FT. LAUDERDALE, FLA. – The use of full-flow cardiopulmonary bypass, coupled with neurological monitoring, improved cognitive and motor outcomes in a prospective neurologic outcome study of 97 neonates with transposition of the great arteries (both single- and two-ventricle lesions) who underwent an arterial switch operation.
The cohort study, conducted by Dr. Dean B. Andropoulos and his colleagues at the Texas Children’s Hospital in Houston, examined early MRI changes and longer-term neurodevelopmental outcomes after the arterial switch operation (ASO) was performed using a cardiopulmonary bypass (CPB) protocol that avoided deep hypothermic circulatory arrest (DHCA) and low-flow CPB.
Dr. Dean B. Andropoulos
The ASO was performed by using CPB with 150-mL/kg per min flows with no low-flow CPB or DHCA; pH stat management; hematocrit 30% or higher; and hypothermia to 24° -28° C. Regional oxygen saturation greater than 50% was maintained by using near infrared spectroscopic monitoring.
Neurologic assessment was performed using brain MRI performed immediately before the operation and 7 days postoperatively. The Bayley Scales of Infant and Toddler Development, Third Edition were used at 12 and 36 months (mean score of 100).
Dextrotransposition of the great arteries was present in 31 of the 97 enrolled patients. Ten of these 31 (32%) had preoperative MRI change, and 19 of 31 (61%) showed new postoperative MRI change, with 75% showing minimal new white matter injury, he said at the annual meeting of the Society of Thoracic Surgeons.
At 2 months, Bayley Scales were performed on 17 of the patients. Their mean cognitive score was 106.5, mean motor score was 90.4, and mean language score was 89.4. Twelve patients had Bayley III testing at 36 months, with a cognitive score of 106.5, motor score of 107.4, and language score of 98.2.
"Our series demonstrates a significant incidence of pre-existing MRI changes, and 61% have new postoperative changes, but all changes in this series were mild," said Dr. Andropoulos.
"At 12 months, the cognitive score of these children was above the population mean, but their motor and language performance was lower. By 36 months, language and motor scores had improved significantly. Thus, full-flow CPB coupled to cerebral monitoring may improve neurological outcomes."
Because of these results, "future studies of ASO patients should include short- and long-term neurodevelopmental studies," he said.
With greatly improved 30-day neonatal arterial switch operation mortality rates (for example, at the Texas Children’s Hospital in Houston there were no 30-day hospital mortalities for 175 ASOs since 2000), there are increasing expectations for better neurologic outcomes, according to Dr. Andropoulos, and such considerations are increasingly important.
Dr. Andropoulos reported having no financial conflicts.