Long-term neurodevelopmental outcomes in school-aged children after neonatal arterial switch operation

Inflammatory response and neurodevelopmental outcome after open-heart surgery in children

Long-term neurodevelopmental sequelae are commonly detectable in children after open-heart surgery with cardiopulmonary bypass (CPB). The objective of the study was to determine the neurodevelopmental outcome in these children in relation to postoperative inflammatory reaction. This is a prospective, observational study on children with congenital heart defects (n = 32) undergoing elective open-heart surgery in a tertiary pediatric cardiac center. Neurodevelopmental outcome was assessed in the median 6 months after CPB. Neurological examination was done in all children before the operation and, additionally, complete neurodevelopmental status was assessed preoperatively in 14 children. Three hours after the end of CPB, plasma concentrations of interleukin (IL)-6 and IL-8 were strongly elevated (p < 0.001). Moreover, there was a rise of neutrophils and C-reactive protein at 24 h postoperatively (p < 0.001). Intellectual performance after surgery was correlated with preoperative performance, r ( S ) = 0.83, p < 0.001 (mean IQ scores after CPB = 90.4 +/- 18.4 and before CPB = 87.5 +/- 14.5, p = 0.20). Multiple regression analysis demonstrated that preoperative IQ scores accounted for 83.8% of the variance of postoperative IQ scores (p < 0.0001). Inflammatory variables were not significant predictors of postoperative IQ scores. The frequency of neuromotor abnormalities at 6 months after CPB was influenced by the presence of a cyanotic heart defect, duration of CPB and aortic clamp time, and plasma levels of IL-6 shortly after CPB (R (2) = 67.8%, p = 0.002). In conclusion, in the examined population, preexisting neurodevelopmental impairment is frequent and predicts postoperative outcome. The high frequency of postoperative neuromotor disabilities seems to be associated with the type of congenital heart defect but also with the procedure and possible complications of CPB.

Preventing brain injury in newborns with congenital heart disease: brain imaging and innovative trial designs

BACKGROUND AND PURPOSE

Newborns with congenital heart disease are at high risk for brain injury and adverse neurodevelopmental outcomes. MRI enables the objective determination of the severity of brain injury in critically ill newborns with congenital heart disease. We will rationalize the use of MRI as a surrogate for neurodevelopmental outcome and describe novel randomization techniques that can be used in trials in this population.

METHODS

This article describes the evidence for the use of MRI and the link with neurodevelopmental outcome established in newborns. We also discuss the use of adaptive randomization techniques for future clinical trials in newborns with congenital heart disease. These strategies will be highlighted using an example.

RESULTS

Brain injuries occur with high frequency in newborns with congenital heart disease. It is not until school age that the full extent of neurological sequelae becomes apparent and the rapid pace of innovation in neonatal cardiac surgery prevents timely evaluation of changes in care. MRI provides a timely, safe, and reliable outcome measure and has been extensively studied in newborns with other conditions in which the link between brain injury and neurodevelopmental outcome has been established. Clinical trials using MRI as an outcome measure as well as adaptive randomization can improve the efficiency of such trials.

CONCLUSIONS

Clinical trials of brain protection are urgently needed in newborns with congenital heart disease given the unacceptable frequency of brain injury in this population; MRI provides an early surrogate marker of long-term neurodevelopmental outcome and adaptive randomization can be used to improve the efficiency of these clinical trials.

Open-heart surgery at school age does not affect neurocognitive functioning

AIMS

Although neurocognitive problems after open-heart surgery for congenital heart disease are frequent, due to a shortage of prospective studies assessing neurocognitive functioning both before and after the procedure, the exact nature of the deficits usually remains unknown. The present study aims at assessing the neurocognitive effects of, in particular, cardiopulmonary bypass at school age. In addition, surgery-related risk factors for reduced neurocognitive outcome are explored.

METHODS AND RESULTS

Participants were aged between 6 and 16 years. Forty-three children indicated for open-heart surgery and a comparison group of 19 children scheduled for interventional cardiac catheterization completed a neurocognitive assessment battery before and 1 year after their procedures. Forty healthy matched controls did so at a 1 year interval. The baseline-to-follow-up outcomes were similar in all three groups. The observed improvements most likely resulted from increased age and the repeated neurocognitive assessment. No risk factors for postsurgical neurocognitive deficits were identified.

CONCLUSION

The present study demonstrates that at school age cardiac surgery using full-flow cardiopulmonary bypass does not affect neurocognitive functioning.

Long-term outcome of speech and language in children after corrective surgery for cyanotic or acyanotic cardiac defects in infancy

The purpose of this prospective study was to assess whether outcome of speech and language in children 5-10 years after corrective surgery for tetralogy of Fallot (TOF) or ventricular septal defect (VSD) in infancy was influenced by the preoperative condition of hypoxemia or cardiac insufficiency and whether it was associated with perioperative risk factors and neurodevelopmental outcome. A total of 35 unselected children, 19 with TOF and hypoxemia and 16 with VSD and cardiac insufficiency, operated with combined deep hypothermic circulatory arrest and low-flow cardiopulmonary bypass at mean age 0.7+/-0.3 (mean+/-standard deviation) years, underwent, at mean age 7.4+/-1.6 years, standardized evaluation of speech and language functions. Results were compared between subgroups and related to perioperative factors, sociodemographic and neurodevelopmental status. Age at testing, socioeconomic status and history of speech and language development were not different between the subgroups. In contrast, total scores on oral and speech motor control functions (TFS) as well as on oral and speech apraxia (Mayo Test) were significantly reduced (p<0.02 to <0.05), and scores on anatomical oral structures tended to be lower (p<0.09) in the TOF group as compared to the VSD group. No differences were found for auditory word recognition and phonological awareness as assessed by the Auditory Closure subtest of the Illinois Test of Psycholinguistic Abilities and the test of auditory analysis skills, respectively. In all children, higher age at testing and better socioeconomic status were associated with better results in all domains of assessment (p<0.001 to <0.04). Consistent impairments of all oral and speech motor control functions (TFS and Mayo Test) were present in 29% of all children with a mean age of 6.5 years in contrast to 43% with normal performance and a mean age of 8.3 years. On the receptive speech tasks, only 6% scored below the normal range of their age group. TFS subscores were significantly correlated with age, bypass duration and motor function, but not correlated with socioeconomic status, duration of cardiac arrest, intelligence and academic achievement. Children with preoperative hypoxemia due to cyanotic cardiac defects in infancy are at higher risk for dysfunction in speech and language than those with cardiac insufficiency due to acyanotic heart defects. Age at testing, socioeconomic status, and duration of cardiopulmonary bypass influenced test results. Long-term outcome in speech and language functions can be considered as a sensitive indicator of overall child development after cardiac surgery.

