Hypoplastic left heart syndrome: from fetus to fontan

Stenting of the Patent Ductus Arteriosus

Since PDA stenting was first attempted in the early 1990s, significant technical advancements have improved outcomes and some centers have even transitioned to exclusive PDA stenting for all infants with duct-dependent pulmonary circulation. In addition to its use in infants with duct-dependent pulmonary circulation, PDA stenting has also been adapted as a percutaneous palliative option for suprasystemic pulmonary arterial hypertension and as a component of the hybrid procedure. In this article, the authors aim to review indications and outcomes for PDA stenting, describe the procedure, and discuss future directions.

Fetal aortic valvuloplasty as the first step in a complex therapeutic strategy

BACKGROUND

Fetal aortic valvuloplasty (FAV) is proposed to prevent hypoplastic left heart syndrome due to fetal critical aortic stenosis.

OBJECTIVE

to report our experience on FAV as the first step in a complex therapeutic strategy.

METHOD

Series of patients with FAV over an 18-year period.

RESULTS

27 FAVs were performed in 26 fetuses, with technical success in 82% (22/27) and periprocedural fetal demise in 22% (6/27), decreasing to 15% in the second half-cohort. Loss to follow-up was due to birth or postnatal therapy in other centers (5) and termination of pregnancy (1), A normal-sized LV at birth was observed in 46% (6/13), 4 neonates underwent aortic valvuloplasty and 2 cardiac surgeries, with 5/6 achieving biventricular circulation at 28 days, and 3 transplant-free survival at mid-term follow-up. The 7/13 born with a borderline LV underwent LV rehabilitation strategy, with survival at 28 days in 4/7 and at mid-term in 3: one with biventricular circulation, one with a ventricle-and-a-half repair, and one lost to follow-up.

CONCLUSION

FAV was feasible in most cases, with no maternal complications, and biventricular circulation at 28 days in ∼40% of survivors. After FAV, a diverse range of postnatal cardiac interventions are performed, reflecting the challenging innovation in current cardiovascular therapy.

Fetal Echocardiographic Evaluation of Tricuspid Valve and Right Ventricular Function Including Global Longitudinal Strain in Hypoplastic Left Heart Syndrome and Association with Postnatal Outcomes

Despite significant advancements in the care of patients with hypoplastic left heart syndrome (HLHS) morbidity and mortality remain high. Postnatal right ventricular dysfunction and tricuspid regurgitation (TR) are associated with worse outcomes in HLHS. We aim to determine if right ventricle functional parameters and TR on fetal echocardiogram are associated with postnatal outcomes in HLHS patients. Retrospective review was performed on all fetuses with HLHS from 2014 to 2022 at our institution. Initial and follow up fetal echocardiogram measurements of right ventricular myocardial performance index (MPI), fractional area change (FAC) and global longitudinal strain (GLS) were retrospectively measured. The presence and severity of TR was recorded from the fetal echocardiogram reports. Postnatal outcomes including transplant-free survival, hospital length of stay > 30 days after initial palliation and need for bidirectional Glenn at < 4 months were reviewed. Forty-three subjects met inclusion criteria. Mean gestational age at presentation was 26.1 ± 5.9 weeks. Nine subjects died and 3 required heart transplantation. Initial fetal echocardiogram MPI was significantly lower (better) (0.36 ± 0.06 vs 0.44 ± 0.11; p =  < 0.001) and FAC was significantly higher (better) (45 ± 6% vs 40 ± 8%; p = 0.035) in transplant-free survivors. Fetal right ventricular GLS and presence of mild TR were not associated with postnatal outcome. In fetuses with HLHS, abnormal MPI and right ventricular FAC are associated with decreased transplant-free survival. There was no observed association between GLS and postnatal outcomes. To our knowledge this is the first study examining fetal right ventricular function and GLS in HLHS patients and its link to postnatal outcomes.

Longitudinal analysis of systemic ventricular function and atrioventricular valve function after the Norwood procedure

OBJECTIVES

To evaluate longitudinal systemic ventricular function and atrioventricular valve regurgitation in patients after the neonatal Norwood procedure.

METHODS

Serial postoperative echocardiographic images before Fontan completion were assessed in neonates who underwent the Norwood procedure between 2001 and 2020. Ventricular function and atrioventricular valve regurgitation were compared between patients with modified Blalock-Taussig shunt and right ventricle to pulmonary artery conduit.

