Right Ventricular Outflow Tract Stenting in Tetralogy of Fallot Infants With Risk Factors for Early Primary Repair

Transcatheter-Based Interventions for Tetralogy of Fallot Across All Age Groups

Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease. Palliative procedures, either surgical or transcatheter, aim to improve oxygen saturation, affording definitive procedures at a later stage. Transcatheter interventions have been used before and after surgical palliative or definitive repair in children and adults. This review aims to provide an overview of the different catheter-based interventions for TOF across all age groups, with an emphasis on palliative interventions, such as patent arterial duct stenting, right ventricular outflow tract stenting, or balloon pulmonary valvuloplasty in infants and children and transcatheter pulmonary valve replacement in adults with repaired TOF, including the available options for a large, dilated native right ventricular outflow tract.

Current status of transcatheter intervention for complex right ventricular outflow tract abnormalities

Various transcatheter interventions for the right ventricular outflow tract (RVOT) have been introduced and developed in recent decades. Transcatheter pulmonary valve perforation was first introduced in the 1990s. Radiofrequency wire perforation has been the approach of choice for membranous pulmonary atresia in newborns, with high success rates, although complication rates remain relatively common. Stenting of the RVOT is a novel palliative treatment that may improve hemodynamics in neonatal patients with reduced pulmonary blood flow and RVOT obstruction. Whether this option is superior to other surgical palliative strategies or early primary repair of tetralogy of Fallot remains unclear. Transcatheter pulmonary valve replacement has been one of the biggest innovations in the last two decades. With the success of the Melody and SAPIEN valves, this technique has evolved into the gold standard therapy for RVOT abnormalities with excellent procedural safety and efficacy. Challenges remain in managing the wide heterogeneity of postoperative lesions seen in RVOT, and various technical modifications, such as pre-stenting, valve ring modification, or development of self-expanding systems, have been made. Recent large studies have revealed outcomes comparable to those of surgery, with less morbidity. Further experience and multicenter studies and registries to compare the outcomes of various strategies are necessary, with the ultimate goal of a single-step, minimally invasive approach offering the best longer-term anatomical and physiological results.

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.

Pulmonary reperfusion injury in post-palliative intervention of oligaemic cyanotic CHD: a new catastrophic consequence or just revisiting the same old story?

Pulmonary reperfusion injury is a well-recognised clinical entity in the setting pulmonary artery angioplasty for pulmonary artery stenosis or chronic thromboembolic disease, but not much is known about this complication in post-palliative intervention of oligaemic cyanotic CHD. The pathophysiology of pulmonary reperfusion injury in this population consists of both ischaemic and reperfusion injury, mainly resulting in oxidative stress from reactive oxygen species generation, followed by endothelial dysfunction, and cytokine storm that may induce multiple organ dysfunction. Other mechanisms of pulmonary reperfusion injury are "no-reflow" phenomenon, overcirculation from high pressure in pulmonary artery, and increased left ventricular end-diastolic pressure. Chronic hypoxia in cyanotic CHD eventually depletes endogenous antioxidant and increased the risk of pulmonary reperfusion injury, thus becoming a concern for palliative interventions in the oligaemic subgroup. The incidence of pulmonary reperfusion injury varies depending on multifactors. Despite its inconsistence occurrence, pulmonary reperfusion injury does occur and may lead to morbidity and mortality in this population. The current management of pulmonary reperfusion injury is supportive therapy to prevent deterioration of lung injury. Therefore, a general consensus on pulmonary reperfusion injury is necessary for the diagnosis and management of this complication as well as further studies to establish the use of novel and potential therapies for pulmonary reperfusion injury.

Outcomes Following Balloon Pulmonary Valvuloplasty in Symptomatic Neonates With Tetralogy of Fallot-A CCRC Study

Background

Complete repair (CR) can be delayed in neonates with symptomatic tetralogy of Fallot (sTOF) using surgical or transcatheter palliation to relieve cyanosis. Balloon pulmonary valvuloplasty (BPV) is an established treatment for pulmonary valve stenosis; however, its effectiveness in palliating neonates with sTOF has not been well investigated.

Methods

A retrospective chart review between 2005 and 2017 on neonates with sTOF who underwent initial BPV from 9 participating centers of the Congenital Cardiac Research Collaborative was performed. Primary outcome was CR at >30 days after BPV without interval reintervention (RI).

Results

In total, 47 neonates with sTOF underwent BPV, of whom 27 (57%) underwent CR at >30 days after BPV without RI. The median time to CR was 151 days (106-210). RI before CR occurred in 17 patients (36%): surgical shunt (n = 7), outflow tract stenting (n = 6), patent ductus arteriosus stenting (n = 2), and surgical outflow patch (n = 2). Valve-sparing repair at CR was performed in 6 patients (13%) after initial BPV. RI or CR ≤30 days from BPV was associated with smaller infundibular diastolic diameter (P = .004). An infundibular diastolic diameter of <3.4 mm demonstrated 75% sensitivity and 67% specificity to predict early CR or RI.

Conclusions

BPV can be an effective palliative therapy in select neonates with sTOF to delay CR. A smaller diastolic infundibulum diameter is a predictor of RI or early CR, and valve-sparing repair is uncommon, making patient selection and alternative palliative methods key when considering BPV palliation in neonates with sTOF.

Surgical correction of an infundibular pulmonic stenosis and ventricular septal defect in a Shetland Sheepdog

A four-month-old male Shetland Sheepdog presented with exercise intolerance. Physical examination revealed an IV/VI left cranial systolic heart murmur. Echocardiography showed a severe infundibular pulmonic stenosis and a concomitant restrictive ventricular septal defect. As clinical signs of congestive right-sided heart failure worsened and were refractory to medical treatment, surgical correction was advised. Via sternotomy, with cardiopulmonary bypass and cardioplegic cardiac arrest, ventricular septal defect closure and resection of the stenotic infundibular band were performed through right ventriculotomy, followed by patch enlargement. Postoperative recovery was uneventful and echocardiography showed complete resolution of the stenosis and successful closure of the ventricular septal defect. Follow-up echocardiography revealed restenosis after seven weeks and recurrence of right-sided heart failure three months postoperatively. Stenting of the restenosis was attempted via a hybrid procedure with sternotomy and direct transventricular approach. The dog developed fatal ventricular fibrillation during stent deployment. This is the first dog in which surgical right ventricular patch enlargement under cardiopulmonary bypass is reported for the treatment of a primary infundibular pulmonic stenosis.

