Carotid endarterectomy in awake patients with contralateral carotid artery occlusion

Objectives: Patients with severe stenosis of an internal carotid artery with contralateral occlusion (ICO) are at an increased risk for stroke, and therefore surgical treatment is usually recommended. Carotid endarterectomy (CEA) under regional anesthesia enables constant monitoring of neurologic status and selective shunting in cases of clinically evident cerebral ischemia. In this study, we assess the selective use of shunts based solely on changes in neurological status in awake patients with ICO undergoing CEA as well as their complication rates. Methods: During 1996-1998, we studied intraoperative findings and results of CEA under regional anesthesia with clinical monitoring of neurological status in two groups: (1) patients with stenosis (>70% by NASCET) and contralateral occlusion (n=50) and (2) patients with stenosis and no contralateral occlusion (n=94). Results: Shunt insertion was required in 42% of group 1, and 6% in group 2. All of the patients in group 1 requiring shunts had stump pressures <50 torr. The average stump pressure of group 1(40 torr) was significantly lower than that of group 2 (75 torr), and was also lower than that of patients with severe contralateral stenosis (35 patients, 76 torr). Perioperative stroke rates were identical in both groups (2.1%). Conclusion: Since ICO patients are at a high risk for brain ischemia during ICA clamping, they require shunt insertion frequently. Patients with no contralateral occlusion require shunting at a much lower rate - even in the presence of severe contralateral stenosis. Regional anesthesia allows for early detection of brain ischemia and therefore, the perioperative results in both groups are similar.