Contemporary Patterns of Management of Tetralogy of Fallot: Data From The Society of Thoracic Surgeons Database

Hemodynamic evaluation of biomaterial-based surgery for Tetralogy of Fallot using a biorobotic heart, in silico, and ovine models

Tetralogy of Fallot is a congenital heart disease affecting newborns and involves stenosis of the right ventricular outflow tract (RVOT). Surgical correction often widens the RVOT with a transannular enlargement patch, but this causes issues including pulmonary valve insufficiency and progressive right ventricle failure. A monocusp valve can prevent pulmonary regurgitation; however, valve failure resulting from factors including leaflet design, morphology, and immune response can occur, ultimately resulting in pulmonary insufficiency. A multimodal platform to quantitatively evaluate the effect of shape, size, and material on clinical outcomes could optimize monocusp design. This study introduces a benchtop soft biorobotic heart model, a computational fluid model of the RVOT, and a monocusp valve made from an entirely biological cell-assembled extracellular matrix (CAM) to tackle the multifaceted issue of monocusp failure. The hydrodynamic and mechanical performance of RVOT repair strategies was assessed in biorobotic and computational platforms. The monocusp valve design was validated in vivo in ovine models through echocardiography, cardiac magnetic resonance, and catheterization. These models supported assessment of surgical feasibility, handling, suturability, and hemodynamic and mechanical monocusp capabilities. The CAM-based monocusp offered a competent pulmonary valve with regurgitation of 4.6 ± 0.9% and a transvalvular pressure gradient of 4.3 ± 1.4 millimeters of mercury after 7 days of implantation in sheep. The biorobotic heart model, in silico analysis, and in vivo RVOT modeling allowed iteration in monocusp design not now feasible in a clinical environment and will support future surgical testing of biomaterials for complex congenital heart malformations.

Comparison of Right Ventricular Outflow Tract Reconstruction Techniques on Mid-Term Pulmonic Valve Fate

Introduction: The pulmonic valve-sparing technique (PVS) is an emerging approach of right ventricular outflow tract reconstruction in tetralogy of Fallot (TOF) correction aimed at reducing the incidence of pulmonic regurgitation (PR) and the need for subsequent reintervention. This study aims to compare the long-term occurrence of moderate to severe PR/stenosis (PR/PS) between three different approaches. Patients and Methods: We conducted a retrospective cohort study involving 173 patients who underwent TOF correction at Chiang Mai University hospital between January 2006 and December 2016. The patients were divided into three groups: transannular patch (TAP; n = 88, 50.9%), monocusp insertion (MCI; n = 40, 23.1%), and PVS (n = 45, 26%). The study assessed freedom from moderate to severe PR/PS. Results: The median overall follow-up time was 79.8 months (interquartile range: 50.7-115.5 months. The PVS exhibited larger PV Z-score (-2.6 ± 2.3 mm, P < .001), with predominantly tricuspid morphology (64.4%). The PVS had significantly shorter median ventilator time, intensive care unit stay, hospital stay, and longer median follow-up time. Postoperative moderate-severe PR was lower in the PVS group (P < .001), with no significant difference in PS (P = .356) and complications among the groups. Freedom from moderate-severe PR/PS was longer in the MCI group (2.8, 0.2-42.3 months vs 30.9, 0.2-50.9 months, respectively). Multivariable analysis showed TAP and MCI had a higher risk of developing moderate-severe PR (hazard ratio [HR] 2.51; 95% confidence interval [CI] 1.23-5.13 vs HR 1.41; 95%CI 0.59-3.38) but lower risk of moderate-severe PS (HR 0.14; 95%CI 0.02-0.9 vs HR 0.39; 95%CI 0.05-3.19). Conclusion: Pulmonic valve-sparing reconstruction showed promise in preventing late moderate-severe PR in patients with favorable PV anatomy. However, it should be noted that this technique is associated with a higher incidence of PS.

Primary surgical repair of tetralogy of fallot at the Uganda Heart Institute: a ten-year review of 30day mortality and morbidity

BACKGROUND

Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease (CHD) worldwide. It accounts for 7% of CHD cases in Uganda and leads to fatal outcomes in the long term without surgery. Surgery is often delayed in developing countries like Uganda due to limited resources.

OBJECTIVE

This study aimed to determine the early surgical outcomes of patients with TOF who underwent primary intracardiac repair at the Uganda Heart Institute (UHI) and to identify factors associated.

METHODOLOGY

This retrospective chart review evaluated outcomes of primary TOF repair patients at UHI from February 2012 to October 2022. Patient outcomes were assessed from surgery until 30 days post-operation.

RESULTS

Out of the 104 patients who underwent primary TOF repair at UHI, records of 88 patients (84.6%) were available for review. Males accounted for 48.9% (n = 43). The median age at the time of operation was 4 years (with an interquartile range of 2.5-8.0 years), ranging from 9 months to 16 years. Genetic syndromes were present in 5/88 (5.7%). These included 2 patients with trisomy 21, 2 with Noonan's, and 1 with 22q11.2 deletion syndrome. Early postoperative outcomes for patients included: residual ventricular septal defects in 35/88 (39.8%), right ventricular dysfunction in 33/88 (37.5%), residual pulmonary regurgitation in 27/88 (30.7%), residual right ventricular outflow tract obstruction in 27/88 (30.0%), pleural effusion in 24/88 (27.3%), arrhythmias in 24/88(27.3%), post-operative infections in 23/88(26.1%) and left ventricular systolic dysfunction in 9/88 (10.2%). Out of the children who underwent surgery after one year of age, 8% (7 children) died within the first 30 days. There was a correlation between mortality and post-operative ventilation time, cardiopulmonary bypass (CPB) time, aortic cross-clamp time, preoperative oxygen saturations, RV and LV dysfunction and the operating team.

CONCLUSION

The most frequent outcomes after surgery were residual ventricular septal defects and right ventricular failure. In our study, the 30-day mortality rate following TOF repair was 8%. Deceased patients had lower pre-operative oxygen levels, longer CPB and cross-clamp times, longer post-operative ventilation, RV/LV dysfunction, and were more likely operated by the local team.

Effectiveness of pulmonary valve-sparing strategy for transatrial-transpulmonary repair of tetralogy of Fallot: a single institution experience

OBJECTIVE

We report the midterm results of our strategy utilizing transatrial-transpulmonary repair for tetralogy of Fallot at a single institution in a low-middle income country.

METHODS

Medical records were retrospectively reviewed for 532 consecutive patients who underwent definitive repair of tetralogy of Fallot at our institution from 2010 to 2020.

RESULTS

The median age and weight of patients in the study patients were 11.6 months (interquartile range, 8.6-17.2 months) and 7.5 kg (interquartile range, 6.8-8.8 kg). The pulmonary valve annulus was preserved (no transannular patch) in 398 patients (75%) and a mini-transannular patch was utilized for 134 patients (25%). The overall survival was 98% at 1 year, and 97% at 10-years follow-up, respectively. Longer postoperative ventilation time was the only risk factor correlated to early death (p = 0.004; Odds Risk, 1.04; 95% confidence intervals, 1.01-1.07). Fourteen patients required pulmonary valve replacement (2.6%, 14/532), four required surgical resection to relieve right ventricular outflow tract obstruction (0.8%, 4/532), and freedom from reoperation of the right ventricular outflow tract was 87% at 10 years. The only risk factor for right ventricular outflow tract reoperation was a postoperative systolic pressure gradient through the right ventricular outflow tract of greater than 50 mmHg (p < 0.001; HR, 47; 95% confidence intervals, 9.1-244). In total, 94.6% (471/489) of the patients were asymptomatic at the latest follow-up without significant arrhythmia.

CONCLUSION

At our institution in an low-middle income country, the transatrial-transpulmonary repair for tetralogy of Fallot has excellent midterm results with few reoperations required. Close long-term follow-up is essential for patients who undergo repair with a mini-transannular patch and may eventually require pulmonary valve replacement.

Bilateral remote ischemic conditioning in children: A two-center, double-blind, randomized controlled trial in young children undergoing cardiac surgery

Objective

The study objective was to determine whether adequately delivered bilateral remote ischemic preconditioning is cardioprotective in young children undergoing surgery for 2 common congenital heart defects with or without cyanosis.