RESULTS

A total of 335 patients were identified including 273 hypoplastic left heart syndrome and 62 of its variants. Median age at Norwood was 8 (7-12) days. Modified Blalock-Taussig shunt was performed in 171 patients and the right ventricle to pulmonary artery conduit in 164 patients. Longitudinal ventricular function and atrioventricular valve regurgitation were evaluated using a total of 4352 echocardiograms. After the Norwood procedure, ventricular function was initially worse (1-30 days) but thereafter better (30 days to stage II) in the right ventricle to pulmonary artery conduit group (P < 0.001). After stage II, the ventricular function was inferior in the right ventricle to the pulmonary artery conduit group (P < 0.001). Atrioventricular valve regurgitation between the Norwood procedure and stage II was more frequent in the modified Blalock-Taussig shunt group (P < 0.001). After stage II, there was no significant difference in atrioventricular valve regurgitation between the groups (P = 0.171).

CONCLUSIONS

The effect of shunt type on haemodynamics after the Norwood procedure seems to vary according to the stage of palliation. After the Norwood, the modified Blalock-Taussig shunt is associated with poorer ventricular function and worse atrioventricular valve regurgitation compared to right ventricle to pulmonary artery conduit. Whereas, after stage II, modified Blalock-Taussig shunt is associated with better ventricular function and comparable atrioventricular valve regurgitation, compared to the right ventricle to pulmonary artery conduit.

Liver Biopsy Leads to Serendipitous Diagnosis of Glycogen Storage Disease Type IX in a Patient With Fontan-Associated Liver Disease

Fontan-associated liver disease (FALD) is a form of congestive hepatopathy resulting from Fontan palliation procedures in patients with single ventricle physiology. Although there is variation between pediatric centers, the surveillance for FALD may include liver biopsies for assessment of degree of fibrosis. Our report describes a 7-year-old girl with hypoplastic left heart syndrome who underwent Fontan palliation at age 2, and presented with disproportionate hepatomegaly, elevated liver enzymes, and increased stiffness on liver elastography. Liver biopsy showed diffuse hepatocellular cytoplasmic glycogenation, leading to the diagnosis of glycogen storage disease IX. This case demonstrates the importance of investigating unexpected physical exam findings and the potential for serendipitous benefit of liver biopsy in FALD.

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.

Hypoplastic Left Heart Syndrome: A Review

Hypoplastic left heart syndrome is a rare and poorly understood congenital disorder featuring a univentricular myocardium, invariably resulting in early childhood death if left untreated. The process to palliate this congenital cardiomyopathy is of high complexity and may include invasive interventions in the first week of life. The preferred treatment strategy involves a staged correction with 3 surgical procedures at different points in time. The Norwood procedure is usually performed within the first weeks of life and aims to increase systemic circulation and relieve pulmonary vascular pressure. This procedure is followed by the bidirectional Glenn and the Fontan procedures in later life, which offer to decrease stress in the ventricular chamber. The prognosis of children with this disease has greatly improved in the past decades; however, it is still largely driven by multiple modifiable and nonmodifiable variables. Novel and clever alternatives have been proposed to improve the survival and neurodevelopment of these patients, although they are not used as standard of care in all centers. The neurodevelopmental outcomes among these patients have received particular attention in the last decade in light to improve this very limiting associated comorbidity that compromises quality of life.

The care of the patients with hipoplastic left heart syndrome in places of social and economic vulneability. An ethical analysis

The birth of a child means hope and joy, particularly for the parents and the healthcare team. When this child is born with a severe malformation and a poor prognosis, as in the case of hypoplastic left heart syndrome, the scenario is one of great uncertainty and emotional suffering. The role of the health team becomes fundamental for the identification of conflicts of values and for the search for shared decisions that promote the best benefit to the child. When the diagnosis is made during fetal life, it is necessary to develop counseling strategies appropriate to the context of each family. In places with limited care resources, precarious prenatal care and short temporal conditions, the recommended counseling is compromised. Indication of treatment requires technical competence and a detailed analysis of ethical issues, and consultation with institutional clinical bioethics services or commissions is important. The article proposes to address the moral conflicts of two clinical cases and the respective bioethical analysis that involves principles and values in contexts of vulnerability and uncertainty, contrasting two situations where the indication of treatment was based on accessibility to treatment.

