Hybrid Palliation for Hypoplastic Borderline Left Ventricle: One More Chance to Biventricular Repair

Treatment options for hypoplastic borderline left ventricle (LV) are critically dependent on the development of the LV itself and include different types of univentricular palliation or biventricular repair performed at birth. Since hybrid palliation allows deferring major surgery to 4-6 months, in borderline cases, the decision can be postponed until the LV has expressed its growth potential. We aimed to evaluate anatomic modifications of borderline LV after hybrid palliation. We retrospectively reviewed data from 45 consecutive patients with hypoplastic LV who underwent hybrid palliation at birth between 2011 and 2015. Sixteen patients (mean weight 3.15 Kg) exhibited borderline LV and were considered for potential LV growth. After 5 months, five patients underwent univentricular palliation (Group 1), eight biventricular repairs (Group 2) and three died before surgery. Echocardiograms of Groups 1 and 2 were reviewed, comparing LV structures at birth and after 5 months. Although, at birth, all LV measurements were far below the normal limits, after 5 months, LV mass in Group 2 was almost normal, while in Group 1, no growth was evident. However, aortic root diameter and long axis ratio were significantly higher in Group 2 already at birth. Hybrid palliation can be positively considered as a "bridge-to-decision" for borderline LV. Echocardiography plays a key role in monitoring the growth of borderline LV.

Left heart growth and biventricular repair after hybrid palliation

OBJECTIVES

We evaluated the outcomes of biventricular repair after initial hybrid palliation performed in small infants with various forms of left ventricle hypoplasia.

METHODS

Between September 2010 and January 2020, a total of 27 patients had biventricular repair after hybrid palliation at a median age of 11 days. Indications for the hybrid approach included growth promotion of the left ventricle outflow tract and/or the aortic valve in 14 patients and that of the left ventricle in 13 patients. Seven reinterventions and 7 reoperations were performed during the interstage period. Significant growth of left ventricle parameters was noted during the median interstage period of 62 days. Sixteen subjects had aortic arch repair, ventricular septal defect closure and relief of subaortic stenosis; 5 patients had the Ross-Konno procedure; 5 patients underwent the Yasui procedure; and 1 patient had unbalanced atrioventricular septal defect and aortic arch repair.

RESULTS

Twenty-three patients (85.2%) are alive at a median follow-up of 3.3 years. Two and 3 patients died early and late after achieving biventricular circulation, respectively. There were 22 reinterventions and 15 reoperations after biventricular repair.

CONCLUSIONS

Hybrid palliation can stimulate left heart growth in some patients with left ventricle hypoplasia. More patients may eventually achieve biventricular circulation than was initially thought. Additional interventions and operations are foreseeable. Despite ventricular rehabilitation, some patients with borderline left ventricles may develop restrictive physiology.

Outcomes following aortic valve procedures in 201 complex congenital heart disease cases-results from the UK National Audit

OBJECTIVES

Some patients with complex congenital heart disease (cCHD) also require aortic valve (AoV) procedures. These cases are considered high risk but their outcome has not been well characterized. We aim to describe these scenarios in the current practice, and provide outcome data for counselling and decision-making.

METHODS

This was a retrospective study using the UK National Congenital Heart Disease Audit data on cCHD patients undergoing aortic valve replacement, balloon dilation (balloon aortic valvuloplasty) or surgical repair (surgical aortic valve repair) between 2000 and 2012. Coarsened exact matching was used to pair cCHD with patients undergoing AoV procedures for isolated valve disease.

RESULTS

A total of 201 patients with a varied spectrum of cCHD undergoing 242 procedures were included, median age 9.4 years (1 day-65 years). Procedure types were: balloon aortic valvuloplasty (n = 31, 13%), surgical aortic valve repair (n = 57, 24%) and aortic valve replacement (n = 154, 63%). Mortality at 30 days was higher in neonates (21.8% vs 5.3%, P = 0.02). Survival at 10 years was 83.1%, freedom from aortic valve replacement 83.8% and freedom from balloon aortic valvuloplasty/surgical aortic valve repair 86.3%. Neonatal age (P < 0.001), single ventricle (P = 0.08), concomitant Fontan/Glenn (P = 0.002) or aortic arch procedures (0.02) were associated with higher mortality. cCHD patients had lower survival at 30 days (93% vs 100%, P = 0.003) and at 10 years (86.4% vs 96.1%, P = 0.005) compared to matched isolated AoV disease patients.