Pulmonary Artery Hypoplasia in Neonates With Tetralogy of Fallot

BACKGROUND

Neonates with symptomatic tetralogy of Fallot (sTOF) with hypoplastic pulmonary arteries (hPA) are considered high risk. Data are needed to inform the impact of hPA on outcomes, and the ideal management strategy.

OBJECTIVES

The objectives of this study were to quantify the impact of hPA on outcomes in neonates with sTOF and measure the impact of strategy on pulmonary artery (PA) growth in this population.

METHODS

Neonates with sTOF from 2005 to 2017 were reviewed from the Congenital Cardiac Research Collaborative. Criteria for hPA included a unilateral PA z score <-2.0 and contralateral PA z score <0. Primary outcome was mortality. Secondary outcomes included reintervention and PA growth.

RESULTS

We included 542 neonates with sTOF, including 188 (35%) with hPA and 354 (65%) with normal PA, with median follow-up of 4.1 years. Median right and left hPA z scores were -2.19 (25th-75th percentile: -2.55 to -1.94) and -2.23 (25th-75th percentile: -2.64 to -1.91), respectively. Staged repair (vs primary TOF repair) was less common in the hPA cohort (36 vs 44%; P = 0.07). Survival was similar between groups (unadjusted P = 0.16; adjusted P = 0.25). Reintervention was more common in the hPA group (HR: 1.28; 95% CI: 1.01-1.63; P = 0.044); there was no difference after definitive repair (HR: 1.21; 95% CI: 0.93-1.58; P = 0.16). PA growth at 1 year was greater in the hPA cohort, particularly for the right PA (P < 0.001).

CONCLUSIONS

Despite perception, the presence of hPA in neonates with sTOF conferred no increase in overall hazard of mortality or reintervention after definitive repair. PA growth was superior in the hPA cohort. These findings suggest that the presence of hPA does not adversely impact outcomes in sTOF.

Transcatheter Interventions for Neonates with Congenital Heart Disease: A Review

Newborns with congenital heart disease often require interventions linked to high morbidity and mortality rates. In the last few decades, many transcatheter interventions have become the first-line treatments for some critical conditions in the neonatal period. A catheter-based approach provides several advantages in terms of procedural time, length of hospitalization, repeatability and neurodevelopmental issues (usually related to cardiopulmonary bypass). The main transcatheter procedures will be reviewed, as they are now valid alternatives to conventional surgical management.

Congenital Heart Defects and 22q11.2 Deletion Syndrome: A 20-Year Update and New Insights to Aid Clinical Diagnosis

Congenital heart defects (CHDs) are one of the most prevalent clinical features described in individuals diagnosed with 22q11.2 deletion syndrome (22q11.2DS). Therefore, cardiac malformations may be the main finding to refer for syndrome investigation, especially in individuals with a mild phenotype. Nowadays, different cytogenetic methodologies have emerged and are used routinely in research laboratories. Hence, choosing an efficient technology and providing an accurate interpretation of clinical findings is crucial for 22q11.2DS patient's diagnosis. This systematic review provides an update of the last 20 years of research on 22q11.2DS patients with CHD and the investigation process behind each diagnosis. A search was performed in PubMed, Embase, and LILACS using all entry terms to DiGeorge syndrome, CHDs, and cytogenetic analysis. After screening, 60 papers were eligible for review. We present a new insight of ventricular septal defect as a possible pivotal cardiac finding in individuals with 22q11.2DS. Also, we describe molecular technologies and cardiac evaluation as valuable tools in order to guide researchers in future investigations.

Retrograde Pulmonary Valve Perforation and Stenting through a Major Aorto-Pulmonary Collateral Artery

Management of pulmonary atresia, ventricular septal defect with major aorto-pulmonary collateral arteries, and hypoplastic native pulmonary arteries focuses on growth of the native pulmonary arteries. One strategy to grow the native pulmonary arteries is through pulmonary valve perforation followed by right ventricular outflow tract stenting, if suitable. We present a unique case of retrograde pulmonary valve perforation and stenting of the right ventricular outflow tract through a major aorto-pulmonary collateral artery.

Tetralogy of Fallot Repair After Neonatal Right Ventricular Outflow Tract Stenting: Initial Multicenter Experience in Argentina

Initial management of patients with tetralogy of Fallot, unfavorable anatomy, and reduced pulmonary blood flow is controversial and continues to be a clinical challenge. Pulmonary to systemic shunt anastomosis or primary correction in neonates and small infants is associated with higher morbimortality and increased number of reoperations. Initial right ventricle outflow tract stenting palliation has emerged as an attractive alternative. We report our experience in 14 patients operated on with tetralogy of Fallot and previous right ventricle outflow tract stenting from March 2018 to June 2022. All stented patients had pulmonary annulus and main pulmonary artery Z score ≤ -2.5. Surgical outcomes, complications, and mortality at 30 days were evaluated. Patient's age and weight at surgery were 5.9 months (2-17) and 6.1 kg (3.9-8.9), respectively. Stents were completely removed in 57.1% of patients. A transannular patch was placed in 10 patients, 3 patients required a right ventricle to pulmonary artery conduit due to coronary anomalies and in 1 patient, the pulmonary valve was preserved. Length of stay and ventilation time were 13.6 days (5-27) and 44.8 h (6-44), respectively. Mean time for right ventricle outflow tract stent implantation to surgical correction was 4 months (2-16). There was no mortality, and mean follow-up time of this cohort was 23.1 month (1-41). Surgical correction of severe tetralogy of Fallot after right ventricle outflow tract stenting is an effective alternative achievable without an increase in morbidity and mortality. Difficulty in stent extraction is related to the time since implantation. More number of patients and longer follow-up time are needed to confirm these initial results.

Right ventricular outflow tract stenting promotes pulmonary artery development in tetralogy of fallot

Background

Right ventricular outflow tract (RVOT) stenting seems to be suggested as a promising treatment option and an alternative to modified Blalock-Taussig shunt (mBTS) in the initial palliation of patients with Fallot-type lesions in recent years. This study sought to assess the effect of RVOT stenting on the growth of the pulmonary artery (PA) in patients with Tetralogy of Fallot (TOF).