Factors associated with adverse neurodevelopmental outcomes in infants with congenital heart disease

OBJECTIVE

To review reported neurodevelopmental outcome data for patients with congenital heart disease, identify risk factors for adverse neurodevelopmental sequelae and summarize potential neuromonitoring strategies that have been described.

METHODS

A Medline search was performed utilizing combinations of the keywords congenital heart, cardiac, neurologic, neurodevelopment, neuromonitoring, quality of life, and outcome. All prospective and longitudinal follow-up studies of patients with congenital heart disease were included. Additionally, studies that examined neuroimaging, neuromonitoring, and clinical factors in relation to outcome were examined. Case reports and editorials were excluded. Additional references were retrieved from selected articles if the abstract described an evaluation of neurodevelopmental outcomes and/or predictors of outcome in patients with congenital heart disease.

RESULTS

Overall, patients with CHD have increased rates of neurodevelopmental impairments, although intelligence appears to be in the normal range. Preoperative risk stratification, intraoperative techniques, postoperative care, and neuromonitoring strategies may all contribute to ultimate long-term neurodevelopmental outcomes in patients with CHD postsurgical repair.

CONCLUSIONS

As advances in the medical and surgical management improves survival in patients with CHD, increasing knowledge about neurodevelopmental outcomes and the factors that affect them will provide for strategies to optimize long-term outcome in this high-risk population.

Five-year neurocognitive and health outcomes after the neonatal arterial switch operation

OBJECTIVES

We sought to assess the 5-year neurocognition and health of an interprovincial inception cohort undergoing the arterial switch operation for transposition of the great arteries.

METHODS

Sixty-nine consecutive neonates had operations from 1996-2003 with full-flow cardiopulmonary bypass and selective deep hypothermic circulatory arrest. Outcomes were recorded at 58 +/- 9 months of age. Univariate and multivariate analyses were used to identify outcome predictors, including surgical subtype and preoperative, operative, and postoperative variables.

RESULTS

There was 1 (1.5%) operative death. Two children were lost to follow-up, and 1 was excluded because of postdischarge meningitis. Outcomes are reported for 65 survivors. Two (3%) children have cerebral palsy, and 7 (11%) have language disorders, 4 of whom also meet the criteria for autism spectrum disorder. Two of the 4 children with autism have an affected older sibling. Of the 61 children without autism, scores approach those of peers, with a full-scale intelligence quotient of 97 +/- 16, a verbal intelligence quotient of 97 +/- 18, a performance intelligence quotient of 96 +/- 15, and a visual-motor integration score of 95 +/- 16. Mother's education, birth gestation or weight, and postoperative plasma lactate values account for 21% to 32% of the variance of these scores. Septostomy adds 7% to the variance of visual-motor integration scores.

CONCLUSIONS

Most preschool children do well after surgical correction for transposition of the great arteries, including complex forms. Potentially modifiable variables include high preoperative plasma lactate levels and septostomy. A minority of children were given diagnoses of language disorders, including autism, in which familial factors likely contribute to outcome.

Guidelines for the outpatient management of complex congenital heart disease

An increasingly complex group of children is now being followed as outpatients after surgery for congenital heart disease. A variety of complications and physiologic perturbations, both expected and unexpected, may present during follow-up, and should be anticipated by the practitioner and discussed with the patient and family. The purpose of this position article is to provide a framework for outpatient follow-up of complex congenital heart disease, based on a review of current literature and the experience of the authors.

Are children with congenital cardiac malformations at increased risk of deficits in social cognition?

In this review, I summarize observations suggesting that social cognition deficits are an important element of the neurodevelopmental morbidities of children with congenital cardiac malformations. Referred to as "theory of mind" deficits, they pertain to the ability to "read" other people, that is, to infer their internal states and thus to interpret their actions appropriately. I also hypothesize that children with such congenital cardiac malformations have difficulty identifying and describing their own internal states, which is referred to as alexithymia. These hypotheses are based on data collected as part of a prospective study of the neurologic outcomes of children with concordant atrioventricular and discordant ventriculo-arterial connections, or transposition. On a variety of tasks that assess pragmatic language and discourse skills, such as elicited personal narratives, free play with a parent, and written narratives, the children consistently performed below age-expected levels and in ways that suggested the presence of "theory of mind" deficits. Their narratives lacked coherence, failed to include critical information required by a listener, and made infrequent reference to internal states. In ongoing evaluations of the children as adolescents, we are testing these hypotheses more systematically by administering several instruments specifically developed to assess "theory of mind" and alexithymia.

Perioperative neuroprotective strategies

Long-term neurodevelopmental impairment is common in newborns and infants undergoing corrective or palliative congenital heart surgery. The etiologies of neurodevelopmental morbidity in these children are multifactorial and include prenatal, preoperative, intraoperative, and postoperative factors. Perioperative neurologic monitoring is thought to be integral to prevention or rescue from adverse neurologic events. Recent advances in perfusion techniques for congenital heart surgery now ensure adequate cerebral O(2) delivery during all phases of cardiopulmonary bypass. Periventricular leukomalacia and other serious neurologic injury can be minimized by an optimized perfusion strategy of continuous high-flow, high hematocrit cardiopulmonary bypass, minimal use of deep hypothermic circulatory arrest, antegrade cerebral perfusion during aortic arch reconstruction, pH-stat blood gas strategy, and cerebral monitoring with NIRS and trans-cranial Doppler. Because there is evidence that brain injury can also occur in the prenatal, preoperative, and postoperative periods, improved strategies to prevent injury in these arenas are much needed. Extensive further clinical investigation is warranted to identify neuroprotective management strategies for the operating room and intensive care unit to preserve neurologic function and optimize long-term neurodevelopmental outcomes in children with congenital heart disease.

Do parental ratings on cognition reflect neuropsychological outcome in congenital heart disease?

AIM

To describe the parental view of the cognitive skills of their child with a surgically corrected congenital heart disease (CHD) and compare it to objectified cognitive measures in children with CHD 6-12 years postoperatively.

