Hybrid therapy for hypoplastic left heart syndrome: Myth, alternative, or standard?

Increased physiologic dead space fraction is associated with mortality after comprehensive stage 2 operation

OBJECTIVE

Our objective was to assess the predictive value of physiologic dead space fraction for mortality in patients undergoing the comprehensive stage 2 operation.

METHODS

This was a single-centre retrospective observational study conducted at a quaternary free-standing children's hospital specialising in hybrid palliation of single ventricle cardiac disease. 180 patients underwent the comprehensive stage 2 operation. 76 patients (42%) underwent early extubation, 59 (33%) standard extubation, and 45 (25%) delayed extubation. We measured time to extubation, post-operative outcomes, length of stay and utilised Fine gray models, Youden's J statistic, cumulative incidence function, and logistic regression to analyse outcomes.

RESULTS

Delayed extubation group suffered significantly higher rates of mortality (31.1% vs. 6.8%), cardiac arrest (40.0% vs. 10.2%), stroke (37.8% vs. 11.9%), and need for catheter (28.9% vs. 5.1%) and surgical intervention (24.4% vs. 8.5%) (P < 0.001). Physiologic dead space fraction was significantly higher in the delayed extubation group and in non-survivors with a value of 0.3, which was found to be the discriminatory point by Youden's J statistic. For a 0.1 unit increase in physiologic dead space fraction on post-operative day 1, the odds of a patient expiring increase by a factor of 2.26 (95% CI 1.41-3.97, p < 0.001) and by a factor of 3.79 (95% CI 1.65-11.7, p 0.01) on post-operative day 3.

CONCLUSIONS

Delayed extubation impacts morbidity and mortality in patients undergoing the comprehensive stage 2 operation. Increased physiologic dead space fraction in the first 60 hours after arrival to the ICU is associated with higher mortality.

Bilateral pulmonary artery banding facilitates the systemic ventricular outflow tract growth for biventricular and univentricular repair candidates of complex arch anomaly

Various surgical approaches address complex heart disease with arch anomalies. Bilateral pulmonary artery banding (bPAB) is a strategy for critically ill patients with complex arch anomalies. Some reports argued the potential effect of bPAB on the growth of the left ventricular outflow tract (LVOT) during inter-stage after bPAB. This study aimed to analyze the LVOT growth for biventricular repair candidates with arch anomaly and systemic ventricular outflow tract (SVOT) for univentricular repair candidates with arch anomaly. This retrospective study analyzed 17 patients undergoing initial bPAB followed by arch repair. The Z-scores of LVOT and SVOT were compared between pre-bPAB and pre-arch repair. Patient characteristics, transthoracic echocardiogram data, and PAB circumferences were reviewed. The diameter of the minimum LVOT for biventricular repair (BVR) candidates, the pulmonary valve (neo-aortic valve, neo-AoV) and the pulmonary trunk (the neo-ascending aorta, neo-AAo) for univentricular repair (UVR) candidates, and the degree of aortic or neo-aortic insufficiency in each candidate was statistically analyzed. 17 patients were divided into the UVR candidates (group U) with 9 patients and the BVR candidates (group B) with 8 patients. In group B, the median value of the Z-score of the minimum LVOT increased from -3.2 (range: - 4.1 ~ - 1.0) at pre-PAB to -2.8 (range: - 3.6 ~ - 0.3) at pre-arch repair with a significant difference (p = 0.012). In group U, the median value of the Z-score of the neo-AoV increased from 0.5 (range: - 1.0 ~ 1.7) at pre-bPAB to 1.2 (range: 0.2 ~ 1.9) at pre-arch repair with a significant difference (p < 0.01). The median value of the Z-score of the neo-AAo was also increased from 3.1 (range: 1.5 ~ 4.6) to 4.3 (range: 3.1 ~ 5.9) with a significant difference (p = 0.028). The growth of the LVOT for BVR candidates and SVOT for UVR candidates during the inter-stage between bPAB and arch repair was observed. These results suggest the potential advantage of bPAB in surgical strategies. Further research is needed to validate these findings and refine surgical approaches.

Short and Mid-term Outcomes of Ductal Graft with Bilateral Pulmonary Banding in Hypoplastic Left Heart Syndrome and Variants

This study evaluates a novel surgical technique inspired by the hybrid Norwood procedure, which involves ductal graft placement and bilateral pulmonary artery banding. This technique is designed to avoid the high-risk classical Norwood stage 1 operation and to avoid the need for first stage invasive catheter interventions and interstage catheter interventions when ductal stent placement is not feasible in developing countries with limited resources. Between June 2015 and December 2022, 14 patients with hypoplastic left heart syndrome and variants were treated using this procedure at our center. Polytetrafluoroethylene graft was used for ductal graft procedure and polytetrafluoroethylene bands were used for bilateral pulmonary banding. Atrial septectomy was done selectively. Patients with adequate left heart growth underwent biventricular repair and pulmonary debanding. Patients without left heart growth underwent cavopulmonary anastomosis or necessary intermediate surgical revisions. Seven patients out of 14 reached the second stage. Two received biventricular repair, three underwent bidirectional cavopulmonary anastomosis, and two required repeat palliations other than bidirectional cavopulmonary anastomosis. Modifications of the Norwood procedure is an ongoing process due to the complex nature of hypoplastic left heart syndrome and variants. As experience grows, the mortality associated with ductal graft and bilateral pulmonary banding procedure may decrease, making this technique an alternative for centers where classical Norwood operation or hybrid palliation is not possible, especially in developing countries with limited resources. We might predict promising outcomes, especially for patients with hypoplastic left heart complex where biventricular repair is expected.

Hybrid Interventions in Congenital Heart Disease: A Review of Current Practice and Rationale for Use

BACKGROUND

Hybrid interventions have become a common option in the management for a variety of patients with congenital heart disease. In this review, we discuss the data that have driven decision making about hybrid interventions to date.

METHODS

The existing literature on various hybrid approaches was reviewed and summarized. In addition, the key tenants to creating a successful hybrid program within a congenital heart center are elucidated.