Methods

We performed a prospective, double-blind, randomized controlled trial at 2 centers in the United Kingdom. Children aged 3 to 36 months undergoing tetralogy of Fallot repair or ventricular septal defect closure were randomized 1:1 to receive bilateral preconditioning or sham intervention. Participants were followed up until hospital discharge or 30 days. The primary outcome was area under the curve for high-sensitivity troponin-T in the first 24 hours after surgery, analyzed by intention-to-treat. Right atrial biopsies were obtained in selected participants.

Results

Between October 2016 and December 2020, 120 eligible children were randomized to receive bilateral preconditioning (n = 60) or sham intervention (n = 60). The primary outcome, area under the curve for high-sensitivity troponin-T, was higher in the preconditioning group (mean: 70.0 ± 50.9 μg/L/h, n = 56) than in controls (mean: 55.6 ± 30.1 μg/L/h, n = 58) (mean difference, 13.2 μg/L/h; 95% CI, 0.5-25.8; P = .04). Subgroup analyses did not show a differential treatment effect by oxygen saturations (pinteraction = .25), but there was evidence of a differential effect by underlying defect (pinteraction = .04). Secondary outcomes and myocardial metabolism, quantified in atrial biopsies, were not different between randomized groups.

Conclusions

Bilateral remote ischemic preconditioning does not attenuate myocardial injury in children undergoing surgical repair for congenital heart defects, and there was evidence of potential harm in unstented tetralogy of Fallot. The routine use of remote ischemic preconditioning cannot be recommended for myocardial protection during pediatric cardiac surgery.

Tetralogy of Fallot in Low- and Middle-Income Countries

Low- and middle-incomes countries (LMICs) have limited resources for the diagnosis and treatment of congenital heart diseases such as tetralogy of Fallot. This is in part due to lack of infrastructures, financial means, and expertise. As a result, patients undergo surgery much later than in high-income countries. This delay in treatment results in right ventricular dysfunction, cardiac arrhythmias, and poor psychomotor development-complications that are all related to chronic hypoxia. There are limited data and a few small studies of patients treated for tetralogy of Fallot in LMICs, and, therefore, the aim of this review is to analyse and summarize the surgical outcomes of this LMIC population.

Adult Congenital Heart Disease in the Emergency Department

While congenital heart disease historically was a pathology primarily restricted to specialized pediatric centers, advances in technology have dramatically increased the number of people living into adulthood, the number of complications faced by these patients, and the number of patients visiting non-specialized emergency departments for these concerns. Clinicians need to be aware of the issues specific to patients' individual congenital defects but also have an understanding of how typical cardiac pathology may manifest in this special group of patients. This manuscript attempts to provide an overview of this diverse but increasingly common group of adult patients with congenital heart diseases, including a review of their anatomical variants, the complications they face at the highest rates, and ways that emergency physicians may need to manage these patients differently to avoid causing harm.

Optimal Surgical Management of Tetralogy of Fallot

Tetralogy of Fallot with pulmonary stenosis has a diverse clinical spectrum with the degree of right ventricular outflow tract obstruction (RVOTO) and size of the branch pulmonary arteries driving clinical management. Optimal surgical management involves consideration of patient clinical status and degree and location (subvalvar, valvar, and supravalvar) of RVOTO. Timing of repair requires multidisciplinary decision-making and complete surgical repair with relief of RVOTO by either transannular patch or valve sparing repair techniques. The central goals of contemporary surgical management of tetralogy of Fallot incorporate maximizing survival, minimizing reintervention, and preserving right ventricular function across the lifespan.

Considerations in Timing of Surgical Repair in Tetralogy of Fallot

Certain aspects of the treatment of tetralogy of Fallot (TOF) repair remain controversial. The optimal timing of the elective repair of asymptomatic patients and the ideal strategy for managing symptomatic neonates and infants with TOF are still debated despite years of experience in TOF treatment. In this article, we discuss why a surgical correction at 3-6 months of age is likely the ideal time frame for the elective repair of TOF. We also elaborate on our strategy for managing symptomatic neonates and infants with TOF and why we prefer an early single-stage primary repair.

A uniform strategy of primary repair of tetralogy of Fallot: Transventricular approach results in low reoperation rate in the first decade

OBJECTIVES

To review outcomes after a uniform strategy of transventricular repair of tetralogy of Fallot.

METHODS

A total of 244 consecutive patients underwent transventricular primary repair of tetralogy of Fallot from 2004 to 2019. Median age at operation was 71 days; 57 (23%) patients were premature; 57 (23%) patients had low birth weight (<2.5 kg), and 40 (16%) had genetic syndromes. The diameter of pulmonary valve annulus, right pulmonary artery (PA), and left PA were 6.0 ± 1.8 mm (z score, -1.7 ± 1.3), 4.3 ± 1.4 mm (z score, -0.9 ± 1.2) and 4.1 ± 1.5 mm (z score, -0.5 ± 1.3).

RESULTS

Three (1.2%) operative deaths were recorded. Ninety patients (37%) underwent transannular patching. Postoperative echocardiographic peak right ventricular outflow tract gradient decreased from 72 ± 27 mm Hg to 21 ± 16 mm Hg. Median intensive care unit and hospital stay were 3 and 7 days. The survival rate at 10 years was 94.6% ± 1.8%. Reintervention was required 86 times (55 catheter interventions) in 56 patients following tetralogy of Fallot repair. The freedom from all-cause reintervention rate at 10 years was 70.5% ± 3.6%. Cyanotic spells (hazard ratio, 2.14; 95% CI, 1.22-3.90; P < .01) and smaller pulmonary valve annulus z score (hazard ratio, 1.26; 95% CI, 1.01-1.59; P = .04) were associated with increasing risk of all reinterventions. Freedom from redo surgery for right ventricular outflow tract obstruction and right ventricular dilatation at 10 years were, respectively, 85.0% ± 3.1% and 98.7% ± 0.9%. Freedom from valve implantation was 96.7% ± 1.5% at 10 years.

CONCLUSIONS

A uniform strategy of primary repair of tetralogy of Fallot through a transventricular approach resulted in low reoperation rate in the first decade. The need of pulmonary valve implantation was limited to <4% at 10 years.

Pulmonary Annulus Growth Pattern in Patients with Tetralogy of Fallot Prior to Surgical Repair

Objectives

The size of the pulmonary valve annulus often determines the feasibility of pulmonary valve preservation at the time of intracardiac repair of Tetralogy of Fallot. Currently, there is limited available data regarding the growth pattern and the determining factors that contribute towards pulmonary valve annulus growth.

Methods

This retrospective study included patients who underwent surgical repair of Tetralogy of Fallot with or without prior palliation. These patients had an echocardiogram at the time of initial diagnosis and a second echocardiogram prior to intracardiac repair. The sizes of the pulmonary annulus, the right and left pulmonary arteries with z-scores were recorded. Patients with improvement in the pulmonary annulus z-scores between the 2 echocardiographic examinations were allocated in Group I (n = 46) and Group II (n = 68) were those with no improvement.

Results

A total of 114 patients were included in the study. The right and left pulmonary arteries size and z scores improved significantly between the 2 echocardiograms. Although the median size of the pulmonary annulus increased between the 2 echocardiograms (6 and 7.9 mm; P<0.001), there was no significant change in the z-score (-2.2, -2.34; P = 0.185). Multivariate logistic regression analysis showed that gender, blood group, presence of collaterals, and palliation with Blalock-Taussig shunt had no impact on the improvement in pulmonary annulus z-score.

Conclusion

In Tetralogy of Fallot, the pulmonary valve annulus z-score may not change significantly prior to the intracardiac repair. Although in certain subgroups there may be an improvement, there was no specific factor that could be identified and had an influence on this improvement.

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.

Contemporary Patterns of Care in Tetralogy of Fallot: Analysis of The Society of Thoracic Surgeons Data

BACKGROUND

Against the background of earlier studies, recent patterns in surgical management of tetralogy of Fallot (TOF) were assessed.