Methods

Retrospective review analyzing 5 patients with Fallot-type congenital heart disease with small pulmonary arteries who underwent palliative with RVOT stenting and 9 patients underwent modified Blalock-Taussig shunt within 9 years period. Differential left PA (LPA) and right PA (RPA) growth was measured by Cardiovascular Computed Tomography Angiography (CTA).

Results

RVOT stenting improved arterial oxygen saturation from median of 60% (interquartile range [IQR]: 37% to 79%) to 95% (87.5% to 97.5%) (p = 0.028). The LPA diameter Z-score improved from -2.843 (-3.51-2.037) to -0.78 (-2.3305-0.19) (p = 0.03), the RPA diameter Z-score improved from median -2.843 (-3.51-2.037) to -0.477 (-1.1145-0.459) (p = 0.002), the Mc Goon ratio increased from median 1 (0.8-1.105) to 1.32 (1.25-1.98) (p = 0.017). There were no procedural complications and all 5 patients have undergone final repair in the RVOT stent group. In the mBTS group, the LPA diameter Z-score improved from -1.494 (-2.242-0.6135) to -0.396 (-1.488-1.228) (p = 0.15), the RPA diameter Z-score improved from median -1.328 (-2.036-0.838) to 0.088 (-0.486-1.223) (p = 0.007), and there were 5 patients occur different complications and 4 patients was not attained the standards of final surgical repair.

Conclusion

RVOT stenting, compared with mBTS, seems to better promote pulmonary artery growth, improve arterial oxygen saturations, and have less procedure complications in patients with TOF who being absolute contraindicated for primary repair due to high risks.

Rescue right ventricular outflow tract stenting for refractory hypoxic spells

BACKGROUND

While right ventricular outflow tract stenting (RVOTS) has become an acceptable alternative to palliative surgery in Tetralogy of Fallot (TOF) and similar physiologies, its utility for relief of refractory hypoxic spells is unclear.

METHODS

Patients who underwent RVOTS for emergency relief of refractory hypoxic spells were identified. Specific modifications to enable expeditious RVOTS included use of stent delivery systems (guiding catheter or long sheath) upfront to minimize catheter exchanges; using coronary wires to cross RVOT initially; stabilizing the catheter with a wire in the aorta while crossing RVOT with a second wire.

RESULTS

From 2015 to 2022, 11 patients underwent RVOTS for hypoxic spells refractory to medical management. Their median age was 27 days (IQR 8.5-442.5); weight 3.27 kg (2.7-8.96); 9 males. Median pulmonary annulus Z score was -4.13 (IQR-4.85 to -0.86). Thirteen stents with median diameter 5 (4-6.5) mm and length 19 (16-19.75) mm were implanted, fluoroscopy time:13.6 (11-26.3) min; procedure time (60, 30-70 min). All were ventilated. Oxygen saturations improved from 45% (40-60) to 90% (84-92); (p < 0.0001) with no major complications. Postprocedure ventilation was needed for 21 (20-49) hours and 4 required diuretic infusion for pulmonary over-circulation. Four needed re-stenting 13 days to 5 months later. At median follow-up of 7 (4-17) months; 2 died from unrelated causes, 3 underwent surgery (two correction and one aorto-pulmonary shunt) and 6 await surgery.

CONCLUSION

RVOTS enables safe, expeditious and effective short-term palliation for refractory hypoxic spells. Specific technical modifications facilitate safety, ease and swiftness.

The American Association for Thoracic Surgery (AATS) 2022 Expert Consensus Document: Management of infants and neonates with tetralogy of Fallot

OBJECTIVE

Despite decades of experience, aspects of the management of tetralogy of Fallot with pulmonary stenosis (TOF) remain controversial. Practitioners must consider newer, evolving treatment strategies with limited data to guide decision making. Therefore, the TOF Clinical Practice Standards Committee was commissioned by the American Association for Thoracic Surgery to provide a framework on this topic, focused on timing and types of interventions, management of high-risk patients, technical considerations during interventions, and best practices for assessment of outcomes of the interventions. In addition, the group was tasked with identifying pertinent research questions for future investigations. It is recognized that variability in institutional experience could influence the application of this framework to clinical practice.

METHODS

The TOF Clinical Practice Standards Committee is a multinational, multidisciplinary group of cardiologists and surgeons with expertise in TOF. With the assistance of a medical librarian, a citation search in PubMed, Embase, Scopus, and Web of Science was performed using key words related to TOF and its management; the search was restricted to the English language and the year 2000 or later. Articles pertaining to pulmonary atresia, absent pulmonary valve, atrioventricular septal defects, and adult patients with TOF were excluded, as well as nonprimary sources such as review articles. This yielded nearly 20,000 results, of which 163 were included. Greater consideration was given to more recent studies, larger studies, and those using comparison groups with randomization or propensity score matching. Expert consensus statements with class of recommendation and level of evidence were developed using a modified Delphi method, requiring 80% of the member votes with 75% agreement on each statement.

RESULTS

In asymptomatic infants, complete surgical correction between age 3 and 6 months is reasonable to reduce the length of stay, rate of adverse events, and need for a transannular patch. In the majority of symptomatic neonates, both palliation and primary complete surgical correction are useful treatment options. It is reasonable to consider those with low birth weight or prematurity, small or discontinuous pulmonary arteries, chromosomal anomalies, other congenital anomalies, or other comorbidities such as intracranial hemorrhage, sepsis, or other end-organ compromise as high-risk patients. In these high-risk patients, palliation may be preferred; and, in patients with amenable anatomy, catheter-based procedures may prove favorable over surgical palliation.

CONCLUSIONS

Ongoing research will provide further insight into the role of catheter-based interventions. For complete surgical correction, both transatrial and transventricular approaches are effective; however, the smallest possible ventriculotomy should be utilized. When possible, the pulmonary valve should be spared; and if unsalvageable, reconstruction can be considered. At the conclusion of the operation, adequate relief of the right ventricular outflow obstruction should be confirmed, and identification of a significant fixed anatomical obstruction should prompt further intervention. Given our current knowledge and the gaps identified, we propose several key questions to be answered by future research and potentially by a TOF registry: When to palliate or proceed with complete surgical correction, as well as the ideal type of palliation; the optimal surgical approach for complete repair for the best long-term preservation of right ventricular function; and the utility, efficacy, and durability of various pulmonary valve preservation and reconstruction techniques.