RESULTS

Hybrid strategies for single-ventricle patients, pulmonary atresia with intact ventricular septum, branch pulmonary artery stenosis, and muscular ventricular septal defect closure have important benefits and limitations compared with traditional approaches.

CONCLUSION

A growing body of evidence supports the use of hybrid interventions in congenital heart disease. But important questions remain regarding improved survival and other long-term outcomes, such as neurocognition, that might impact widespread adoption as a primary treatment strategy.

Comparison of Morbidity and Mortality Outcomes between Hybrid Palliation and Norwood Palliation Procedures for Hypoplastic Left Heart Syndrome: Meta-Analysis and Systematic Review

Background/Objectives: Hybrid palliation (HP) procedures for hypoplastic left heart syndrome (HLHS) are increasing. Our objective was to compare mortality and morbidity following HP and NP (Norwood palliation) procedures. Methods: Systematic review and meta-analysis of HLHS patients of peer-reviewed literature between 2000 and 2023. Mortality and/or heart transplantation in HP versus NP in the neonatal period, interstage period, and at 1, 3 and 5 years of age, and morbidity including completion of Stage II and Stage III palliation, unexpected interventions, pulmonary artery pressures, right ventricle function, neurodevelopmental outcomes and length of hospital stay were evaluated. Results: Twenty-one (meta-analysis: 16; qualitative synthesis: 5) studies evaluating 1182 HLHS patients included. HP patients had higher interstage mortality (RR = 1.61; 95% CI: 1.10-2.33; p = 0.01) and 1-year mortality (RR = 1.22; 95% CI: 1.03-1.43; p = 0.02) compared to NP patients without differences in 3- and 5-years mortality. HP procedure in high-risk HLHS patients had lower mortality (RR = 0.48; 95% CI: 0.27-0.87; p = 0.01) only in the neonatal period. HP patients underwent fewer Stage II (RR = 0.90; 95% CI: 0.81-1.00; p = 0.05) and Stage III palliation (RR = 0.78; 95% CI: 0.69-0.90; p < 0.01), had more unplanned interventions (RR = 3.38; 95% CI: 2.04-5.59; p < 0.01), and longer hospital stay after Stage I palliation (weighted mean difference = 12.88; 95% CI: 1.15-24.62; p = 0.03) compared to NP patients. Conclusions: Our study reveals that HP, compared to NP for HLHS, is associated with increased morbidity risk without an improved survival rate.

Hybrid Interventions in Congenital Heart Disease

Hybrid interventions in congenital heart disease (CHD) embody the inherent collaboration between congenital interventional cardiology and cardiothoracic surgery. Hybrid approaches to complex and common lesions provide the opportunity to circumvent the limitations of patient size, vascular access, severity of illness, and anatomy that would otherwise be prohibitive to surgical and percutaneous techniques alone. This review describes several important hybrid approaches to interventions in CHD.

Increased utilization of the hybrid procedure is not associated with improved early survival for newborns with hypoplastic left heart syndrome: a single-centre experience

OBJECTIVES

The primary objectives were to examine utilization of the Hybrid versus the Norwood procedure for patients with hypoplastic left heart syndrome or variants and the impact on hospital mortality. The Hybrid procedure was 1st used at our institution in 2004.

METHODS

Review of all subjects undergoing the Norwood or Hybrid procedure between 1 January 1984 and 31 December 2022. The study period was divided into 8 eras: era 1, 1984-1988; era 2, 1989-1993; era 3, 1994-1998; era 4, 1999-2003; era 5, 2004-2008; era 6, 2009-2014; era 7, 2015-2018 and era 8, 2019-2022. The primary outcome was in-hospital mortality. Mortality rates were computed using standard binomial proportions with 95% confidence intervals. Rates across eras were compared using an ordered logistic regression model with and adjusted using the Tukey-Kramer post-hoc procedure for multiple comparisons. In the risk-modelling phase, logistic regression models were specified and tested.

RESULTS

The Norwood procedure was performed in 1899 subjects, and the Hybrid procedure in 82 subjects. Use of the Hybrid procedure increased in each subsequent era, reaching 30% of subjects in era 8. After adjustment for multiple risk factors, use of the Hybrid procedure was significantly and positively associated with hospital mortality.

CONCLUSIONS

Despite the increasing use of the Hybrid procedure, overall mortality for the entire cohort has plateaued. After adjustment for risk factors, use of the Hybrid procedure was significantly and positively associated with mortality compared to the Norwood procedure.

Mortality and Heart Transplantation After Hybrid Palliation of Hypoplastic Left Heart Syndrome: A Systematic Review and Meta-Analysis

BACKGROUND

Newborns with hypoplastic left heart syndrome (HLHS) who are considered at increased risk for death following Norwood/Sano surgery often undergo hybrid palliation (HP) as initial surgery. We aimed to compile the HP experience in HLHS and its variants and assess the rates of, and risk factors for, death and heart transplantation.

METHODS

CINAHL, CINAHL PLUS, PubMed/MEDLINE, and SCOPUS were systematically searched for HP outcome studies of death or heart transplantation in HLHS between 1998 and 2022. Pooled incidence was estimated, and potential risk factors were identified using random-effects meta-analysis and reconstructed time-to-event data from Kaplan-Meier curves.

RESULTS

Thirty-three publications were included in our review. Overall, of 1,162 patients 417 died and 57 underwent heart transplantation, resulting in a combined outcome of 40.7%, (474/1,162). There was a trend toward decreasing mortality risk across the stages of palliation. Pooled mortality between HP and comprehensive stage 2 palliation was 25%, after stage 2 up to Fontan palliation was 16%, and 6% post-Fontan. The incidence of death or heart transplantation was higher in high-risk patients-43% died and 10% received heart transplantation.

CONCLUSION

Our systematic review and meta-analysis found high rates of death or heart transplantation in HP of HLHS patients between HP and Fontan surgeries. All patients should be closely followed during the initial interstage period, which is associated with the highest hazard. Prospective studies on appropriate patient selection, indications, and / or alternatives, as well as refining HP strategies for managing newborns with HLHS are needed to improve outcomes.

