High-risk carotid endarterectomy: challenges for carotid stent protocols

Carotid angioplasty and stenting is under investigation in clinical trials as an alternative to endarterectomy. Some clinicians have hypothesized that stenting would be applicable for patients at high risk who need carotid revascularization. To further test this hypothesis, we stratified our carotid endarterectomy procedures according to current carotid stent protocols.

We reviewed our computerized registry and the clinical charts of patients who underwent carotid endarterectomy. Each procedure was categorized as high risk or low risk, according to the following six separate high-risk factors: 1, severe cardiac dysfunction; 2, the requirement for combined coronary and carotid vascularization; 3, severe pulmonary dysfunction; 4, contralateral internal carotid artery occlusion; 5, previous ipsilateral carotid endarterectomy; and 6, anatomically limited access for carotid endarterectomy. Rates of stroke at 30 days, cardiac complications, and death were tabulated.

Between January 1, 1998, and December 31, 2000, 415 carotid endarterectomies were performed on 389 patients. Ninety-eight procedures (23.6%) were classified as high risk on the basis of the following factors: 1, severe cardiac dysfunction (n = 30); 2, requirement for combined coronary and carotid revascularization (n = 14); 3, severe pulmonary dysfunction (n = 8); 4, contralateral carotid occlusion (n = 31); 5, previous ipsilateral carotid endarterectomy (n = 25); and 6, anatomically limited access (n = 4). Seven patients had ipsilateral postoperative strokes (1.7%), with two additional patients having contralateral hemispheric strokes. One patient died from exacerbation of congestive heart failure 9 days after undergoing a second carotid endarterectomy. The total stroke and death rate was 2.6% for all the patients. Two of the 98 procedures in the high-risk group were complicated with ipsilateral stroke (2.0%) as compared with six of the 317 low-risk procedures (1.9%; P = 1). Six procedures were complicated with cardiac dysfunction after surgery, including myocardial infarction, congestive heart failure, or the new onset of atrial fibrillation. Three cardiac complications occurred in the low-risk group (1%), and three occurred in the high-risk group (3.1%; P =.15).

This series shows that patients at high risk can undergo carotid endarterectomy with stroke rates equivalent to the rates of patients at low risk. The cardiac morbidity rate may be increased in the high-risk group. Carotid stenting is unlikely to offer any improvement in stroke risk as compared with carotid endarterectomy, but stenting may reduce non-stroke morbidity rates associated with some high-risk cases.