In vitro performance of Lifetech IBS Angel™ (iron-based bioresorbable scaffold) stents during overdilation for use in pediatric patients

Objectives

The objective of this study was to assess the mechanical performance of the Lifetech IBS Angel stents during overdilation as is often required in pediatric applications; including time of first fracture, foreshortening, and the type of fracturing that occurs.

Materials and methods

In vitro testing was performed and repeated for each stent three times under physiologic conditions with continuous audiovisual imaging allowing for post-testing evaluations. Assessment of sheath fit was also completed.

Results

A total of 47 stents on monorail system were overdilated to complete fracture after passing through either a 4 or 5 French sheath. First strut fracture occurred in 4 and 6 mm stents when they reached greater than 50% overexpansion. Larger stents could achieve at least 30% increased diameter prior to first strut fracture. No fragmentation of any of the stents was seen throughout testing.

Conclusion

The IBS Angel has thin struts allowing for a lower profile with increased maneuverability and use with smaller sheaths. Embolization potential of strut fragments was not seen. Increased diameter well beyond design parameters was seen in all with acceptable foreshortening.

Palliation Strategy to Achieve Complete Repair in Symptomatic Neonates with Tetralogy of Fallot

Neonates with symptomatic tetralogy of Fallot (sTOF) may undergo palliations with varying physiology, namely systemic to pulmonary artery connections (SPC) or right ventricular outflow tract interventions (RVOTI). A comparison of palliative strategies based on the physiology created is lacking. Consecutive sTOF neonates undergoing SPC or RVOTI from 2005-2017 were reviewed from the Congenital Cardiac Research Collaborative. The primary outcome was survival with successful complete repair (CR) by 18 months. A variety of secondary outcomes were assessed including overall survival, hospitalization-related comorbidities, and interstage reinterventions. Propensity score adjustment was utilized to compare treatment strategies. The cohort included 252 SPC (surgical shunt = 226, ductus arteriosus stent = 26) and 68 RVOTI (balloon pulmonary valvuloplasty = 48, RVOT stent = 11, RVOT patch = 9) patients. Genetic syndrome (29 [42.6%] v 75 [29.8%], p = 0.04), weight < 2.5 kg (28 [41.2%] v 68 [27.0%], p = 0.023), bilateral pulmonary artery Z-score < - 2 (19 [28.0%] v 36 [14.3%], p = 0.008), and pre-intervention antegrade flow (48 [70.6%] v 104 [41.3%], p < 0.001) were more common in RVOTI. Significant center differences were noted (p < 0.001). Adjusted survival to CR by 18 months (HR = 0.87, 95% CI = 0.63-1.21, p = 0.41) and overall survival (HR = 2.08, 95% CI = 0.93-4.65, p = 0.074) were similar. RVOTI had increased interstage reintervention (HR = 2.15, 95% CI = 1.36-3.99, p = 0.001). Total anesthesia (243 [213, 277] v 328 [308, 351] minutes, p < 0.001) and cardiopulmonary bypass times (117 [103, 132] v 151 [143, 160] minutes, p < 0.001) favored RVOTI. In this multicenter comparison of physiologic palliation strategies for sTOF, survival to successful CR and overall survival were similar; however, reintervention burden was significantly higher in RVOTI.

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.

Transcatheter Cardiac Interventions in the Newborn: JACC Focus Seminar

For neonates with critical congenital heart disease requiring intervention, transcatheter approaches for many conditions have been established over the past decades. These interventions may serve to stabilize or palliate to surgical next steps or effectively primarily treat the condition. Many transcatheter interventions have evidence-based records of effectiveness and safety, which have led to widespread acceptance as first-line therapies. Other techniques continue to innovatively push the envelope and challenge the optimal strategies for high-risk neonates with right ventricular outflow tract obstruction or ductal-dependent pulmonary blood flow. In this review, the most commonly performed neonatal transcatheter interventions will be described to illustrate the current state of the field and highlight areas of future opportunity.

Right ventricular outflow tract anomalies: Neonatal interventions and outcomes

Right ventricular outflow tract (RVOT) anomalies comprise a wide spectrum of congenital heart disease, typically characterized by obstruction to flow from the right ventricle to pulmonary arteries. This review highlights important considerations surrounding management strategy as well as clinical outcomes for the neonate with RVOT anomaly, including: pulmonary atresia with intact ventricular septum, congenital pulmonary valve stenosis, tetralogy of Fallot, and Ebstein anomaly with anatomic or physiologic RVOT obstruction.

Anomalous coronary artery in Tetralogy of Fallot-Feasibility of right ventricular outflow tract stenting as initial palliation

This study addresses the outcome of right ventricle outflow tract (RVOT) stenting in Tetralogy of Fallot (ToF) with anomalous coronaries crossing the RVOT. RVOT stenting in ToF patients has emerged as an alternative to Blalock Taussig shunting. This is a single center study of patients who underwent RVOT stenting for symptomatic ToF at Birmingham Children's Hospital between 2005 and 2020. A total of 122 patients underwent RVOT stenting as initial palliation over a 15-year period, 10 patients had anomalous coronaries crossing the RVOT (study group) and 112 not (comparative group). Median age of the study group was 72.5 days (interquartile range [IQR]: 28-103) with a weight of 4.7 kg (IQR: 3.5-4.9). No significant differences were found between the two groups regarding the patients' weights and ages, procedure and screening times, or hospital stay. Four had valve sparing stenting. Oxygen saturations increased from a median of 75.5% (IQR: 70-82) to 94.5% (IQR: 90-95), p < 0.002. Postprocedure median hospital stay was 3 days (IQR: 2-6). Six patients underwent interstage catheterization reintervention and one needed early surgical palliation due to stent suboptimal position. Complete repair could be delayed for a median of 11.1 months (IQR: 5.6-19.2). At surgical repair, the patients had a median age of 12.3 months (IQR: 7.5-25.6) and weight of 7.7 kg (IQR: 6.8-10.8). There were no deaths. RVOT stenting in ToF with anomalous coronaries is safe and effective. Dilatable stents should be used when two-stage delayed conduit repair is the default approach.