METHODS

A retrospective review of The Society of Thoracic Surgeons (STS) Congenital Database (2010-2020) was performed on patients aged <18 years with TOF or pulmonary stenosis and primary procedure TOF surgical repair or palliation. Procedural frequencies were examined by epoch. Demographics, clinical variables, and outcomes were compared between the initial palliation and primary repair groups. Among those operated on at 0 to 60 days of age, variation in palliation rates across hospitals was assessed.

RESULTS

The 12,157 operations included 11,307 repairs (93.0%) and 850 palliations (7.0%); 68.5% of all palliations were modified Blalock-Taussig-Thomas shunts. Of 1105 operations on neonates, 45.4% (502) were palliations. Among neonates, palliations declined from 49.0% (331 of 675) in epoch 1 (2010-2015) to 39.8% (171 of 430) in epoch 2 (2016-2020; P = .0026). Overall, the most prevalent repair technique (5196 of 11,307; 46.0%) was ventriculotomy with transanular patch, which was also used in 520 of 894 (58.2%) of repairs after previous cardiac operations. Patients undergoing initial palliation demonstrated more preoperative STS risk factors (50.1% vs 24.3% respectively; P < .0001) and more major morbidity and mortality than patients undergoing primary repair (21.2% vs 7.46%; P < .0001). In the 0- to 60-day age group, risk factor-adjusted palliation rates across centers varied considerably, with 32 of 99 centers performing significantly more or significantly fewer palliations than predicted on the basis of their case mix.

CONCLUSIONS

Surgical palliation rates have decreased across all age groups despite increasing prevalence of risk factors. Ventriculotomy with transanular patch remains the most prevalent repair type. The considerable center-level variation in rates of palliation was not completely explained by case mix.

Outcomes of Transannular Repair of Tetralogy of Fallot With a Contegra® Monocuspid Patch

BACKGROUND

Surgical repair of tetralogy of Fallot (ToF) depends on the anatomical variations of the heart defect. A group of patients with a hypoplastic pulmonary valve annulus required a transannular patch. This study aimed to evaluate the early and late outcomes of ToF repair with a transannular Contegra® monocuspid patch in a single center.

METHODS

A retrospective review of medical records was conducted. This study included 224 children with a median age of 13 months who underwent ToF repair with a Contegra® transannular patch in over 20 years of observation. The primary outcomes were hospital mortality and need for early reoperations. The secondary outcomes were late death and event-free survival.

RESULTS

The hospital mortality in our group was 3.1%, whereas two patients required early reoperation. Three patients were excluded from the study because follow-up data were not available. In the remaining group of patients (212 patients), the median follow-up was 116 (range, 1-206) months. One patient died because of sudden cardiac arrest at home six months after surgery. Event-free survival was observed in 181 patients (85.4%), whereas the remaining 30 patients (14.1%) required graft replacement. The median time to reoperation was 99 (range, 4-183) months.

CONCLUSIONS

Although surgical treatment of ToF has been performed for more than 60 years worldwide, the optimal approach in children with a hypoplastic pulmonary valve annulus remains debatable. Among options, the Contegra® monocuspid patch can be effectively used in transannular repair of ToF with good long-term results.

Grafts and Patches: Optimized but Not Optimal Materials for Congenital Heart Surgery

A variety of materials are available for the surgery of children with congenital heart defects. In addition to growth-related mismatch, degeneration of the material in particular frequently leads to reoperation. Therefore, the choice of conduits and patches should be made carefully. This article provides an overview of the most commonly implanted materials in pediatric cardiac surgery.Structural changes can be detected in all available materials. Depending on the age at implantation and the site of implantation, the extent and time course of material degeneration vary. Autologous material is still the gold standard in reconstructive surgery. Biological materials have largely replaced artificial materials in clinical use.The search for the ideal material continues. In pediatric cardiac surgery, there are only optimized but no optimal materials.

Right Ventricular Strain in Patients With Ductal-Dependent Tetralogy of Fallot

BACKGROUND

Right ventricular (RV) dysfunction is an independent predictor of poor outcomes in patients with tetralogy of Fallot (TOF), and global longitudinal strain (GLS) is a well-validated echocardiographic technique to measure RV function. Although trends in RV GLS have been examined in patients with TOF, they have not been studied specifically in those with ductal-dependent TOF, a group in which there is not a clear consensus on the best surgical strategy. The aim of this study was to assess the midterm trajectory of RV GLS in patients with ductal-dependent TOF, drivers of this trajectory, and differences in RV GLS between repair strategies.

METHODS

This was a retrospective two-center cohort study of patients with ductal-dependent TOF who underwent repair. Ductal dependence was defined as being initiated on prostaglandin therapy and/or undergoing surgical intervention on or before 30 days of life. RV GLS was measured on echocardiography preoperatively, early after complete repair, and at 1 and 2 years of age. RV GLS was trended over time and compared between surgical strategies and with control subjects. Mixed-effects linear regression models were used to evaluate the factors associated with changes in RV GLS over time.

RESULTS

Forty-four patients with ductal-dependent TOF were included in the study, of whom 33 (75%) underwent primary complete repair and 11 (25%) underwent staged repair. Complete TOF repair was performed at a median of 7 days in the primary-repair group and 178 days in the staged-repair group. RV GLS improved over time from post-complete repair echocardiography through 2 years of age (-17.4% [interquartile range, -15.5% to -18.9%] vs -21.5% [interquartile range, -18.0% to -23.3%], P < .001). However, compared with age-matched control subjects, patients had worse RV GLS at all time points. There was no difference in RV GLS between the staged and primary complete repair groups at 2-year follow-up. Shorter intensive care unit length of stay after complete repair was independently associated with improvement in RV GLS over time. Strain improved by 0.07% (95% CI, 0.01 to 0.12) for each fewer day in the intensive care unit (P = .03).

CONCLUSIONS

RV GLS improves over time among patients with ductal-dependent TOF, though it is consistently reduced compared with control subjects, suggesting an altered deformation pattern in patients with ductal-dependent TOF. There was no difference in RV GLS between the primary- and staged-repair groups at midterm follow-up, suggesting that repair strategy is not a risk factor for worse RV strain in the mid postoperative period. A shorter complete-repair intensive care unit length of stay is associated with an improved trajectory of RV GLS.

Right Ventricular Outflow Tract Stenting is a Safe and Effective Bridge to Definitive Repair in Symptomatic Infants With Tetralogy of Fallot1

INTRODUCTION

Right ventricular outflow tract (RVOT) stent angioplasty is a palliative procedure for neonates and infants with symptomatic tetralogy of Fallot prior to surgical repair. We review our institutional outcomes of RVOT stenting.

METHODS

Retrospective review of all infants with tetralogy of Fallot under 3 months of age who underwent primary native RVOT stent angioplasty at The Children's Hospital at Westmead, Sydney, Australia between January 2010 and December 2020. Demographics and echocardiographic pulmonary artery dimensions were collected pre-stent angioplasty and prior to surgical repair.

RESULTS

Twenty (20) infants underwent primary RVOT stenting. Median age at stent was 14 days (interquartile range [IQR] 7-32) and median weight 2.7 kg (IQR 2.1-3.4). Three patients underwent hybrid per-ventricular procedures. Indication for RVOT stenting was recurrent hyper-cyanotic spells in 12 (60%) and duct-dependent pulmonary blood flow in 8 (40%). Saturations increased from a median of 80% (IQR 75-85) to 91% (IQR 90-95) post procedure (P<0.001). A single major complication occurred: transient complete atrioventricular dissociation requiring isoprenaline infusion for <24 hours. Twelve (12, 60%) required catheter re-intervention prior to definitive repair for further augmentation of pulmonary blood flow. There were two non-cardiac deaths distant from the stent procedure, but prior to surgical repair. Median right and left pulmonary artery Z-scores increased respectively from -2.06 (IQR -2.99 to -0.17) and -1.2 (IQR -2.59 to -0.14) prior to RVOT stent, to -0.74 (IQR [-1.21 to 0.26], P=0.01) and 0.06 (IQR [-1.87 to 1.15], P=0.006) by the time of definitive repair. Eighteen (18) patients achieved definitive repair at a median age of 6.1 months (IQR 4.7-7.3). Palliation with more than one RVOT stent was associated with an increased duration of cardiac bypass (P=0.035) and cross-clamp (P=0.044) time at definitive repair.