Association between the initiation of insurance coverage for fetal echocardiography and mortality from congenital heart disease in infants: An interrupted time series analysis

BACKGROUND

The effectiveness of fetal echocardiography in reducing the mortality from congenital heart disease (CHD) is largely unknown.

OBJECTIVES

This study aimed to evaluate whether the widespread use of fetal echocardiography owing to the initiation of insurance coverage in Japan was associated with a decreasing trend in the annual number of CHD-related deaths.

METHODS

Data regarding the number of deaths from CHD in infants aged <12 months were extracted from Japanese demographic statistics (2000-2018). Segmented regression analysis was performed on the interrupted time series data by stratifying the sample into CHD subgroups based on ICD-10 classification and sex.

RESULTS

After the initiation of insurance coverage for fetal echocardiography in 2010, a decrease was observed in the trends of annual deaths in patients with congenital malformations of aortic and mitral valves (ratio of trends before and after the initiation of insurance coverage for fetal echocardiography 0.96, 95% confidence interval 0.93, 0.99). In this group, the decrease persisted after adjusting for annual total infant deaths and cardiac surgery mortality and in the analysis of trends in the proportion of deaths in this group per total CHD deaths. However, a decrease in trends was not observed in other patient groups with CHD. In the sex-stratified analysis, a decrease was noted only in male patients with congenital malformations of aortic and mitral valves.

CONCLUSIONS

The nationwide trend in annual CHD deaths decreased after the initiation of insurance coverage for fetal echocardiography only among patients with congenital malformation of aortic and mitral valves. These findings suggest that prenatal diagnosis with fetal echocardiography has led to improved mortality outcomes among these patients in Japan.

Long-term neurodevelopmental outcome and serial cerebral magnetic resonance imaging assessment in Fontan patients at school age

OBJECTIVES

Children with univentricular congenital heart disease undergoing staged surgical palliation are at risk for impaired neurodevelopmental (ND) outcome. Little is known about the long-term effects on brain growth until school age.

METHODS

In a prospective two-centre study, consecutive patients undergoing stage I (Hybrid or Norwood) to stage III (Fontan procedure) were evaluated by 2 serial cerebral magnetic resonance imaging examinations, somatic growth and ND testing before Fontan procedure at 2 years of age (Bayley-III) and after Fontan at 6-8 years of age (Wechsler Intelligence Scale for Children-third edition). Magnetic resonance imaging findings were compared with 8 healthy controls. Medical and sociodemographic characteristics were documented and related to cerebral and ND findings.

RESULTS

We examined 33 children (16 female) at a mean age of 2.3 (0.35) and 6.8 (± 0.7) years. The mean Bayley-III cognitive scales were 99.1 (9.9), language scales 98.4 (11.9) and motor scales 98.5 (13.8) at the first examination. Follow-up at school age showed a mean total IQ of 86.7 (13.6). The rate of structural brain lesions increased from 39% at 2 years to 58% at school age. Bayley-III language scale (P = 0.021) and mean Wechsler Intelligence Scale for Children-third edition (P = 0.019) were lower in children with pathological MR findings. Total brain volume (P < 0.001), total grey matter volume (P = 0.002), deep grey matter volume (P = 0.001) and white matter volume (P < 0.001) were smaller in patients compared to age- and gender-matched healthy controls.

CONCLUSIONS

Smaller brain volumes and structural brain lesions in complex congenital heart defect patients at school age are associated with impaired ND outcome. For the evaluation of predictive surgical or clinical factors, larger multicentre studies are needed.

Survival After Intervention for Single-Ventricle Heart Disease Over 15 Years at a Single Institution

BACKGROUND

Children with single-ventricle (SV) heart disease possess a spectrum of heart malformations, yet progress through similar hemodynamic states, suggesting differences in outcomes are related to fundamental morphologic differences, patient characteristics, or procedural pathways. We sought to provide a holistic overview of survival after intervention for SV heart disease at our institution.

METHODS

SV heart disease was defined as patients born with a hypoplastic or dysfunctional ventricle with uncertain or unacceptable candidacy for a 2-ventricle circulation. Patients were stratified into 8 diagnostic groups and 11 procedural categories based on the initial interventional procedure.

RESULTS

Between 2005 and 2020, 381 patients born with SV heart disease underwent intervention at our institution. Ten-year survival was highest for patients with double inlet left ventricle (89% ± 7%) and lowest for patients with hypoplastic left heart syndrome (55% ± 5%). Initial palliation with less invasive procedures, such as ductal stent (4-year: 100%) or pulmonary artery banding (10-year: 95% ± 5%), demonstrated superior survival compared with more invasive procedures such as the Norwood procedure (10-year: 59% ± 4%). Survival of patients who achieved a biventricular circulation was superior to patients who remained with SV physiology (10-year: 87% ± 5% vs 63% ± 3%, P = .04). In a multivariable analysis, chromosomal/syndromic abnormality, lower weight, hybrid Norwood procedure, nonleft ventricular dominance, and earlier year of operation were risk factors for death.

CONCLUSIONS

Survival differences in patients with SV heart disease were related primarily to underlying cardiac anatomy, patient characteristics, and procedural complexity. Left ventricular dominance, more recent intervention, and attainment of a 2-ventricle circulation were associated with improved survival.

Miniature Minimally Invasive Pulmonary Banding in Neonates (MINI-MICS): A Novel Technique

Single-ventricular cardiopathies are challenging conditions requiring multiple surgical interventions to hopefully achieve adulthood. In neonates, pulmonary artery banding allows ventricular adaptation and pulmonary vascular bed protection. Here we present a novel minimally invasive approach to pulmonary artery banding through a 1.5 cm left parasternal minithoracotomy. This technique not only allows for a less traumatic first procedure but also a less manipulated mediastinum and untouched sternum for the consequent surgeries to come. This technique is reproducible in experienced hands and shows favorable and promising results when performed properly.