Surgical versus transcatheter palliation for insufficient pulmonary blood supply in infants with cyanotic CHD

Infants with complex cyanotic CHD can become symptomatic from insufficient pulmonary blood supply following either ductal closure or due to outflow tract obstruction. Blalock-Taussig shunt mortality remains significant and recent studies have highlighted the advantages of using transcatheter alternatives. We present here our experience in changing our primary choice of palliation from the Blalock-Taussig shunt to transcatheter palliation with either a ductal stent or, if antegrade flow is present, a right ventricular outflow tract stent.This is a retrospective, single-unit cohort study. Eighty-seven infants underwent palliation for insufficient pulmonary blood flow at under 3 months of age between 2012 and 2019. On an intention-to-treat basis, 29 underwent insertion of a Blalock-Taussig shunt, 36 duct stents, and 22 right ventricular outflow tract stents at median ages of 15, 9, and 32 days, respectively, and median weights of 3.3, 3.1, and 3.1 kg, respectively. No primary Blalock-Taussig shunts have been performed in our institution since 2017.At 30-days there had been one death in each group (univariable p = 0.93) and deaths prior to repair totalled three in the shunt group, four in the ductal stent group, and two in the right ventricular outflow tract stent group (univariable p = 0.93). Reintervention on the pulmonary circuit prior to next stage of surgery was more frequent in those undergoing transcatheter intervention, reaching statistical significance by logrank (p = 0.012).In conclusion, within this work we provide further evidence of the safety and efficacy of transition from a primary surgical to primary transcatheter palliation pathway in infants with insufficient pulmonary blood supply.

In-hospital Morbidity and Mortality Following Modified Blalock-Taussig-Thomas Shunts

BACKGROUND

The modified Blalock-Taussig-Thomas shunt (mBTTs) is a critically important palliation for patients with insufficient pulmonary blood flow associated with congenital heart disease. Following creation of a mBTTs, patients experience high rates of early postoperative morbidity and mortality.

METHODS

This is a single-institution retrospective cohort study. A query of the Society of Thoracic Surgeons database identified relevant patients whose health records were manually queried for echocardiography and operative reports. Patients with ductal-dependent systemic circulation were excluded. Primary outcomes were early serious adverse events and in-hospital mortality. Secondary outcomes were time to primary outcomes and postoperative lengths of stay. We investigated the correlation of demographics, presence of competitive pulmonary blood flow, and surgical and anatomic factors on outcomes.

RESULTS

After exclusions, our cohort resulted in 155 patients. 33 (21.3%) patients experienced an early serious adverse event, ten (6.5%) early shunt malfunction, and 11 (7.1%) in-hospital mortality. Smaller shunt size, smaller shunted pulmonary artery size, surgical approach, and site of proximal shunt anastomosis were independently associated with morbidity and mortality.

CONCLUSIONS

Anatomical elements imparting increased resistance along the mBTTs predispose to increased morbidity and mortality, particularly in the early postoperative period. Despite the significant heterogeneity of patients receiving such shunts, similar risk profiles are observed regardless of lesion or presence of competitive flow. Surgical approach via thoracotomy with shunt anastomosis to the subclavian artery, where feasible, results in the subclavian artery as the point of natural resistance allowing for placement of larger shunts, yielding lower morbidity and mortality.

Right ventricular afterload in repaired D-TGA is associated with inefficient flow patterns, rather than stenosis alone

Treatment of D- transposition of great arteries (DTGA) involves the Arterial Switch Operation (ASO), which can create PA branch stenosis (PABS) and alter PA blood flow energetics. This altered PA flow may contribute to elevated right ventricular (RV) afterload more significantly than stenosis alone. Our aim was to correlate RV afterload and PA flow characteristics using 4D flow cardiac magnetic resonance (CMR) imaging of a mock circulatory system (MCS) incorporating 3D printed replicas. CMR imaging and clinical characteristics were analyzed from 22 ASO patients (age 11.9 ± 8.7 years, 68% male). Segmentation was performed to create 3D printed PA replicas that were mounted in an MRI-compatible MCS. Pressure drop across the PA replica was recorded and 4D flow CMR acquisitions were analyzed for blood flow inefficiency (energy loss, vorticity). In post-ASO patients, there is no difference in RV mass (p = 0.07), nor RV systolic pressure (p = 0.26) in the presence or absence of PABS. 4D flow analysis of MCS shows energy loss is correlated to RV mass (p = 0.01, r = 0.67) and MCS pressure differential (p = 0.02, r = 0.57). Receiver operating characteristic curve shows energy loss detects elevated RV mass above 30 g/m² (p = 0.02, AUC 0.88) while index of PA dimensions (Nakata) does not (p = 0.09, AUC 0.79). PABS alone does not account for differences in RV mass or afterload in post-ASO patients. In MCS simulations, energy loss is correlated with both RV mass and PA pressure, and can moderately detect elevated RV mass. Inefficient PA flow may be an important predictor of RV afterload in this population.

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.

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.

Palliative Endovascular Intervention in Infants with Tetralogy of Fallot: A Case Series

Fundamento

Tendo em vista os casos de lactentes sintomáticos com Tetralogia de Fallot (TF), baixo peso ao nascimento e anatomia complexa, o implante de stent na via de saída do ventrículo direito (VSVD) tem sido indicado alternativamente à cirurgia de Blalock-Taussig (BT).

Objetivo

Avaliar o implante endovascular de stent na VSVD como abordagem primária no lactente com TF e não candidato à cirurgia de BT, bem como relatar seus resultados a médio prazo e até a retirada do stent na cirurgia corretiva.

Métodos

Entre outubro de 2015 e abril de 2018, uma série de seis lactentes portadores de TF receberam stents para desobstrução da VSVD. Os parâmetros hemodinâmicos foram comparados em períodos pré e pós-implante.

Resultados

As medianas de idade e peso no momento do procedimento foram de 146,5 dias e 4,9 kg, respectivamente. O gradiente sistólico máximo diminuiu de 63,5 mmHg para 50,5 mmHg, enquanto o diâmetro dos ramos pulmonares direito e esquerdo aumentou de 3,5 mm para 4,9 mm e 4,3 mm, respectivamente. O índice de Nakata aumentou de 96,5 mm para 108,3 mm; assim como o peso, de 4,9 kg para 5,5 kg. A saturação de oxigênio aumentou de 83,5% para 93%. Houve um caso de migração do stent e dois óbitos, um deles devido à embolização do stent e o outro não teve relação com o procedimento.