CONCLUSIONS

AoV procedures in cCHD can be performed with good results outside infancy, but with higher mortality than in isolated AoV disease. Neonates and patients with single ventricle defects, especially those undergoing concomitant Fontan/Glenn, have worse outcomes.

Outcomes of hybrid and Norwood Stage I procedures for the treatment of hypoplastic left heart syndrome and its variants

Background

In this study, we present the outcomes of hybrid and Norwood Stage I procedures for the treatment of hypoplastic left heart syndrome and its variants.

Methods

In this study, a total of 97 pediatric patients who were operated due to hypoplastic left heart syndrome and its variants between March 2011 and October 2018 were retrospectively analyzed. Thirty-two of the patients (28 males, 4 females; median age 5 days; range, 1 to 25 days) underwent Norwood Stage I operation (Group N), while the remaining 65 patients (44 males, 21 females; median age 6 days; range, 1 to 55 days) underwent a hybrid procedure (Group H). Both treatment strategies were compared.

Results

The median body weight in Group H was significantly lower and the number of patients with a low birth weight (<2,500 g) was significantly higher than Group N (p=0.002 and 0.004, respectively). The postoperative early mortality rate was similar between the groups. Univariate and multivariate analyses revealed that the need for preoperative mechanical ventilation was a significant factor for mortality (p=0.004 and 0.003, respectively). Syndromic appearance was also a significant factor the multivariate analysis (p=0.03). There was a statistically significant difference between the groups in terms of the inter-stage mortality rates (p=0.0045). Second-stage procedure was performed in 32 patients. The early mortality rate after the Glenn operation was 7.6%. Six patients died after comprehensive Stage II operation. Five patients underwent biventricular repair and 8 patients had third-stage fenestrated extracardiac Fontan operation (Group N, n=7 and Group H, n=1). The Kaplan-Meier survival curve demonstrated that Group N had a higher survival rate at both one and five years than Group H, although the difference was not statistically significant (p=0.15). Subgroup analysis showed that the Norwood procedure with Sano modification had the highest survival rate with 40% at five years.

Conclusion

Our study results show that patients undergoing the Norwood procedure have a more uneventful course of inter-stage period and Stage II and III, despite drawbacks early after Stage I procedure. Based on our experiences, we recommend performing the hybrid intervention in patients with a poor clinical condition and a body weight of <2,500 g.

Staged Biventricular Repair After Hybrid Procedure in High-Risk Neonates and Infants

BACKGROUND

Single-stage biventricular repair remains a challenging and difficult decision in high-risk newborns and early infants with the presence of left ventricular outflow tract obstruction (LVOTO) or borderline hypoplasia of the left ventricle (LV).

METHODS

Six high-risk patients underwent the initial hybrid procedure (bilateral pulmonary banding + ductal stenting) for staged biventricular repair. Their median age was 17 days (range: 7-55 days). The diagnosis was interrupted aortic arch (IAA), ventricular septal defect (VSD), and LVOTO (n = 3); IAA and VSD (n = 1); and aortic annular hypoplasia, aortic arch hypoplasia, VSD, and LVOTO (n = 1). The last patient had borderline LV with large atrial septal defect (ASD) and aortic arch hypoplasia. The patient with borderline LV had also ASD closure with small fenestration.

RESULTS

One patient died of sepsis after the hybrid procedure. Other patients underwent biventricular repair 8 to 13 months later. Three patients had conventional repair with conal septum resection. The other patient with IAA, in whom LVOTO was considered nonresectable, underwent Yasui operation. The last patient with borderline LV had enough development of left heart structures during follow-up and underwent aortic arch repair. One patient who had conal septum resection died after biventricular repair. One patient needed a tracheostomy; four patients were discharged uneventfully and their clinical conditions were good on postoperative year 1.

CONCLUSION

Staged biventricular repair with the initial hybrid procedure may be a feasible and safe alternative in high-risk neonates and early infants. Hybrid intervention may provide the development of cardiac structures in time and a better evaluation for the possibility of biventricular repair in borderline patients.

