Neurological Injury After Neonatal Cardiac Surgery

Neurodevelopmental Outcomes of the Child with Congenital Heart Disease

Survival after bypass surgery in moderate and severe congenital heart disease (CHD) has increased dramatically. Although cardiac outcome is often very good, these children are at increased risk of developmental impairments in all developmental domains. Risk factors for developmental impairment include a genetic disorder, preterm birth, longer intensive care stay, poorer socioeconomic environment, and more complex forms of CHD. Health care providers, patients, and parents must be aware and informed about noncardiac sequelae and tertiary centers performing open-heart surgery in neonates and infants must establish a neurodevelopmental follow-up program to provide regular neurodevelopmental assessments. These allow for individual counseling and early detection and treatment of developmental problems.

Neurodevelopmental Outcomes After Neonatal Surgery for Major Noncardiac Anomalies

CONTEXT

Increasing concerns have been raised about the incidence of neurodevelopmental delay in children with noncardiac congenital anomalies (NCCA) requiring neonatal surgery.

OBJECTIVE

This study aimed to determine the incidence and potential risk factors for developmental delay after neonatal surgery for major NCCA.

DATA SOURCES

A systematic search in PubMed, Embase and the Cochrane Library was performed through March 2015.

STUDY SELECTION

Original research articles on standardized cognitive or motor skills tests.

DATA EXTRACTION

Data on neurodevelopmental outcome, the Bayley Scales of Infant Development, and risk factors for delay were extracted.

RESULTS

In total, 23 eligible studies were included, reporting on 895 children. Meta-analysis was performed with data of 511 children, assessed by the Bayley Scales of Infant Development at 12 and 24 months of age. Delay in cognitive development was reported in a median of 23% (3%-56%). Meta-analysis showed a cognitive score of 0.5 SD below the population average (Mental Development Index 92 ± 13, mean ± SD; P < .001). Motor development was delayed in 25% (0%-77%). Meta-analysis showed a motor score of 0.6 SD below average (Psychomotor Development Index 91 ± 14; P < .001). Several of these studies report risk factors for psychomotor delay, including low birth weight, a higher number of congenital anomalies, duration of hospital admission, and repeated surgery.

LIMITATIONS

All data were retrieved from studies with small sample sizes and various congenital anomalies using different neurodevelopmental assessment tools.

CONCLUSIONS

Cognitive and motor developmental delay was found in 23% of patients with NCCA. Meta-analysis showed that the mean neurodevelopmental outcome scores were 0.5 SD below the normative score of the healthy population.

Neurologic Injury Associated with Rewarming from Hypothermia: Is Mild Hypothermia on Bypass Better than Deep Hypothermic Circulatory Arrest?

Many known risk factors for adverse cardiovascular and neurological outcomes in children with congenital heart defects (CHD) are not modifiable; however, the temperature and blood flow during cardiopulmonary bypass (CPB), are two risk factors, which may be altered in an attempt to improve long-term neurological outcomes. Deep hypothermic circulatory arrest, traditionally used for aortic arch repair, has been associated with short-term and long-term neurologic sequelae. Therefore, there is a rising interest in using moderate hypothermia with selective antegrade cerebral blood flow on CPB during aortic arch repair. Rewarming from moderate-to-deep hypothermia has been shown to be associated with neuronal injury, neuroinflammation, and loss of cerebrovascular autoregulation. A significantly lesser degree of rewarming is required following mild (33-35°C) hypothermia as compared with moderate (28-32°C), deep (21-27°C), and profound (less than 20°C) hypothermia. Therefore, we believe that mild hypothermia is associated with a lower risk of rewarming-induced neurologic injury. We hypothesize that mild hypothermia with selective antegrade cerebral perfusion during CPB for neonatal aortic arch repair would be associated with improved neurologic outcome.

Factors associated with neurodevelopment for children with single ventricle lesions

OBJECTIVE

To measure neurodevelopment at 3 years of age in children with single right-ventricle anomalies and to assess its relationship to Norwood shunt type, neurodevelopment at 14 months of age, and patient and medical factors.

STUDY DESIGN

All subjects in the Single Ventricle Reconstruction Trial who were alive without cardiac transplant were eligible for inclusion. The Ages and Stages Questionnaire (ASQ, n = 203) and other measures of behavior and quality of life were completed at age 3 years. Medical history, including measures of growth, feeding, and complications, was assessed through annual review of the records and phone interviews. The Bayley Scales of Infant Development, Second Edition (BSID-II) scores from age 14 months were also evaluated as predictors.

RESULTS

Scores on each ASQ domain were significantly lower than normal (P < .001). ASQ domain scores at 3 years of age varied nonlinearly with 14-month BSID-II. More complications, abnormal growth, and evidence of feeding, vision, or hearing problems were independently associated with lower ASQ scores, although models explained <30% of variation. Type of shunt was not associated with any ASQ domain score or with behavior or quality-of-life measures.

CONCLUSION

Children with single right-ventricle anomalies have impaired neurodevelopment at 3 years of age. Lower ASQ scores are associated with medical morbidity, and lower BSID-II scores but not with shunt type. Because only a modest percentage of variation in 3-year neurodevelopmental outcome could be predicted from early measures, however, all children with single right-ventricle anomalies should be followed longitudinally to improve recognition of delays.

Neuroprotective strategies--what do we really need to know?

While preliminary data are encouraging, definitive data are lacking to conclusively demonstrate the benefit of perioperative neurologic monitoring in improving neurodevelopmental outcomes in children who require surgery for congenital heart disease. Nonetheless, in the current era, some form of perioperative neurologic monitoring is important. Strategies include bicortical near infrared spectroscopy monitoring in the pre- and postoperative periods along with bicortical near infrared spectroscopy and transcranial Doppler intraoperatively. These monitors provide real-time information concerning cerebral oxygen delivery and blood flow. These strategies will allow us to refine treatments to optimize neurodevelopmental potential in children with congenital heart disease.