Hemodynamic cerebral ischemia during carotid endarterectomy evaluated by intraoperative monitoring and post-operative diffusion-weighted imaging.

OBJECTIVE

We used the result of monitoring to evaluate patients with post-operative neurological deficits attributable to hemodynamic cerebral ischemia owing to cross-clamping of the carotid artery.

METHODS

We evaluated 131 carotid endarterectomy (CEA) procedures performed on 118 patients, 96 men and 22 women ranging in age from 38 to 82 years (mean: 67.1 years). For monitoring, we used a combination of somatosensory evoked potential (SEP), functional dynamic electroencephalography (EEG), near-infrared spectroscopy (NIRS) and transcranial Doppler (TCD). Patients who awoke with neurological deficits after CEA immediately underwent diffusion-weighted imaging (DWI) and magnetic resonance angiography (MRA).

RESULTS

In 30 of the 131 procedures (22.9%), intraoperative monitoring disclosed abnormalities after cross-clamping of the internal carotid artery (ICA). In two of these 30 patients, shunt was not introduced, because of full recovery of monitoring after blood pressure increasing, however, one patient demonstrated transient ischemic attack (TIA). In six of remaining 28 patients who need shunt, transient hemodynamic cerebral ischemia occurred, however, all patients recovered gradually within 18 hours after CEA. No new lesions were detected on post-operative DWI of the seven patients and MRA demonstrated good patency of the carotid artery. The other 101 patients whose intraoperative monitoring after cross-clamping of the ICA did not disclose abnormalities demonstrated no hemodynamic TIA.

CONCLUSION

Hemodynamic ischemia owing to cross-clamping of the ICA is rare in patients treated by CEA. However, in patients manifesting neurological deficits upon awakening from CEA, DWI and MRA should be performed immediately to facilitate their prompt treatment.