Cardiovascular intensive care unit variables inform need for feeding tube utilization in infants with hypoplastic left heart syndrome

OBJECTIVE

Feeding strategies in infants with hypoplastic left heart syndrome (HLHS) following stage 1 palliation (S1P) include feeding tube utilization (FTU). Timely identification of infants who will fail oral feeding could mitigate morbidity in this vulnerable population. We aimed to develop a novel clinical risk prediction score for FTU.

METHODS

This was a retrospective study of infants with HLHS admitted to the Boston Children's Hospital cardiovascular intensive care unit for S1P from 2009 to 2019. Infants discharged with feeding tubes were compared with those on full oral feeds. Variables from early (birth to surgery), mid (postsurgery to cardiovascular intensive care unit transfer), and late (inpatient transfer to discharge) hospitalization were analyzed in univariate and multivariable models.

RESULTS

Of 180 infants, 66 (36.7%) discharged with a feeding tube. In univariate analyses, presence of a genetic disorder (early variable, odds ratio, 3.25; P = .014) and nearly all mid and late variables were associated with FTU. In the mid multivariable model, abnormal head imaging, ventilation duration, and vocal cord dysfunction were independent predictors of FTU (c-statistic 0.87). Addition of late variables minimally improved the model (c-statistic 0.91). A risk score (the HV2 score) for FTU was developed based on the mid multivariable model with high specificity (93%).

CONCLUSIONS

Abnormal head imaging, duration of ventilation, and presence of vocal cord dysfunction were associated with FTU in infants with HLHS following S1P. The predictive HV2 risk score supports routine perioperative head imaging and vocal cord evaluation. Future application of the HV2 score may improve nutritional morbidity and hospital length of stay in this population.

Recent advances in biological pumps as a building block for bioartificial hearts

The field of biological pumps is a subset of cardiac tissue engineering and focused on the development of tubular grafts that are designed generate intraluminal pressure. In the simplest embodiment, biological pumps are tubular grafts with contractile cardiomyocytes on the external surface. The rationale for biological pumps is a transition from planar 3D cardiac patches to functional biological pumps, on the way to complete bioartificial hearts. Biological pumps also have applications as a standalone device, for example, to support the Fontan circulation in pediatric patients. In recent years, there has been a lot of progress in the field of biological pumps, with innovative fabrication technologies. Examples include the use of cell sheet engineering, self-organized heart muscle, bioprinting and in vivo bio chambers for vascularization. Several materials have been tested for biological pumps and included resected aortic segments from rodents, type I collagen, and fibrin hydrogel, to name a few. Multiple bioreactors have been tested to condition biological pumps and replicate the complex in vivo environment during controlled in vitro culture. The purpose of this article is to provide an overview of the field of the biological pumps, outlining progress in the field over the past several years. In particular, different fabrication methods, biomaterial platforms for tubular grafts and examples of bioreactors will be presented. In addition, we present an overview of some of the challenges that need to be overcome for the field of biological pumps to move forward.

Defining Expectations for Infants With Hypoplastic Left Heart Syndrome Who Survive Initial Surgical Palliation

BACKGROUND

Overall one-year non-mortality outcomes for surgically palliated hypoplastic left heart syndrome (HLHS) patients remain understudied. Using the metric Days Alive and Outside of Hospital (DAOH), the present study sought to characterize expectations for surgically palliated patients' first year of life.

METHODS

The Pediatric Health Information System database was used to identify by ICD-10 code all HLHS patients who underwent surgical palliation (Norwood/hybrid and/or heart transplantation [HTx]) during their index neonatal admission and were successfully discharged alive (n  =  2227) and for whom one-year DAOH could be calculated. DAOH quartiles were used to group patients for analysis.

RESULTS

Median one-year DAOH was 304 (interquartile range [IQR] 250-327), including a median index admission length of stay of 43 days (IQR 28-77). Patients required a median 2 (IQR 1-3) readmissions, each spanning 9 days (IQR 4-20). One-year readmission mortality or hospice discharge occurred in 6% of patients. Patients with lower-quartile DAOH had a median DAOH of 187 (IQR 124-226), whereas upper-quartile DAOH patients had a median DAOH of 335 (IQR 331-340) (P < .001). Readmission mortality/hospice-discharge rates were 14% and 1%, respectively (P < .01). On multivariable analysis, factors independently associated with lower-quartile DAOH included interstage hospitalization (odds ratio [OR] 44.78 [95% confidence interval [CI] 25.1-80.2]), index-admission HTx (8.73 [4.66-16.3]), preterm birth (1.97 [1.34-2.90]), chromosomal abnormality (1.85 [1.26-2.73]), age >7 days at surgery (1.50 [1.14-1.99]), and non-white race/ethnicity (1.33 [1.01-1.75]).