Conclusões

O implante de stent na VSVD como procedimento paliativo na TF se mostra uma alternativa promissora para o tratamento de lactentes com má anatomia e baixo peso ao nascimento.

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.

Right ventricular outflow tract stenting in symptomatic infants without the use of a long delivery sheath

BACKGROUND AND OBJECTIVES

Right ventricular outflow tract (RVOT) stenting improves systemic oxygenation and facilitates pulmonary arterial growth in symptomatic infants prior to repair of tetralogy of Fallot. The aim of this study was to evaluate the safety and efficacy of RVOT stenting without the use of a long delivery sheath.

METHODS

Retrospective data analysis of patients under 1 year of age undergoing RVOT stenting from January 2010 to January 2020 at a single tertiary pediatric cardiology center.

RESULTS

Sixty-three RVOT stents were deployed during 53 procedures into 44 patients. The median age and weight at insertion were 41 days (range 2-204) and 3.6 kg (range 1.59-7) respectively. Thirty-one procedures were semi-elective and 22 were emergencies. Stent positioning was guided by transthoracic echocardiogram and/or RV angiography from a pigtail micro-catheter placed via the aorta. The median total procedure and fluoroscopy times were 67.5 (range 15-145) and 19 min (1-107), respectively. The median length of hospital stay was 7 days (range 1-258). Twenty-one patients were admitted to ICU post-procedure with a median ICU length of stay of 3 days (range 3-11). There were three major complications including two deaths within 30 days of the procedure. A patient with Cornelia de Lange Syndrome (1.8 kg) died following stent migration and inability to wean from emergency cardiopulmonary bypass and the second infant had an unexplained asystolic arrest post-procedure while awaiting transfer to ICU.

CONCLUSIONS

RVOT stenting is technically possible with minimal complications without the need for a long delivery sheath. Additional imaging with transthoracic echocardiography can facilitate the safe deployment of the stent.

[The adult with tetralogy of fallot: what the clinical cardiologist needs to know]

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease. After more than seven decades of the first palliative surgery, TOF prognosis has changed dramatically. The prevalence of TOF is approximately 3 per 10 000 births, representing 7 to 10% of congenital heart disease. With a higher survival into adulthood, the clinical cardiologist faces challenges in the management of this population, from severe pulmonary regurgitation to heart failure and ventricular arrhythmias. Its prevalence is approximately 3 per 10 000 live births, representing 7 to 10% of congenital heart disease. This review will describe the most relevant aspects of the care of adult patients with this disease.

Comparison of Management Strategies for Neonates With Symptomatic Tetralogy of Fallot

BACKGROUND

Neonates with tetralogy of Fallot and symptomatic cyanosis (sTOF) require early intervention.

OBJECTIVES

This study sought to perform a balanced multicenter comparison of staged repair (SR) (initial palliation [IP] and subsequent complete repair [CR]) versus primary repair (PR) treatment strategies.

METHODS

Consecutive neonates with sTOF who underwent IP or PR at ≤30 days of age from 2005 to 2017 were retrospectively reviewed from the Congenital Cardiac Research Collaborative. The primary outcome was death. Secondary outcomes included component (IP, CR, PR) and cumulative (SR): hospital and intensive care unit lengths of stay; durations of cardiopulmonary bypass, anesthesia, ventilation, and inotrope use; and complication and reintervention rates. Outcomes were compared using propensity score adjustment.

RESULTS

The cohort consisted of 342 patients who underwent SR (IP: surgical, n = 256; transcatheter, n = 86) and 230 patients who underwent PR. Pre-procedural ventilation, prematurity, DiGeorge syndrome, and pulmonary atresia were more common in the SR group (p ≤0.01). The observed risk of death was not different between the groups (10.2% vs 7.4%; p = 0.25) at median 4.3 years. After adjustment, the hazard of death remained similar between groups (hazard ratio: 0.82; 95% confidence interval: 0.49 to 1.38; p = 0.456), but it favored SR during early follow-up (<4 months; p = 0.041). Secondary outcomes favored the SR group in component analysis, whereas they largely favored PR in cumulative analysis. Reintervention risk was higher in the SR group (p = 0.002).

CONCLUSIONS

In this multicenter comparison of SR or PR for management of neonates with sTOF, adjusted for patient-related factors, early mortality and neonatal morbidity were lower in the SR group, but cumulative morbidity and reinterventions favored the PR group, findings suggesting potential benefits to each strategy.

Are early palliative procedures providing an adequate long-term benefit in young cyanotic infants from developing countries, despite advances in surgery and interventions?

OBJECTIVES

Ductal stents, right ventricular outflow tract stents, and aortopulmonary shunts are used to palliate newborns and infants with reduced pulmonary blood flow. Current long-term outcomes of these palliations from resource-restricted countries are unknown.

METHODS

This single-centre, retrospective, observational study analysed the technical success, immediate and late mortality, re-interventions, and length of palliation in infants ≤5 kg who underwent aortopulmonary shunts, ductal, and pulmonary outflow stents. Patients were grouped by their anatomy.

RESULTS

There were 69 infants who underwent one of the palliations. Technical success was 90% for aortopulmonary shunts (n = 10), 91% for pulmonary outflow stents (n = 11) and 100% for ductal stents (n = 48). Early mortality within 30 days in 12/69 patients was observed in 20% after shunts, 9% after pulmonary outflow stents, and 19% after ductal stents. Late mortality in 11 patients was seen in 20% after shunts, 18% after outflow stents, and 15% after ductal stents. Seven patients needed re-interventions; two following shunts, one following outflow stent, and four following ductal stents for hypoxia. Among the anatomical groups, 10/12 patients with pulmonary atresia, intact ventricular septum survived after valvotomy and ductal stenting. Survival to Glenn shunt after ductal stent for pulmonary atresia, intact ventricular septum and diminutive right ventricle was very low in two out of eight patients, but very good (100%) for other univentricular hearts. Among 35 patients with biventricular lesions, 22 survived to the next stage.

