Surgical treatment of tetralogy of Fallot in symptomatic neonates and young infants

Young infants with symptomatic tetralogy of Fallot: Shunt or primary repair?

Objectives

The optimal treatment strategy for symptomatic young infants with tetralogy of Fallot (TOF) is unclear. We sought to compare the outcomes of staged repair (SR) (shunt palliation followed by second-stage complete repair) versus primary repair (PR) at 2 institutions that have exclusively adopted each strategy.

Methods

We performed propensity score-matched comparison of 143 infants under 4 months of age who underwent shunt palliation at one institution between 1993 and 2021 with 122 infants who underwent PR between 2004 and 2018 at another institution. The primary outcome was mortality. Secondary outcomes were postoperative complications, durations of perioperative support and hospital stays, and reinterventions. Median follow-up was 8.3 years (interquartile range, 8.1-13.4 years).

Results

After the initial procedure, hospital mortality (shunt, 2.8% vs PR, 2.5%; P = .86) and 10-year survival (shunt, 95%; 95% confidence interval [CI], 90%-98% vs PR, 90%; 95% CI, 81%-95%; P = .65) were similar. The SR group had a greater risk of early reinterventions but similar rates of late reinterventions. Propensity score matching yielded 57 well-balanced pairs. In the matched cohort, the SR group had similar freedom from reintervention (55%; 95% CI, 39%-68% vs 59%; 95% CI, 43%-71%; P = .85) and greater survival (98%; 95% CI, 88%-99.8% vs 85%; 95% CI, 69%-93%; P = .02) at 10 years, as the result of more noncardiac-related mortalities in the PR group.

Conclusions

In symptomatic young infants with TOF operated at 2 institutions with exclusive treatment protocols, the SR strategy was associated with similar cardiac-related mortality and reinterventions as the PR strategy at medium-term follow-up.

Differential lncRNA/mRNA expression profiling and ceRNA network analyses in amniotic fluid from foetuses with ventricular septal defects

Background

Long noncoding RNAs (lncRNAs) have been shown to be involved in the regulation of numerous biological processes in embryonic development. We aimed to explore lncRNA expression profiles in ventricular septal defects (VSDs) and reveal their potential roles in heart development.

Methods

Microarray analyses were performed to screen differentially expressed lncRNAs (DE-lncRNAs) and mRNAs (DE-mRNAs) in the amniotic fluid between the VSD group and the control group. Bioinformatics analyses were further used to identify the functional enrichment and signaling pathways of important mRNAs. Then, a coding-noncoding gene coexpression (CNC) network and competitive endogenous RNAs (ceRNA) network were drawn. Finally, qRT‒PCR was performed to verify several hub lncRNAs and mRNAs in the network.

Results

A total of 710 DE-lncRNAs and 397 DE-mRNAs were identified in the VSD group. GO and KEGG analyses revealed that the DE-mRNAs were enriched in cardiac development-related biological processes and pathways, including cell proliferation, cell apoptosis, and the Sonic Hedgehog signaling pathway. Four VSD related mRNAs was used to construct the CNC network, which included 149 pairs of coexpressing lncRNAs and mRNAs. In addition, a ceRNA network, including 15 lncRNAs, 194 miRNAs, and four mRNAs, was constructed to reveal the potential regulatory relationship between lncRNAs and protein-coding genes. Finally, seven RNAs in the ceRNA network were validated, including IDS, NR2F2, GPC3, LINC00598, GATA3-AS1, PWRN1, and LINC01551.

Conclusion

Our study identified some lncRNAs and mRNAs may be potential biomarkers and therapeutic targets for foetuses with VSD, and described the lncRNA-associated ceRNA network in the progression of VSD.

Biventricular strain and strain rate impairment shortly after surgical repair of tetralogy of Fallot in children: A case-control study

Background

Early biventricular dysfunction in repaired tetralogy of Fallot (TOF) children may lead to poor clinical outcomes. We aimed to assess biventricular function in TOF children before and after surgery by speckle tracking echocardiography (STE) and compare them with the controls.

Methods

Twenty repaired TOF children and 20 normal children as controls were assessed by STE. Tricuspid annular plane systolic excursion (TAPSE), left ventricular ejection fraction (LVEF), biventricular strain, and strain rate were compared before and after surgery and between TOF children and controls.

Results

Postoperative LVEF (p = 0.001), strain (p = 0.001), and strain rate (p = 0.001) for left ventricle improved significantly compared to preoperative phase. However, postoperative left ventricular strain (p = 0.05) and strain rate (p = 0.01) in TOF children were significantly impaired compared to controls. Postoperative LVEF was correlated inversely with postoperative strain rate (r = −0.40, p = 0.04). Postoperative TAPSE (p = 0.001), strain (p = 0.001), and strain rate (p = 0.001) for right ventricle significantly worsened when compared with the preoperative phase. Moreover, postoperative TAPSE (p = 0.001), strain (p = 0.001), and strain rate (p = 0.01) were significantly impaired compared to controls. Postoperative right ventricular strain rate was correlated significantly with the weight of children (r = 0.48, p = 0.02), and postoperative left ventricular strain showed significant correlations with aortic clamp time (r = 0.44, p = 0.04) and with ICU stay (r = −0.46, p = 0.04).

Conclusion

Despite normal LVEF, TOF children exhibit impaired left ventricular strain and strain rate after surgery. TAPSE, strain, and strain rate for the right ventricle worsen after surgical repair. STE‐driven strain can be used to detect early ventricular dysfunction and the associated prognostic implications.

