Blood pressure in human large cerebral arteries: a feasibility study

Abstract

The lack of direct measures of brain blood pressure (BBP) has severely restricted understanding of cerebral pressure-flow relationships and their control. We sought to evaluate the feasibility of directly measuring BBP and its pulsatility between the aorta and middle cerebral artery (MCA) during elective endovascular surgical procedures. We report five case studies (four female, 61 ± 13 yr; means ± SD) of patients undergoing cerebrovascular interventional procedures for aneurysm and stenoses, using direct BBP measures with the COMET 2 pressure guidewire system (Boston Scientific). Patients were supine, intubated, and under anesthesia. The sensor wire was inserted via the femoral artery, measuring, as feasible, blood pressure (BP) in the aorta to MCA vascular segments, referenced to the radial artery BP waveform (arterial catheter). Mean arterial pressure varied between the radial (80 ± 18 mmHg), internal carotid artery (ICA; 70 ± 25 mmHg), and MCA (62 ± 29 mmHg), and marked interindividual heterogeneity was observed. Pulse pressure was higher in the radial artery (68 ± 23 mmHg) compared with the intracranial ICA (ICAi; 43 ± 29 mmHg) and MCA (M1; 25 ± 12 mmHg) segments. Direct measures of BBP in humans are feasible in this interventional surgery model. Although limited by the small sample size, the results suggest a heterogenous pattern of change between systemic and brain measures of blood pressure and pulse pressure.