CONCLUSIONS

In symptomatic neonates and infants with tetralogy of Fallot at high-risk of peri-operative complications, RVOT stent angioplasty can safely and effectively augment pulmonary blood flow prior to definitive repair.

Right-sided weakness in a Rwandan patient with untreated Tetralogy of Fallot

BACKGROUND

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease encountered in pediatrics with surgical repair being the definitive treatment. Long-term survival after surgical repair has improved; however, reported mortality rates in untreated TOF are significant. Associated complications include neurological sequelae such as brain abscess and stroke. In countries without early intervention for congenital heart disease (including TOF), delayed presentations and complications require recognition by healthcare workers.

CASE PRESENTATION

A 22-year-old male with a history of untreated TOF presented to Rwanda's tertiary university hospital, University Teaching Hospital of Kigali, with acute right-sided hemiparesis. Diagnostic imaging identified a left-sided brain lesion consistent with brain abscess and cardiac mass, concerning endocardial vegetation. He was managed with intravenous antibiotics but subsequently died due to complications of septicemia.

DISCUSSION

In countries where surgical repair of TOF is not available, early recognition and medical management are key in temporizing the development of devastating sequelae. Describing the prevalence of CHD in Rwanda is urgent, requiring further research by which effective prevention and treatment strategies can be developed.

Staged vs Complete Repair in Tetralogy of Fallot With Pulmonary Atresia

BACKGROUND

We sought to compare outcomes for infants with tetralogy of Fallot with pulmonary atresia (TOF/PA) and confluent pulmonary arteries who underwent staged or primary complete surgical repair.

METHODS

This retrospective study included infants undergoing initial surgical intervention between 0 and 60 days of age with TOF/PA without aortopulmonary collaterals from 2009 to 2018 at 20 centers. The primary outcome was days alive and out of the hospital in the first year of life (DAOH365). Secondary outcomes were mortality at 1 year of age and a composite major complication outcome. Multivariable modeling with generalized estimating equations were used to compare outcomes between groups.

RESULTS

Of 221 subjects, 142 underwent staged repair and 79 underwent primary complete repair. There was no significant difference in median DAOH365 between the staged and primary repair groups (317 days [interquartile range, 278-336] vs 338 days [interquartile range, 314-348], respectively; adjusted P = .13). Nine staged repair patients (7%) died in the first year of life vs 5 primary repair patients (6%; adjusted odds ratio, 1.00; 95% CI, 0.25-3.95). At least 1 major complication occurred in 37% of patients who underwent staged repair vs 41% of patients who underwent primary complete repair (P = .75), largely driven by the need for unplanned cardiac reinterventions.

CONCLUSIONS

For infants with TOF/PA with confluent pulmonary arteries, a surgical strategy of staged or primary complete repair resulted in statistically similar DAOH365, early mortality, and morbidity.

Evolution of Pulmonary Valve Management During Repair of Tetralogy of Fallot: A 14-year Experience

BACKGROUND

The optimal repair strategy for tetralogy of Fallot remains controversial. This report presents a 14-year evolution of management of the pulmonary valve (PV) from transannular patch to valve-sparing repair to neovalve creation using living right atrial appendage tissue.

METHODS

A retrospective review of 172 consecutive patients undergoing complete repair for TOF between January 2007 and June 2021 was performed. Clinical and follow-up data were analyzed by repair group. Neopulmonary valve (NPV) creation using right atrial appendage tissue was introduced in 2019. Failure of valve-sparing repair was defined as needing reintervention for recurrent right ventricular outflow tract obstruction (RVOTO).

RESULTS

Median age and weight at repair were 4.9 months and 6 kg, respectively. Median preoperative PV size and z-score were 6.4 mm (5.2-8.3 mm) and -3.2 (-4.1 to -2.1), respectively. Patients who underwent valve-sparing repair had larger PV size and z-score compared with patients who underwent transannular patch procedures (8 mm vs 5.6 mm; -2.1 vs -3.2; both P < .001). There were no hospital mortalities. Overall follow-up was 44 months. At last follow-up, 10% of patients who underwent valve-sparing repair had repeat intervention for recurrent RVOTO. Patients who had failed valve-sparing repair had significantly lower PV z-scores (-2.6 vs -1.9; P = .01). An NPV was used in 8 patients with a median PV z-score of -4 (-4.7 to -3.9). At 6 months, 6 patients (75%) had mild or trivial pulmonary insufficiency after NPV placement.

CONCLUSIONS

Repair of tetralogy of Fallot is a safe operation with excellent outcomes. Valve-sparing repair avoids right ventricular dilation but may fail for RVOTO at a PV z-score <-2. NPV creation offers an alternative option in patients with a small PV.

An In Vitro Circulatory Loop Model of the Pediatric Right Ventricular Outflow Tract as a Platform for Valve Evaluation

PURPOSE

Tetralogy of Fallot and other conditions affecting the right ventricular outflow tract (RVOT) are common in pediatric patients, but there is a lack of quantitative comparison among techniques for repairing or replacing the pulmonary valve. The aim of this study was to develop a robust in vitro system for quantifying flow conditions after various RVOT interventions.

METHODS

An infant-sized mock circulatory loop that includes a 3D-printed RVOT anatomical model was developed to evaluate flow conditions after different simulated surgical repairs. Physiologically correct flow and pressure were achieved with custom compliant tubing and a tunable flow restrictor. Pressure gradient, flow regurgitation, and coaptation height were measured for two monocusp leaflet designs after tuning the system with a 12 mm Hancock valved conduit.

RESULTS

Measurements were repeatable across multiple samples of two different monocusp designs, with the wider leaflet in the 50% backwall model consistently exhibiting lower pressure gradient but higher regurgitation compared to the leaflet in the 40% backwall model. Coaptation height was measured via direct visualization with endoscopic cameras, revealing a shorter area of contact for the wider leaflet (3.3-4.0 mm) compared to the narrower one (4.3 mm).

CONCLUSION

The 3D-printed RVOT anatomical model and in vitro pulmonary circulatory loop developed in this work provide a platform for planning and evaluating surgical interventions in the pediatric population. Measurements of regurgitation, pressure gradient, and coaptation provide a quantitative basis for comparison among different valve designs and positions.

Long-Term Results after Fallot Repair

BACKGROUND

 The aim of this study was to evaluate the long-term outcome and freedom from pulmonary valve replacement (PVR) after initial repair of tetralogy of Fallot (TOF).

PATIENTS AND METHODS

 The cohort of 306 patients treated between 1980 and 2017 was divided into anatomical subgroups according to the diagnosis of TOF-pulmonary stenosis, TOF-pulmonary atresia and TOF-double outlet right ventricle. Patients were treated with transannular patch (TAP), valve sparing repair (VSR), or conduits from the right ventricle to the pulmonary arteries (RVPA conduits).

RESULTS

 There were 21 deaths (6.9%), 14 being hospital deaths (4.6%) after primary correction and four deaths (1.3%) occurred after PVR. One patient died after a non-cardiac operation (0.3%). There were two late deaths (0.7%). During the past 12 years no early mortality has been observed. Ninety-one patients (30.4%) received PVR after a median of 12.1 ± 7.0 years with an early mortality of 4.4% (n = 4) and no late mortality. A significant difference in freedom from reoperation after TAP, VSR, and RVPA-conduits could be identified. Multivariate analysis displayed transannular repair (p = 0.016), primary palliation (p <0.001), the presence of major aortopulmonary collateral arteries (MAPCA; p = 0.023), and pulmonary valve Z-scores < - 4.0 (p = 0.040) as significant risk factors for PVR.

CONCLUSION

 TOF repair has a beneficial long-term prognosis with low morbidity and mortality. Pulmonary valve Z-scores < - 4.0, transannular repair, and presence of MAPCAs are associated with earlier PVR. Non-VSRs and TOF-pulmonary atresia lead to earlier reoperation but have no negative impact on survival.