The Evolution of Therapeutic Strategies: Niche Apportionment for Hybrid Palliation

Hybrid palliation, the concept to stabilize univentricular circulation with bilateral pulmonary artery banding and maintenance of ductal patency, has significantly widened the therapeutic spectrum for patients with single-ventricle malformations or borderline hypoplasia. The concept has already been a part of early attempts to improve outcome in hypoplastic left heart syndrome but has not attracted much attention initially. Technical refinement and expertise have led to results that ultimately allowed the palliative strategy to gain traction and to be selectively adopted. By now, we have gained almost 2 decades of experience, and as much as hybrid palliation has changed our approach to single-ventricle management, new strategies and indications have been formed by this experience. We therefore review concepts and patterns of use of hybrid palliation as well as benefits and challenges of the respective pathways to highlight the current status of the hybrid procedure.

Hybrid Palliation for Interrupted Aortic Arch With Small Aortic Valve

OBJECTIVES

Open heart surgery for interrupted aortic arch in the neonatal period is still a high-risk procedure related in part to patient factors such as low birth weight, other morphologic anomalies, and, especially, small aortic valve size. Recently, we performed hybrid palliation with bilateral pulmonary artery banding and ductal stenting as the first-stage palliation for such cases. In this study, the outcomes of this procedure were examined.

METHODS

Six cases of interrupted aortic arch with a small aortic valve underwent the hybrid procedure in the neonatal period in our institute from 2010 to 2015 (mean age: 6.8 days, mean body weight: 3.2 kg, mean z score of the aortic valve annulus: -8.3). Their postoperative clinical courses and results of the second-stage surgery were evaluated.

RESULTS

No mortality or severe morbidity was seen in association with initial hybrid palliation. Five of six patients were discharged from the hospital; the one exception had a significant urinary tract anomaly. None needed an additional catheter intervention or surgical procedure postoperatively. All surviving patients underwent second-stage surgery; three had biventricular repair by the conventional method or Damus-Kaye-Stansel anastomosis with the Rastelli procedure and the other three proceeded toward staged Fontan reconstruction. Growth of the aortic valve was seen in four patients, and increased indexed left ventricle volume was recognized in one after the palliation.

CONCLUSION

Hybrid palliation could be useful not only to avoid high-risk neonatal surgery but also to allow for eventual selection of the second-stage surgery based on the observations of potential interval development of left ventricular structures.

Comparison of self-expandable and balloon-expanding stents for hybrid ductal stenting in hypoplastic left heart complex

OBJECTIVES

We aimed to compare the procedural and mid-term performance of a specifically designed self-expanding stent with balloon-expandable stents in patients undergoing hybrid palliation for hypoplastic left heart syndrome and its variants.

BACKGROUND

The lack of specifically designed stents has led to off-label use of coronary, biliary, or peripheral stents in the neonatal ductus arteriosus. Recently, a self-expanding stent, specifically designed for use in hypoplastic left heart syndrome, has become available.

METHODS

We carried out a retrospective cohort comparison of 69 neonates who underwent hybrid ductal stenting with balloon-expandable and self-expanding stents from December, 2005 to July, 2014.

RESULTS

In total, 43 balloon-expandable stents were implanted in 41 neonates and more recently 47 self-expanding stents in 28 neonates. In the balloon-expandable stents group, stent-related complications occurred in nine patients (22%), compared with one patient in the self-expanding stent group (4%). During follow-up, percutaneous re-intervention related to the ductal stent was performed in five patients (17%) in the balloon-expandable stent group and seven patients (28%) in self-expanding stents group.

CONCLUSIONS

Hybrid ductal stenting with self-expanding stents produced favourable results when compared with the results obtained with balloon-expandable stents. Immediate additional interventions and follow-up re-interventions were similar in both groups with complications more common in those with balloon-expandable stents.

Hybrid Stage I Procedure as Initial Palliation for Neonate With Hypoplastic Left Heart Syndrome and Right Congenital Diaphragmatic Hernia

During the past decade, a hybrid procedure has emerged and dramatically evolved as an alternative stage I palliation to the conventional Norwood procedure in neonates with hypoplastic left heart syndrome (HLHS). The hybrid approach avoids the need for cardiopulmonary bypass (CPB) utilizing stenting of the arterial duct and bilateral pulmonary artery banding. Cerebral and coronary perfusion pressure is maintained, and the pulmonary vasculature is protected from higher systemic pressure. Elimination of risks associated with CPB gains vital time to stabilize the patient and correct coexisting noncardiac anomalies and allows growth in preparation for the later stages of the Fontan pathway. The association of HLHS with right congenital diaphragmatic hernia (CDH) is rare. We report performing a successful hybrid stage I palliation on a neonate with HLHS and severe right CDH.

