Internal carotid artery patency following common carotid artery occlusion: management of the asymptomatic patient.

Rarely, internal carotid artery (ICA) patency is maintained above a common carotid artery occlusion (CCAO) through collateral flow of the ipsilateral external carotid artery or an aberrant ICA branch. Several small series report excellent results of ICA revascularization in relieving cerebral ischemic symptoms in these patients. The natural history of CCAO with patent ICA in the asymptomatic patient, however, is unknown. The Greenville Memorial Hospital Vascular Teaching Service registry and all carotid duplex scans done in the Greenville Hospital System vascular laboratory from January 1994 through December 1997 were reviewed. Data collection included chart review, phone interviews, and the review of angiograms and duplex scans. This study suggests that carotid duplex is more sensitive for detecting ICA flow after CCAO than routine contrast angiography. It also suggests that while rare in presentation, asymptomatic patients with CCAO and a patent ICA appear to have a benign neurologic course and can probably be observed without a high risk of stroke.