Hypoplastic Left Heart Syndrome Palliation: Technical Aspects and Common Pitfalls of the Hybrid Approach

The Giessen hybrid strategy is used for initial palliation of HLHS and variants when the intent is to pursue further staged palliative reconstruction toward Fontan circulation. It is also used for initial palliation of HLHC and other anomalies with potential for eventual biventricular repair. From June 1998 - October 2021, 197 patients with HLHS and related variants underwent hybrid stage 1. Follow-up is complete (median 8.3 [range 0-23.3] years). Operative mortality for hybrid stage I was 3.6% (7/197); reduced to 2.8% since 2010 (4/141). Interstage mortality was 4.1% (8/197). Operative mortality for comprehensive stage II was 5.8% (10/172), and since 2010 was 1.8% (2/113 patients). Fontan completion has been accomplished in 117 patients, and 33 are still awaiting stage III. Twelve patients underwent heart transplantation. Over 23 years, overall survival is 77.7% and transplant-free survival is 73.6%.

Neurodevelopmental and functional outcome in hypoplastic left heart syndrome after Hybrid procedure as stage I

BACKGROUND

Patients with hypoplastic left heart syndrome (HLHS) undergoing staged palliation until Fontan procedure are at risk for impaired neurodevelopmental (ND) outcome. The Hybrid procedure with bilateral pulmonary artery banding, ductal stenting, and balloon atrioseptostomy may offer a less invasive stage I procedure compared to the Norwood stage I procedure avoiding early neonatal cardiopulmonary bypass (CPB) surgery. Despite altered fetal cerebral hemodynamics, the type of stage I procedure may be a covariate influencing ND outcome and functional outcome may also be altered due to postponing neonatal CPB surgery. Within this review, we analyzed ND outcome as well as functional outcome after Hybrid procedure as stage I procedure.

METHODS

The review analyzed original publications (OPs) published before March 15, 2022, identified by Cochrane, EMBASE, OVID, Scopus, and Web of science. An OP was included if short-to-long-term neurodevelopment outcome, brain development, somatic, and cardiac outcome in patients for HLHS and variants treated by Hybrid procedure were analyzed. In addition to database searches, we reviewed all references of the analyzed OP to obtain a comprehensive list of available studies. The author, year of publication, demographic characteristics of study population, study design (prospective or retrospective), study assessment, and main findings were summarized.

RESULTS

Twenty-one OPs were included with data of patients with ND outcome and functional cardiac outcome. Overall, there is an impaired mid-term ND outcome in patients with Hybrid procedure as stage I for HLHS. Only slight differences between stage I procedures (Hybrid vs. Norwood) in two comparing studies have been determined affecting right ventricular remodeling, short- and mid-term ND outcome, reduced brain growth until two years of age, sufficient quality of life, and altered hemodynamics influencing brain volumes and cerebral perfusion pattern.

CONCLUSIONS

Despite some minor differences regarding the mid-term follow-up in patients with HLHS comparing Hybrid vs. Norwood procedure, its impact on ND outcome seems rather low. This may be explained by the large number of covariates as well as the small study populations and the different selection criteria for patients undergoing Hybrid or Norwood procedure as stage I.

Clinical update on the hybrid comprehensive stage II operation

Objective

We previously described the hybrid comprehensive stage II operation as an alternate surgical procedure for a subset of patients with single ventricle congenital heart disease with adequate native ascending aortic outflow. Here we provide a clinical update on the 4 patients who have undergone this procedure.

Methods

After undergoing a hybrid approach to the stage I Norwood palliation, the hybrid comprehensive stage II procedure was performed with an incision to the main pulmonary artery (PA), dilation of the ductal stent, creation of a stented baffle between the branch PAs, and a bidirectional Glenn connection. With this approach, dissection of the distal arch and creation of a Damus-Kaye-Stansel anastomosis was avoided. A standard Fontan procedure was planned after the usual period of growth.

Results

The first patient, who had trisomy 21 and elevated PA pressures, died postoperatively due to left PA thrombosis. The subsequent 3 patients survived the procedure and remain clinically well. All have required catheterizations for reintervention on their stented intrapulmonary baffles and ductal arches, and all have undergone successful completion of their Fontan procedures.

Conclusions

The hybrid comprehensive stage II is a feasible, less complex alternative to the conventional comprehensive stage II operation in a subset of patients with single ventricle physiology. Early postoperative anticoagulation therapy to avoid PA thrombosis is recommended, and restenting of the ductal arch is anticipated. Although the long-term consequences of separate outflow tracts supplying the upper and lower body is unknown, the 3 surviving patients with this circulation are doing well with their Fontan circulation at midterm follow-up.

Cardiovascular Drug Therapy during Interstage After Hybrid Approach: A Single-Center Experience in 51 Newborns with Hypoplastic Left Heart

BACKGROUND

Newborns with hypoplastic left heart (HLH) are usually palliated with the Norwood procedure or a hybrid stage I procedure. Hybrid is our preferred approach. Given the critical relationship between stage I, interstage, and comprehensive stage II or advanced biventricular repair, we hypothesized that appropriate drug treatment is a significant therapeutic cornerstone, especially for the management of the high-risk interstage.

METHODS

We report a single-center observational study addressing the cardiovascular effects of, in particular, oral β-blockers and the additional use of angiotensin-converting enzyme (ACE) and mineralocorticoid inhibitors.

RESULTS

In total, 51 newborns-30 with HLH syndrome (HLHS) and 21 with HLH complex (HLHC)-with a median bodyweight of 3.0 kg (range 1.9-4.4; nine with bodyweight ≤ 2500 g) underwent an uneventful "Giessen hybrid approach" using a newly approved duct stent. All patients were discharged home with a single, double or triple therapy consisting of ß-blockers, ACE and mineralocorticoid inhibitors; 90% of the patients received bisoprolol, 10% received propranolol, 72% received lisinopril, and 78% received spironolactone. Resting heart rate decreased from 138 bpm (range 112-172; n = 51) at admission to 123 bpm (range 99-139; n = 51) at discharge and 110 bpm before stage II/biventricular repair/heart transplantation (range 90-140; n = 37) accompanied by favorable bodyweight gain. No side effects were evident.

