Cerebral blood volume changes during closure by surgery of patent ductus arteriosus.

BACKGROUND

Surgical closure of a patent ductus arteriosus (PDA) in very low birth weight (VLBW) infants has been associated with impaired neurodevelopmental outcome. Surgical PDA closure may result in abrupt changes of cerebral haemodynamics.

OBJECTIVE

To examine the cerebral blood volume changes occurring after surgical closure of PDA.

DESIGN

Continuous cerebral near-infrared spectroscopy (NIRS) recording throughout PDA surgery.

SETTING

Tertiary neonatal intensive care unit, with PDA surgery performed on the ward.

PATIENTS: Ten VLBW infants, median birth weight 748 g (range 590-1070), gestational age 24 (23-27) weeks, chronological age 14 (12-22) days.

INTERVENTION: Surgical closure of PDA.

MAIN OUTCOME MEASURES: Changes in cerebral oxygenated haemoglobin, cerebral deoxygenated haemoglobin, and tissue oxygenation index (measured), changes in cerebral blood volume (CBV) and cerebral haemoglobin difference (calculated) as measured by NIRS.

RESULTS

During the first 2 minutes after closure of the PDA, CBV increased significantly (mean (SD) 0.14 (0.12) ml/100 g tissue; p = 0.01) and returned to baseline within 2-5 minutes. Cerebral oxygenation did not change.

CONCLUSIONS

There is a short-lasting increase in CBV immediately after surgical closure of PDA, but no change in cerebral oxygenation. These transient changes are unlikely to cause harm.