Neurological Injury and Cerebral Blood Flow in Single Ventricles Throughout Staged Surgical Reconstruction

Cerebral Blood Flow, Brain Injury, and Aortic-Pulmonary Collateral Flow After the Fontan Operation

Patients with a single ventricle develop aortopulmonary collaterals (APCs) whose flow has been shown to be inversely proportional to cerebral blood flow (CBF) in a previous cross-sectional study. Longitudinal CBF and APC flow in patients with Fontan physiology adjusting for brain injury (BI) has never been reported. Decreased CBF and BI may adversely impact neurodevelopment. A prospective longitudinal cohort of 27 patients with Fontan physiology (aged 10 ± 1.9 years, 74% male) underwent cardiac and brain magnetic resonance imaging 3 to 9 months and 6.0 ± 1.86 years after Fontan operation to measure the CBF and APC flow and to reassess the BI (focal BI, generalized insult, and hemorrhage). CBF was measured using jugular venous flow and APC flow was measured by the difference between aortic flow and caval return. Multivariate modeling was used to assess the relation between the change in APC flow and BI. A strong inverse relation was found between CBF/aortic flow change and APC flow/aortic flow and APC flow/body surface area change (R2 = 0.70 and 0.72 respectively, p <0.02). Overall, the CBF decreased by 9 ± 11% and the APC flow decreased by 0.73 ± 0.67 l/min/m2. The evolution of CBF and APC flow were significantly and inversely related when adjusting for time since Fontan operation, gender, and BI on the multivariate modeling. Every unit increase in APC flow change was associated with an 8% decrease in CBF change. In conclusion, CBF and APC flow change are inversely related across serial imaging, adjusting for time from Fontan operation, gender, and BI. CBF and APC aortic flow decrease over a 6-year period. This may adversely impact neurodevelopment. Because APCs can be embolized, this may be a modifiable risk factor. Clinical trials numbers: NCT02135081 and NCT02919956.

The prevalence of abnormal spirometry in children with CHD

BACKGROUND

The burden of pulmonary disease in children with CHD remains under-recognised. Studies have examined children with single ventricle and two ventricle heart disease and documented a decreased forced vital capacity. Our study sought to further explore the pulmonary function of children with CHD.

METHODS

A retrospective review was performed of spirometry in CHD patients over a 3-year period. Spirometry data were corrected for size, age, and gender and analysed using z-scores.

RESULTS

The spirometry of 260 patients was analysed. About 31% had single ventricle (n = 80, 13.6 years (interquartile range 11.5-16.8)) and 69% had two ventricle circulation (n = 180, 14.4 years (interquartile range 12.0-17.3)). Single ventricle patients were found to have a lower median forced vital capacity z-score compared to two ventricle patients (p = 0.0133). The prevalence of an abnormal forced vital capacity was 41% in single ventricle patients and 29% in two ventricle patients. Two ventricle patients with tetralogy of Fallot and truncus arteriosus had similar low forced vital capacity comparable to single ventricle patients. The number of cardiac surgeries predicted an abnormal forced vital capacity in two ventricle patients except tetralogy of Fallot patients.

CONCLUSION

Pulmonary morbidity in patients with CHD is common with a decreased forced vital capacity noted in single ventricle and two ventricle patients. Forced vital capacity is lower in patients with single ventricle circulation; however, two ventricle patients with tetralogy of Fallot or truncus arteriosus have similar lung function in comparison to the single ventricle group. The number of surgical interventions was predictive of forced vital capacity z-score in some but not all two ventricle patients and not predictive in single ventricle patients suggesting a multifactorial to pulmonary disease in children with CHD.

Prevalence and detection rate of major congenital heart disease in twin pregnancies in Denmark

OBJECTIVE

To investigate the national prevalence and prenatal detection rate (DR) of major congenital heart disease (mCHD) in twin pregnancies without twin-to-twin transfusion syndrome (TTTS)-associated CHD in a Danish population following a standardized prenatal screening program.

METHODS

This was a national registry-based study of data collected prospectively over a 10-year period. In Denmark, all women with a twin pregnancy are offered standardized screening and surveillance programs in addition to first- and second-trimester screening for aneuploidies and malformation, respectively: monochorionic (MC) twins every 2 weeks from gestational week 15 and dichorionic (DC) twins every 4 weeks from week 18. The data were retrieved from the Danish Fetal Medicine Database and included all twin pregnancies from 2009-2018, in which at least one fetus had a pre- and/or postnatal mCHD diagnosis. mCHD was defined as CHD requiring surgery within the first year of life, excluding ventricular septal defects. All pregnancy data were pre- and postnatally validated in the local patient files at the four tertiary centers covering the entire country.

