Intraoperative Vascular Neuromonitoring in Patients with Subarachnoid Hemorrhage: A Pilot Study Using Combined...

Area of Science:

• Neuroscience
• Medical Technology
• Critical Care Medicine

Background:

• Intraoperative monitoring of cerebral microcirculation is crucial for predicting neurologic outcomes in subarachnoid hemorrhage (SAH) patients.
• A novel noninvasive real-time measurement technique was evaluated for detecting microcirculatory changes.

Purpose of the Study:

• To assess the utility of the O2C laser-Doppler spectrophotometry system for intraoperative monitoring of cerebral microcirculation.
• To correlate microcirculatory parameters with postoperative neurologic outcomes in SAH patients.

Main Methods:

• The O2C system measured capillary venous oxygenation (SO2), hemoglobin concentration, blood cell velocity, and blood flow in 14 SAH patients undergoing aneurysm clipping.
• Somatosensory evoked potentials (SEPs) were recorded concurrently.
• Neurologic outcomes were assessed using the modified Rankin Scale at discharge and 12 months post-surgery.

Main Results:

• Decreased microcirculatory flow and increased SO2 correlated with poorer functional outcomes.
• Microcirculatory monitoring indicated ischemia in 6 of 8 patients, consistent with electrophysiological SEP changes and postoperative CT-detected infarcts.
• SEP abnormalities strongly correlated with infarct demarcation on CT scans.

Conclusions:

• Intraoperative laser-Doppler flowmetry and spectrophotometry show potential for predicting postoperative outcomes in SAH patients.
• Further large-cohort studies are required to validate these findings and the clinical utility of this novel monitoring method.