Remote ischemic postconditioning increased cerebral blood flow and oxygenation assessed by magnetic resonance imaging in newborn piglets after hypoxia-ischemia

Sigrid Kerrn-Jespersen; Mads Andersen; Kristine Bennedsgaard; Ted Carl Kejlberg Andelius; Michael Pedersen; Kasper Jacobsen Kyng; Tine Brink Henriksen

doi:10.3389/fped.2022.933962

Remote ischemic postconditioning increased cerebral blood flow and oxygenation assessed by magnetic resonance imaging in newborn piglets after hypoxia-ischemia

Front Pediatr. 2022 Sep 29:10:933962. doi: 10.3389/fped.2022.933962. eCollection 2022.

Authors

Sigrid Kerrn-Jespersen^{1

2}, Mads Andersen^{1

2}, Kristine Bennedsgaard^{1

2}, Ted Carl Kejlberg Andelius^{1

2}, Michael Pedersen³, Kasper Jacobsen Kyng^{1

2}, Tine Brink Henriksen^{1

2}

Affiliations

¹ Department of Paediatrics and Adolescent Medicine, Aarhus University Hospital, Aarhus, Denmark.
² Department of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.
³ Comparative Medicine Laboratory, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.

Abstract

Background: We have previously investigated neurological outcomes following remote ischemic postconditioning (RIPC) in a newborn piglet model of hypoxic-ischemic encephalopathy. The aim of this study was to further investigate potential mechanisms of neuroprotection by comparing newborn piglets subjected to global hypoxia-ischemia (HI) treated with and without RIPC with regards to measures of cerebral blood flow and oxygenation assessed by functional magnetic resonance imaging.

Materials and methods: A total of 50 piglets were subjected to 45 min global HI and randomized to either no treatment or RIPC treatment. Magnetic resonance imaging was performed 72 h after the HI insult with perfusion-weighted (arterial spin labeling, ASL) and oxygenation-weighted (blood-oxygen-level-dependent, BOLD) sequences in the whole brain, basal ganglia, thalamus, and cortex. Four sham animals received anesthesia and mechanical ventilation only.

Results: Piglets treated with RIPC had higher measures of cerebral blood flow in all regions of interest and the whole brain (mean difference: 2.6 ml/100 g/min, 95% CI: 0.1; 5.2) compared with the untreated controls. They also had higher BOLD values in the basal ganglia and the whole brain (mean difference: 4.2 T2*, 95% CI: 0.4; 7.9). Measures were similar between piglets treated with RIPC and sham animals.

Conclusion: Piglets treated with RIPC had higher measures of cerebral blood flow and oxygenation assessed by magnetic resonance imaging in the whole brain and several regions of interest compared with untreated controls 72 h after the HI insult. Whether this reflects a potential neuroprotective mechanism of RIPC requires further study.

Keywords: arterial spin labeling; blood-oxygen-level-dependent; hypoxic-ischemic encephalopathy; magnetic resonance imaging; remote ischemic postconditioning.