CONCLUSIONS

Cyanotic infants, despite undergoing technically successful palliation had a high inter-stage mortality irrespective of the type of palliation. Duct stenting in univentricular hearts and in pulmonary atresia with an intact ventricular septum and adequate sized right ventricle tended to have low mortality and better long-term outcome. Completion of biventricular repair after palliation was achieved only in 63% of patients, reflecting unique challenges in developing countries despite advances in intensive care and interventions.

Stenting of the right ventricular outflow tract as an initial intervention in Tetralogy of Fallot with pulmonary stenosis and major aortopulmonary collateral arteries

OBJECTIVES

To assess the role of right ventricular outflow tract stenting as the primary intervention in Tetralogy of Fallot with pulmonary stenosis and major aortopulmonary collateral arteries.

BACKGROUND

The management of a subset of infants with Tetralogy of Fallot with pulmonary stenosis and major aortopulmonary collateral arteries requires a staged approach including rehabilitation of diminutive native pulmonary arteries, conventionally using an aortopulmonary shunt. We share our experience of pulmonary artery rehabilitation with right ventricular outflow tract stenting.

METHODS

Retrospective review of all patients with Tetralogy of Fallot with pulmonary stenosis who underwent right ventricular outflow tract stenting as primary intervention over an 8-year period.

RESULTS

Ten patients underwent right ventricular outflow tract stent insertion at a median age of 61 days (interquartile range (IQR) 8.3-155 days). Median weight at stent deployment was 4.2 kg (IQR 3.2-5.7 kg). Oxygen saturations improved from a median of 79% (IQR 76-80%) to 92% (IQR 90-95%), p = 0.012. The median right and left pulmonary artery z score increased from -3.51 (IQR -4.59 to -2.80) and -2.07 (IQR -3.72 to 0.15) to a median of -1.17 (IQR -2.26 to 0.16) p < 0.05, and 0.24 (IQR -1.09 to 1.84) p < 0.05, respectively, at subsequent angiogram. Nine patients underwent further catheterisation. Four patients underwent complete anatomical repair. Only one patient required unifocalisation, as most patients had a native supply to all-important lung segments.

CONCLUSION

Right ventricular outflow tract stenting is a useful procedure in the subset of patients with Tetralogy of Fallot with pulmonary stenosis and major aortopulmonary collateral arteries, where native pulmonary arterial growth is required to facilitate repair.

Comparison of management strategies for neonates with symptomatic tetralogy of Fallot and weight <2.5 kg

OBJECTIVE

To compare management strategies for neonates <2.5 kg with tetralogy of Fallot and symptomatic cyanosis who either undergo staged repair (SR) (initial palliation followed by later complete repair) or primary repair (PR).

METHODS

Consecutive neonates with tetralogy of Fallot and symptomatic cyanosis weighing <2.5 kg at initial intervention and between 2005 and 2017 were retrospectively reviewed from the Congenital Cardiac Research Collaborative. Primary outcome was mortality and secondary outcomes included component (eg, initial palliation, complete repair, or primary repair) and cumulative (SR: initial palliation followed by later complete repair) hospital and intensive care unit lengths of stay, durations of ventilation, inotrope use, cardiopulmonary bypass time, procedural complications, and reintervention. Outcomes were compared with propensity score adjustments with PR as the reference group.

RESULTS

The cohort included 76 SR (initial palliation: 53 surgical and 23 transcatheter) and 44 PR patients. The observed risk of overall mortality was similar between SR and PR groups (15.8% vs 18.2%: P = .735). The adjusted hazard of mortality remained similar between groups overall (hazard ratio, 0.59; 95% confidence interval, 0.26-1.36; P = .214), as well as during short-term (<4 months: hazard ratio, 0.37; 95% confidence interval, 0.13-1.09; P = .071) and midterm (>4 months: hazard ratio, 1.32; 95% confidence interval, 0.30-5.79; P = .717) follow-up. Reintervention in the first 18 months was common in both groups (53.2% vs 48.4%; hazard ratio, 1.69; 95% confidence interval, 0.96-2.28; P = .072). Adjusted procedural complications and neonatal morbidity burden were overall lower in the SR group. Cumulative secondary outcome burdens largely favored the PR group.

CONCLUSIONS

In this study comparing SR and PR treatment strategies for neonates with tetralogy of Fallot and symptomatic cyanosis and weight <2.5 kg, mortality and reintervention burden was highly independent of treatment strategy. Other potential advantages were observed with each approach.

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.

Short to medium term outcomes of right ventricular outflow tract stenting as initial palliation for symptomatic infants with complete atrioventricular septal defect with associated tetralogy of Fallot

OBJECTIVES

To assess the impact of right ventricular outflow tract (RVOT) stenting as the primary palliation in infants with complete atrioventricular septal defect with associated tetralogy of Fallot (cAVSD/TOF).

BACKGROUND

Historically, palliation of symptomatic patients with cAVSD/TOF has been achieved through surgical systemic to pulmonary artery shunting. More recently RVOT stenting has evolved as an acceptable alternative in patients with tetralogy of Fallot.

METHODS

Retrospective review of all patients with cAVSD/TOF who underwent RVOT stenting as palliation over a 13-year period from two large tertiary referral centers.

RESULTS

Twenty-six patients underwent RVOT stenting at a median age of 57 days (interquartile range [IQR] 25.5-106.5). Median weight for stent deployment was 3.7 kg (IQR 2.91-5.5 kg). RVOT stenting improved oxygen saturations from a median of 72% (IQR 70-76%) to 90% (IQR 84-92%), p < .001. There was a significant increase in the median Z-score for both branch pulmonary arteries at median follow-up of 255 days (IQR 60-455). Eight patients required RVOT stent balloon dilatations and 8 patients required re-stenting for progressive desaturation. The median duration between reinterventions was 122 days (IQR 53-294 days). Four patients died during the follow-up period. No deaths resulted from the initial intervention. To date, definitive surgical intervention was achieved in 19 patients (biventricular repair n = 15) at a median age of 369 days (IQR 223-546 days).

CONCLUSION

RVOT stenting in cAVSD/TOF is a safe and effective palliative procedure in symptomatic infants, promoting pulmonary artery growth and improving oxygen saturations.