Preserving the pulmonary valve in Tetralogy of Fallot repair: Reconsidering the indication for valve-sparing

BACKGROUND

Tetralogy of Fallot (TOF) repair is a frequent procedure, and although valve-sparing (VS) repair is preferred, determining which patients can successfully undergo this operation remains controversial. We sought to identify parameters to determine a selective, accurate indication for VS repair.

METHODS

We reviewed 71 patients (82%) undergoing VS repair. We analyzed hemodynamic data, intraoperative reports, and follow-up echocardiography results to identify acceptable indications. Patients requiring pulmonary valve (PV) reintervention versus no reintervention were compared.

RESULTS

PV annulus size at repair was z-score of -2.0 (-5.3, 1.3). Approximately half (51%) had a z-score less than -2. Cox regression results showed this was not a risk factor for reintervention (p = .59). Overall, 1-, 3-, 5-, and 10-year freedom from PV reintervention rates were 95.8%, 92.8%, 91% and 77.8%, respectively. Residual pulmonary stenosis (PS) at initial repair was relatively higher in the reintervention group compared with no reintervention group (40 [28, 51] mmHg vs. 30 [22, 37] mmHg; p = .08). For patients with residual PS, pressure gradient (PG) was consistent over time across both groups (PV reintervention: -3 [-15, 8] mmHg vs. no reintervention: 0 [-9, 8] mmHg). The risk of PV reintervention is 3.7-fold higher when the PG from intraoperative TEE is greater than 45 mmHg (p = .04).

CONCLUSIONS

Our review of the midterm outcomes of expanded indication for VS suggests intraoperative decision to convert to transannular patch is warranted if intraoperative postprocedure TEE PG is greater than 45 mmHg or RV pressure is higher than half of systemic pressure to prevent reintervention.

Long-term outcomes of staged repair of tetralogy of Fallot

BACKGROUND

The optimal management strategy for symptomatic young infants with tetralogy of Fallot (TOF) is yet to be determined. We aimed to evaluate the long-term outcomes of a staged approach with initial shunt palliation followed by complete repair.

METHODS

Between January 1993 and July 2021, 160 children with TOF underwent a systemic-to-pulmonary shunt at our institution, including 65 neonates (41%). The mean duration of follow-up was 12.3 ± 8.1 years.

RESULTS

Hospital mortality was 3% (4 of 160), all occurring in patients with a shunt size-to-weight ratio ≥1.2 mm/kg. Composite morbidity-defined as cardiac arrest, postoperative mechanical circulatory support, or unplanned reoperation-occurred in 21% (33 of 160). On multivariable analysis, a shunt size-to-weight ratio ≥1.2 mm/kg and prematurity were independent predictors of composite morbidity. Interstage mortality was 3% (4 of 156). A limited transannular patch was used in 75% (113 of 150) of TOF repairs. Actuarial survival at 20 years after shunt was 90% (95% confidence interval [CI], 79%-95%). Actuarial freedom from reinterventions at 20 years after TOF repair was 40% (95% CI, 28%-52%). Neonates had comparable composite morbidity, mortality, and late risk of reinterventions to older children.

CONCLUSIONS

Staged repair of TOF in symptomatic young infants results in low mortality but high rates of reinterventions at long-term follow-up. A shunt size-to-weight ratio ≥1.2 mm/kg is a significant risk factor for mortality and morbidity prior to complete repair. Neonates undergoing shunt insertion have comparable outcomes to older children.

Transcatheter Approaches to Palliation for Tetralogy of Fallot

To this day, controversy still exists regarding the optimal method to treat symptomatic neonates and infants with Tetralogy of Fallot (TOF). Symptomatic (severely cyanotic or ductal dependent) infants with TOF can undergo either a staged repair approach (consisting of initial palliation followed by complete repair) or primary repair. Traditionally, initial palliative procedures have been surgical, for example placement of a Blalock-Taussig-Thomas (BTT) shunt. Recent advances in technology have facilitated the introduction of catheter-based procedures as palliative techniques, for example, patent ductus arteriosus (PDA) stenting and right ventricular outflow tract (RVOT) stenting as more durable solutions than balloon pulmonary valvuloplasty (BPV). In this article, we discuss the rationale for these procedures, technical aspects of these procedures and outcomes data compared to traditional surgical procedures. Recent data have suggested that RVOT and PDA stenting procedures offer many advantages over traditional surgical palliative procedures as palliative methods in this patient population. This comes at a cost of increased reintervention burden, which may be considered part of the overall treatment strategy in smaller neonates and can be minimized with a focus on technical aspects and overall treatment strategies. Advanced surgical techniques are required at the eventual complete repair to negotiate removal of stent material and pulmonary artery reconstruction in some instances. Further adoption of catheter based palliative procedures for infants with symptomatic TOF has the potential to tip the outcomes towards favoring a staged approach, particularly in high-risk infants.

Surgical Strategies for Preservation of Pulmonary Valve Function in a Radical Operation for Tetralogy of Fallot: A Systematic Review and Meta-Analysis

Objective

To evaluate the efficacy and safety of different surgical strategies to preserve pulmonary valve function. Surgical procedures evaluated include intraoperative balloon pulmonary valvuloplasty (IBPV), pulmonary valve reconstruction, and commissurotomy and pulmonary cusp augmentation (PCA) in patients who underwent a radical operation for Tetralogy of Fallot (ToF).

Materials and Methods

The five databases searched in the current study included the Cochrane Library, PubMed, China National Knowledge Infrastructure, VIP, and WanFang data. A systematic search for control trials was performed in each database from the start date of each database until December 2021. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of included studies.

Results

A total of 15 retrospective studies with a total number of 1,396 participants were included in this study. In subgroup 1 (IBPV vs. TAP), patients undergoing IBPV had a less degree of regurgitation at 1–2 years after the surgery. The reintervention rate increased in the IBPV group at 5 years. In subgroup 2 (pulmonary valve reconstruction vs. TAP), the degree of regurgitation decreased in the pulmonary valve reconstruction group at 1 month after the surgery. In subgroup 3 (valve-sparing operation vs. TAP), the comparison demonstrated decreased rates for surgical mortality and reintervention at 5–10 years after the surgery.

Conclusion

We proposed that pulmonary valve function in a radical operation for ToF was preserved. IBPV, pulmonary valve reconstruction, and commissurotomy and PCA can be performed during the surgical procedure based on the developmental status and anatomical characteristics of the right ventricular outflow tract (RVOT), pulmonary valve, and pulmonary artery.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42022300987].

Technique for Neo-Pulmonary Valve Creation With Living Tissue for Repair of Atrioventricular Septal Defect and Tetralogy of Fallot

Long-standing effects of pulmonary regurgitation after transannular patch repair in Tetralogy of Fallot (ToF) can be especially deleterious in the setting of combined ToF and complete atrioventricular septal defect (CAVSD). We present a technique for a complete repair of combined ToF/CAVSD using right atrial appendage tissue to create a competent neo-pulmonary valve. This technique provides advantages of right heart protection via pulmonary valve competence and the use of living tissue capable of growth with the patient, potentially obviating the need for repeat interventions.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the use of cardiovascular magnetic resonance in pediatric congenital and acquired heart disease : Endorsed by The American Heart Association

Cardiovascular magnetic resonance (CMR) has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of CMR in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of CMR in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Society for Cardiovascular Magnetic Resonance/European Society of Cardiovascular Imaging/American Society of Echocardiography/Society for Pediatric Radiology/North American Society for Cardiovascular Imaging Guidelines for the Use of Cardiac Magnetic Resonance in Pediatric Congenital and Acquired Heart Disease: Endorsed by The American Heart Association

Cardiovascular magnetic resonance has been utilized in the management and care of pediatric patients for nearly 40 years. It has evolved to become an invaluable tool in the assessment of the littlest of hearts for diagnosis, pre-interventional management and follow-up care. Although mentioned in a number of consensus and guidelines documents, an up-to-date, large, stand-alone guidance work for the use of cardiovascular magnetic resonance in pediatric congenital 36 and acquired 35 heart disease endorsed by numerous Societies involved in the care of these children is lacking. This guidelines document outlines the use of cardiovascular magnetic resonance in this patient population for a significant number of heart lesions in this age group and although admittedly, is not an exhaustive treatment, it does deal with an expansive list of many common clinical issues encountered in daily practice.