CONCLUSIONS

In the current era, surgically palliated HLHS infants spend approximately 10 months alive and outside of the hospital, although outcomes are highly variable. Knowledge of the factors associated with lower DAOH can inform expectations and guide management decisions.

Palliated Hypoplastic Left Heart Syndrome Patients Experience Superior Waitlist and Comparable Post-Heart Transplant Survival to Non-Single Ventricle Congenital Heart Disease Patients

Congenital heart disease (CHD) is a well-established risk factor for inferior waitlist and post-heart transplant survival in children. Differences in outcomes between CHD subgroups are understudied. The present study compared outcomes for palliated hypoplastic left heart syndrome (HLHS) patients to other non-single ventricle CHD (non-SVCHD) and non-CHD patients. United Network for Organ Sharing was used to identify children (age < 18) listed for heart transplant in the United States between 2016 and 2021. CHD sub-diagnoses were only available for United Network for Organ Sharing status 1a after 2015, thereby defining the cohort. Waitlist outcomes were studied using competing-risk time-to-event analysis for transplantation, mortality/decompensation, and alive-on-waitlist. Multivariable Cox proportional hazards regression analyses were used to identify factors associated with inferior post-transplant survival. Patients included: palliated-HLHS (n = 477), non-SVCHD (n = 686), and non-CHD (n = 1261). At listing, Palliated-HLHS patients were older than non-SVCHD (median 2-year [IQR 0-8] vs median 0-year [0-3], respectively) and younger than non-CHD (median 7-year [0-14]) (P < 0.001 vs both), and were more likely to be white (P < 0.01 vs both). Upon time-to-event analysis, rates of waitlist mortality/decompensation rates were greater among non-SVCHD than palliated-HLHS. Post-transplant survival was comparable between palliated-HLHS and non-SVCHD (P = 0.920) but worse compared to non-CHD (P < 0.001). Both palliated-HLHS (HR 2.40 [95% CI 1.68-3.42]) and non-SVSCHD (2.04 [1.39-2.99]) were independently associated with post-transplant mortality. Palliated-HLHS patients with heart failure experience significantly worse post-transplant outcomes than non-CHD but, compared to other CHD patients, experience superior waitlist and comparable post-transplant survival. While a high-risk cohort, HLHS patients can achieve gratifying waitlist and post-transplant survival.

The horizon of pediatric cardiac critical care

Pediatric Cardiac Critical Care (PCCC) is a challenging discipline where decisions require a high degree of preparation and clinical expertise. In the modern era, outcomes of neonates and children with congenital heart defects have dramatically improved, largely by transformative technologies and an expanding collection of pharmacotherapies. Exponential advances in science and technology are occurring at a breathtaking rate, and applying these advances to the PCCC patient is essential to further advancing the science and practice of the field. In this article, we identified and elaborate on seven key elements within the PCCC that will pave the way for the future.

Non-invasive biomarkers of Fontan-associated liver disease

Background & Aims

Fontan-associated liver disease (FALD) has emerged as an important morbidity following surgical palliation of single ventricle congenital heart disease. In this study, non-invasive biomarkers that may be associated with severity of FALD were explored.

Methods

A retrospective cohort of paediatric patients post-Fontan who underwent liver biopsy at a high volume at a paediatric congenital heart disease centre was reviewed.

Results

Among 106 patients, 66% were male and 69% were Hispanic. The mean age was 14.4 ± 3.5 years, and biopsy was performed 10.8 ± 3.6 years post-Fontan. The mean BMI was 20.8 ± 5 kg/m², with 27.4% meeting obesity criteria. Bridging fibrosis was observed in 35% of patients, and 10.4% of all patients had superimposed steatosis. Bridging fibrosis was associated with lower platelet counts (168.3 ± 58.4 vs. 203.9 ± 65.8 K/μl for congestive hepatic fibrosis score [CHFS] 0–2b, p = 0.009), higher bilirubin (1.7 ± 2.2 vs. 0.9 ± 0.7 mg/dl, p = 0.0090), higher aspartate aminotransferase-to-platelet ratio index [APRI] and fibrosis-4 [FIB-4] scores (APRI: 0.5 ± 0.3 vs. 0.4 ± 0.1, p <0.01 [AUC: 0.69] and FIB-4: 0.6 ± 0.4 vs. 0.4 ± 0.2, p <0.01 [AUC: 0.69]), and worse overall survival (median 2 years follow-up post-biopsy, p = 0.027). Regression modelling of temporal changes in platelet counts before and after biopsy correlated with fibrosis severity (p = 0.005).