RESULTS

A total of 60 cases from 59 twin pregnancies were included. The prevalence of mCHD was 4.6 (95% CI, 3.5-6.0) per 1000 twin pregnancies (1.9 (95% CI, 1.3-2.5) per 1000 live births). The prevalences for DC and MC were 3.6 (95% CI, 2.6-5.0) and 9.2 (95% CI, 5.8-13.7) per 1000 twin pregnancies, respectively. The national prenatal DR of mCHD in twin pregnancies for the entire period was 68.3%. The highest DRs were in cases with univentricular hearts (100%) and the lowest with aortopulmonary window, total anomalous pulmonary venous return, Ebstein's anomaly, aortic valve stenosis and coarctation of the aorta (0-25%). Mothers of children with prenatally undetected mCHD had a significantly higher body mass index (BMI) compared to mothers of children with a prenatally detected mCHD (median, 27 kg/m2 and 23 kg/m2 , respectively; P = 0.02).

CONCLUSIONS

The prevalence of mCHD in twins was 4.6 per 1000 pregnancies and was higher in MC than DC pregnancies. The prenatal DR of mCHD in twin pregnancies was 68.3%. Maternal BMI was higher in cases of prenatally undetected mCHD. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Postnatal cerebral hemodynamics in infants with severe congenital heart disease: a scoping review

Patients with severe congenital heart disease (CHD) are at risk for impaired neurodevelopment. Cerebral blood supply may be diminished by congenital anomalies of cardiovascular anatomy and myocardial function. The aim of this scoping review was to summarize the current knowledge on cerebral hemodynamics in infants with severe CHD. A scoping review was performed. Five databases were searched for articles published from 01/1990 to 02/2022 containing information on cerebral hemodynamics assessed by neuroimaging methods in patients with severe CHD within their first year of life. A total of 1488 publications were identified, of which 26 were included. Half of the studies used Doppler ultrasound, and half used magnetic resonance imaging techniques. Studies focused on preoperative findings of cerebral hemodynamics, effects of surgical and conservative interventions, as well as on associations between cerebral hemodynamics and brain morphology or neurodevelopment. Cerebral perfusion was most severely affected in patients with single ventricle and other cyanotic disease. Neuroimaging methods provide a large variety of information on cerebral hemodynamics. Nevertheless, small and heterogeneous cohorts complicate this field of research. Further studies are needed to improve our understanding of the link between CHD and altered cerebral hemodynamics to optimize neuroprotection strategies. IMPACT: Postnatal cerebral hemodynamics are altered in infants with congenital heart disease (CHD) as compared to healthy controls, especially in most severe types such as single ventricle or other cyanotic CHD. Associations of these alterations with brain volume and maturation reveal their clinical relevance. Research in this area is limited due to the rarity and heterogeneity of diagnoses. Furthermore, longitudinal studies have rarely been conducted. Further effort is needed to better understand the deviation from physiological cerebral perfusion and its consequences in patients with CHD to optimize neuroprotection strategies.

Sex-Specific Cerebral Blood Flow Alterations in Youth Operated for Congenital Heart Disease

Background Lower cerebral blood flow (CBF) has previously been documented preoperatively in neonates with congenital heart disease (CHD). However, it remains unclear if these CBF deficits persist over the life span of CHD survivors following heart surgery. When exploring this question, it is critical to consider the sex differences in CBF that emerge during adolescence. Therefore, this study aimed to compare global and regional CBF between postpubertal youth with CHD and healthy peers and examine if such alterations are related to sex. Methods and Results Youth aged 16 to 24 years who underwent open heart surgery for complex CHD during infancy and age- and sex-matched controls completed brain magnetic resonance imaging, including T1-weighted and pseudo-continuous arterial spin labeling acquisitions. Global gray matter CBF and regional CBF in 9 bilateral gray matter regions were quantified for each participant. Compared with female controls (N=27), female participants with CHD (N=25) presented with lower global and regional CBF. In contrast, there were no differences in CBF between male controls (N=18) and males with CHD (N=17). Concurrently, female controls had higher global and regional CBF compared with male controls, with no differences in CBF between female and male participants with CHD. CBF was lower in individuals with a Fontan circulation. Conclusions This study provides evidence of altered CBF in postpubertal female participants with CHD despite undergoing surgical intervention during infancy. Alterations to CBF could have implications for later cognitive decline, neurodegeneration, and cerebrovascular disease in women with CHD.

