Acute subdural haematoma exacerbates cerebral blood flow disorder and promotes the development of intraoperative brain bulge in rats with severe traumatic brain injury

Abstract

Abstract Background Intraoperative brain bulge (IOBB) is a malignant complication of decompressive craniectomy (DC) in patients with severe traumatic brain injury (TBI), which seriously worsens the prognosis of patients. Previous studies have shown that malignant intraoperative brain bulge (IOBB) may be associated with excessive arterial hyperaemia, but changes in cerebral vein have not been mentioned. In the current literature, rat models of severe brain injury-associated brain bulge have rarely been reported. Methods To gain an in-depth understanding of cerebrovascular changes and the cascade of responses related to brain bulge, we introduced acute SDH into the Marmarou model for the preparation of high intracranial pressure (ICP) to simulate the pathological conditions experienced by patients with severe brain injury. Results With the introduction of a 400 µL haematoma, ICP increased to 56.9 ± 2.3 mmHg, mean arterial pressure showed reactive decrease, and the blood flow of cerebral cortical arteries and veins on the non-SDH-affected side decreased to < 10%. These changes could not fully recover even after DC. This resulted in generalised damage to the neurovascular unit and a lag effect to the venous blood reflux, which triggered malignant IOBB formation during DC. Conclusion An excessive increase in ICP causes cerebrovascular dysfunction and brings about a cascade of damage to brain tissue, which forms the basis for the development of diffuse brain swelling. The subsequent heterogeneous responses of the cerebral arteries and veins during craniotomy may be the main cause of primary IOBB. Clinicians should pay particular attention to the redistribution of CBF to various vessels when performing DC in patients with severe TBI.