CONCLUSION

In view of drug risk/benefit profiles, as well as the variable morphology and hemodynamics, the highly selective β1-adrenoceptor blocker bisoprolol is our preferred drug for treatment of HLHS/HLHC in the interstage. We avoid using ACE inhibitor monotherapy and exclude potential risks for coronary and cerebral perfusion pressure beforehand.

Emergency surgical stent retrieval following stent dislodgement during ductal stenting for hybrid palliation

Stenting of the ductus arteriosus is part of the hybrid treatment of high-risk patients with hypoplastic left heart syndrome. Dislodgement of a ductal stent is a rare complication. We present challenges faced in successful surgical retrieval of a dislodged ductal stent in a high-risk infant undergoing hybrid palliation for hypoplastic left heart syndrome.

Hypoplastic Left Heart: Stage-I Will be Performed Interventionally, Soon

The hypoplasia of left-sided heart structures shows great variability and complexity. What the many variants have in common is that their heart structures are neither fully developed before nor after birth. Fetuses and newborns require an individual therapy depending on anatomy and function of the heart. Fetal interventions focus on improving left heart structures by catheter-based interventions and maternal hyperoxygenation which promotes growth as the left ventricular preload and blood flow within the cavity increase. Stage-I management of newborns with single ventricle physiology is usually based on the Norwood/Sano surgery or the Hybrid approach. Two more steps are required to ultimately achieve a Fontan circulation. Some centers also use the Hybrid approach for subsequent Norwood operation beyond the neonatal period. After the Hybrid approach, a comprehensive stage-II or corrective surgery is performed, the latter if a bi-ventricular circulation is possible. With progressively improved catheter-based interventions, particularly ductal stenting and manipulations of the atrial septum, the next advance is to develop a bespoke flow restrictor that can be easily inserted into the branches of the pulmonary artery. The main goal is to avoid complex heart operations under general anesthesia, followed by substantial intensive care in the neonatal period, especially for patients with complex heart defects. Based on the current state of the art of surgical treatment of hypoplastic left heart syndrome and variants with the Norwood surgery or the Hybrid approach, our main focus is on an alternative percutaneous transcatheter technique in the sense of a completely non-surgical stage-I approach.

Small and borderline left ventricular outflow tract - a perplexing maladie

The left ventricular outflow tract (LVOT) comprises of the subvalvular area, the aortic valve, and the supravalvular region. Obstructive lesion of LVOT is a spectrum with varying levels and degree of obstruction with or without associated hypoplasia of the left ventricle. Decision-making in small and borderline LVOT can be challenging. Imaging modalities such as echocardiography and magnetic resonance imaging and scores based on imaging aid in the decision making in truly borderline cases. Newer treatment strategies like staged left ventricular rehabilitation and hybrid procedure have come to the fore in the past decade or so. Although these do not address small LVOT per se, they delay the decision-making to a more appropriate age. The goal of management in these cases is to achieve a biventricular repair whenever feasible. Several surgical techniques could be employed to achieve this goal. However, it is important to be cognizant of the fact that an overzealous approach to achieve a biventricular repair might be counterproductive. A univentricular palliation could be a safer alternative; especially considering the possibility of a future transplant candidacy.

Biventricular Conversion in the Borderline Hypoplastic Heart

PURPOSE OF REVIEW

The development of biventricular repair and conversion pathways for patients with borderline hypoplastic heart disease represents an area of recent inquiry and innovation. This review summarizes emerging techniques and novel treatment algorithms for borderline hypoplastic heart disease with a focus on surgical advances within the last 10 years.

RECENT FINDINGS

Many patients with borderline hypoplastic heart disease are amenable to primary biventricular repair, or biventricular conversion following single-ventricle palliation coupled with ventricular rehabilitation strategies. New insights into the potential for growth and recovery of borderline ventricles have been uncovered. However, questions remain regarding optimal patient selection and the long-term outcomes of select patient groups treated with single-ventricle palliation versus biventricular repair/conversion or transplantation. Efforts to direct a greater proportion of borderline hypoplastic heart patients towards a biventricular circulation are accelerating and represent important avenues for progress and future research in the field of congenital heart disease.

Anesthesia for bilateral pulmonary banding as part of hybrid stage I approach palliating neonates with hypoplastic left heart syndrome

BACKGROUND

Neonatal management of patients with hypoplastic left heart syndrome and complex remains a challenging task, whereby the "hybrid" palliation is often reserved for high-risk patients as a "rescue" procedure.

AIM

This study documents the anesthetic challenges and potential complications associated with the Giessen hybrid stage I approach.

METHODS

The Giessen hybrid stage I approach is focused on surgical bilateral pulmonary artery banding. Retrospective perioperative data were analyzed. Contrary to a stable group A, inotropic treatment before surgery for treatment of postnatal shock classified patients as unstable (Group B). Clinical outcomes considered were inhospital mortality, duration of postoperative mechanical ventilation, postoperative time at the intensive care unit, perioperative vasoactive medication requirements, and red blood cell transfusion.

RESULTS

From June 1998 to December 2015, 185 patients were allocated to Group A (n = 165) and Group B (n = 20). The inhospital mortality was 2.2% with no difference between the groups. There was also no difference in the postoperative time on mechanical ventilation and the time in the intensive care unit. Vasoactive medication was more often required in Group B (100%) compared to Group A (19%). In Group B, more red blood cells were transfused 6.0 ± 8.3 vs 2.0 ± 5.8 mL/kg in Group A (P < .05, 95% CI 0.0 - 2.6).

CONCLUSION

Considering a learning curve, anesthesia for surgical bilateral pulmonary artery banding palliating patients with hypoplastic left heart syndrome and complex can safely be performed, independent from the preoperative clinical status.