MRI Phase-Contrast Blood Flow in Fasting Pediatric Patients with Fontan Circulation Correlates with Exercise Capacity

Purpose

To assess regional blood flow in fasting pediatric patients with Fontan circulation by using MRI and to explore associations with clinical parameters.

Materials and Methods

In this retrospective study, pediatric patients who had undergone the Fontan procedure (<18 years of age) and had undergone clinical cardiac MRI, performed after at least 4 hours of fasting, between 2018 and 2021 were included. Regional blood flow was compared with published healthy volunteer data (n = 19) and assessed in relation to hemodynamic parameters and clinical status. Data are presented as medians, with first to third quartiles in parentheses. Mann-Whitney U, Kruskal-Wallis, χ2, and Spearman rank correlation tests were used.

Results

Fifty-five patients (38 boys) with median age at MRI of 14 years (IQR, 11-16 years) and median time from Fontan procedure to MRI of 10 years (IQR, 8-12 years) were included. Patients after Fontan procedure had lower ascending aortic, inferior vena cava, and total systemic blood flow compared with healthy volunteers (3.00 L/min/m2 [IQR, 2.75-3.30 L/min/m2] vs 3.61 L/min/m2 [IQR, 3.29-4.07 L/min/m2]; 1.73 L/min/m2 [IQR, 1.40-1.94 L/min/m2] vs 2.24 L/min/m2 [IQR, 2.06-2.75 L/min/m2]; 2.78 L/min/m2 [IQR, 2.45-3.10 L/min/m2] vs 3.95 L/min/m2 [IQR, 3.20-4.30 L/min/m2], respectively; P < .001). Portal vein flow was greater than hepatic vein flow in 25% of patients. Fontan blood flow was inversely correlated with pre-Fontan mean pulmonary artery pressure (Spearman rank correlation coefficient [rs ]= -0.42, P = .005) and ventricular end diastolic pressure (rs = -0.33, P = .04) and positively correlated with post-Fontan percent predicted oxygen consumption at peak workload (rs = 0.34, P = .02).

Conclusion

Reference ranges are provided for regional systemic blood flow derived by using MRI in fasting pediatric patients with Fontan circulation, who had lower systemic blood flow compared with healthy volunteers. Lower fasting Fontan blood flow correlated with lower exercise capacity.Keywords: Pediatrics, Heart, Congenital, MR Imaging, Hemodynamics/Flow Dynamics, Cardiac Supplemental material is available for this article. © RSNA, 2022.

Clinical significance of assessing cerebral blood volume by time-domain near-infrared spectroscopy in children with congenital heart disease

BACKGROUND

Despite providing cerebral tissue oxygen saturation (StO₂ ), the lack of quantitative information for continuous wave near-infrared spectroscopy (CW-NIRS) is an obstacle in evaluating cerebral hemodynamic conditions. Time-domain NIRS (TD-NIRS) provides both StO₂ and cerebral blood volume and has recently become clinically available.

AIM

To investigate if the additional monitoring of cerebral blood volume by TD-NIRS facilitates the understanding of cerebral hemodynamic conditions in patients with congenital heart disease.

METHODS

Preoperative TD-NIRS values were retrospectively reviewed in patients who underwent a cardiac surgery or catheter examination. We compared the values between patients with single and two ventricles. Moreover, we investigated the association of these values with the demographic and clinical variables.

RESULTS

There was no significant difference in StO2 between single ventricle and two ventricles groups (median: 59.9 vs. 54.4, median difference [95% CI]: -4.06 [-9.90 to 2.90], p = .37). However, cerebral blood volume was significantly higher in the single ventricle group (median: 4.68 vs. 2.84, median difference [95% CI]: -2.01 [-2.88 to -1.06], p < .001). Spearman's rank correlation analysis demonstrated an association between StO2 and postmenstrual age (r = 0.35, p = .03). In contrast, cerebral blood volume was correlated with single ventricle physiology (r = 0.62, p < .001), postmenstrual age (r = 0.74, p < .001), central venous pressure (r = 0.38, p = .02), and SaO2 (r = -0.38, p = .02). The multivariable regression analysis identified the postmenstrual age, single ventricle physiology, and SaO2 as independent factors associated with cerebral blood volume. In the logistic analysis, cerebral blood volume was identified as a significant predictor of unfavorable conditions.

CONCLUSION

Cerebral blood volume monitoring detected differences in cerebral hemodynamic conditions, related to the age and the type of ventricle physiologies. However, the differences were not apparent in StO₂ . The additional monitoring of cerebral blood volume by TD-NIRS would facilitate a better understanding of cerebral hemodynamic conditions in patients with congenital heart disease.

