Optimal outcome for "high-risk" carotid endarterectomy

While carotid endarterectomy (CEA) can often be accomplished with a very low stroke risk, certain scenarios-prior ipsilateral stroke, contralateral carotid occlusion, or acute cerebral ischemia-have been associated with neurologic morbidity and mortality rates exceeding 10%. The routine use of temporary intraluminal carotid shunts has been thought to be obligatory in such patients, notwithstanding the fact that these devices are obtrusive and may be associated with an increased risk of perioperative stroke. Among 175 patients undergoing CEA, 68 could be classified as "high-risk" (contralateral carotid occlusion, n = 24; prior ipsilateral stroke, n = 28; acute cerebral ischemia, n = 16). CEA was performed under regional or local anesthetic block in all 68 patients. Sixty-six patients (97%), including 22 of 24 (92%) with contralateral carotid occlusion, underwent CEA (carotid occlusion times averaging 22 minutes [range: 12 to 42 minutes]) without insertion of a carotid shunt. Two patients (2.9%) with contralateral carotid occlusion lost consciousness 7 and 10 minutes after carotid clamping, but regained neurologic normalcy after shunt insertion. A single patient (1.5%) experienced a fatal stroke due to heparin-induced "white clot" syndrome. Rates of shunt insertion and of perioperative stroke did not differ from those in 107 "low-risk" CEA patients. Cerebral collateral circulation is well developed even in compromised CEA patients. The necessity for temporary carotid shunts may be reduced by the use of "awake" anesthesia in such cases. Carotid shunting may be no more necessary, and operative outcome no less favorable, in "high-risk" than in uncomplicated CEA patients.