Hybrid Procedures: A Surgeon's Viewpoint on the Next 10 Years

Many forces are once again bringing the congenital heart surgeon and interventional cardiologist, and the teams that support them, ever closer together in what has been deemed Hybrid Approaches to congenital heart disease. The goal of these hybrid approaches is to improve the quantity and quality of life for the patients we serve.

Transcatheter ductus arteriosus stenting in paediatric cardiology: Indications, results and perspectives

Stenting the arterial duct emerged in the early 1990s as an alternative to a variety of surgical interventions in neonates with a duct-dependent pulmonary or systemic circulation complex defect. Furthermore, palliative ductal stenting has been applied in older children with severe suprasystemic pulmonary arterial hypertension, as an alternative to surgical shunts, such as Potts anastomosis. Early results of this technique were discouraging, but by learning from the failures of the past, ductal stenting has become a reliable palliative therapy. In this review, we aim to describe the historical evolution of ductal stenting, its different clinical applications and outcomes, and future perspectives for this strategy in congenital cardiac catheterization.

Smaller brain volumes at two years of age in patients with hypoplastic left heart syndrome - Impact of surgical approach

BACKGROUND

Brain growth in hypoplastic left heart syndrome (HLHS) is reduced before and after birth. Little is known about further brain growth until two years of age before Fontan procedure and the potential impact of type of surgery.

METHODS

In a prospective, two-center study 29 patients with HLHS and variants were treated by Norwood (n = 5) or Hybrid procedure (n = 24). At two years of age a cerebral MRI was performed and brain volumes (total gray, deep gray, white matter) and cerebrospinal fluid volume were calculated using FreeSurfer image analysis suite and compared to a healthy control group (n = 8).

RESULTS

The total brain volumes in patients with HLHS were smaller compared to controls (HLHS: 893 ± 76 ml vs. controls: 1015 ± 148 ml, p = 0.005). This difference was found in all three brain compartments after Norwood procedure, whereas patients after Hybrid procedure had total and deep gray volumes comparable to controls. When comparing Norwood to Hybrid patients, deep gray matter volume reduction was more pronounced (Norwood: 38.4 ± 4.1 ml vs. Hybrid: 44.4 ± 3.9 ml, p = 0.005) than white matter reduction (Norwood: 255 ± 19 ml vs. Hybrid: 285 ± 31 ml, p = 0.032).

CONCLUSIONS

Smaller total and regional brain volumes were found two years after Norwood or Hybrid procedure in children with HLHS. The brain volume reduction was more distinct after Norwood than after Hybrid procedure. Longitudinal studies are needed to identify impact of early staged-surgeries on brain development and may become part of the decision-making process in individual patients.

Hypoplastic left heart syndrome [HLHS]: treatment options in present era

Hypoplastic left heart syndrome (HLHS) is the most severe form of congenital heart defect (CHD). The first successful intervention for it was undertaken by Norwood in 1983. Since then, there have been much development in the pre, intra, and postoperative treatment option in staged palliative surgical procedures. Early diagnostic management, prenatal interventions, innovative diagnostic methods, constantly modified surgical techniques, and hybridization contribute to a significant progress in treatment options. This will allow for defining an optimal strategy of improving survival and quality of life in HLHS patients. The development of intervention cardiology makes possible the stepwise treatment of the defect with one operation only. The first and third stage may be done by hybrid or interventional methods, then only the second stage of treatment needs to be done surgically. The world experience and all the available literature says that the 1st-stage procedure could be done now safely either directly or with a bridge to Norwood followed by the stage 2 with a Glen or Hemi-Fontan and followed by a Fontan down the lane surgically.

Neurodevelopmental outcome in hypoplastic left heart syndrome after hybrid procedure

BACKGROUND

Little is known about the mid-term outcome and brain development in patients following the hybrid approach for hypoplastic left heart syndrome (HLHS). This study investigates neurodevelopmental outcome, quality of life (QoL) and brain MRI findings in HLHS preschoolers treated with the hybrid approach.

METHODS

Twenty HLHS patients (60% males) have been examined after neonatal hybrid Stage I and comprehensive stage II operation at the Pediatric Heart Center Giessen, Germany, between 2012 and 2016. Patients were evaluated with the Bayley Scales of Infant and Toddler Development III (Bayley-III), neurological examination, the Preschool Children Quality of Life Questionnaire (TAPQOL) at age 26.5±3.6 months, and again at 39.7±3.9 months with the Pediatric Cardiac Quality of Life Inventory (PCQLI). Furthermore, brain volumetric measurements and conventional brain MRI findings (27.3±4.5 months) were analyzed and compared with six healthy controls (29.2±11.1 months, P=0.53). Children with verified genetic comorbidities were excluded.

RESULTS

Mean cognitive, language, and motor composite scores on the Bayley-III were not different from healthy norms (100±15), and were 101±9.3 (P=0.48), 100±13 (P=0.93), and 98±11.7 (P=0.45), respectively. Status post stroke was the most common brain MRI abnormality, and was found in 3/19 (16%) patients, most common affecting the middle cerebral artery territory. In comparison to controls, total white matter volumes were reduced (P=0.014), and cerebrospinal fluid (CSF) volumes were increased (P=0.042) in patients. Overall health-related QoL in 2 to 3 years aged children HLHS was good, but inferior scores in the motor subscale were noted compared to healthy norms (P=0.007). However, at 3 to 4 years, parents reported comparable QoL for their children in the PCQLI to children with biventricular heart lesion.

CONCLUSIONS

HLHS patients followed by hybrid approach without major complications show a favorable neurodevelopment at 2-3 years of age. Despite extensive health-related burden, the vast majority of Fontan preschoolers with HLHS showed a good health-related QoL. Nevertheless, comprehensive care and establishing routine follow-up examinations are important to recognize long-term challenges and further improve neurodevelopmental outcome of this high-risk patient population.