Differences in Cardiopulmonary Fitness Between Boy and Girls With Repaired Tetralogy of Fallot

OBJECTIVE

Many studies have demonstrated that patients with repaired tetralogy of Fallot (rTOF) have generally poorer cardiopulmonary fitness (CPF). However, little is known about how the disease results in different CPF in each sex. Therefore, this study aimed to investigate whether sex (and gender) differences affect CPF in children and adolescents with rTOF.

METHODS

This retrospective study recruited adolescents and children (aged 10-18) with rTOF following an acute stage of tetralogy of Fallot (TOF) who received cardiopulmonary exercise testing (CPET) in the past 10 years. CPF was determined by symptom-limited CPET with a treadmill under ramped Bruce protocol. Boys and girls were categorized into groups based on body mass index (BMI) and fat mass index (FMI). The BMI was grouped by Taiwanese obesity cutoff points. The FMI was categorized by the body fat percentage. Excess adiposity was defined as (1) "overweight" and "obese" by BMI and (2) greater than the sex- and age-specific 75th percentile of whole subjects by FMI.

RESULTS

A total of 185 participants (104 boys and 81 girls) with rTOF were recruited for the final analysis. Within the BMI category, 76 boys and 63 girls were in the normal group, whereas 28 boys and 18 girls were in the excessive adiposity group. Within the FMI category, 77 boys and 60 girls were in the normal group, whereas 27 boys and 21 girls were in the excessive adiposity group. The analysis of the body composition of rTOF subjects showed that there was no statistically significant difference between the subgroups of the two sexes, but both showed a smaller body size than normal Taiwanese children. When comparing the CPF within different BMI and FMI groups, the children in the excessive adiposity group had significantly lower values in metabolic equivalents (MET) at anaerobic threshold, peak MET, and measured peak oxygen consumption (VO₂) to predicted peak VO₂, regardless of sex. Moreover, boys (60.90%) presented poorer CPF than girls (74.22%, p < 0.001).

CONCLUSION

In Taiwan, patients with rTOF had poorer CPF than healthy peers. This study found that girls with rTOF had better CPF than boys with rTOF. The effect of gender stereotypes on sports participation and self-efficacy might be one of the contributing factors; however, further investigations are warranted to determine the causal effect.

Tricuspid annular abnormalities following different surgical strategies in adults with corrected tetralogy of Fallot (Results from the CSONGRAD Registry and MAGYAR-Path Study)

BACKGROUND

Although there is an increasing number of patients with corrected tetralogy of Fallot (cTOF), who reach adulthood due to recent successful surgical procedures, some of them suffers from late complications, including functional tricuspid regurgitation (FTR). The purpose of the present study was to examine tricuspid annular (TA) abnormalities in adult cTOF patients and their relationship right atrial (RA) volumes respecting the cardiac cycle assessed by three-dimensional speckle-tracking echocardiography (3DSTE). Moreover, the effect of different surgical procedures on TA morphologic and functional parameters was examined as well.

METHODS

The study comprised 24 cTOF patients (32.8±13.5 years, 9 males) in which early palliative surgery and late total correction were performed in 12 cases (pcTOF), while early total reconstruction was performed in 12 subjects (etrTOF). Their results were compared to those of 33 matched healthy adults (36.7±7.2 years, 15 males).

RESULTS

Dilated end-systolic and end-diastolic TA morphologic parameters and their body surface area-indexed counterpart could be detected in cTOF patients as compared to that of controls. TA fractional area change and TA fractional shortening proved to be reduced in cTOF patients as well as in etrTOF and pcTOF patients compared to controls. None of the TA morphologic and functional parameters showed any differences between etrTOF and pcTOF patients. Increased maximum, preatrial contraction and minimum RA volumes could be detected in cTOF patients compared to controls, which correlated with TA dimensions.

CONCLUSIONS

TA is dilated with reduced function in adult patients with cTOF. TA dilation is related to RA volumes. etrTOF and pcTOF patients have similar TA dimensions and TA functional properties.

KEYWORDS

Fallot; tricuspid annulus; three-dimensional (3D); speckle-tracking; echocardiography.

Early experience with surgical strategies aimed at preserving the pulmonary valve and annulus during repair of tetralogy of Fallot

Background :

During repair of tetralogy of fallot (TOF) we modified surgical strategies to preserve the valve and annulus if the pulmonary valve leaflets are pliable and not significantly dysplastic.

Methods :

Initially, the repair was done from the main pulmonary artery (Group-1, 215 patients) and later through an additional incision in the infundibulum of the right ventricle (Group-2, 73 patients). Recently, we changed the approach to commissurotomy of the fused leaflets by releasing the supra valvar tethering and delamination of the cuspal apparatus till the base to improve the mobility of the cusps and do a controlled commissurotomy (Group-3, 14 patients). With delamination, we could extend the limit of the repair to a z-score of –3.5.

Results :

There was no hospital mortality; two patients died at home after discharge. A mean follow-up of 42.01 months ± 19.25 is available for 198 patients (92%) for group 1, 16.03 ± 7.45 for group 2, and 4.07 ± 2.09 for group 3. The re-intervention-free survival is 94.4% in group 1. The z value improved from -3 (-3–-2) to -1.2 (-3 – 0), P = 0.001 in Group 1, from -2.8 (-3–-2.4) to -1 (-1.1–-0.7), P = 0.001 in Group 2 and from –3 (-4–-3) to -1, P = 0.001 in Group 3. In all the groups, there was trivial or mild pulmonary regurgitation.

Conclusions :

During repair of TOF, adequate valve/annulus sparing is possible if the repair is done from both the main pulmonary artery and infundibular incisions using the delamination technique.

Long-Term Outcome Following Pulmonary Valve Replacement in Repaired Tetralogy of Fallot

BACKGROUND

Late pulmonary valve replacement following repair of tetralogy of Fallot may become necessary in patients with chronic pulmonary insufficiency. There is limited information on the long-term outcome of these prostheses, which is the focus of this study.

METHODS

We conducted a retrospective study of patients with repaired tetralogy of Fallot who underwent pulmonary valve replacement from 1990 to 2015 in our institution. We investigated imaging and clinical parameters including mortality and late adverse events (reintervention [surgical or transcatheter]), infective endocarditis, or arrhythmias requiring device implantation or ablation.

RESULTS

There were 69 patients divided into 3 groups: Carpentier-Edwards (n = 14), Contegra (n = 40), and pulmonary homograft (n = 15). The mean age at the time of pulmonary valve replacement was 21 ± 12 years. The mean follow-up was 8.5 ± 4.7 years. The mean preoperative and postoperative right ventricular end-diastolic volume index was 210 ± 42 and 120 ± 24 mL/m², respectively. There were no mortalities. Late adverse events were observed in 23 (33%) patients: 15 (22%) reintervention (surgical or transcatheter), 11 (16%) endocarditis, and 11 (16%) arrhythmias. Overall, 1-, 5-, and 10-year freedom from surgical reintervention was 98.5%, 93.6%, and 79.3%, respectively. The Contegra group had significantly higher pulmonary valve gradients, a higher risk of developing late adverse events compared to Carpentier-Edwards (P = .046) and pulmonary homograft (P = .055) in multivariate analysis and increased risk for reintervention in the univariate analysis (hazard ratio: 3.4; 95% CI: 0.92-13; P value.066).

CONCLUSION

Pulmonary valve replacement in patients with repaired tetralogy of Fallot has acceptable short- and intermediate-term outcomes. Contegra prosthesis had a higher risk of late adverse events with higher pulmonary valve gradients.

Applicability and Durability of Valve-Sparing Tetralogy of Fallot Repair

BACKGROUND

Although valve-sparing repair remains ideal for patients with tetralogy of Fallot, the durability of valve-sparing repair and which patients may have been better served with a transannular patch remain unclear.

METHODS

Retrospective review was performed of tetralogy of Fallot operations at our institution from January 2008 to December 2018. Standard demographic data were collected, including echocardiographic parameters, operative details, and clinical outcomes. Statistical analysis was performed comparing the transannular patch and valve-sparing repair groups.

