Stenting of the right ventricular outflow tract in the high-risk infant with cyanotic teratology of Fallot

Right ventricular outflow tract stenting for late presenter unrepaired Fallot physiology: a single-center experience

Objectives

The purpose of this study was to assess the clinical outcome after right ventricular outflow tract (RVOT) stenting in late presenter patient with unrepaired Fallot physiology.

Background

In younger patients, RVOT stenting is an alternative to mBTT shunt; however, there have been few reports of this palliative technique in late presenter population, including adults.

Methods

This was a single-center, retrospective study of nonrandomized, palliated Fallot patients. Clinical outcomes such as left ventricular ejection fraction and saturation were measured in 32 individuals following RVOT stenting in adults (n = 10) and children (n = 22). The Statistical Package for Social Science (SPSS) 26.0 software was used to analyze the statistical data.

Results

During the procedure, the average stent diameter and length were 8.84 ± 1.64 mm and 35.46 ± 11.23 mm, respectively. Adult patients received slightly longer stents than pediatric patients (43.60 ± 11.64 mm vs. 31.77 ± 9.07 mm). Overall, patients' saturation increased from 58.56 ± 19.03% to 91.03 ± 8.98% (p < 0.001), as did their left ventricular ejection fraction (LVEF) from 64.00 ± 18.21% to 75.09 ± 12.98% (p = 0.001). Three patients improved their LVEF from 31 to 55%, 31 to 67%, and 26 to 50%. The median length of stay was 8 (2-35) days, with an ICU stay of 2 (0-30) days. The median time from RVOT stent palliation to total repair was 3 months (range: 1 month-12 months).

Conclusions

RVOT stenting is a safe and effective method for increasing saturation and ejection fraction not only in newborn infants but also in late presenters, including adults with unrepaired Fallot physiology.

Advances in the Treatment of Pulmonary Valve Stenosis

Pulmonary valve stenosis represents the most common congenital heart defect of dogs and appears to be increasing in prevalence due to the growing popularity of brachycephalic breeds. Current treatments include beta-blockade and balloon pulmonary valvuloplasty, though evidence-based approaches to this disease are lacking. Balloon pulmonary valvuloplasty is most effective for fused, doming valves leaving a large population of dogs with thick, dysplastic valves that fail to respond adequately to balloon dilation. Transpulmonary stent implantation is an emerging therapy to consider for dogs with valve dysplasia or who have failed balloon pulmonary valvuloplasty; current experience with transpulmonary stent implantation is provided.

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.

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.

Fetal cardiac parameters for predicting postnatal operation type of fetuses with tetralogy of Fallot

Background

To assess fetal cardiac parameters predictive of postnatal operation type in fetuses with tetralogy of Fallot (TOF).

Methods

Echocardiographic data obtained in the second and third trimesters were retrospectively reviewed for fetuses diagnosed with TOF between 2014 and 2018 at Asan Medical Center. The following fetal cardiac parameters were analyzed: 1) pulmonary valve annulus (PVA) z-score, 2) right pulmonary artery (RPA) z-score, 3) aortic valve annulus (AVA) z-score, 4) pulmonary valve peak systolic velocity (PV-PSV), 5) PVA/AVA ratio, and 6) RPA/descending aorta (DAo) ratio. These cardiac parameters were compared between a primary corrective surgery group and a palliative shunt operation followed by complete repair group.

Results

A total of 100 fetuses with TOF were included. Only one neonatal death occurred. Ninety patients underwent primary corrective surgery and 10 neonates underwent a multistage surgery. The PVA z-score, RPA z-score, and RPA/DAo ratio measured in the second trimester and the PVA z-score, RPA z-score, and PVA/AVA raio measured in the third trimester were significantly lower in the multistage surgery group, while the PV-PSV as measured in both trimesters were significantly higher in the multistage surgery group.

Conclusion

Fetal cardiac parameters are useful for predicting the operation type necessary for neonates with TOF.

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.