METHODS

Parents completed a questionnaire on several cognitive functions of their child. Children with CHD and healthy controls (n=86, aged 8 years 8 months +/- 1 year 6 months) underwent an abbreviated IQ-testing and a neurodevelopmental assessment.

RESULTS

Parents of the children with CHD more frequently indicated lower sustained attention (p<0.05), lower divided attention (p<0.001), more problems with memory and learning skills (p<0.05), and deficient gross motor functioning (p<0.01) compared to the parents of healthy controls. Intellectual and neuropsychological assessment revealed a lower estimated full-scale IQ (p<0.01), worse sensorimotor functioning (p<0.001), and lower performances on language (p<0.001), attention/executive functioning (p<0.05), and memory (p<0.05) in the CHD-group. Several items of the questionnaire were significant predictors for worse neurodevelopmental outcome.

CONCLUSION

Overall, the objective and subjective measures on cognitive functioning are in agreement and indicate the presence of neurocognitive deficits in children with CHD. This study endorses the accuracy and usefulness of a parental questionnaire to report on the cognitive functioning of the child and urges the investigation of neurocognitive functioning in children with CHD at follow-up.

Neurology of congenital heart disease: insight from brain imaging

Understanding of the specific pathophysiology of acquired brain injury in infants with CHD will help optimise treatment and brain protection strategies

Long-term behavior and quality of life after corrective cardiac surgery in infancy for tetralogy of Fallot or ventricular septal defect

The objective of this study was to evaluate behavior and quality of life in children after corrective cardiac surgery in infancy. Twenty cyanotic (tetralogy of Fallot) and 20 acyanotic children (ventricular septal defect), operated at a mean age of 0.7 years with deep hypothermic circulatory arrest (DHCA) and low-flow cardiopulmonary bypass (CPB), were assessed at a mean age of 7.4 years by the Child Behavior Checklist (CBCL) and the German KINDL. Test results were related to perioperative and neurodevelopmental outcome. Compared to healthy children and not significantly different between the groups, internalizing and externalizing problems were elevated, school performance and total competence were reduced, and self- and parent-reported quality of life was not reduced. Parent-reported problems and reduced physical status were correlated with longer durations of DHCA and CPB. Internalizing and externalizing problems, reduced school competence, and reduced self-esteem were associated with reduced endurance capacity. Externalizing problems were related to reduced gross motor function. Poor school competence was related to reduced intelligence and academic achievement. Children with preoperative hypoxemia in infancy due to cyanotic cardiac defects are not at significantly higher risk for behavioral problems and reduced quality of life than those with acyanotic heart defects. The risk of long-term psychosocial maladjustment after corrective surgery in infancy is increased compared to that for normal children and related to the presence of neurodevelopmental dysfunction.

Neurocognitive, functional, and health outcomes at 5 years of age for children after complex cardiac surgery at 6 weeks of age or younger

OBJECTIVE

This work provides neurocognitive, functional, and health outcomes for 5-year survivors of early infant complex cardiac surgery, including those with chromosomal abnormalities.

PATIENTS AND METHODS

Of 85 children (22.4% mortality), 61 received multidisciplinary, individual evaluation and parental questionnaires at 5 years. Full-scale, verbal, and performance IQ scores were compared by using analysis of variance among children who received different surgeries (arterial switch, 20; Norwood for hypoplastic left heart syndrome, 14; simple total anomalous pulmonary venous connection, 6; miscellaneous, 21; and chromosomal abnormalities, 8). Predictions from mental scores at 2 years for IQ scores at 5 years were determined.

RESULTS

Children with chromosomal abnormalities had lower full-scale and verbal IQs at 5 years than other survivors, with no differences found among the remaining groups. For children post-Norwood, performance IQ scores remained lower than for children after the arterial-switch operation. Prediction of full-scale IQ (<70) from 2-year mental scores for all 61 children were as follows: sensitivity, 87.5%; specificity, 88.1%; positive predictive value, 53.8%; and negative predictive value, 97.9%. For full-scale IQ of <85, predictions were 90.0%, 87.8%, 78.3%, and 94.7%, respectively. For those 53 without chromosomal abnormalities, full-scale IQ <70, respective predictions were 86.7%, 90.0%, 28.6%, and 97.8%, and for full-scale IQ <85, respective predictions were 85.7%, 89.7%, 75.0%, and 94.6%. Parental report indicated good health in 80% and adequate function in 67% to 88% of the children, although health-utilization numbers suggest that these reports are optimistic.

CONCLUSIONS

Five-year full-scale and verbal IQs were similar among groups, excluding those with chromosomal abnormalities. Children with chromosomal abnormalities had the lowest scores. Excluding those with chromosomal abnormalities, the mean mental scores for the children as a group tended to increase from 2 to 5 years of age, with an overall high percentage of correct classifications at 2 years.

Neuropsychological performance in school-aged children with surgically corrected congenital heart disease

OBJECTIVE

As surgical management of children with congenital heart disease (CHD) advanced, developmental outcome became the main focus of contemporary research. In this study, we specify the cognitive profile of children with CHD, 6 to 12 years postoperatively.

STUDY DESIGN

Patients with CHD (n = 43, mean age 8 years, 8 months) and healthy controls (n = 43, mean age 8 years, 11 months), were examined with an abbreviated intelligence scale (Wechsler Intelligence Scale for Children-3rd edition, Dutch version) and a developmental neuropsychological assessment battery (NEPSY [a developmental NEuroPSYchological assessment]).

RESULTS

We identified significantly lower scores for the CHD group on Estimated Full Scale IQ (P < .01). Neuropsychological assessment revealed lower scores for the CHD group on the cognitive domains of Sensorimotor Functioning (P < .001), Language (P < .001), Attention and Executive Functioning (P < .05), and Memory (P < .05). Children with CHD displayed more impulsive test behavior than healthy peers. No differences on IQ or cognitive domains were found between the cyanotic and the acyanotic CHD group.

CONCLUSIONS

Six to 12 years postoperatively, children with CHD display a neuropsychological profile with mainly mild motor deficits and subtle difficulties with language tasks. Attention/executive functioning and memory also appear involved but to a lesser degree. Long-term follow-up of children with surgically corrected CHD, even when hemodynamically successful, is warranted, as they are at risk for neurodevelopmental delay at school age.

