Expectative management of a patent ductus arteriosus: pays the brain the price?

Background: Due to an increasing concern about the adverse effects of an invasive PDA-closure and the lack of evidence that early closure is superior, an expectant policy towards closure of a hemodynamically significant patent Ductus Arteriosus (hsPDA) is usually preferred. However, based on earlier research (van Bel F et al., Pediatrics 2016), we hypothesize that a prolonged duration of a hsPDA can induce suboptimal brain growth.

Aim: To investigate a possible relation between duration of hsPDA and cerebral oxygenation with MRI-determined brain growth and neurodevelopmental outcome at two years.

Patients/Methods: All preterm infants born <29.0 wk gestation, admitted to our NICU and subject to surgical ductal closure between 2008 and 2018 were included. NIRS-monitored cerebral oxygen saturation (rScO2) during and up to 48 h after ductal closure and a volumetric MRI at term equivalent age is standard policy for this patient group, as is a Bayley III developmental test at two years of age.

Results: 90 of the 94 infants fulfilled the inclusion criteria (mean[range]:25.9 wk [24.0-28.9]; 864 g [540-1350]. Days of a hsPDA ranged from 1-to-41,postnatal age at surgery ranged from 3-to-47 days. MLR-analysis showed that only duration of hsPDA negatively influenced cerebellar growth and motor-and cognitive outcome at two y of age. No other brain regions were involved. Delayed recovery of rScO2 after ductal closure had a negative effect on motor- and cognitive outcomes at two years of age (table).

Summary and Discussion: Prolonged duration of a hsPDA negatively affects cerebellar growth and neurodevelopmental outcome. Delayed normalization of cerebral oxygenation after ductal closure was negatively associated with neurodevelopmental outcome. The mechanisms behind these findings may be related to adverse hemodynamic effects of a hsPDA: a compromised left ventricle (LV) contractility after a longstanding duct has been suggested by several reports (Baumgart et al., Pediatr Res 2018). In case of delayed ductal closure, it may therefore be essential to be informed about LV-function and oxygenation of vital organ systems, particularly the immature brain.