Neurodevelopmental and Mental Health Outcomes in Patients With Fontan Circulation: A State-of-the-Art Review

Children, adolescents and adults living with Fontan circulation face numerous neurological and developmental challenges. As the population with complex CHD increases thanks to outstanding improvement in medical and surgical care, the long-term developmental and mental health sequelae have become a public health priority in pediatric and congenital cardiology. Many patients with a Fontan circulation experience difficulty in areas of cognition related to attention and executive functioning, visual spatial reasoning and psychosocial development. They are also at high risk for mental health morbidities, particularly anxiety disorders and depression. Several hemodynamic risk factors, beginning during the fetal period, may influence outcomes and yield to abnormal brain growth and development. Brain injury such as white matter lesions, stroke or hemorrhage can occur before, during, or after surgery. Other sociodemographic and surgical risk factors such as multiple catheterizations and surgeries and prolonged hospital stay play a detrimental role in patients' neurodevelopmental prognosis. Prevention and intervention to optimize long-term outcomes are critical in the care of this vulnerable population with complex CHD.

Relationships Between Regional Cerebral Blood Flow and Neurocognitive Outcomes in Children and Adolescents With Congenital Heart Disease

To identify regional cerebral blood flow (rCBF) alterations in children and adolescents with congenital heart disease (CHD) in relation to neurocognitive outcomes using a nonbiased data-driven approach. This is a prospective, observational study of children and adolescents with CHD without brain injury and healthy controls using pseudo-continuous arterial spin labeling (pCASL) MRI. Quantitative rCBF was compared between participants with CHD and healthy controls using a voxelwise data-driven method. Mediation analysis was then performed on a voxelwise basis, with the grouping variable as the independent variable, neurocognitive outcomes (from the NIH Toolbox Cognitive Battery) as the dependent variables, and rCBF as the mediator. After motion correction, a total of 80 studies were analyzable (27 for patients with CHD, 53 for controls). We found steeper age-related decline in rCBF among those with CHD compared to normal controls in the insula/ventromedial prefrontal regions (salience network) and the dorsal anterior cingulate and precuneus/posterior cingulate (default mode network), and posterior parietal/dorsolateral prefrontal (central executive network) (FWE-corrected P< 0.05). The reduced rCBF in the default mode/salience network was found to mediate poorer performance on an index of crystallized cognition from the NIH Toolbox Cognitive Battery in those with CHD compared to controls. In contrast, reduced rCBF in the central executive network/salience network mediated reduced deficits in fluid cognition among patients with CHD compared to controls. Regional cerebral blood flow alterations mediate domain-specific differences in cognitive performance in children and adolescents with CHD compared to healthy controls, independent of injury, and are likely related to brain and cognitive reserve mechanisms. Further research is needed to evaluate the potential of interventions in CHD targeting regional cerebral blood flow across lifespan.

Neurodevelopmental outcomes in congenital heart disease through the lens of single ventricle patients

PURPOSE OF REVIEW

This review aims to summarize and organize the current body of literature on this contemporary topic, alongside a more general discussion of neurodevelopmental complications of congenital heart disease.

RECENT FINDINGS

It is theorized that the causes of the neurodevelopment disabilities are multifactorial resulting from structural central nervous system abnormalities, haemodynamic alterations and/or biochemical changes. It is therefore imperative that all patients with single ventricle anatomy and physiology receive long-term neurologic and developmental assessments in addition to their cardiac monitoring.

SUMMARY

Advancements in surgical techniques and medical management have improved survivorship of these medically complex patients. Neurodevelopmental sequelae are one of the most common comorbidities affecting this patient population leading to long-term challenges in motor, language, social and cognitive skills.

Abnormal Right-Hemispheric Sulcal Patterns Correlate with Executive Function in Adolescents with Tetralogy of Fallot

Neurodevelopmental disabilities are the most common noncardiac conditions in patients with congenital heart disease (CHD). Executive function skills have been frequently observed to be decreased among children and adults with CHD compared with peers, but a neuroanatomical basis for the association is yet to be identified. In this study, we quantified sulcal pattern features from brain magnetic resonance imaging data obtained during adolescence among 41 participants with tetralogy of Fallot (ToF) and 49 control participants using a graph-based pattern analysis technique. Among patients with ToF, right-hemispheric sulcal pattern similarity to the control group was decreased (0.7514 vs. 0.7553, P = 0.01) and positively correlated with neuropsychological testing values including executive function (r = 0.48, P < 0.001). Together these findings suggest that sulcal pattern analysis may be a useful marker of neurodevelopmental risk in patients with CHD. Further studies may elucidate the mechanisms leading to different alterations in sulcal patterning.