RESULTS

Sixty-seven patients underwent tetralogy of Fallot repair with a median age of 4.5 (3.2-6.0) months and weight of 5.8 (5.2, 6.7) kg. Seventeen (25%) patients underwent transannular patch repair and 50 (75%) patients underwent valve-sparing repair. There was no difference in age or weight between patients who underwent a transannular patch repair and those who underwent a valve-sparing repair. At last follow-up (median 42 months), there was a trend of a higher peak pulmonary valve/right ventricular outflow tract gradient (P = .06) in the valve-sparing group, but no difference in the pulmonary valve annulus z-scores. Additionally, the pulmonary valve z-scores in the valve-sparing group decreased from -2.3 ± 1.0 on predischarge echocardiogram of to -1.2 ± 1.6 on last follow-up, with the peak gradient on predischarge 23 (0-37) mm Hg remaining stable on last follow-up at 18 (0-29) mm Hg. There was one reoperation: pulmonary valve replacement six years after a transannular patch.

CONCLUSIONS

Obtaining a postrepair pulmonary valve z-score of -2 yields satisfactory, stable valve-sparing repair with pulmonary valve growth, acceptable gradients, minimal regurgitation, and high freedom from reintervention during follow-up.

Characterization of Flow Dynamics in the Pulmonary Bifurcation of Patients With Repaired Tetralogy of Fallot: A Computational Approach

The hemodynamic environment of the pulmonary bifurcation is of great importance for adult patients with repaired tetralogy of Fallot (rTOF) due to possible complications in the pulmonary valve and narrowing of the left pulmonary artery (LPA). The aim of this study was to computationally investigate the effect of geometrical variability and flow split on blood flow characteristics in the pulmonary trunk of patient-specific models. Data from a cohort of seven patients was used retrospectively and the pulmonary hemodynamics was investigated using averaged and MRI-derived patient-specific boundary conditions on the individualized models, as well as a statistical mean geometry. Geometrical analysis showed that curvature and tortuosity are higher in the LPA branch, compared to the right pulmonary artery (RPA), resulting in complex flow patterns in the LPA. The computational analysis also demonstrated high time-averaged wall shear stress (TAWSS) at the outer wall of the LPA and the wall of the RPA proximal to the junction. Similar TAWSS patterns were observed for averaged boundary conditions, except for a significantly modified flow split assigned at the outlets. Overall, this study enhances our understanding about the flow development in the pulmonary bifurcation of rTOF patients and associates some morphological characteristics with hemodynamic parameters, highlighting the importance of patient-specificity in the models. To confirm these findings, further studies are required with a bigger cohort of patients.

Management of Neonates Admitted with Tetralogy of Fallot: Changing Patterns Across the United States

BACKGROUND

This study describes the evolving in-hospital management strategies for neonates who are diagnosed with Tetralogy of Fallot (ToF).

METHODS

The Pediatric Health Information System (PHIS) database was used to identify admitted patients 0-1 month old with ToF from 2010-2019. Era 1: 2010-2014; Era 2: 2015-2019. ICD codes were used to identify related interventions, which occurred during this admission but not necessarily as a neonate: full repair, systemic-to-pulmonary shunt, and percutaneous stent in the RVOT &/or PDA.

RESULTS

6,021 neonates were diagnosed with ToF. 2,030(34%) of them underwent an intervention:60% had total repair, 31% systemic-to-pulmonary shunt, 9% percutaneous stent. In the no-intervention cohort, in-hospital mortality was 9%. In-hospital mortality between repair(6%), shunt(6%), and stent(3%) patients(p=0.446) did not differ. Regarding regional practices, no-intervention was most frequently employed in the Midwest (69%vs.65% average for all other regions(avg),p=0.075) while interventions overall were performed most frequently in the West (36%vs.33.5% avg, p=0.075). Amongst the interventions, full repair was most frequent in the Northeast (76%vs.57% avg,p<0.001), shunt was most frequent in the Midwest (39%vs28% avg, p<0.001), and stent was most frequent in the South (11%vs.7%avg,p=0.083). Between Eras 1 & 2, the type of intervention changed: full repair (52%vs69%,p<0.001) and stent (1%vs16%,p<0.001) increased, while shunt decreased (47%vs15%,p<0.001).

CONCLUSIONS

Although the majority of neonates admitted with ToF are discharged with no intervention, over 1/3 undergo some intervention with a 3-6% mortality. Though the proportion of these patients intervened upon is unchanged over the past decade, the types of intervention have changed and significant regional differences exist.

Association of Pulmonary Valve Morphology Differences With Outcomes in Tetralogy of Fallot Repair With Right Ventricular Outflow Tract Incision

Background: Current observational studies may not have large samples to investigate the relationship between pulmonary valve (PV) morphology differences and outcomes after complete repair for tetralogy of Fallot (TOF) by right ventricular outflow tract (RVOT) incision. This study aimed to assess the impact of PV morphology differences on outcomes after complete repair for TOF. Methods: This is a retrospective cohort study. Consecutive patients who underwent TOF repair with RVOT incision at Fuwai Hospital from January 2012 to December 2017 were included and compared according to PV morphology differences (unicuspid or bicuspid was abnormal morphology, while the tricuspid valve was normal morphology). The primary outcome was defined as a composite of death, or reintervention, or significant annular peak gradient (APG), or significant pulmonary regurgitation (PR), whichever occurred first. Multivariable Cox model analysis was used to assess the relationships between PV morphology differences and outcomes. Subgroup analysis and Propensity-score analysis were performed as sensitivity analyses to assess the robustness of our results. Results: The cohort included a total of 1,861 patients with primary diagnosis of TOF, with 1,688 undergoing CR-TOF with RVOT incision. The median age was 318 days [interquartile range (IQR): 223-534 days], a median weight of 8.9 kg (IQR: 7.6-10.5 kg) and 60.0% (1,011) were male. Complete follow-up data were available for 1,673 CR-TOF patients with a median follow-up duration of 49 months. Adjusted risks for the primary outcome and significant APG were lower for patients with normal PV morphology at follow up [adjusted hazard ratio (HR): 0.68; 95% CI: 0.46-0.98; adjusted HR: 0.22; 95% CI: 0.07-0.71, respectively]. The trend for the primary outcome during follow-up remained unchanged, even in subgroups and propensity score matching analyses. Conclusions: In this analysis of data from a large TOF cohort, patients with normal tricuspid PVs were associated with a decreased risk of the primary outcome and a lower risk of significant APG, as compared with patients with abnormal unicuspid or bicuspid PVs.

Finding the Optimal Timing for Repair of Standard Tetralogy of Fallot: Analysis of Cardiac Magnetic Resonance and Echocardiography Parameters Related to Intermediate Term Outcomes in a Pediatric Population

INTRODUCTION

Right ventricular (RV) dilatation is the determining prognostic factor in the long-term follow up of patients with repaired Tetralogy of Fallot (TOF). The objective of this study is to analyze whether the results vary depending on the timing of the complete repair and on the surgical technique applied.

MATERIAL-METHODS

This is a retrospective longitudinal study in which patients with standard TOF were divided into 3 groups depending on their age at surgical repair: group 1 = Early repair (n = 12,1-8 months), group 2 = Late repair (n = 26, > 8 months), and group 3 = Late repair with previous palliative surgery (n = 17, > 8 months). Clinical, echocardiographic and cardiac magnetic resonance (CMR) data from patients that had received complete reparative surgery in our institution from January 2000 to March 2014 were analyzed and compared.

RESULTS

55 patients with echocardiogram and CMR studies (13.39 ± 3.59 years) were reviewed. All patients had at least moderate pulmonary regurgitation (PR). We observed a positive correlation between PR and right ventricular end-diastolic volume (r² = 0.418; p = 0,004). Group 3 had more severe right ventricular dilatation than patients in groups 1 and 2 (p = 0.001). No differences in right ventricular end-diastolic volume, PR, and pulmonary trunk dimensions were observed between groups 1 and 2. Patients in group 3 had a longer hospital stay.