Conclusions

In this large, relatively homogeneous adolescent population in terms of age, ethnicity, and Fontan duration, bridging fibrosis was observed in 35% of patients within the first decade post-Fontan. Bridging fibrosis was associated with worse survival. Changes in platelet counts, even years before biopsy, and APRI/FIB-4 scores had modest discriminatory power in identifying patients with advanced fibrosis. Steatosis may represent an additional risk factor for disease progression in obese patients. Further prospective studies are necessary to develop strategies to screen for FALD in the adolescent population.

Lay summary

In this study, the prevalence of Fontan-associated liver disease (FALD) in the young adult population and clinical variables that may be predictive of fibrosis severity or adverse outcomes were explored. Several lab-based, non-invasive markers of bridging fibrosis in FALD were identified, suggesting that these values may be followed as a prognostic biomarker for FALD progression in the adolescent population.

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FALD is universal within 10 years post-Fontan, with 35% of patients having bridging fibrosis.

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Of our adolescent patient population, 10% had concomitant hepatic steatosis, which was associated with obesity.

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Regression modelling demonstrates that temporal changes in platelet counts correlate with severity of fibrosis in FALD.

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AST-to-platelet ratio index and FIB-4 scores correlate with bridging fibrosis with a high specificity.

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Bridging fibrosis in FALD is associated with worse survival.

Caring perceptions and experiences of fathers of children with congenital heart disease: A systematic review of qualitative evidence

AIM

To identify fathers' perceptions and experiences of caring for their children with congenital heart disease.

DESIGN

A qualitative systematic review.

DATA SOURCES

PubMed, Clinical Key, the Joanna Briggs Institute Evidence-based practice database, CINAHL Complete, Embase and PsycINFO were searched for all journal articles published before May 2020.

REVIEW METHODS

After applying the selection criteria, five studies were identified reporting on fathers with children between 1 month and 12 years. The quality of the articles was evaluated.

RESULTS

Six main themes regarding fathers' perceptions and experiences of caring for their children with congenital heart disease were identified: (1) lack of disease knowledge, (2) responsibility to the family and emotional suppression, (3) gratitude for the sustained life of their children, (4) acceptance of being different from others, (5) regrouping and planning for the future and (6) the struggles of father-child relationships.

CONCLUSION

In caring for their children with congenital heart disease, fathers are akin to a suffering warrior, full of hardship. With a self-imposed sense of responsibility and suppressed emotions, fathers may feel lonely and hurt, but they must fight for their families and children.

Post-Left Atrium Space Index in Fetuses With Total Anomalous Pulmonary Venous Connection and Other Congenital Heart Diseases

OBJECTIVES

We aimed to explore the value of the post-left atrium space (PLAS) index in the diagnosis of total anomalous pulmonary venous connection (TAPVC) and the effect of other congenital heart diseases on the PLAS index in the fetus.

METHODS

The PLAS index of 69 fetuses with TAPVC was analyzed retrospectively. Approximately 252 healthy fetuses were randomly selected as controls, and 110 cases of intracardiac malformations were randomly selected for comparison. The PLAS index was defined as the ratio of the left atrium-descending aorta distance divided by the descending aorta diameter from the 4-chamber view in the end-systolic phase.

RESULTS

There were no significant differences in the PLAS index among the 3 groups of isolated TAPVC subtypes (P > .05), or among the isolated TAPVC group and the simple and complex cardiac anomaly groups (P > .05). Compared with the control group, the PLAS index of the TAPVC group was significantly increased (P < .001). The PLAS index was significantly higher in the TAPVC group than in hypoplastic left heart syndrome, endocardial cushion defect, conotruncal defect, and ventricular septal defect groups (P < .05). The PLAS indices of the hypoplastic left heart syndrome, endocardial cushion defect, and conotruncal defect groups were all higher than that of the control group (P < .05). There was no significant difference in the PLAS index between the ventricular septal defect and control groups (P > .05).

