[Anesthetic management of a patient undergoing PTA stent placement for right common carotid artery stenosis]

A 60-year-old man underwent percutaneous transluminal angioplasty (PTA) stent replacement of the right common carotid artery. Preoperative angiogram revealed bilateral vertebral artery occlusion and 50% stenosis in contralateral internal carotid artery. Anesthesia was induced and maintained with fentanyl and propofol by TCI. rSO2, BIS and EEG were monitored. Moderate hypothermia (33-35 degrees C) was induced by concomitant use of milrinone. Edaravone, a novel free radical scavenger, and Sendai cocktail were administered before interruption of carotid flow. During 5 minutes of test occlusion by balloon, right rSO2 decreased from 61% to 49% and EEG showed slow waves with decreased amplitude. Therefore we decided to perform PTA and stenting separately. Right rSO2 decreased from 62% to 48% during PTA (6 min occlusion), while rSO2 decreased from 66% to 50% during stenting (7.5 min occlusion). EEG also showed the similar changes as observed during test occlusion. After the procedures, rSO2 and EEG recovered in a short time. Postoperative angiogram showed an improvement of carotid artery stenosis and intracranial vessels showed no branch occlusion. Patient was maintained hypothermic (35 degrees C) for 2 days after surgery. He recovered without additional neurological complications. We found that rSO2 was a useful, real-time and non-invasive method for evaluation of cerebral ischemia in our patient.