Attentional Dysfunction in Children After Corrective Cardiac Surgery in Infancy

BACKGROUND

Attentional dysfunction in children after corrective cardiac surgery in infancy has rarely been evaluated and is the topic of the present work.

METHODS

Forty unselected children, 20 with tetralogy of Fallot and hypoxemia and 20 with ventricular septal defect and cardiac insufficiency, operated on at a mean age 0.7 (SD 0.3) years with deep hypothermic circulatory arrest and low flow cardiopulmonary bypass, were evaluated at mean age 7.4 (SD 1.6) years by the computerized form of the Attention Network Test providing performance measures of three networks of attention: alerting, orienting, and executive control. Parental ratings of attentional dysfunction were derived from the Child Behavior Checklist. Results were compared with healthy controls, between patient groups, and correlated with perioperative risk factors and current neurodevelopmental status.

RESULTS

Executive control was reduced in the tetralogy of Fallot group, alerting and orienting were found normal and not different between patient groups. Durations of aortic cross clamping inversely correlated with orienting; durations of cardiopulmonary bypass correlated with mean reaction time and inversely correlated with executive control. Motor function and acquired abilities correlated with executive control and orienting. Parent-reported problems on the Child Behavior Checklist inversely correlated with executive control and mean accuracy.

CONCLUSIONS

Children with preoperative hypoxemia in infancy due to cyanotic cardiac defects are at increased risk for attentional dysfunction in the field of executive control, compared with normal children and with those who have acyanotic heart defects. Besides unfavorable perioperative influences, preoperative hypoxemia is considered responsible for additional damage to the highly oxygen sensitive regions of the prefrontal cortex and striate body assumed to be associated with the executive control network of attention.

Intellectual, neuropsychological, and behavioral functioning in children with tetralogy of Fallot

OBJECTIVE

Although it is known that pediatric cardiac surgery holds risks for later development, few studies investigated the long-term development in children with tetralogy of Fallot. The purpose of this study was to define their intellectual capacities, neuropsychological profile, and behavioral functioning 6 to 12 years postoperatively.

METHODS

Patients (n = 18; age, 8 years, 3 months +/- 1 year, 6 months) were examined with a short-form intelligence scale (Wechsler Intelligence Scale for Children, 3rd edition, Dutch version) and a neuropsychological assessment battery (NEPSY). Their parents completed a behavioral questionnaire. The patient group was compared with an acyanotic congenital heart disease group and a healthy control group.

RESULTS

No significant differences between the patient group and the acyanotic group emerged. Compared with the healthy control group, children with tetralogy of Fallot showed significantly lower scores on the estimated Full Scale IQ (P < .05) and on the NEPSY domains Language (P < .01) and Sensorimotor Functioning (P < .01). Also, the subtests Tower (P < .05), Memory for Names (P < .05), Narrative Memory (P < .05), and Design Copy (P < .05) elicited group differences. Parental reports revealed significantly higher scores on attention problems (P < .05) and the total problem scale (P < .05), as well as significantly lower school performances than those of healthy peers (P < .01).

CONCLUSIONS

In children with tetralogy of Fallot, we identified a lower estimated full-scale intelligence than in healthy peers and a neuropsychological profile characterized by primarily mild motor deficits and difficulties with language tasks. Parents of the children with tetralogy of Fallot indicated attention problems and rated the child's school competencies to be lower than in healthy control subjects.

Intermediate-term outcomes of the arterial switch operation for transposition of great arteries in neonates: Alive but well?

OBJECTIVES

This interprovincial inception cohort study outlines the operative and intermediate outcomes of all neonates at a single institution with a broad referral area who underwent the arterial switch operation for transposition of great arteries, including complex types. Predictors of outcome are explored.

METHODS

A total of 88 consecutive neonates underwent the arterial switch operation between 1996 and 2004 with full-flow (150 mg/kg/min) cardiopulmonary bypass with selective deep hypothermic circulatory arrest. Overall and event-free survivals were calculated. Health and neurodevelopment (Bayley Scales of Infant Development II) were assessed at 18 to 24 months of age. Univariate and multivariate analyses, sensitivity, and specificity were determined to identify preoperative, intraoperative, and postoperative factors associated with mental and/or motor delay.

RESULTS

There was 1 operative mortality (1.1%). At the average 4-year follow-up, survival was 98.9% and freedom from reintervention was 93.2%. Eighty-five children were assessed. Three were excluded because of unrelated postoperative diagnoses. For the remaining 82, mean scores were 89 +/- 17 (49-118) for mental skills and 92 +/- 15 (49-125) for motor skills. Anatomic complexity, cardiopulmonary bypass, and deep hypothermic circulatory arrest times were not associated with developmental outcome. Preoperative variables of low gestational age and high preoperative lactate correctly classified 84.1% of mentally and/or motor-delayed children.

CONCLUSION

Transposition of great arteries, including complex types, can be corrected with low surgical risk and good intermediate survival; however, neurodevelopmental outcome is a concern. These data suggest that although anatomic complexity may not affect late outcome, there may be potentially modifiable preoperative factors that can be optimized to improve developmental outcomes.

Neurocognitive consequences of surgically corrected congenital heart defects: A review

With advances in surgical procedures, neuropsychological assessment after congenital heart defects and pre, peri- and/or postoperative predictors of adverse outcome has become an important focus in research. We aim to summarize neuropsychological sequelae associated with different types of congenital heart defects, critically review the methodology used in more than 20 empirical studies that were retrieved from biomedical electronic search engines, and identify possible directions for future research. Despite the lack of adequate control groups and long-term studies, there seem to be some cognitive deficits. The largest group of children with isolated congenital heart defects present with normal intellectual capacities. However, they tend to show language deficits and motor dysfunction. Although performances on memory tasks are good, unambiguous conclusions concerning their attentional and executive functioning are still lacking. Serious behavioral problems are not an issue. In addition to a detailed description of the (neuro) psychological consequences of pediatric cardiac surgery, an overview of the predictors of the cognitive defects is provided.