CONCLUSIONS

The PLAS index is a sensitive parameter for the diagnosis of fetal TAPVC. There were no significant differences in the PLAS index among different TAPVC types. Complex intracardiac anomalies have an influence on the PLAS index.

Tissue engineering solutions to replace contractile function during pediatric heart surgery

Pediatric heart surgery remains challenging due to the small size of the pediatric heart, the severity of congenital abnormalities and the unique characteristics of each case. New tools and technologies are needed to tackle this enormous challenge. Tissue engineering strategies are focused on fabricating contractile heart muscle, ventricles, Fontan pumps and whole hearts, and a transplantable tissue equivalent has tremendous implications in pediatric heart surgery to provide functional cardiac tissue. This technology will prove to be a game-changer in the field of pediatric heart surgery and provide a novel toolkit for pediatric heart surgeons. This review will provide insight into the potential applications of tissue engineering technologies to replace lost contractile function in pediatric patients with heart abnormalities.

Left heart hypoplasia operated using double pulmonary arterial banding with double arterial duct stenting: A case report

Hypoplastic left heart syndrome is a heterogeneous group of congenital cardiac malformations which associates hypoplastic/aplastic left ventricle, mitral and aortic valve, hypoplastic/atresia and severe aortic artery coarctation, and represents a medical-surgical emergency. We present a case of a newborn hospitalised in three clinics (two clinics from Timisoara and one from Vienna), and operated for hypoplastic left heart syndrome, without aortic coarctation, using a mixed technique cardiovascular repair surgery. The initial therapeutic conduct included maintaining the permeability of the arterial canal with prostaglandin E1. At the Vienna General Hospital, at the age of 17 days, bilateral banding of the pulmonary artery was performed and, at the age of 20 days, during the cardiac catheterisation, the Rashkind procedure (balloon atrial septostomy) was performed, with two stents being implanted in the arterial canal. Postoperative complications were postcardiotomy syndrome, pneumonia with Enterococcus faecalis and Stenotrophomonas maltophilia, sepsis with methicillin-resistant Staphylococcus aureus, coagulopathy, mixed anaemia, and metabolic acidosis. The patient died 1 month after the intervention due to cardiorespiratory arrest, bilateral congestive heart failure, left heart hypoplasia with shunt through the arterial canal and pulmonary artery banding, multiorgan failure, and severe secondary haemorrhagic disease. In conclusion, the initial cardiac surgical reconstruction consisted of a mixed technique, and anticoagulant medical treatment with heparin, antibiotics (bacterial endocarditis prophylaxis to be performed throughout life); postintervention hypoxic and infectious complications resulted in multiorgan failure and death.

Technical Performance Score: A Predictor of Outcomes After the Norwood Procedure

BACKGROUND

The Technical Performance Score (TPS) can predict outcomes after congenital cardiac surgery. We sought to validate TPS as a predictor of both short- and long-term outcomes of the Norwood procedure.

METHODS

We conducted a retrospective review of patients who underwent the Norwood procedure from 1997 to 2017. We assigned TPS (class 1, no residua; class 2, minor residua; class 3, major residua or reintervention for major residua before discharge) based on subcomponent scores from discharge echocardiograms or unplanned reinterventions, or both. Multivariable Cox or competing risk analysis, adjusted for preoperative patient- and procedure-related covariates, examined the association of TPS with postoperative hospital length of stay, transplant-free survival, and postdischarge reinterventions.

RESULTS

Among 500 patients, 319 (64%) were male, 54 (11%) were premature, 56 (11%) had noncardiac anomalies/syndromes, 146 (29%) had preoperative risk factors, and 480 (96%) were assigned TPS. On multivariable analysis, class 3 had greater hazard for reinterventions in transplant-free survivors (class 3: subdistribution hazard ratio [HR], 2.06; 95% confidence interval [CI] 1.34-3.16; P = .001) and was associated with increased hospital length of stay vs class 1 (HR, 0.25; 95% CI, 0.18-0.34; P < .001). Transplant-free survival after Norwood surgery was shorter for both class 2 (HR, 2.48; 95% CI, 1.68-3.66; P < .001) and class 3 (HR, 3.29; 95% CI, 2.18-4.95; P < .001).

CONCLUSIONS

TPS predicts early and late outcomes after Norwood. Absence of residual lesions results in improved long-term prognosis for single-ventricle patients. TPS may improve outcomes after Norwood by identifying patients warranting closer follow-up and potentially earlier reintervention.