Extended Application of the Hybrid Procedure in Neonates with Left-Sided Obstructive Lesions in an Evolving Cardiac Program

The hybrid approach to management of hypoplastic left heart syndrome (HLHS) was developed as an alternative to neonatal Norwood surgery, providing a less invasive initial palliation for HLHS. We describe our experience in extending the concept of the hybrid procedure to palliate neonates with anatomically compromised systemic arterial blood flow in a variety of congenital cardiac anomalies and supporting its application as first-line palliation in centers developing their HLHS programs. Retrospective review of patients undergoing therapy for HLHS at a single institution from June 2008 to December 2014 was performed. Subject demographics, clinical and procedural data, along with follow-up, were collected. Thirteen patients had initial hybrid palliation for HLHS during the time frame indicated at a median age of 8 days (range 1-29 days) and median weight of 3.4 kg (range 2.4-4.6 kg). Diagnoses included typical HLHS (n = 6), right-dominant unbalanced atrioventricular septal defect with arch hypoplasia (n = 4), double outlet right ventricle [subpulmonic VSD (n = 1) and intact ventricular septum (n = 1)] with hypoplastic transverse aortic arch and borderline left ventricular dimensions. Standard approach with bilateral pulmonary artery banding and ductal stenting was carried out in all thirteen patients. Two patients required two ductal stents at the time of index procedure. There were no intraprocedural complications. Median intubation length post-procedure was 4 days (range 1-74 days). Median hospital stay post-procedure was 47 days (range 15-270 days). The overall mortality rate on follow-up through comprehensive stage 2 over the 6-year experience was 38 % (5 out of 13). Of note, the mortality rate was significantly lower in the latter 3 years of the study period when the procedure was adopted as a primary palliation for HLHS (14 % or 1 out of 7) compared to the initial 3-year period when it was reserved for higher risk cohorts (67 % or 4 out of 6). Median time to subsequent surgery was 3 months (range 1-4 months). One patient required further ductal stenting on follow-up and developed subsequently airway compression. On median follow-up of 24 months, two patients required pulmonary artery arterioplasty. The hybrid procedure may be used for palliation for a variety of cardiac lesions to avoid high-risk surgery in the neonatal period. This approach may be also an alternative in centers performing lower number of Norwood surgery, which has been associated with higher mortality.

Hybrid interventional procedures in congenital heart disease

The evolution of congenital cardiac surgery has seen significant innovative advances in collaborative efforts between congenital cardiac surgeons and interventionalists to provide the least invasive intervention with the greatest hemodynamic benefit for patients with congenital heart disease. This review looks at how this collaborative approach has evolved and is being applied to treat a number of congenital conditions across the age ranges.

Maternal hyperoxygenation and foetal cardiac MRI in the assessment of the borderline left ventricle

Using phase-contrast MRI in a foetus with borderline left ventricular hypoplasia at 37 weeks' gestation we showed an increase in pulmonary blood flow during maternal hyperoxygenation. The associated increase in venous return to the left atrium, however, resulted in reversal of the atrial shunt, with no improvement in left ventricular output. The child initially underwent single ventricle palliation with a neonatal hybrid procedure, but following postnatal growth of the left ventricle tolerated conversion to a biventricular circulation at 5 months of age. We conclude that when there is significant restriction of filling or outflow obstruction across the left heart, neither prenatal nor postnatal acute pulmonary vasodilation can augment left ventricular output enough to support a biventricular circulation. Chronic pulmonary vasodilation may stimulate the growth of the left-sided structures allowing biventricular repair, raising the intriguing question of whether chronic maternal oxygen therapy might obviate the need for neonatal single ventricle pallation in the setting of borderline left ventricular hypoplasia.

The hybrid approach for palliation of hypoplastic left heart syndrome: Intermediate results of a single-center experience

INTRODUCTION

Hypoplastic left heart syndrome (HLHS) is a major cause of cardiac death during the first week of life. The hybrid approach is a reliable, reproducible treatment option for patients with HLHS. Herein we report our results using this approach, focusing on its efficacy, safety and late outcome.

METHODS

We reviewed prospectively collected data on patients treated for HLHS using a hybrid approach between July 2007 and September 2014.

RESULTS

Nine patients had a stage 1 hybrid procedure, with seven undergoing a comprehensive stage 2 procedure. One patient completed the Fontan procedure. Five patients underwent balloon atrial septostomy after the hybrid procedure; in three patients, a stent was placed across the atrial septum. There were three deaths: two early after the hybrid procedure and one early after stage two palliation. Overall survival was 66%.