Metabolic alterations and neurodevelopmental outcome of infants with transposition of the great arteries

Abnormal neurodevelopment has been reported for infants who were born with transposition of the great arteries (TGA) and underwent arterial switch operation (ASO). This study evaluates the cerebral metabolism of TGA infants at birth and before ASO and neurodevelopment 1 year after ASO. Proton magnetic resonance spectroscopy (1H-MRS) was performed on 16 full-term TGA brains before ASO within 3-6 days after birth. The brain metabolite ratios of [NAA/Cr], [Cho/Cr], and [mI/Cr] evaluated measured. Ten infants were evaluated at 1 year using the Bayley Scales of Infants Development II (BSED II). Cerebral metabolism of infants with TGA was altered in parietal white matter (PWM) and occipital gray matter (OGM) at birth before ASO. One year after ASO, [Cho/Cr] in PWM remained altered, but all metabolic ratios in OGM were normal. The results of BSID II at 1 year showed delayed mental and psychomotor development. This delayed neurodevelopmental outcome may reflect consequences of the altered cerebral metabolism in PWM measured by 1H-MRS. It is speculated that the abnormal hemodynamics due to TGA in utero may be responsible for the impaired cerebral metabolism and the subsequent neurodevelopmental deficit.

Is the arterial switch operation as good over the long term as we thought it would be?

Surgical intervention for hearts with transposition, defined as concordant atrioventricular and discordant ventriculo-arterial connections, has been one of the landmark achievements in the field of paediatric cardiac surgery. In the early 1950s, pioneer surgeons attempted to palliate patients with transposed arterial trunks with an early form of the arterial switch operation. As a result of initially dismal outcomes secondary to difficulties with coronary arterial transfer, the unprepared nature of the morphologically left ventricle, and primitive methods for cardiopulmonary bypass, the arterial switch was abandoned in favour of several procedures achieving correction at atrial and venous levels, culminating in the Mustard and Senning operations.1,2These innovative procedures produced the earliest surviving children with transposition. Although the atrial switch procedures achieved widespread acceptance and success during the mid-1960s through the mid-1980s, the search for an operation to return the great arteries to their normal anatomic positions continued. This pursuit was stimulated primarily by the accumulating observations in mid-to-late term follow up studies of: an increasing frequency of important arrhythmic complications, including sinus nodal dysfunction, atrial arrhythmias, and sudden, unexplained death, by the development of late right ventricular dysfunction and significant tricuspid regurgitation in a ventricle potentially unsuited for a lifetime of systemic function by a small but important prevalence of obstruction of the systemic and/or pulmonary venous pathways, and by dissatisfaction with the operative mortality in the subgroup of infants complicated by additional presence of a large ventricular septal defect.3–6As we have already discussed, a number of novel procedures to achieve anatomic correction had been described as early as 1954, but clinical success was not accomplished until 1975, when Jatene and co-workers7astounded the world of paediatric cardiology with their initial description.

Intellectual development of infants, children and adolescents with congenital heart disease

Cardiac disease is the most common congenital defect in children, affecting between 3 and 10 in every 1000 live births. While significant advances in medical and surgical management have resulted in increasing numbers of survivors, it is also recognized that there is a growing population of children living with neurological impairment and lowered intellectual function. The aetiology of such impairment is multi-factorial and hypoxia is one of the factors involved. This article provides an overview of the effects of hypoxia on the intellectual development of infants, children and adolescents with congenital heart disease.

Pyramidal tract maturation after brain injury in newborns with heart disease

OBJECTIVE

Our objective was to quantify white matter tract development in term newborns with congenital heart disease, a population at high risk for perioperative brain injury, using magnetic resonance imaging diffusion tensor tractography (DTT).

METHODS

Twenty-five newborns with congenital heart disease were imaged before and after surgery, with a median of 2 weeks between serial magnetic resonance imaging examinations. DTT was performed to segment bilateral pyramidal tracts using semiautomated fiber tracking software, and manual region of interest measurements were taken for comparison.

RESULTS

Significant maturational rates of increasing fractional anisotropy (median, 4.4% per week) and decreasing mean diffusivity (D(av)) (median, -2.0% per week) in the pyramidal tract were measured in infants without brain injury. Fractional anisotropy maturation rates were highest in newborns with normal scans, intermediate (median, 2.4% per week) in those with postoperative injury, and lowest (median, 0.9% per week) in those with preoperative injury, indicating a significant trend across brain injury groups (p = 0.015). D(av) maturation rates did not differ across injury groups (p = 0.15). Manual region of interest measures showed greater variability in serial measurements, and no significant differences were identified between injury groups, suggesting that DTT may provide more sensitive measures.

INTERPRETATION

DTT is feasible in term newborns and may help to characterize abnormal white matter tract development following acquired brain injury.

Long-Term Neurodevelopmental Outcome and Exercise Capacity After Corrective Surgery for Tetralogy of Fallot or Ventricular Septal Defect in Infancy

BACKGROUND

The purpose of this prospective study was to assess whether neurodevelopmental status and exercise capacity of children 5 to 10 years after corrective surgery for tetralogy of Fallot or ventricular septal defect in infancy was different compared with normal children and influenced by the preoperative condition of hypoxemia or cardiac insufficiency.

METHODS

Forty unselected children, 20 with tetralogy of Fallot and hypoxemia and 20 with ventricular septal defect and cardiac insufficiency, operated on with combined deep hypothermic circulatory arrest and low flow cardiopulmonary bypass at a mean age of 0.7 +/- 0.3 years (mean +/- SD), underwent, at mean age 7.4 +/- 1.6 years, standardized evaluation of neurologic status, gross motor function, intelligence, academic achievement, language, and exercise capacity. Results were compared between the groups and related to preoperative, perioperative, and postoperative status and management.

RESULTS

Rate of mild neurologic dysfunction was increased compared with normal children, but not different between the groups. Exercise capacity and socioeconomic status were not different compared with normal children and between the groups. Compared with the normal population, motor function, formal intelligence, academic achievement, and expressive and receptive language were significantly reduced (p < 0.01 to p < 0.001) in the whole group and in the subgroups, except for normal intelligence in ventricular septal defect patients. Motor dysfunction was significantly higher in the Fallot group compared with the ventricular septal defect group (p < 0.01) and correlated with neurologic dysfunction, lower intelligence, and reduced expressive language (p < 0.05 each). Reduced New York Heart Association functional class was correlated with lower exercise capacity and longer duration of cardiopulmonary bypass (p < 0.05 each). Reduced socioeconomic status significantly influenced dysfunction in formal intelligence (p < 0.01) and academic achievement (p < 0.05). Preoperative risk factors such as prenatal hypoxia, perinatal asphyxia, and preterm birth, factors of perioperative management such as cardiac arrest, lowest nasopharyngeal temperature, and age at surgery, and postoperative risk factors as postoperative cardiocirculatory insufficiency and duration of mechanical ventilation were not different between the groups and had no influence on outcome. Degree of hypoxemia in Fallot patients and degree of cardiac insufficiency in ventricular septal defect patients did not influence the outcome within the subgroups.

