Reconstitution of "totally" occluded internal carotid arteries: angiographic and technical considerations

The authors describe their experiences with five patients with delayed transient ischemic symptoms homolateral to internal carotid artery (ICA) occlusions. In each instance, initial arteriograms were interpreted as showing irreversible occlusions of these arteries in the neck and microvascular bypass procedures were contemplated. However, after repeat arteriographic evaluations with a modified injection technique, certain angiographic features were identified that suggested the mechanism of the symptoms in these patients and that their ICA's could be reconstituted in the neck. This was successfully accomplished in each patient with complete relief of ischemic symptoms. The angiographic technique employed and the arterial flow patterns identified in these patients are discussed. The details of the operative technique are described. It is concluded that routine arteriographic techniques may be inadequate to identify the reversible carotid occlusion. This may account for some of the confusion which surrounds the surgery of these vessels as well as the failure of extracranial-intracranial bypass to relieve recurrent ischemic symptoms in these individuals.