Pattern of head circumference growth following bidirectional Glenn in infants with single ventricle heart disease

BACKGROUND

Infants with single ventricle congenital heart disease demonstrate increasing head growth after bidirectional Glenn; however, the expected growth trajectory has not been well described.

AIMS

1) We will describe the pattern of head circumference growth in the first year after bidirectional Glenn. 2) We will determine if head growth correlates with motor developmental outcomes approximately 12 months after bidirectional Glenn.

METHODS

Sixty-nine single ventricle patients underwent bidirectional Glenn between 2010 and 2016. Patients with structural brain abnormalities, grade III-IV intra-ventricular haemorrhage, significant stroke, or obstructive hydrocephalus were excluded. Head circumference and body weight measurements from clinical encounters were evaluated. Motor development was measured with Psychomotor Developmental Index of the Bayley Scales of Infant Development, Third Edition. Generalised estimating equations assessed change in head circumference z-scores from baseline (time of bidirectional Glenn) to 12 months post-surgery.

RESULTS

Mean age at bidirectional Glenn was 4.7 (2.3) months and mean head circumference z-score based on population-normed data was -1.13 (95% CI -1.63, -0.63). Head circumference z-score increased to 0.35 (95% CI -0.20, 0.90) (p < 0.0001) 12 months post-surgery. Accelerated head growth, defined as an increase in z-score of >1 from baseline to 12 months post-surgery, was present in 46/69 (66.7%) patients. There was no difference in motor Psychomotor Developmental Index scores between patients with and without accelerated head growth.

CONCLUSION

Single ventricle patients demonstrated a significant increase in head circumference after bidirectional Glenn until 10-12 months post-surgery, at which time growth stabilised. Accelerated head growth did not predict sub-sequent motor developmental outcomes.

Licochalcone A improves the cognitive ability of mice by regulating T- and B-cell proliferation

Licochalcone A (LA), a flavonoid found in licorice, has anticancer, antioxidant, anti-inflammatory, and neuroprotective properties. Here, we explored the effect of injecting LA into the tail vein of middle-aged C57BL/6 mice on their cognitive ability as measured by the Morris water maze (MWM) test and cerebral blood flow (CBF). The related mechanisms were assessed via RNA-seq, and T (CD3e⁺) and B (CD45R/B220⁺) cells in the spleen and whole blood were quantified via flow cytometry. LA improved the cognitive ability, according to the MWM test results, and upregulated the CBF level of treated mice. The RNA-seq results indicate that LA affected the interleukin (IL)-17 signaling pathway, which is related to T- and B-cell proliferation, and the flow cytometry data suggest that LA promoted T- and B-cell proliferation in the spleen and whole blood. We also performed immune reconstruction via a tail vein injection of lymphocytes into B-NDG (NOD-Prkdc^scidIl2rg^tm1/Bcge) mice before treating them with LA. We tested cognitive ability by subjecting these animals to new object recognition tests and quantified the splenic and whole blood T and B cells. Cognitive ability improved after immune reconstruction and LA treatment, and LA promoted T- and B-cell proliferation in the spleen and whole blood. This study demonstrates that LA, by activating the IL-17 signaling pathway, promotes T- and B-cell proliferation in the spleen and whole blood of mice and improves cognitive ability. Thus, LA may have immune-modulating therapeutic potential for improving cognition.

Effects of different ventilation on cerebral oxygen saturation and cerebral blood flow before and after modified ultrafiltration in infants during ventricular septal defect repair

OBJECTIVE

To analyse the changes of different ventilation on regional cerebral oxygen saturation and cerebral blood flow in infants during ventricular septal defect repair.

METHODS

Ninety-two infants younger than 1 year were enrolled in the study. End-expiratory tidal pressure of carbon dioxide was maintained at 40-45 and 35-39 mmHg in relative low and high ventilation groups. Regional cerebral oxygen saturation and flow velocity of the middle cerebral artery were recorded after anaesthesia (T0), cut pericardium (T1), separation from cardiopulmonary bypass (T2), the end of modified ultrafiltration, (T3) and at the end of operation (T4).

RESULTS

The relative low ventilation group exhibited a significantly high regional cerebral oxygen saturation at each time point except for T2 (T0:77 ± 4, T1:76 ± 5, T3:76 ± 8, T4:76 ± 8, respectively, p < 0.001). Flow velocity of the middle cerebral artery in the relative low ventilation group was higher compared to the relative high ventilation group at each time point except for T2 (T0:53 ± 14, T1:54 ± 15, T3:53 ± 17, T4:52 ± 16, respectively, p < 0.001). Between the two groups, T2 showed the lowest middle cerebral artery flow velocity (relative low ventilation: 39 ± 15, relative high ventilation: 39 ± 11, p < 0.001).