CONCLUSIONS

Children with preoperative hypoxemia in infancy are at higher risk for motor dysfunction than children with cardiac insufficiency. Corrective surgery in infancy for tetralogy of Fallot or ventricular septal defect with combined circulatory arrest and low flow bypass is associated with reduced neurodevelopmental outcome, but not with reduced exercise capacity in childhood. In our experience, the general risk of long-term neurodevelopmental impairment is related to unfavorable effects of the global perioperative management. Socioeconomic status influences cognitive capabilities.

Current insights regarding neurological and developmental abnormalities in children and young adults with complex congenital cardiac disease

Over a decade ago, I co-authored a review in Cardiology in the Young regarding neurological outcomes following surgery for congenital cardiac disease.1In that review, I placed much emphasis on the conduct of cardiopulmonary bypass, and its role in neurodevelopmental disabilities. Much has been learned in the intervening years regarding the multifactorial causes of abnormal school-age development, in particular, the role of prenatal, perioperative, socioeconomic, and genetic influences. In this update, I will highlight some of the recent advances in our understanding of the protean causes of neurological, behavioral, and developmental abnormalities in children and young adults with complex forms of congenital cardiac disease. In addition, I will summarize the current data on patients at particular high-risk for adverse neurodevelopmental outcomes, specifically those with a functionally univentricular heart who have had staged reconstruction with ultimate conversion to the Fontan circulation.

Long-term and developmental outcomes of children with complex congenital heart disease

As short-term survival of complex congenital heart disease continues to improve dramatically with advances in medical and surgical treatment, further efforts must be made to understand the long-term outcomes of our efforts. As survival continues to improve, cardiovascular morbidity and, equally importantly, neurodevelopmental and social outcomes must be a continual focus in our treatment of these complex patients. Further study of these effects is underway, and more is certainly warranted. Understanding should lead to modification of current techniques and management strategies, all with the ultimate goal of improving our patients' quality of life.

Increasing duration of deep hypothermic circulatory arrest is associated with an increased incidence of postoperative electroencephalographic seizures

OBJECTIVE

Electroencephalographic seizures have been shown to occur in 5% to 20% of neonates and infants after biventricular repair of a variety of cardiac defects. Occurrence of a seizure is a predictor of adverse long-term neurodevelopmental sequelae. The contemporary incidence of postoperative seizures after repair of cardiac defects such as hypoplastic left heart syndrome and other forms of single ventricle is not known.

METHODS

A prospective study of 178 patients less than 6 months of age undergoing cardiopulmonary bypass with or without deep hypothermic circulatory arrest (DHCA) was conducted at a single institution from September 2001 through March 2003 to identify postoperative seizures assessed by 48-hour continuous video electroencephalographic monitoring.

RESULTS

Cardiac defects included transposition of the great arteries with or without a ventricular septal defect (n = 12), ventricular septal defect with or without coarctation (n = 28), tetralogy of Fallot (n = 24), hypoplastic left heart syndrome or variant (n = 60), other functional single ventricle (n = 14), and other defects suitable for biventricular repair (n = 40). Median age at the time of the operation was 7 days (range, 1-188 days) and was 30 days or less in 110 (62%) patients. DHCA was used in 117 (66%) patients, with multiple episodes in 9 patients. Median total duration of DHCA was 40 minutes (range, 1-90 minutes). Electroencephalographic seizures were identified in 20 (11.2%) patients. Seizures occurred in 15 (14%) of 110 neonates and 5 (7%) of 68 older infants. Seizures occurred in 1 (4%) of 24 patients with tetralogy of Fallot, 1 (8%) of 12 with transposition of the great arteries, and 11 (18%) of 60 with hypoplastic left heart syndrome or variant. By stepwise logistic regression analysis, once increasing duration of total DHCA (P = .001) was considered, no other variable improved prediction of occurrence of a seizure. Patients with DHCA duration of more than 40 minutes had an increased incidence of seizures (14/58 [24.1%]) compared with those with a DHCA duration of 40 minutes or less (4/59 [6.8%], P = .04). The incidence of seizures for patients with a DHCA duration of 40 minutes or less was not significantly different from those in whom DHCA was not used (2/61 [3.3%], P = .38).

CONCLUSIONS

In the current era, continuous electroencephalographic monitoring demonstrates early postoperative seizures in 11.2% of a heterogeneous cohort of neonates and infants with complex congenital heart defects. Increasing duration of DHCA was identified as a predictor of seizures. However, the incidence of seizures in children with limited duration of DHCA was similar to that in infants undergoing continuous cardiopulmonary bypass alone.

Electroencephalographic changes after pediatric cardiac surgery with cardiopulmonary bypass: is slow wave activity unfavorable?

Pediatric cardiac surgery with cardiopulmonary bypass (CPB) is frequently associated with neurologic deficits. We describe the postoperative EEG changes, assess their possible causes, and evaluate their relevance to neurologic outcome. Thirty-one children and five neonates with congenital heart disease were included. EEG recording started after intubation and continued until 22-96 h after CPB. In addition to conventional analysis, spectral analysis was performed for occipital and frontal electrodes, and differences between pre- and postoperative delta power (delta-deltaP) were calculated. Maximum values of occipital delta-deltaP that occurred within 48 h after CPB were correlated with clinical variables and with perioperative markers of oxidative stress and inflammation. Occipital delta-deltaP correlated with frontal delta-deltaP, and maximum delta-deltaP correlated with conventional rating. Distinct rise of deltaP was detected in 18 of 21 children without any acute or long-term neurologic deficits but only in five of 10 children with temporary or permanent neurologic deficits. Furthermore, maximally registered delta-deltaP was inversely associated with duration of CPB and postoperative ventilation. Maximal delta-deltaP was also inversely associated with the loss of plasma ascorbate (as an index of oxidative stress) and plasma levels of IL-6 and IL-8. Slow wave activity frequently occurs within 48 h after CPB. However, our data do not support the notion that EEG slowing is associated with adverse neurologic outcome. This is supported by the fact that EEG slowing was associated with less oxido-inflammatory stress.