Ideal intensive care unit course following comprehensive stage II in hypoplastic left heart syndrome

Comprehensive stage II is the advanced surgical part of the staged treatment of a newborn with hypoplastic left heart syndrome (HLHS) palliated initially by a Giessen-Hybrid approach. We report an almost ideal course following comprehensive stage II operation with focus on postoperative intensive care strategy. Following a short introduction of the postnatally performed Giessen-Hybrid approach, in which the surgical part is focused on bilateral pulmonary banding and duct stenting as well as manipulation of the atrial septum is postponed to transcatheter approach, it should be emphasized, that the quality of inter-stage I is eminently important for the success of the following comprehensive stage II. Furthermore, the interplay of the responsible surgeon, anesthesiologist, cardiologist and intensivist is mandatory for working as a team with a similar pathophysiological background. Presupposed a sophisticated surgical and anesthesiologic management, the immediate post-operative intensive care is crucial for the patient's final outcome, not only in terms of mortality but even morbidity (long-term neurological condition). Detailed treatment strategies are presented by pathophysiological reasonable hypotheses and the current pharmacological knowledge. Aiming to improve systemic and regional oxygen delivery and lowering oxygen consumption, as a sine qua none for a favorable patient's outcome.

Interrelationship Between Hemodynamics, Brain Volumes, and Outcome in Hypoplastic Left Heart Syndrome

BACKGROUND

The long-term impact of altered hemodynamics after stage II in children with hypoplastic left heart syndrome (HLHS) and hypoplastic left heart complex (HLHC) on cerebral growth and neurodevelopmental outcome is unknown. We aimed to investigate whether elevated central venous and atrial filling pressures before the Fontan procedure may be associated with smaller brain volumes and poorer neurodevelopmental outcome after the initial hybrid procedure.

METHODS

In a two-center cohort study semiautomated segmentation of cerebral magnetic resonance imaging scans was conducted in 25 children with HLHS/HLHC (25 hybrid) before the Fontan procedure (27.6 ± 4.3 months) and in 8 healthy control subjects (29.7 ± 9.5 months). Study patients were evaluated with the Bayley Scales of Infant and Toddler Development III (Bayley-III) and a neurologic examination. Hemodynamic measures after stage II were assessed with cardiac catheterization at 2 years of age before Fontan completion. Children with known genetic comorbidities were excluded.

RESULTS

In HLHS/HLHC patients higher atrial filling pressures (6 ± 3 mm Hg; range, 2-14) were correlated with reduced brain volumes and lower language composite score, whereas higher Glenn pressures (10 ± 3 mm Hg; range, 6-16) were related to higher cerebrospinal fluid, reduced brain volumes, and lower cognitive, language, and motoric composite scores in the Bayley-III. Compared with control subjects white matter volumes were reduced and cerebrospinal fluid volumes increased in study patients.

CONCLUSIONS

These data suggest that altered cardiovascular hemodynamics after stage II influence brain growth and neurodevelopmental outcome in infants with HLHS/HLHC.

Giessen Procedure as Comprehensive Stage II Palliation With Aortic Arch Reconstruction After Hybrid Bilateral Pulmonary Artery Banding and Ductal Stenting for Hypoplastic Left Heart Syndrome

This article reviews our experience using hybrid stage I palliation in the neonatal period and subsequently with comprehensive stage II palliation for hypoplastic left heart syndrome. Between June 1998 and April 2017, 154 patients with the diagnosis of hypoplastic left heart syndrome and variants underwent a hybrid stage I palliation (bilateral pulmonary artery banding and ductal stenting). One hundred thirty-nine patients could be further univentricularly palliated. One hundred twenty-one patients underwent a comprehensive stage II operation with an operative mortality of 6.6%. The hybrid procedure provides reproducible results with reduced in-hospital, interstage, and long-term mortality and lower rates of aortic arch reinterventions.

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.

Impact of Hybrid Stage 1 Palliation for Hypoplastic Left Heart Syndrome: Histopathological Findings

The purpose of the study is to analyze the impact of hybrid stage 1 palliation on right ventricular myocardial pathology in hypoplastic left heart syndrome. Sufficient amount of right ventricular biopsies could be obtained from 16 of 32 patients who underwent Norwood operation between 2007 and 2013. Histopathological findings of right ventricle in patients who underwent primary Norwood operation (primary group, n = 5), patients with aortic atresia (HS1P AA group, n = 6) or aortic stenosis (HS1P AS group, n = 5) who underwent staged Norwood palliation following hybrid stage 1 palliation were compared. To eliminate the influence of right ventricular pressure afterload, right ventricular biopsies were obtained from patients with truncus arteriosus communis (TAC group, n = 6) at total correction. The percentage of myocardial fibrosis was significantly higher in both HS1P groups than in TAC group; moreover, it was significantly higher in HS1P AA group than in primary group. Capillary vascular density was significantly lower in all hypoplastic left heart syndrome groups than in TAC group. At the sub-endocardial layer, collagen type I/III ratios were higher in HS1P AA group than in other hypoplastic left heart syndrome groups. The proportions of N-cadherin immunolocalized to myocyte termini were lower in all hypoplastic left heart syndrome groups than in TAC group. Right ventricle in hypoplastic left heart syndrome showed more significant ischemic change and myocardial immaturity than that in truncus arteriosus communis. Hybrid stage 1 palliation for aortic atresia would be a risk factor for further right ventricular myocardial ischemia.

Neuro-developmental outcome in single-ventricle patients: is the Norwood procedure a risk factor?

OBJECTIVES

Complex neonatal surgery is considered a risk factor for neuro-developmental impairment in single-ventricle patients. Neuro-developmental outcome was compared between preschool-aged Fontan patients who underwent a Norwood procedure and single-ventricle patients not requiring neonatal surgery with cardiopulmonary bypass.

METHODS

Verbal, performance and full-scale intelligence quotient (IQ) were evaluated with the Wechsler Preschool and Primary Scale of Intelligence. Cognitive functions were assessed with the German 'Kognitiver Entwicklungstest für das Kindergartenalter' (KET-KID). Risk factors for impaired neuro-development were evaluated.