Hybrid Approach for Embolized Right Ventricular Outflow Tract Stent

Displacement and embolization of the stent is one of the major complications of right ventricular outflow tract (RVOT) stenting. Since embolized stents cannot be retrieved percutaneously as they cannot be crimped into pre-stenting state (unlike duct occluders and septal devices, which can be pulled back into the sheath), surgery remains the gold standard treatment. We describe a hybrid approach for the retrieval of the embolized RVOT stent, which will decrease morbidity when compared to the standard surgical approach that is otherwise required.

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.

Can We Still Improve Survival Outcomes of Neonatal Biventricular Repairs?

BACKGROUND

We sought to identify modifiable factors to improve survival of neonatal biventricular repair by analyzing the cause of death and predictors of mortality and reintervention in the last 2 decades.

METHODS

Between 1995 and 2016, 991 consecutive neonates were included. The cohort was divided by era: era I was from 1995 to 1999, era II 2000 to 2007, and era III 2008 to 2016. The Kaplan-Meier method was used to estimate freedom from death and reintervention. Univariable and multivariable Cox regression was applied to assess predictors for mortality or reintervention in the contemporary cohorts (2000-2016).

RESULTS

Median age was 8 days (range, 5-13), and median body weight at operation was 3.3 kg (range, 2.9-3.6). The most common diagnosis was transposition with intact ventricular septum (32%), followed by transposition with ventricular septal defect (14.5%), and simple left-to-right shunt lesion (10.9%). There was significant improvement in survival from era I to eras II and III but no difference between eras II and III (1 year: 82.1% vs 89.4% vs 89.6%, respectively; P < .001). The most common cause of death was sudden death in eras I and III and cardiac in era II. Multivariable analysis revealed preoperative (P = .005)/postoperative (P < .001) extracorporeal membrane oxygenation and postoperative renal replacement (P < .001) as independent predictors for mortality. The reintervention rates were comparable between eras II and III (P = .53). Atrioventricular septal defects and common atrial trunk were identified as predictors for reintervention.

CONCLUSIONS

Survival after neonatal biventricular repair remained unchanged. Preventing sudden death, myocardial protection, and minimizing residual lesions are potential targets to improve outcomes.

Current outcomes and treatment of tetralogy of Fallot

Tetralogy of Fallot (ToF) is the most common type of cyanotic congenital heart disease. Since the first surgical repair in 1954, treatment has continuously improved. The treatment strategies currently used in the treatment of ToF result in excellent long-term survival (30 year survival ranges from 68.5% to 90.5%). However, residual problems such as right ventricular outflow tract obstruction, pulmonary regurgitation, and (ventricular) arrhythmia are common and often require re-interventions. Right ventricular dysfunction can be seen following longstanding pulmonary regurgitation and/or stenosis. Performing pulmonary valve replacement or relief of pulmonary stenosis before irreversible right ventricular dysfunction occurs is important, but determining the optimal timing of pulmonary valve replacement is challenging for several reasons. The biological mechanisms underlying dysfunction of the right ventricle as seen in longstanding pulmonary regurgitation are poorly understood. Different methods of assessing the right ventricle are used to predict impending dysfunction. The atrioventricular, ventriculo-arterial and interventricular interactions of the right ventricle play an important role in right ventricle performance, but are not fully elucidated. In this review we present a brief overview of the history of ToF, describe the treatment strategies currently used, and outline the long-term survival, residual lesions, and re-interventions following repair. We discuss important remaining challenges and present the current state of the art regarding these challenges.

Interventional Treatment of Cardiac Emergencies in Children with Congenital Heart Diseases

Cardiac emergencies in children represent an extremely important issue in medical practice. In general, interventional treatment could be optional in many situations, however it can be indicated in emergency conditions. There are many diseases at pediatric age that can benefit from interventional treatment, thus reducing the surgical risks and subsequent complications. Balloon atrioseptostomy, patent ductus arteriosus (PDA) closure, percutaneous or hybrid closure of a ventricular septal defect, pulmonary or aortic valvuloplasty, balloon angioplasty for aortic coarctation, implantation of a stent for coarctation of the aorta, for severe stenosis of the infundibulum of the right ventricle, or for PDA correction are among the procedures that can be performed in emergency situations. This review aims to present the current state of the art in the field of pediatric interventional cardiology.

Hybrid procedure of right ventricle outflow tract stenting in small infants with pulmonary atresia and ventricular septal defect: early and mid-term results from a single centre

IntroductionPulmonary atresia, ventricular septal defect, major aorto-pulmonary collateral arteries, and pulmonary arteries hypoplasia are rare and complex congenital defects that require early interventions to relieve cyanosis and enhance the growth of native pulmonary arteries. The treatment of these patients is still controversial. Surgical techniques require cardiopulmonary bypass which is poorly tolerated by small infants. Percutaneous techniques such as radiofrequency perforation can be challenging. The hybrid technique consists of perventricular stenting of the right ventricle outflow tract through medial sternotomy, to restore native pulmonary flow.

METHODS

We retrospectively reviewed the cardiovascular database of our centre in order to analyse our experience in hybrid procedure. We detected six patients who underwent hybrid first approach between November 2007 and December 2015. We report our early results and mid-term outcomes.

RESULTS

Median age at the procedure was 26 days, median weight was 3150 g, and median Nakata index was 52 mm2/m2. All procedures were successful except for one: this patient underwent a surgical shunt. No immediate and early deaths or major complications occurred and oxygen saturation levels increased in all the patients. Patients were followed up for a period of 12-103 months, and four of them underwent a procedure of unifocalisation at the mean age of 12.5 months.

CONCLUSIONS

We reported data from the largest series of patients who underwent this hybrid procedure. Our experience demonstrated encouraging results to expand the use of this approach to bridge high-risk patients with diminutive pulmonary arteries to a second step of surgical repair.

EDUCATIONAL SERIES IN CONGENITAL HEART DISEASE: Tetralogy of Fallot: diagnosis to long-term follow-up

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect, affecting 3 in 10,000 live births. Surgical correction in early childhood is associated with good outcomes, but lifelong follow-up is necessary to identify the long-term sequelae that may occur. This article will cover the diagnosis of TOF in childhood, the objectives of surveillance through adulthood and the value of multi-modality imaging in identifying and guiding timely surgical and percutaneous interventions.