High Flow Rates During Modified Ultrafiltration Decrease Cerebral Blood Flow Velocity and Venous Oxygen Saturation in Infants

BACKGROUND

The intracranial hemodynamic effects of modified ultrafiltration in children are unknown. We investigated the effects of different blood flow rates during modified ultrafiltration on the cerebral hemodynamics of children with weights above and below 10 kg.

METHODS

Thirty-one children (weights: < or = 10 kg, n = 21; > 10 kg, n = 10) undergoing cardiopulmonary bypass were studied. Middle-cerebral artery blood flow velocities and cerebral mixed venous oxygen saturations were measured before, five minutes from the beginning, and at the end of ultrafiltration. Patients were classified according to their blood flow rates during ultrafiltration in three groups: high (> or = 20 mL/kg/min), moderate (10-19 mL/kg/min), and low flow rates (< 10 mL/kg/min).

RESULTS

During modified ultrafiltration, blood pressures and hematocrit increased (p < 0.001), but cerebral blood flow velocities and mixed venous oxygen saturations decreased (p < 0.001). A significant correlation was found between blood flow rates of ultrafiltration and the decline in mean cerebral blood flow velocity (r = - 0.48; p = 0.005) and cerebral oxygen saturation (r = - 0.49; p = 0.005) or hematocrit increase (r = 0.59; p = 0.001). Infants exposed to high flow rates had greater reduction of cerebral blood flow velocity and regional mixed venous saturation and higher hematocrit at the end of ultrafiltration compared with those subjected to moderate and low flow rates (p < 0.04). No significant difference was found between moderate and low flow groups. The flow rate of ultrafiltration was the only independent predictor of the changes in cerebral mixed venous oxygen saturation (p = 0.033).

CONCLUSIONS

High blood flow rates through the ultrafilter during modified ultrafiltration transiently decrease the cerebral circulation in young infants compared with lower blood flow rates. These effects may be related to an increased diastolic runoff from the aorta into the ultrafiltration circuit that leads to a "stealing" effect from the intracranial circulation, which may be important in infants with dysfunctional cerebral autoregulation.

Cerebral oxygen saturation and electrical brain activity before, during, and up to 36 hours after arterial switch procedure in neonates without pre-existing brain damage: its relationship to neurodevelopmental outcome

OBJECTIVE

To monitor the pattern of cerebral oxygen saturation (rSat), by use of NIRS, in term infants before, during and after the arterial switch operation and to evaluate its relation to neurodevelopmental outcome.

METHODS

In 20 neonates without pre-existing brain damage hemodynamics and arterial oxygen saturation (AO2-Sat) were monitored simultaneously with rSat and amplitude-integrated EEG (aEEG) from 4 h to 12 h before up to 36 h after cardiopulmonary bypass (CPB) and short duration of cardiac arrest during deep hypothermia (DHCA). The Bayleys developmental scale was performed at 30 months.

RESULTS

Before surgery rSat was <50% in 16 patients. During CPB rSat increased to normal values, with a sharp decrease during brief CA (median 6.5 min). Post-CPB rSat showed a transient decrease (30-45%) despite normal PaO2 with sustained normalization after 6-26 h. Recovery time of the rSat seemed longer when pre-operative rSat was below 35%, and for lower minimum nasopharyngeal temperature and longer duration of CPB and of DHCA. Recovery time of the aEEG varied and did not correlate with normalization of rSat. Neurodevelopmental outcome was normal in all but two patients. Patients with lower pre-operative rSat (<35%) tended to have lower DQ (developmental quotient) scores at 30-36 months. (median: mental 102 and motor 101 (range 58-125) compared with mental 100 and motor 110 (range 83-125))

CONCLUSION

Despite prompt normalization of circulation and oxygenation after surgery, recovery of rSat of the brain took 6-26 h, probably because of higher energy demand after CPB. Pre-operative cerebral oxygenation may be underestimated as a possible cause of adverse post-operative outcome.

Late neurodevelopmental outcome after repair of total anomalous pulmonary venous connection

Objective We sought to define the neurodevelopmental status of school-aged survivors of total anomalous pulmonary venous connection repaired during infancy. Methods All school-aged survivors of total anomalous pulmonary venous connection repair performed at a single institution were eligible. Thirty children returned for neurologic examination and neurodevelopmental testing. Results The median age at total anomalous pulmonary venous connection repair was 16 days (range, 1-141 days), and age at testing was 11 years (range, 6-19 years). Pulmonary venous return was supracardiac in 14 patients, infracardiac in 12 patients, cardiac in 3 patients, and mixed in 1 patient. Preoperative obstructed total anomalous pulmonary venous connection was present in 6 patients. Circulatory arrest was used in all repairs, with a median duration of 35 minutes (range, 17-55 minutes). At follow-up, microcephaly (head circumference <5%) was present in 28%. Neuromuscular examination was suspect or abnormal in 27%. Mean Full-scale IQ (95.3 +/- 18.5) and Verbal IQ (98.6 +/- 20.2) were not different from population norms, but Performance IQ (92.3 +/- 16.9) was significantly lower than population norms ( P = .02). Fine motor skills and visual-motor coordination were significantly impaired ( P < .01 for Grooved Pegboard and Test of Visual-Motor Integration). Patients with total anomalous pulmonary venous connection also had difficulty with tests of attention (Test of Everyday Attention for Children, P < .01), but results of tests of memory function were not significantly different from population norms. Conclusions School-aged survivors of infant total anomalous pulmonary venous connection repair exhibit a significant incidence of neurodevelopmental difficulties. Fine motor function, visual-motor integration, and attention are the most commonly affected domains. Evaluation of these children is indicated to identify those who are at risk for learning disabilities and who could benefit from early intervention.