RESULTS

Neuro-developmental assessment was completed in 95 patients (Norwood: n = 69; non-Norwood: n = 26). Median (interquartile range) IQ and KET-KID scores were in the normal range. Except for verbal KET-KID, scores did not differ between Norwood and non-Norwood patients (verbal IQ: 98 (86-105) vs 93 (85-102), P = 0.312; performance IQ: 91 (86-100) vs 96 (86-100), P = 0.932; full-scale IQ: 93 (86-101) vs 89 (84-98), P = 0.314; KET-KID verbal: 48 (17-72) vs 25 (2-54), P = 0.020; KET-KID non-verbal: 33 (18-62) vs 45 (15-54), P = 0.771; KET-KID global: 42 (14-65) vs 28 (6-63), P = 0.208). Full-scale IQ was below average (<85 points) in 14 (20%) Norwood and 9 (35%) non-Norwood cases (P = 0.181). Global KET-KID was below average (<16th percentile) in 19 (28%) and 10 (38%) patients (P = 0.326). Smaller head circumference z-score and complications before neonatal surgery were independently associated with lower scores.

CONCLUSIONS

Neuro-developmental outcome of preschool-aged Fontan patients was in the normal range. The Norwood procedure was not a risk factor for neuro-developmental impairment. Preoperative condition and patient-related factors were more important determinants than variables related to surgical palliation.

Long-Term Results of Bilateral Pulmonary Artery Banding Versus Primary Norwood Procedure

Bilateral pulmonary artery banding (PAB) has emerged to be an attractive option as an initial procedure for the treatment of hypoplastic left heart syndrome (HLHS), and some centers report excellent survival. However, its usage is variable among institutions and its true efficacy is unknown due to reporting biases. We aimed to describe the results of bilateral PAB use, preoperative risk factors, and long-term outcomes compared with primary Norwood procedure, using a national database. Infants who underwent bilateral PAB or Norwood procedure as an initial palliation for HLHS between January 2008 and December 2012 listed in the Japan Congenital Cardiovascular Surgery Database (JCCVSD) were included. The total number of patients diagnosed with HLHS was 334. Bilateral PABs were performed for 256 patients and primary Norwood procedures for 78 patients, as an initial procedure. Actuarial 5-year survival was 59.0%. The primary Norwood procedure group had better 5-year survival [75.5%; 95% confidence interval (CI) 63.2-84.1] than the bilateral PAB group (75.5 vs. 54.0%, log-rank p < 0.001). However, the bilateral PAB group had more significant risk factors. When the risk-adjusted outcomes were evaluated, there was no significant difference between the primary Norwood group and the bilateral PAB group (76.4 vs. 78.1%, log-rank p = 0.87) in higher volume institutions. The primary Norwood group had better 5-year survival than the bilateral PAB group, but preoperative risk was higher in the bilateral PAB group. Because outcomes are comparable when performed at higher HLHS volume institutions, proper patient selection is important in achieving good long-term result.

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.

Ventricular function and vascular dimensions after Norwood and hybrid palliation of hypoplastic left heart syndrome

Objective

Norwood and hybrid procedure are two options available for initial palliation of patients with hypoplastic left heart syndrome (HLHS). Our study aimed to assess potential differences in right ventricular (RV) function and pulmonary artery dimensions using cardiac magnetic resonance (CMR) in survivors with HLHS.

Methods

42 Norwood (mean age 2.4±0.8) and 44 hybrid (mean age 2.0±1.0 years) patients were evaluated by CMR after stage II palliation prior to planned Fontan completion. Initial stage I Norwood procedure was performed using a modified Blalock-Taussig shunt, while the hybrid procedure consisted of bilateral pulmonary artery banding and arterial duct stenting. Need for reinterventions and subsequent outcomes were also assessed.

Results

Norwood patients had larger RV end-diastolic dimensions (91±23 vs 80±31 mL/m2, p=0.004) and lower heart rate (90±15 vs 102±13, p<0.001) than hybrid patients. Both Norwood and hybrid patients showed preserved global RV pump function (59±9 vs 59%±10%, p=0.91), while RV strain, strain rate and intraventricular synchrony were superior in the Norwood group. Pulmonary artery size was reduced (lower lobe index 135±74 vs 161±62 mm2/m2, p=0.02), and reintervention rate was significantly higher in the hybrid group whereas subsequent outcome did not differ significantly (p=0.24).

Conclusions

Norwood and hybrid strategy were associated with equivalent and preserved global RV pump function while development of the pulmonary arteries and reintervention rate were superior using the Norwood approach. Impaired RV myocardial deformation as a potential marker of early RV dysfunction in the hybrid group may have a negative long-term impact in this population.

Perinatal outcomes of congenital heart disease after emergent neonatal cardiac procedures

PURPOSE

We compared outcome of neonates with prenatal and post-natal diagnosis of congenital heart disease presenting in our paediatric heart centre between March 2005 and May 2015 who underwent an emergent intervention within 48 h post-partum.

MATERIALS AND METHODS

In 52/111 (46.8%) with emergent intervention, congenital heart disease was diagnosed prenatally, in 59/111 (53.2%) with no specialized foetal echocardiography, diagnosis was made post-natally. In 98/111 (88.2%), 30-day outcome was known.

RESULTS

Regarding the entire cohort, 30-day survival did not differ significantly in prenatal and post-natal diagnosis group (71.2 vs. 72.9%; p > .1). Infants with prenatal diagnosis were more likely to be born by caesarean section (59.6% vs. 33.9%, p = .01). Those with post-natal diagnosis had a higher need for intubation (32.7% vs. 52.5%; p < .05). Subgroup analysis of HLH/HLHC (hypoplastic left heart/hypoplastic left heart complex) patients revealed higher number of deaths within 30 days of life in the post-natal diagnosis group, although the difference did not reach statistical significance (5/7, 71.4% vs. 5/20, 25.0%; p = .075).

CONCLUSION

For newborns who require emergent neonatal cardiac procedures, our results point towards a lower death rate after prenatal diagnosis of HLH/HLHC.