CONCLUSIONS

In our single-center series, the hybrid approach for HLHS yields intermediate results comparable to those of the Norwood strategy. The existence of dedicated teams for the diagnosis and management of these patients, preferably in high-volume centers, is of major importance in this condition.

Aortic arch augmentation using a pulmonary artery autograft patch and a reversed left subclavian artery flap for an interrupted aortic arch type B complex

Adequate arch augmentation for interrupted aortic arch repair is quite important to avoid post-operative recoarctation and bronchial compression. We describe here two successful cases of aortic arch reconstruction using autologous materials such as a pulmonary artery patch and a reversed left subclavian artery flap in infants with an interrupted aortic arch type B complex.

Biventricular repair after stage II univentricular surgery: palliation is not a one-way path

Surgical decision in mild forms of hypoplastic left heart syndrome can be challenging. Once a univentricular pathway has been chosen, it can be difficult to reconsider a biventricular repair. A commitment to a palliative pathway is usually considered irreversible after initial univentricular repair. We present this case as an example in which the primary surgical palliation pathway was altered, and eventually a successful biventricular repair was performed in a mild variant of hypoplastic left heart syndrome, despite the fact that maneuvers to promote left ventricular growth were not recruited at the time of initial surgery.

Obstructive left heart disease in neonates with a "borderline" left ventricle: diagnostic challenges to choosing the best outcome

In most newborns with left heart obstruction, the choice between a single-ventricle or biventricular management pathway is clear. However, in some neonates with a "borderline" left ventricle, this decision is difficult. Existing criteria do not reliably identify neonates who will have a good long-term outlook after biventricular repair (BVR). The objective of this study was prospective assessment of the outcome after BVR for newborns in whom the left ventricle (LV) was considered "borderline" by an expert group. This study was a prospective follow-up evaluation of neonates with obstructive left heart disease related to a "borderline" LV who underwent biventricular management between January 2005 and April 2011. Of 154 neonates who required intervention for left heart obstruction, 13 (7.8 %) met the echocardiographic (echo) inclusion criteria. At the first and last echo, the z-scores were respectively -1.76 ± 1.37 and -0.66 ± 1.47 (p = 0.013) for the mitral valve, -1.02 ± 1.57 and -0.23 ± 1.78 (p = 0.056) for the aortic valve, and 13.77 ± 5.8 and 20.85 ± 8.9 ml/m(2) (p = 0.006) for the LV end-diastolic volume. At this writing, all 12 survivors are clinically well. However, LV diastolic dysfunction and pulmonary artery hypertension was present in 5 (36 %) of 12 patients. Endocardial fibroelastosis (EFE) was detected in five patients at the last follow-up echo, but only in two patients preoperatively. Cardiac magnetic resonance imaging did not confirm EFE in any of assessed patients. The study authors could not reliably predict the outcome after BVR for neonates with left heart obstruction and a "borderline" LV. The presence of EFE with consequent diastolic dysfunction is more important than LV volume in determining the outcome. Prospective identification of EFE remains challenging.

Cardiovascular hybrid procedure in severe congenital diaphragmatic hernia with significant left heart hypoplasia

The authors discuss an early hybrid cardiovascular intervention in a neonate with left-sided congenital diaphragmatic hernia and significant left heart hypoplasia. The operation included persistent ductus arteriosus stenting and right pulmonary artery calibrated banding (3.5 mm) to increase blood flow in the aorta and to decrease right ventricle overload and decrease blood pressure and overflow in pulmonary circulation. The operation improved the child's general condition and gained time for left ventricle growth and restoration of its function.

Ross-Konno and endocardial fibroelastosis resection after hybrid stage I palliation in infancy: successful staged left-ventricular rehabilitation and conversion to biventricular circulation after fetal diagnosis of aortic stenosis

We report a patient who presented during fetal life with severe aortic stenosis, left-ventricular dysfunction, and endocardial fibroelastosis (evolving hypoplastic left heart syndrome). Management involved in utero and postnatal balloon aortic valvuloplasty for partial relief of obstruction and early postnatal hybrid stage I palliation until recovery of left-ventricular systolic function had occurred. The infant subsequently had successful conversion to a biventricular circulation by combining resection of endocardial fibroelastosis with single-stage Ross-Konno, aortic arch reconstruction, hybrid takedown, and pulmonary artery reconstruction.