Research priorities in Fontan-associated liver disease

PURPOSE OF REVIEW

Fontan-associated liver disease (FALD) is an emerging condition in patients who have undergone surgical correction of univentricular congenital heart disease. There is little known about the epidemiology of FALD, including risk factors for end-organ failure or hepatocellular carcinoma nor a consensus on surveillance guidelines. Furthermore, there is a need to understand the role of heart versus combined heart-liver transplantation in this population. Research is limited by systemic barriers hindering the ability to track longitudinal FALD outcomes.

RECENT FINDINGS

Nearly all patients post-Fontan develop histological features of FALD as a function of time post-Fontan, regardless of Fontan hemodynamics. In cases of end-organ disease, single-center studies have shown promising outcomes of combined heart-liver transplant in this population, with decreased rates of acute rejection. However, despite the burden of disease, it is not currently possible to identify the population of patients with FALD using existing clinical databases and registries due to a lack of diagnostic codes.

SUMMARY

Strategies proposed to address barriers to understanding FALD include developing appropriate diagnostic and transplant-related codes for existing registries. Efforts should also be targeted at initiating prospective studies to understand recognized comorbidities related to Fontan physiology, guided by a team of multidisciplinary subspecialists.

Superior Cavopulmonary Connection: Its Physiology, Limitations, and Anesthetic Implications

The superior cavopulmonary connection (SCPC) or "bidirectional Glenn" is an integral, intermediate stage in palliation of single ventricle patients to the Fontan procedure. The procedure, normally performed at 3 to 6 months of life, increases effective pulmonary blood flow and reduces the ventricular volume load in patients with single ventricle (parallel circulation) physiology. While the SCPC, with or without additional sources of pulmonary blood flow, cannot be considered a long-term palliation strategy, there are a subset of patients who require SCPC palliation for a longer interval than the typical patient. In this article, we will review the physiology of SCPC, the consequences of prolonged SCPC palliation, and modes of failure. We will also discuss strategies to augment pulmonary blood flow in the presence of an SCPC. The anesthetic considerations in SCPC patients will also be discussed, as these patients may present for noncardiac surgery from infancy to adulthood.

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.

Sinus Superflex DS© early collapse in systemic arterial duct

We implanted two sinus Superflex DS© stents in a systemic non-stenotic arterial duct of a newborn with hypoplastic left heart syndrome. Forty-eight hours later an important collapse of the stent was detected and treated with a balloon expandable stent. Sinus Superflex DS© has been specifically designed for systemic ducts. This complication generates doubts about its radial force in this scenario.

Acute Effects of Hypoxic Gas Admixtures on Pulmonary Blood Flow and Regional Oxygenation in Children Awaiting Norwood Palliation

Introduction

Oxygen delivery in patients with functionally univentricular hearts awaiting Norwood palliation depends on a balance between systemic blood flow (Qs) and pulmonary blood flow (Qp). Modulations of pulmonary vascular resistance and systemic vascular resistance are utilized to maintain balanced Qp:Qs in a circulation prone to pulmonary overcirculation at the expense of systemic perfusion. This study aimed to characterize changes in Qp:Qs and regional (cerebral and renal) oxygen delivery in patients awaiting Norwood palliation receiving hypoxic gas admixture therapy.

Methods

Patients who received care prior to Norwood palliation were identified from 2014 to 2018. Of these patients, those with cerebral and renal near-infrared spectroscopy were identified (NIRS). Arterial oxygen saturation by pulse oximetry, renal NIRS, and cerebral NIRS prior to hypoxic gas admixture initiation were compared to values six hours, 12 hours, and 24 hours after initiation.

Results

A total of 28 patients were eligible for inclusion in the study. Arterial saturation by pulse oximetry was 91% prior to initiation and decreased to 86% 24 hours after initiation (p<0.001). Cerebral NIRS were a mean of 60 prior to initiation compared to 58 at 24 hours (p=0.187). Renal NIRS were a mean of 60 prior to initiation compared to 57 at 24 hours (p=0.120). Calculated Qp:Qs was 9.6 at baseline compared to 2.5 at 24 hours (p=0.006). Arteriovenous difference and lactate did not significantly change with hypoxic gas admixture administration.

Conclusion

Administration of hypoxic gas admixture to patients with functionally univentricular hearts awaiting Norwood palliation decreases the ratio of Qp and Qs but does not improve regional oxygenation delivery.