Learning from a case of right ventricular outflow tract stenting in tricuspid atresia with critical pulmonary stenosis

Tricuspid valve atresia with severe pulmonary stenosis is one of the common cyanotic diseases in neonate. Child can succumb due to profound cyanosis and arterial hypoxaemia after closure of patent ductus arteriosus. Evolving procedure of right ventricular outflow tract stenting may be considered as a palliative procedure in such vulnerable group, destined for a later definitive management. The right ventricular outflow tract stenting is described essentially for tetralogy of Fallot physiology with a catheter course across tricuspid valve. We describe a case of successful right ventricular outflow tract stenting in a 5-day-old symptomatic neonate. We discuss the possible routes and the tips to facilitate right ventricular outflow tract stenting in such a case. This happens to be the first reported case description with successful stenting of neonate with tricuspid atresia with critical pulmonic stenosis.

Right ventricular outflow tract stenting during neonatal and infancy periods: A multi-center, retrospective study

Background

The aim of this study was to evaluate the outcomes of right ventricular outflow tract stenting for palliation during the newborn and infancy periods.

Methods

Between January 2013 and January 2018, a total of 38 patients (20 males, 18 females; median age 51 days; range, 3 days to 9 months) who underwent transcatheter right ventricular outflow tract stenting in three centers were retrospectively analyzed. Demographic characteristics, cardiac pathologies, angiographic procedural, and clinical follow-up data of the patients were recorded.

Results

The diagnoses of the cases were tetralogy of Fallot (n=27), double outlet right ventricle (n=8), complex congenital heart disease (n=2), and Ebstein"s anomaly (n=1). The median weight at the time of stent implantation was 3.5 (range, 2 to 10) kg. Five cases had genetic abnormalities. The median pre-procedural oxygen saturation was 63% (range, 44 to 80%), and the median procedural time was 60 (range, 25 to 120) min. Acute procedural success ratio was 87%. Reintervention was needed in seven of patients due to stent narrowing during follow-up. During follow-up period, seven cases died. Total correction surgery was performed in 26 patients without any mortality. While a transannular patch was used in 22 patients, valve protective surgery was implemented in two patients, and the bidirectional Glenn procedure was performed in two patients.

Conclusion

Based on our study results, right ventricular outflow tract stenting is a form of palliation which should be considered particularly in cases in whom total correction surgery is unable to be performed due to morbidity.

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.

Anesthesia for high-risk procedures in the catheterization laboratory

Recent advances in catheterization and imaging technology allow for more complex procedures to be performed in the catheterization laboratory. A number of lesions are now amenable to a percutaneous procedure, eliminating or at least postponing the need for a surgical intervention. Due to the increase in the complexity of the procedures performed, the involvement of anesthesiologists and their close collaboration with the interventional cardiologists have increased. It is important to understand the physiology and pathophysiology of the patients and to anticipate the plans and the potential complications in order to manage them. We are witnessing a rise in the number of complex interventions in newborns and infants, such as balloon valvotomy (critical aortic stenosis, pulmonary stenosis), radio frequency perforation (of pulmonary atresia and intact ventricular septum), right ventricular outflow tract stenting (in Tetralogy of Fallot), ductal stenting (in some ductus-dependent pulmonary circulation), and combined with a surgical procedure (hybrid procedure for hypoplastic left heart syndrome). Multiple registries have been created in order to understand and improve outcomes of patients with congenital heart disease undergoing catheterization procedures and to develop performance and quality metrics, from which data regarding anesthetic-related risks can be extrapolated. Experienced personnel and a multidisciplinary team approach with direct communication among the team members is a must to ensure anticipation and management of critical events when they occur.

Surgical repair of Tetralogy of Fallot following primary palliation: Right ventricular outflow track stenting versus modified Blalock-Taussig shunt

Background

Tetralogy of Fallot (TOF) is a cyanotic disease requiring early intervention. We assessed the effect of right ventricular outflow tract (RVOT) stenting versus modified Blalock-Taussig shunt (mBTS) on outcomes of surgical repair of TOF.

Methods

Fifteen palliated TOF infants underwent complete repair surgery. RVOT stenting was performed in seven infants and mBTS was done in eight infants. Data on sequential patients who underwent surgery were collected and reviewed retrospectively.