CONCLUSIONS

Although all patients from our cohort had significant PR, age at surgery was not related to RV or pulmonary trunk dilatation. Previous palliative surgery was associated with more severe right ventricular dilatation and longer hospital stays. No differences were observed between early and late repair groups. Our study suggests that postponing TOF repair to a late stage does not improve the degree of PR or long-term morbidity from RV dilatation. Palliative surgery should be avoided if possible.

The impact of native Fallot anatomy on future therapeutic requirements and outcomes at follow-up

Background

In patients with repaired Fallot, subsequent surgical or interventional procedures and adverse cardiac events are frequent. We aimed to evaluate the impact of a simple pre-operative anatomic classification based on the size of the pulmonary valve (PV) annulus and branches on future therapeutic requirements and outcomes.

Method

This is a single-center retrospective analysis of patients operated for Fallot before the age of 2 years, from January 1990. Pre-operative anatomy, surgical and interventional procedures and adverse events were extrapolated from clinical records.

Results

Among the 312 patients, a description of the PV and pulmonary arteries (PAs) native anatomy was known in 239 patients (male:147, 61.5%), which were divided in the following 3 groups: group 1 (65 patients) with normal size of both PV and PAs; group 2 (108 patients) with PV hypoplasia but normal size PAs; group 3 (66 patients) with concomitant hypoplasia of the PV and PAs. During the 12.7 years (IQR 6.7–17) follow-up time, 23% of patients required at least one surgical or interventional procedure. At Kaplan–Meier analysis, there was a significant difference in requirement of future surgical or interventional procedures among the 3 groups (p < 0,001). At multivariate Cox regression analysis, hypoplasia of PV and PAs was an independent predictor of subsequent procedures (HR:3.1,CI:1.06–9.1, p = 0.03).

Conclusion

Native anatomy in Tetralogy of Fallot patients affects surgical strategy and follow-up. It would be therefore advisable to tailor patient’s counseling and follow-up according to native anatomy, rather than following a standardized protocol.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12947-021-00249-y.

Right Ventricular Outflow Tract Stenting as Palliation of Critical Tetralogy of Fallot: Techniques and Results

Background. Despite current trends toward early primary repair, the surgical systemic-to-pulmonary shunt is still considered the first-choice palliation in patients with critical tetralogy of Fallot (TOF) and duct-dependent pulmonary circulation unsuitable for primary repair. However, stenting of the right ventricular outflow tract (RVOT) is nowadays emerging as an effective alternative to surgical palliation in selected patients. Methods and results. RVOT stenting is usually performed from a venous route, either femoral or, in selected cases, the right internal jugular vein. Less frequently, mostly in pulmonary infundibular/valvar atresia, this procedure can be performed using a hybrid surgical/interventional approach by surgical exposure of the RVOT, puncture of the atretic valve, and stent deployment under direct vision. The size and type of the most appropriate stent may be chosen, based on ultrasound measurements of the RVOT, to cover the right ventricular infundibulum completely and, at the same time, sparing the pulmonary valve, unless significant pulmonary valve annulus hypoplasia and/or supra-valvular stenosis is a significant component of the obstruction. In the large series so far published, early mortality of RVOT stenting is less than 2%, comparing favourably with either Blalock-Thomas-Taussig shunt or early primary repair. In addition, morbidity and clinical sequelae of this approach do not significantly differ from surgical palliation, even if RVOT stenting shows lesser durability and a higher rate of trans-catheter re-interventions over a mid-term follow-up. Finally, similar but more balanced pulmonary artery growth than surgical palliation following RVOT stenting is reported over a mid-term follow-up. Conclusions. RVOT stenting is a technically feasible, well-tolerated, and effective palliation in critical TOF. This approach is cost-effective with respect to surgical palliation either in high-risk neonates or whenever a short-term pulmonary blood flow source is anticipated due to the early surgical repair. It effectively increases pulmonary blood flow, improves arterial saturation, and promotes balanced pulmonary artery growth over a mid-term follow-up.

Architecture matters: Tissue preservation strategies for tetralogy of Fallot repair

BACKGROUND

Great variability exists in repair strategies for the tetralogy of Fallot. While transannular patching, as introduced by Kirklin, was a breakthrough for primary repair, pulmonary regurgitation and a need for reoperation have led to the development of methods that preserve the natural morphology of the right ventricular outflow tract.

METHODS

State-of-the-art details of tetralogy of Fallot repair are explained from the standpoint of architectural preservation, especially with regard to sparing native tissue such as the annulus, valve, or infundibulum. Particular attention is given to the latest technical details of each approach, benefits and disadvantages, and any long-term data available.

RESULTS

The choice of procedure is complex and unique to each case as transannular patching alone may carry long-term pulmonary risks. Modifications that spare the annulus, valves, or infundibulum may thus be essential as preservation of natural morphology has resulted in excellent mid-term results.

CONCLUSIONS

The complexity of tetralogy of Fallot repair demands constant attention to clinical presentation and vigilance against long-term sequelae. Techniques will continue to improve over time as long-term data guides the refinement of these innovative surgical methods.

Effect of cardiopulmonary bypass reoxygenation on myocardial dysfunction following pediatric tetralogy of Fallot repair

BACKGROUND

Little is known regarding the effect of cardiopulmonary bypass (CPB) reoxygenation on cardiac function following tetralogy of Fallot repair. We hypothesized that hyperoxic reoxygenation would be more strongly associated with myocardial dysfunction in children with tetralogy of Fallot.

METHODS

We investigated the association of perfusate oxygenation (PpO2) associated with myocardial dysfunction among children aged 6-72 months who underwent complete repair of tetralogy of Fallot in 2012-2018. Patients were divided into two groups: lower PpO2 group (≤ 250 mmHg) and higher PpO2 (> 250 mmHg) group based on the highest value of PpO2 during aortic occlusion. The odd ratio (ORs) and 95% confidence intervals (CIs) were estimated by logistic regression models.

RESULTS

This study included 163 patients perfused with lower PpO2 and 213 with higher PpO2, with median age at surgery 23.3 (interquartile range [IQR] 12.5-39.4) months, 164 female (43.6%), and median body mass index 15.59 (IQR 14.3-16.9) kg/m². After adjustment for baseline, clinical and procedural variables, patients with higher PpO2 were associated with higher risk of myocardial dysfunction than those with lower PpO2 (OR 1.770; 95% CI 1.040-3.012, P = 0.035). Higher PpO2, lower SpO2, lower pulmonary annular Z-score, and longer CPB time were independent risk factors for myocardial dysfunction.

CONCLUSIONS

Association exists between higher PpO2 and myocardial dysfunction risk in patients with tetralogy of Fallot, highlighting the modulation of reoxygenation during aortic occlusion to reduce cardiovascular damage following tetralogy of Fallot repair.

TRIAL REGISTRATION

Clinical Trials. gov number NCT03568357. June 26, 2018.

Palliative Balloon Pulmonary Valvotomy in Tetralogy of Fallot: Is There a Role in 2021?

The current treatment practice for Tetralogy of Fallot (TOF) is to undertake complete surgical repair between 6–9 months of age with excellent immediate and long-term results. In patients with increased cyanosis or frequent cyanotic spells, younger age of complete repair as early as 3 months is usually acceptable. Although neonatal TOF repair is reported with good immediate survival from a few centres, post-operative morbidity is significant, and the hospital stay is prolonged. Hence, in neonates and small term and preterm infants with severe cyanosis, palliative procedures such as modified Blalock-Taussig (BT) shunt, ductal stenting, right ventricular outflow tract (RVOT) stenting and balloon pulmonary valvotomy (BPV) have been reported. With the development of low-profile stents, an increasing clinician experience and more predictable outcome with both duct and RVOT stenting, these procedures have gained popularity as the preferred palliations for TOF at most centres. We reviewed the literature to analyse whether BPV for TOF palliation, a technique first reported three decades ago, still has a role in the present era of paediatric cardiac care. In this review, we have concluded that BPV has very specific indications in patients with TOF, with predominantly valvar pulmonary stenosis, and may be a preferred option over other palliative strategies in hypoxemic preterm or low-birth weight infants.