Perioperative predictors of developmental outcome following cardiac surgery in infancy

At 1 year we assessed the neurodevelopmental outcomes in infants undergoing cardiac surgery, seeking to explore the predictive value of perioperative markers of cerebral injury. We prospectively enrolled 47 neurodevelopmentally normal infants prior to planned cardiac surgery. Postoperative monitoring consisted of 10-channel video synchronised, continuous electroencephalography from 6 to 30 h, Doppler assessment of cerebral blood flow in the anterior cerebral artery at 1, 2, 3 and 5 h, and measurement of serum S-100B at 0 and 24 h. Neurodevelopmental assessments were performed using the second edition of the Bayley Scale of Infant Development. Follow-up at 1 year was available on 35 infants. The mean age of these patients at surgery had been 57 +/- 15 days. We observed clinical seizures in 1 patient, with 3 other patients having electroencephalographic abnormalities. At follow-up of 1 year, neurodevelopmental scores were lower than preoperative scores, with mean mental scores changing from 103 +/- 5 to 94 +/- 13 (p = 0.001), and mean motor scores changing from 99 +/- 8 to 89 +/- 20 (p = 0.004). No association was found between electroencephalographic abnormalities, reduced cerebral blood flow, or elevation of serum S-100B levels and impaired neurodevelopmental outcome at 1 year. Infants with electroencephalographic abnormalities had elevation of the levels of S-100B in the serum (p = 0.02). At 1 year of follow-up, infants undergoing cardiac surgery demonstrated a reduction in the scores achieved using the second edition of the Bayley Scale of Infant Development. They require ongoing assessment of their progress. Electroencephalographic abnormalities, cerebral blood flow, or levels of S-100B in the serum were not useful perioperative markers for predicting a poor neurodevelopmental outcome in the clinical setting.

Results of exercise testing at a mean age of 10 years after neonatal arterial switch operation

AIM

This prospective follow-up study investigated long-term exercise capacity at a mean age of 10 y after neonatal arterial switch operation for transposition of the great arteries in a large group of homogeneous unselected children.

METHODS

56 asymptomatic children, aged 7.9-14.3 y (10.5 +/- 1.6, mean +/- SD), were examined with respect to exercise tolerance, electrocardiographic (ECG) response and activity of biochemical markers for myocardial injury. The protocol included standard electrocardiography, M-mode and two-dimensional echocardiography at rest, a Bruce walking treadmill test to voluntary exhaustion, and determination of cardiac troponin I and T, creatine kinase and myoglobin from venous blood samples at rest and 4 h after exercise. Heart rate, blood-pressure response to exercise stress and endurance time were compared with published results of age-matched normal children.

RESULTS

54 patients (96.4%) had normal exercise capacity; a reduction in 2 patients was not due to cardiac disease. Heart rate and systolic blood pressure rose significantly between rest and peak exercise and did not differ from normal controls, whereas diastolic blood pressure was lower. ECG remained normal at rest and on exercise in 54 children (96.4%). Serum values of cardiac troponin I and T, creatine kinase and myoglobin were normal at rest and after exercise in all patients.

CONCLUSION

The study demonstrates excellent long-term exercise capacity after neonatal arterial switch operation. Exercise testing is a useful and non-invasive screening method to detect patients with clinically relevant exercise-induced myocardial ischaemia and should be routinely performed in growing patients.

Long-term results of cardiac and general health status in children after neonatal arterial switch operation

BACKGROUND

The purpose of this study was to assess cardiac and general health status 8 to 14 years after neonatal arterial switch operation for transposition of the great arteries.

METHODS

Sixty unselected children with intact ventricular septum (78.3%) or ventricular septal defect (21.7%) without or with aortic isthmic stenosis (5.1%) were examined 10.5 +/- 1.6 (mean +/- SD) years after neonatal switch and 5.3 +/- 1.6 years after mid-term evaluation. Complete clinical examination, standard and 24-hour Holter electrocardiogram, M-mode, 2D-, Doppler, and color Doppler echocardiography were performed. Results were compared with normal values and to mid-term follow-up results.

RESULTS

Rates of reoperation after arterial switch operation and operation to correct concomitant coarctation were 3.3% and 5.1%, respectively. No patient needed medication, and 93.3% had no limitation of physical activity. All children had normal height and weight; 31.6% had abnormal thoracic configuration after median sternotomy. Most patients (91.7%) were in sinus rhythm. Incidence of complete right bundle branch block (10.0%) was unchanged, as was prevalence of ectopic activity (occasional atrial ectopy 20.0%, ventricular ectopy: occasional 21.7%; frequent 1.7%). Left ventricular dimensions and shortening fraction did not change over time. Diameters of neo-aortic valve annulus and neo-aortic root did not increase, and z-scores decreased between mid-term and present evaluation. Incidence of neo-aortic insufficiency was 13.3% and remained unchanged in comparison with the pre-examination value. Neo-aortic stenosis was not seen. Compared with mid-term follow-up, incidence (41.6%) and degree of supravalvular pulmonary stenosis increased.

CONCLUSIONS

Good cardiac results persist 10 years after neonatal arterial switch operation for transposition of the great arteries. Encouraging findings include preservation of left ventricular function, low incidence of rhythm disturbances, lack of further neo-aortic root dilatation, and unchanged incidence of neo-aortic insufficiency compared with mid-term follow-up. Increased incidence and degree of supravalvular pulmonary stenosis are of concern.

Long term behavioural outcome after neonatal arterial switch operation for transposition of the great arteries

AIMS

To evaluate behavioural outcome and quality of life in children aged 8-14 years after neonatal arterial switch operation for transposition of the great arteries.

METHODS

Sixty children operated as neonates with combined deep hypothermic circulatory arrest and low flow cardiopulmonary bypass were evaluated at age 7.9-14.3 years by the Child Behaviour Checklist (CBCL) and the Inventory for the Assessment of the Quality of Life in Children and Adolescents (IQCL).

RESULTS

Parent reported behavioural outcome on all CBCL problem and competence scores was worse, whereas quality of life on self reported IQCL scores was not reduced compared to the normal population. On multivariate analysis, severe preoperative hypoxia was related to parent reported social problems; peri- and postoperative cardiocirculatory insufficiency was associated with internalizing, externalizing, attention, and total behavioural problems. Reduced expressive language was associated with total behavioural problems, and poor academic achievement was related to parent reported deficits in school performance. Impaired neurological status and reduced endurance capacity both predicted self reported stress by illness.

CONCLUSIONS

The neonatal arterial switch operation with combined circulatory arrest and low flow bypass is associated with parent reported long term behavioural impairment, but not with self reported general reduction in quality of life. This discrepancy may be a result of different perception of illness. In our experience, increased risk of long term psychosocial maladjustment after neonatal corrective cardiac surgery is related to the presence of neurological impairment and reduced endurance capacity.