Carotid thromboendarterectomy: a reappraisal. Criteria for patient selection.

Thromboendarterectomy performed in 35 patients with symptoms distal and ipsilateral to an occluded internal carotid artery resulted in patency in 19 cases (53%). Two factors that influence successful operation are early intervention following occlusion and good collateral circulation. In only 12 patients (34%) could the interval from occlusion to surgery be confidently determined. Four of these vessels, occluded for up to 7 days (100%), and five of eight vessels (63%), occluded for up to 4 weeks, were reopended. In the remaining patients, where the duration of occlusion was indefinite, greater reliance was placed on the evaluation and grading of angiographic collateral supply distal to the occlusion. Patients with Grade 1 to 3 collateral supply should not be explored unless occlusion occurred very recently. Patients with Grades 4 and 5 collateral supply are considered for carotid exploration regardless of the duration of the occlusion, as an alternative to other methods of revascularization.