Cerebral Haemodynamics and Intracranial Pressure during Haemorrhagic Shock and Resuscitation with Total Endovascular Balloon Occlusion of the Aorta in an Animal Model

Abstract Purpose To assess changes of cerebral haemodynamic and intracranial pressure (ICP) in animals, with or without elevated ICP, during controlled haemorrhagic shock and resuscitation with Total REBOA (tREBOA). Method In 22 anesthetized and normoventilated pigs, after placement of catheters for monitoring invasive proximal blood pressure (pMAP), ICP, and vital parameters, and 60 minutes stabilization phase, a controlled haemorrhagic shock (HS), was conducted. In 11 pigs (EICPG), an elevated ICP of 25–30 mmHg at the end HS was achieved by simulating an epidural mass. In 11 pigs (NICPG), the ICP was normal. tREBOA was then applied for 120 minutes. The changes of pMAP and ICP was followed and cerebral perfusion pressure (CPP) calculated. The integrity of the autoregulation was estimated using a calculated modified PRx index. Results After stabilization, hemodynamics and physiological parameters were similar and normal in both groups. At the end of the HS, ICP was 16 mmHg in NICPG vs 32 in EICPG (p = 0.0010). CPP was 30 mmHg in NICPG vs 6 mmHg in EICPG (p = 0.0254). After aorta occlusion CPP increased immediately in both groups reaching after 15 minutes up to104 mmHg in NICPG vs 126 mmHg in EICPG. Cerebrovascular reactivity seems to be altered during bleeding and occlusion phases in both groups with positive PRx. The alteration was more pronounced in EICPG, but reversible in both groups. Conclusion tREBOA is lifesaving by restoration the cerebral circulation defined as CPP in animals with HS with normal or elevated ICP. Despite the observation of short episodes of cerebral autoregulation impairment during the occlusion, mainly in EICPG, tREBOA seems to be an effective tool for improving cerebral perfusion in HS that extends the crucial early window sometimes known as the “golden hour” for resuscitation even after a traumatic brain injury.