Results

Stenting group were significantly younger (1.62 ± 0.34 vs 2.80 ± 0.52, p = 0.001), had lower body weight (3.28 ± 0.48 vs 5.03 ± 0.67, p = 0.001) and lesser body surface area (0.20 ± 0.01 vs 0.26 ± 0.20, p = 0.001) than the mBTS group at palliation. Mean right pulmonary artery (RPA) diameter in stenting group at palliation was 2.9 ± 0.54 mm (z-score -3.08 ± 0.97) and increased at surgery to 4.6 ± 0.49 mm (z-score –0.79 ± 0.66) (p = 0.001). The mean left pulmonary artery (LPA) diameter was 2.5 ± 0.42 mm (z-score -3.3 ± 0.86), which increased to 3.3 ± 0.40 mm (z-score -2.2 ± 0.74) at surgery (p = 0.005). The mean RPA diameter in mBTS group at palliation was 3.2 ± 0.32 mm (z-score –2.9 ± 0.70) and increased at surgery to 4.3 ± 0.55 mm (z-score –1.1 ± 0.94) (p = 0.001). The mean LPA diameter was 2.8 ± 0.26 mm (z-score -3.3 ± 0.62), which increased to 3.2 ± 0.24 mm (z-score –2.4 ± 0.52) at surgery (p = 0.032). Repeat echocardiography showed significant increase in McGoon ratio and Nakata index in both groups (p = 0.001). No significant differences were seen between the two groups regarding surgical procedure and postoperative complications.

Conclusion

RVOT stenting is a safe and effective approach instead of mBTS in hazardous TOF infants with hypercyanotic spell, small PAs and complex anatomies.

Cardiac Interventions in Small Animals: Areas of Uncertainty

There remain areas of uncertainty in optimal technique, preferred candidates, and expected outcome for small animal patients undergoing cardiac intervention. This article highlights issues within interventional cardiology that are in need of study and offers the author's opinion and experience on topics such as variants of pulmonary valve anatomy and alternatives to conventional balloon dilation for pulmonary valve stenosis, patient selection for cutting or high-pressure balloon dilation of aortic valvar or subaortic stenosis, occlusion of patent ductus arteriosus in very small dogs, ductal stenting in conditions with reduced pulmonary blood flow, and alternative considerations for vascular access and closure.

Recent advances in cardiac catheterization for congenital heart disease

The field of pediatric and adult congenital cardiac catheterization has evolved rapidly in recent years. This review will focus on some of the newer endovascular technological and management strategies now being applied in the pediatric interventional laboratory. Emerging imaging techniques such as three-dimensional (3D) rotational angiography, multi-modal image fusion, 3D printing, and holographic imaging have the potential to enhance our understanding of complex congenital heart lesions for diagnostic or interventional purposes. While fluoroscopy and standard angiography remain procedural cornerstones, improved equipment design has allowed for effective radiation exposure reduction strategies. Innovations in device design and implantation techniques have enabled the application of percutaneous therapies in a wider range of patients, especially those with prohibitive surgical risk. For example, there is growing experience in transcatheter duct occlusion in symptomatic low-weight or premature infants and stent implantation into the right ventricular outflow tract or arterial duct in cyanotic neonates with duct-dependent pulmonary circulations. The application of percutaneous pulmonary valve implantation has been extended to a broader patient population with dysfunctional ‘native’ right ventricular outflow tracts and has spurred the development of novel techniques and devices to solve associated anatomic challenges. Finally, hybrid strategies, combining cardiosurgical and interventional approaches, have enhanced our capabilities to provide care for those with the most complex of lesions while optimizing efficacy and safety.

At what age should tetralogy of Fallot be corrected?

Tetralogy of Fallot can be corrected with very low mortality at any age, even in neonates, but this does not necessarily mean that it should be corrected in the neonatal period. Although there are many advantages to early correction, a high proportion of these neonates have residual stenosis or pulmonary regurgitation that impairs ventricular function and may require further surgery or implantation of a pulmonary valve. Before we had the ability to correct this anomaly with low mortality in small children, a variety of palliative procedures had to be performed. Today, with better understanding of the anatomy of tetralogy of Fallot, we should consider what forms of palliation will increase growth of the right ventricular outflow tract in order to reduce the complications of very early surgery.

Stenting of right ventricular outflow tract in Tetralogy of Fallot with subarterial ventricular septal defect: A word of caution

We report a case of Tetralogy of Fallot with severe cyanosis who underwent a successful right ventricular outflow tract stenting. Follow-up echocardiography revealed moderate aortic regurgitation due to the impingement of the stent on the aortic valve. The patient underwent successful surgical correction at which time the stent was removed completely with a resolution of the aortic regurgitation.