CONCLUSION

The infants' regional cerebral oxygen saturation and middle cerebral artery flow velocity performed better in the range of 40-45 mmHg end-expiratory tidal pressure of carbon dioxide during CHD surgery. Modified ultrafiltration increased cerebral oxygen saturation. It was important to regulate ventilation in order to balance cerebral oxygen in infants.

Neurocognitive Dysfunction and Smaller Brain Volumes in Adolescents and Adults With a Fontan Circulation

BACKGROUND

Neurocognitive outcomes beyond childhood in people with a Fontan circulation are not well defined. This study aimed to investigate neurocognitive functioning in adolescents and adults with a Fontan circulation and associations with structural brain injury, brain volumetry, and postnatal clinical factors.

METHODS

In a binational study, participants with a Fontan circulation without a preexisting major neurological disability were prospectively recruited from the Australia and New Zealand Fontan Registry. Neurocognitive function was assessed by using Cogstate software in 107 participants with a Fontan circulation and compared with control groups with transposition of the great arteries (n=50) and a normal circulation (n=41). Brain MRI with volumetric analysis was performed in the participants with a Fontan circulation and compared with healthy control data from the ABIDE I and II (Autism Brain Imaging Data Exchange) and PING (Pediatric Imaging, Neurocognition, and Genetics) data repositories. Clinical data were retrospectively collected.

RESULTS

Of the participants with a Fontan circulation who had a neurocognitive assessment, 55% were male and the mean age was 22.6 years (SD 7.8). Participants with a Fontan circulation performed worse in several areas of neurocognitive function compared with those with transposition of the great arteries and healthy controls (P<0.05). Clinical factors associated with worse neurocognitive outcomes included more inpatient days during childhood, younger age at Fontan surgery, and longer time since Fontan procedure (P<0.05). Adults with a Fontan circulation had more marked neurocognitive dysfunction than adolescents with a Fontan circulation in 2 domains (psychomotor function, P=0.01 and working memory, P=0.02). Structural brain injury was present in the entire Fontan cohort; the presence of white matter injury was associated with worse paired associate learning (P<0.001), but neither the presence nor severity of infarct, subcortical gray matter injury, and microhemorrhage was associated with neurocognitive outcomes. Compared with healthy controls, people with a Fontan circulation had smaller global brain volumes (P<0.001 in all regions) and smaller regional brain volumes in most cerebral cortical regions (P<0.05). Smaller global brain volumes were associated with worse neurocognitive functioning in several domains (P<0.05). A significant positive association was also identified between global brain volumes and resting oxygen saturations (P≤0.04).

CONCLUSIONS

Neurocognitive impairment is common in adolescents and adults with a Fontan circulation and is associated with smaller gray and white matter brain volume. Understanding modifiable factors that contribute to brain injury to optimize neurocognitive function is paramount.

Imaging of complications following Fontan circulation in children - diagnosis and surveillance

The Fontan operation is performed for various cardiac lesions with single-ventricle physiology. The survival rate of Fontan patients is increasing for adolescents and young adults, with an expected 30-year survival of >80%. Medical health care providers including specialists in organ systems and pediatric radiologists need to improve their knowledge about the Fontan circulation and the various organ complications to monitor care. In this review the author explains the basic anatomical and functional features of Fontan palliation and gives an overview of the multiple long-term organ complications that might present in the pediatric population. These include decreased physical capacity, ventricular dysfunction, atrioventricular valve regurgitation and arrhythmia, as well as protein-losing enteropathy, plastic bronchitis, growth/bone composition disturbances, renal dysfunction, and the recently recognized and important liver fibrosis (Fontan-associated liver disease). Neuropsychological and behavioral deficits occur frequently. This review focuses on the key role of radiology in making the diagnosis of these complications, monitoring therapy and predicting outcomes in the pediatric age group. The author discusses how and when radiology is important in Fontan patients, as well as how new techniques enabling quantitative measures in imaging with US, MRI and CT are adapted for pediatric use, and how they contribute to urgently needed surveillance strategies.

Neurodevelopmental Outcomes Among Children With Congenital Heart Disease: At-Risk Populations and Modifiable Risk Factors

As survivable outcomes among patients with complex congenital heart disease (cCHD) have continued to improve over the last several decades, more attention is being dedicated to interventions that impact not just survival but quality of life among patients with cCHD. In particular, patients with cCHD are at risk for impaired neurodevelopmental outcomes. In this review summarizing select presentations given at the 14th Annual Pediatric Cardiac Intensive Care Society's Annual Meeting in 2019, we discuss the neurodevelopmental phenotype of patients with cCHD, patients at greatest risk of impaired development, and three specific modifiable risk factors impacting development.

