparable durability with that of homograft. The performance of expanded polytetrafluoroethylene (ePTFE) is amazing in RVOT position according to limited published data. The past century has witnessed much progress in the materials for RVOT reconstruction. However, lack of growth potential is the dilemma for small-sized conduits. Tissue-engineering based on cell-free scaffolds is the most promising technology to obtain the ideal conduit.

Summary: No conduit has proved to have lifelong durability in RVOT position. We are far from the ideal, but we are not in a state of emergency. In-depth clinical research as well as innovation in material science are needed to help improve the durability of the conduits used in infants and young children.

Time-related risk of pulmonary conduit re-replacement: a Congenital Heart Surgeons' Society Study

BACKGROUND

Patients receiving a right ventricle-to-pulmonary artery conduit in infancy will require successive procedures or replacements, each with variable longevity. We sought to identify factors associated with time-related risk of a subsequent surgical replacement (PC3) or transcatheter pulmonary valve insertion (TPVI) after a second surgically-placed PC (PC2).

METHODS

From 2002 to 2016, 630 patients from 29 Congenital Heart Surgeons' Society member institutions survived to discharge after initial valved PC insertion (PC1) at age < 2 years. Of those, 355 had undergone surgical replacement (PC2) of that initial conduit. Competing risk methodology and multiphase parametric hazard analyses were used to identify factors associated with time-related risk of PC3 or TPVI.

RESULTS

Of 355 PC2 patients (median follow-up of 5.3 years), 65 underwent PC3 and 41 TPVI. Factors at PC2 associated with increased time-related risk of PC3 were smaller PC2 Z score (Hazard Ratio [HR] 1.6, p<0.001), concomitant aortic valve intervention (HR 7.6, p=0.009), aortic allograft (HR 2.2, p=0.008), younger age (HR 1.4, p<0.001), and larger Z score of PC1 (HR 1.2, p=0.04). Factors at PC2 associated with increased time-related risk of TPVI were aortic allograft (HR: 3.3, p=0.006), porcine unstented conduit (HR 4.7, p<0.001), and older age (HR 2.3, p=0.01).

CONCLUSIONS

Aortic allograft as PC2 was associated with increased time-related risk of both PC3 and TPVI. Surgeons may reduce risk of these subsequent procedures by not selecting an aortic homograft at PC2, and by oversizing the conduit when anatomically feasible.

Single collateral artery from descending thoracic aorta supplying pulmonary circulation-Computed tomography and echocardiographic images

Pulmonary atresia (PA) with ventricular septal defect (VSD) is a rare congenital cardiac anomaly in which the pulmonary blood flow is supplied by major aorta pulmonary collateral arteries (MAPCAs). The complete repair includes unifocalization of MAPCAs, closure of VSD, and placement of a right ventricle-to-pulmonary artery conduit. We report a case of VSD with PA, where the computed tomography and echocardiography images described a large single collateral artery arising from descending thoracic aorta dividing into left and right branches and supplying the entire pulmonary circulation.

Current era outcomes of pulmonary atresia with ventricular septal defect: A single center cohort in Thailand

Pulmonary atresia with ventricular septal defect (PA/VSD) is a complex cyanotic congenital heart disease with a wide-range of presentations and treatment strategies, depending on the source of pulmonary circulation, anatomy of pulmonary arteries (PAs), and major aortopulmonary collateral arteries (MAPCAs). Data about the outcomes in developing countries is scarce. We therefore conducted a retrospective study to assess survival rates and mortality risks of 90 children with PA/VSD at Siriraj Hospital, Thailand during 2005-2016. Patients with single ventricle were excluded. Survival and mortality risks were analyzed at the end of 2018. The median age of diagnosis was 0.5 (0-13.8) years. The patients' PAs were categorized into four groups: 1) PA/VSD with confluent PAs (n = 40), 2) PA/VSD with confluent PAs and MAPCAs (n = 21), 3) PA/VSD with non-confluent PAs and MAPCAs (n = 12), and 4) PA/VSD with small native PAs and MAPCAs (n = 17). Of the 88 patients who underwent operations, 32 patients had complete repair at 8.4 ± 4.6 years old. During the follow-up [median time of 5.7 years (7 days-13.6 years)], 17 patients (18.9%) died. The survival rates at 1, 5, and 10 years of age were 95%, 83.7%, and 79.6%, respectively. Significant mortality risks were the presence of associated anomalies and non-confluent PAs.

Midline one-stage complete unifocalization early outcomes from a single center

OBJECTIVE

This study aims to present our experience with single-stage complete unifocalization and intraoperative flow study for the repair of ventricular septal defect, pulmonary atresia, and major aortopulmonary collateral arteries.

METHODS

This study was conducted through retrospective chart review of all the patients who underwent complete single-stage midline unifocalization in a single tertiary-care institution.

RESULTS

Twenty-two patients underwent midline single-stage unifocalization. The median age was 11 months (IQR: 5-21 months). The number of collateral arteries unifocalized was between one and three (median two). In-hospital mortality was 5%. Follow-up was complete; and the median follow-up regarding survival was 20 months (IQR: 10-28 months). There were three late deaths, and the estimated survival rate was 80% at 10 months and on. Out of 22 patients, ventricular septal defect was closed in the first surgery in three patients (14%) and the second surgery in four patients (19%). Total seven patients underwent surgical total repair (32%). Additionally, one out of four patients whose ventricular septal defects were closed with a fenestrated patch is under follow-up with a small ventricular septal defect, while two are waiting for ventricular septal defect closure. Therefore, total eight patients (36%) have reached total correction.

CONCLUSION

Single-stage unifocalization is a feasible treatment option in ventricular septal defect, pulmonary atresia, and major aortopulmonary collateral arteries. This cohort had unfavorable results regarding the rate of complete repair. The pitfalls encountered were related to problems with meticulous surgical technique, complete unifocalization, and correct implementation of the flow study.

An Overview of Pulmonary Atresia and Major Aortopulmonary Collateral Arteries

Pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA/VSD/MAPCAs) is a rare and complex congenital cardiac lesion that has historically carried a poor prognosis. With advancements in surgical management, we have seen an improvement in the outcomes for children affected by this disease. However, this population continues to present challenges due to the complex anatomy and physiology associated with PA/VSD/MAPCA. This summary of material presented during one of the nursing sessions of the 2014 Meeting of the Pediatric Cardiac Intensive Care Society provides an overview for those in cardiac intensive care units who do not have a large experience with this lesion. We will review the anatomy, physiology, surgical approach, postoperative management strategies, and cardiac catheter intervention options for PA/VSD/MAPCAs. We will also discuss recent innovations that may lead to continued improvement in outcomes for this challenging patient population.

Pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals: single-stage complete unifocalization

Pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals (MAPCAs) is a complex lesion. Since the concept of primary one-stage unifocalization evolved in the 1990s, the results of surgical treatment have improved significantly. From the midline approach, most of MAPCAs are dissected in the posterior mediastinal space between the ascending aorta and the superior vena cava. Extensive dissection maximizes the length of each MAPCA, which makes direct anastomosis of native tissue feasible without use of prosthetic materials. Pulmonary blood supply is established by a systemic-pulmonary shunt. The procedure was performed in 13 patients with 7.7% of hospital mortality. There was 1 late death because of infection in a patient with deletion of chromosome 22q11.2. Nine patients underwent intracardiac repair without mortality. The ratio of right ventricular systolic pressure to the systemic pressure after intracardiac repair did not exceed 0.5, except for 1 patient. Although further follow-up is necessary, midline one-stage unifocalization is considered as the standard procedure for this lesion.