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

Background—

Tetralogy of Fallot with cyanosis requiring surgical repair in early infancy reflects poor anatomy and is associated with more clinical instability and longer hospitalization than those who can be electively repaired later. We bridged symptomatic infants with risk factors for early primary repair by right ventricular outflow tract stenting (stent).

Methods and Results—

Four groups of tetralogy of Fallot with confluent central pulmonary arteries were studied: stent group (n=42), primary repair (aged <3 months) with pulmonary stenosis (early-PS group; n=44), primary repair (aged <3 months) with pulmonary atresia (early-PA group; n=49), and primary repair between 3 and 11 months of age (surg>3mo group; n=45). Stent patients had the smallest pulmonary arteries with a median (95% credible intervals) Nakata index (mm 2 /m 2 ) of 79 (66–85) compared with the early-PA 139 (129–154), early-PS 136 (121–153), and surg>3mo 167 (153–200) groups. Only stent infants required unifocalization of aortopulmonary collaterals (17%). Stent and early-PA infants had younger age and lower weight than early-PS infants. Stent infants had the most multiple comorbidities. Stenting allowed deferral of complete surgical repair to an age (6 months), weight (6.3 [5.8–7.0] kg), and Nakata index (147 [132–165]) similar to the low-risk surg>3mo group. The 3 early treatment groups had similar intensive care unit/hospital stays and high reintervention rates in the first 12 months after repair, compared with the surg>3mo group.

Conclusions—

Right ventricular outflow tract stenting of symptomatic tetralogy of Fallot with poor anatomy (small pulmonary arteries) and adverse factors (multiple comorbidities, low weight) relieves cyanosis and defers surgical repair. This allowed pulmonary arterial and somatic growth with clinical results comparable to early surgical repair in more favorable patients.

What Interventional Cardiologists Are Still Leaving to the Surgeons?

Nowadays, development of new technologies is still ongoing with the ultimate goal of maximizing treatment outcomes with less invasiveness and reduced procedural risk. This review is intended to update on when interventionalists need surgical support in common or emerging problems in congenital heart disease.

Management of the Preterm Infant with Congenital Heart Disease

The premature neonate with congenital heart disease (CHD) represents a challenging population for clinicians and researchers. The interaction between prematurity and CHD is poorly understood; epidemiologic study suggests that premature newborns are more likely to have CHD and that fetuses with CHD are more likely to be born premature. Understanding the key physiologic features of this special patient population is paramount. Clinicians have debated optimal timing for referral for cardiac surgery, and management in the postoperative period has rapidly advanced. This article summarizes the key concepts and literature in the care of the premature neonate with CHD.

Surgical Management of Vascular Stents in Pediatric Cardiac Surgery: Clues for a Staged Partnership

Complex cases undergo step surgical and percutaneous procedures, including stent deployment. Concerns arise on stent removal at latest surgery. Our initial experience is presented. Forty-six stents in 35 patients were partially or totally removed at surgery. Univentricular heart was diagnosed in 20 patients. Stents were previously deployed in: ductus (6), right ventricle outflow tract (12), atrial septal defect (4), right pulmonary artery (4), left pulmonary artery (16), inferior vena cava (2), superior vena cava (1) and ascending aorta (1). Surgical procedures performed: 9 transplants, 6 Fontan, 4 Glenn, 1 comprehensive repair (Norwood + Glenn), 1 Glenn takedown, 8 conduit replacement, 2 Fallot, 2 Rastelli, 1 ventricular septal defect closure and 1 iatrogenic aortopulmonary window. Five ductal stents were clipped. Eleven stents in right ventricle, four ones in atrial septal defect, two in right pulmonary artery, seven in the left pulmonary artery and two in inferior vena cava were completely removed. Two stents in right pulmonary artery, one in superior vena cava, one in ascending aorta and nine in the left pulmonary artery were partially retrieved. Handling the stents in ductus, right ventricle and atrial septal defect was straightforward. On the contrary, stent removal in the ductus (comprehensive case), pulmonary branches, both vena cavae or aorta required short periods of deep hypothermia with circulatory arrest. Surgery over stents is increasing in complex, step procedures. Univentricular hearts are most prevalent. Congenital transplant surgery faces new challenges. Stent removal at the time of surgery may require deep hypothermic circulatory arrest.