Perioperative Assessment of Cerebral Oxygen Metabolism in Infants With Functionally Univentricular Hearts Undergoing the Bidirectional Cavopulmonary Connection

OBJECTIVES

The transition from single-ventricle lesions with surgically placed systemic-to-pulmonary artery shunt to the circulation following a bidirectional cavopulmonary connection results in higher pressure in the superior vena cava when compared with the preceding circulation. The aim of this study was to evaluate the impact of this transition on the perioperative cerebral oxygen metabolism.

DESIGN

Prospective observational cohort study.

SETTING

Pediatric critical care unit of a tertiary referral center.

PATIENTS

Sixteen infants after bidirectional cavopulmonary connection.

INTERVENTION

Cardiac surgery (bidirectional cavopulmonary connection).

MEASUREMENTS AND MAIN RESULTS

We measured regional cerebral oxygen saturation, amount of hemoglobin, blood flow velocity, and microperfusion immediately before, 12-24 hours, and 36-48 hours following bidirectional cavopulmonary connection. Based on these measurements, we calculated cerebral fractional tissue oxygen extraction and approximated cerebral metabolic rate of oxygen. Mean pressure in the superior vena cava increased significantly (8 vs 17 mm Hg; p < 0.001) following bidirectional cavopulmonary connection. Mean cerebral oxygen saturation increased from 49.0% (27.4-61.0) to 56.9% (39.5-64.0) (p = 0.008), whereas mean cerebral blood flow velocity decreased from 80.0 arbitrary units (61.9-93.0) to 67.3 arbitrary units (59.0-83.3) (p < 0.001). No change was found in the cerebral amount of hemoglobin and in the cerebral microperfusion. Mean cerebral fractional tissue oxygen extraction (0.48 [0.17-0.63] vs 0.30 [0.19-0.56]; p = 0.006) and approximated cerebral metabolic rate of oxygen (5.82 arbitrary units [2.70-8.78] vs 2.27 arbitrary units [1.19-7.35]; p < 0.001) decreased significantly.

CONCLUSIONS

Establishment of bidirectional cavopulmonary connection is associated with postoperative improvement in cerebral oxygen metabolism. Cerebral amount of hemoglobin did not increase, although creation of the bidirectional cavopulmonary connection results in significant elevation in superior vena cava pressure. Improvement in cerebral oxygen metabolism was due to lower cerebral blood flow velocity and stable microperfusion, which may indicate intact cerebral autoregulation.

Evaluation and Management of the Child and Adult With Fontan Circulation: A Scientific Statement From the American Heart Association

It has been 50 years since Francis Fontan pioneered the operation that today bears his name. Initially designed for patients with tricuspid atresia, this procedure is now offered for a vast array of congenital cardiac lesions when a circulation with 2 ventricles cannot be achieved. As a result of technical advances and improvements in patient selection and perioperative management, survival has steadily increased, and it is estimated that patients operated on today may hope for a 30-year survival of >80%. Up to 70 000 patients may be alive worldwide today with Fontan circulation, and this population is expected to double in the next 20 years. In the absence of a subpulmonary ventricle, Fontan circulation is characterized by chronically elevated systemic venous pressures and decreased cardiac output. The addition of this acquired abnormal circulation to innate abnormalities associated with single-ventricle congenital heart disease exposes these patients to a variety of complications. Circulatory failure, ventricular dysfunction, atrioventricular valve regurgitation, arrhythmia, protein-losing enteropathy, and plastic bronchitis are potential complications of the Fontan circulation. Abnormalities in body composition, bone structure, and growth have been detected. Liver fibrosis and renal dysfunction are common and may progress over time. Cognitive, neuropsychological, and behavioral deficits are highly prevalent. As a testimony to the success of the current strategy of care, the proportion of adults with Fontan circulation is increasing. Healthcare providers are ill-prepared to tackle these challenges, as well as specific needs such as contraception and pregnancy in female patients. The role of therapies such as cardiovascular drugs to prevent and treat complications, heart transplantation, and mechanical circulatory support remains undetermined. There is a clear need for consensus on how best to follow up patients with Fontan circulation and to treat their complications. This American Heart Association statement summarizes the current state of knowledge on the Fontan circulation and its consequences. A proposed surveillance testing toolkit provides recommendations for a range of acceptable approaches to follow-up care for the patient with Fontan circulation. Gaps in knowledge and areas for future focus of investigation are highlighted, with the objective of laying the groundwork for creating a normal quality and duration of life for these unique individuals.

