Awake High-Flow Extracranial to Intracranial Bypass for Complex Cerebral Aneurysms: Institutional Clinical Trial Results

Objective Assess the potential added benefit to patient outcomes of “awake” neurological testing when compared with standard neurophysiologic testing performed under general endotracheal anesthesia. Methods Prospective study of 30 consecutive adult patients who underwent awake high flow extracranial to intracranial (HFEC-IC) bypass. Clinical neurological and neurophysiologic findings were recorded. Primary outcome measures were the incidence of stroke/cerebrovascular accident (CVA), length of stay, discharge to rehabilitation, 30-day modified Rankin scale score, and death. An analysis was also performed of a retrospective control cohort ( n  = 110 patients who underwent HFEC-IC for internal carotid artery (ICA) aneurysms under standard general endotracheal anesthesia). Results Five patients (16.6%) developed clinical awake neurological changes (4, contralateral hemiparesis; 1, ipsilateral visual changes) during the 10-minute ICA occlusion test. These patients had 2 kinks in the graft, 1 vasospasm, 1 requiring reconstruction of the distal anastomosis, and 1 developed blurring of vision that reversed after the removal of the distal permanent clip on the ICA. Three of these 5 patients had asynchronous clinical “awake” neurological and neurophysiologic changes. Two patients (7%) developed CVA. Median length of stay was 4 days. Twenty-eight of 30 patients were discharged to home. Median modified Rankin scale score was 1. There were no deaths in this series. Absolute risk reduction in the awake craniotomy group ( n  = 30) relative to control retrospective group ( n  = 110) was 7% for CVA, 9% for discharge to rehabilitation, and 10% for graft patency. Conclusions Temporary ICA occlusion during HFEC-IC bypass for ICA aneurysms in conjunction with awake intraoperative clinical testing was effective in detecting a subset of patients ( n  = 3, 10%) in whom neurological deficit was not detected by neurophysiologic monitoring alone.