Tissue engineering: Relevance to neonatal congenital heart disease

Congenital heart disease (CHD) represents a large clinical burden, representing the most common cause of birth defect-related death in the newborn. The mainstay of treatment for CHD remains palliative surgery using prosthetic vascular grafts and valves. These devices have limited effectiveness in pediatric patients due to thrombosis, infection, limited endothelialization, and a lack of growth potential. Tissue engineering has shown promise in providing new solutions for pediatric CHD patients through the development of tissue engineered vascular grafts, heart patches, and heart valves. In this review, we examine the current surgical treatments for congenital heart disease and the research being conducted to create tissue engineered products for these patients. While much research remains to be done before tissue engineering becomes a mainstay of clinical treatment for CHD patients, developments have been progressing rapidly towards translation of tissue engineering devices to the clinic.

Tetralogy of Fallot: stent palliation or neonatal repair?

Surgical repair of Tetralogy of Fallot has excellent outcomes, with over 90% of patients alive at 30 years. The ideal time for surgical repair is between 3 and 11 months of age. However, the symptomatic neonate with Tetralogy of Fallot may require earlier intervention: either a palliative intervention (right ventricular outflow tract stent, ductal stent, balloon pulmonary valvuloplasty, or Blalock-Taussig shunt) followed by a surgical repair later on, or a complete surgical repair in the neonatal period. Indications for palliation include prematurity, complex anatomy, small pulmonary artery size, and comorbidities. Given that outcomes after right ventricular outflow tract stent palliation are particularly promising - there is low mortality and morbidity, and consistently increased oxygen saturations and increased pulmonary artery z-scores - it is now considered the first-line palliative option. Disadvantages of right ventricular outflow tract stenting include increased cardiopulmonary bypass time at later repair and the stent preventing pulmonary valve preservation. However, neonatal surgical repair is associated with increased short-term complications and hospital length of stay compared to staged repair. Both staged repair and primary repair appear to have similar long-term mortality and morbidity, but more evidence is needed assessing long-term outcomes for right ventricular outflow tract stent palliation patients.

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.

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.

How and When Should Tetralogy of Fallot be Palliated Prior to Complete Repair?

The controversy regarding the best or ideal surgical management of Tetralogy of Fallot (ToF) stems from the recognition of there being a spectrum of morphology and associated lesions, each of which require a different approach to achieve the three goals of minimizing mortality preserving right ventricular function long-term and minimizing reinterventions. A one-size-fits-all approach to ToF needs to be replaced by a considered and personalized approach in order to yield the best outcomes possible for individual patients. The great majority of patients with ToF undergo primary complete repair between age 3-9 months with excellent outcomes. However, the greatest challenge is the severely cyanotic neonates where primary repair is still associated with high mortality and reintervention rates. Risk factors are low weight and small/poorly developed pulmonary vasculature. High-risk neonates have better outcomes with palliation-but mortality is still high. Palliative interventions in the catherization lab are showing better outcomes than traditional BT shunt and the RVOT stent is emerging as potential game-changer. Primary neonatal repair is still recommended if weight >3 kg and Nakata >100 mm²/m². However, neonates with low weight, small pulmonary arteries or multiple comorbidities (including ToF/AVSD and anomalous LAD) may do better with a staged approach, There is good argument for RVOT stenting as a bridge to complete repair due to its stable circulation without diastolic run off and volume loading of the circulation, and its potential to allow branch PA growth.

Clinical Outcome of Right Ventricular Outflow Tract Stenting Versus Blalock-Taussig Shunt in Tetralogy of Fallot: A systematic Review and Meta-Analysis

AIM

Several studies assessed the effectiveness of different therapeutic procedures for repairing right ventricular outflow tract (RVOT) in tetralogy of Fallot (TOF) patients reporting contradictory results. What has been systematically summarized in the present study was to assess the outcome of RVOT stenting in TOF patients and also to compare its outcome with Blalock-Taussig (BT) shunt procedure.

METHODS AND RESULTS

This study was performed according to established methods and in compliance with Preferred Reporting Items for Systematic review and Meta-Analysis Protocols. Two investigators searched the manuscript databases including Medline, Web of knowledge, Google scholar, Scopus, and Cochrane Central Register of Controlled Trials in the Cochrane Library for all eligible studies in accordance with the considered keywords. In final, 10 articles were eligible for the final analysis. The pooled success rate of RVOT stenting was found to be 93.6% (95% confidence interval [CI]: 89.6% to 96.2%). The overall improvement in arterial oxygen saturation following RVOT stenting was also shown to be 20.1%% (95% CI: 15.8% to 25.3%). The procedural-related death was also 3.7% (95% CI: 1.9% to 7.3%). The assessment of the outcome of RVOT stenting and BT shunt showed no significant difference in improvement rate of arterial O2 saturation (Odds ratio = 1.419, 95% CI: 0.645 to 3.123, P= 0.384) and death rate (risk ratios = 0.341, 95% CI: 0.057 to 2.024, P= 0.236).

CONCLUSION

RVOT stenting leads to appropriate clinical outcome in children suffering TOF Comparing RVOT stenting and BT shunt shows comparable results with respect to clinical sequels. Classifications: Right Ventricular Outflow Tract (RVOT), Tetralogy Of Fallot (TOF), BT shunt.

CONDENSED ABSTRACT

Aim: Present study was to assess the outcome of right ventricular outflow tract (RVOT) stenting in tetralogy of Fallot (TOF) patients and also to compare its outcome with Blalock-Taussig (BT) shunt procedure.

METHODS AND RESULTS

This study was performed according to established methods and in compliance with Preferred Reporting Items for Systematic review and Meta-Analysis Protocols. In final, 10 articles were eligible for the final analysis. The assessment of the outcome of RVOT stenting and BT shunt showed no significant difference in improvement rate of arterial O2 saturation and death rate.

CONCLUSION

RVOT stenting leads to appropriate clinical outcome in children suffering TOF Comparing RVOT stenting and BT shunt shows comparable results with respect to clinical sequels.