Oxygen saturations and neurodevelopmental outcomes in single ventricle heart disease

OBJECTIVES

To evaluate whether the degree of hypoxemia following stage-I and stage-II palliative surgeries predicts neurodevelopmental outcomes at 14 months of age in children with single ventricle congenital heart disease (SVCHD).

DESIGN

We analyzed longitudinal data from two Pediatric Heart Network (PHN) randomized controlled trials, with a total of 328 subjects. Oxygen saturations, measured via pulse oximetry, at time of discharge from stage-I and stage-II surgeries were the primary predictors of interest, and Bayley Scales of Infant Development-II (BSID-II) scores at 14 months old were the primary outcome measure. Relevant covariates from previously-published PHN studies were also included in regression models.

RESULTS

Oxygen saturations at time of discharge from stage-I and stage-II surgeries were not related to BSID-II scores. Having one or more oxygen saturation measurements below 80% was also not associated with BSID-II scores, and neither was change in oxygen saturations over time. These relationships were not altered by inclusion of relevant covariates.

CONCLUSIONS

In this large cohort of children with SVCHD, oxygen saturations post-stage-I and post-stage-II palliation surgeries as measured via pulse oximetry were not associated with neurodevelopmental outcomes at 14 months of age. The relationship between oxygen saturations and neurodevelopment in SVCHD is likely complex, and neurodevelopment is known to be affected by a number of factors. Pulse oximetry may also be an insufficient proxy for cerebral oxygen delivery. Clinically, pulse oximetry readings during the interstage and post-stage-II surgery periods are not a reliable predictor of future neurodevelopmental risk.

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.

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.

Bedside clinical neurologic assessment utilisation in paediatric cardiac intensive care units

IntroductionNeurodevelopmental disabilities in children with CHD can result from neurologic injury sustained in the cardiac ICU when children are at high risk of acute neurologic injury. Physicians typically order and specify frequency for serial bedside nursing clinical neurologic assessments to evaluate patients' neurologic status.Materials and methodsWe surveyed cardiac ICU physicians to understand how these assessments are performed, and the attitudes of physicians on the utility of these assessments. The survey contained questions regarding assessment elements, assessment frequency, communication of neurologic status changes, and optimisation of assessments. RESULTS: Surveys were received from 50 institutions, with a response rate of 86%. Routine clinical neurologic assessments were reported to be performed in 94% of institutions and standardised in 56%. Pupillary reflex was the most commonly reported assessment. In all, 77% of institutions used a coma scale, with Glasgow Coma Scale being most common. For patients with acute brain injury, 82% of institutions reported performing assessments hourly, whereas assessment frequency was more variable for low-risk and high-risk patients without overt brain injury. In all, 84% of respondents thought their current practice for assessing and monitoring neurologic status was suboptimal. Only 41% felt that the Glasgow Coma Scale was a valuable tool for assessing neurologic function in the cardiac ICU, and 91% felt that a standardised approach to assessing pre-illness neurologic function would be valuable. CONCLUSIONS: Routine nursing neurologic assessments are conducted in most surveyed paediatric cardiac ICUs, although assessment characteristics vary greatly between institutions. Most clinicians rated current neurologic assessment practices as suboptimal.

In Utero Evidence of Impaired Somatic Growth in Hypoplastic Left Heart Syndrome

We hypothesized that fetuses with hypoplastic left heart syndrome (HLHS) have impaired growth compared to expected growth for gestational age. This is a retrospective cohort study including singleton fetuses with isolated HLHS identified from a single, referral center's ultrasound database. To account for variable timing of ultrasounds, z-scores for gestational age were assigned for each biometric parameter. We identified 169 fetuses, of which 96 had more than one ultrasound. The median number of ultrasound evaluations per fetus was 2 (range 1-5). The mean gestational age at time of last ultrasound was 33.7 ± 4.3 weeks with a range of 20.4-39.6 weeks. While fetal growth restriction (11%) and microcephaly (3%) were relatively rare, mean z-scores at the time of last ultrasound for estimated fetal weight (mean difference z-score -0.20, p = 0.04) and head circumference (-0.28, p = 0.02) were lower than at the time of the initial ultrasound. Impaired somatic growth, defined as a decrement in z-score of 0.5 or more over time, was common (32%). There is a deceleration in somatic and head growth in fetuses with hypoplastic left heart syndrome that can be identified by routine ultrasound evaluation.