[Dependence of the risk of brain infarct on the degree of severity of occlusive internal carotid artery lesions].

This retrospective study was performed in order to evaluate the relationship between the risk of brain infarction and the severity of 274 internal carotid artery (ICA) stenoses in 218 patients. Clinical, vascular and brain-morphological findings were compared. Of 106 occluded ICAs, 59% had induced a completed stroke with visible hemispheric infarction in 77%, most of them of the territorial type (35%). 32% of 85 high-grade stenoses had led to completed strokes, with territorial, low-flow and microangiopathic patterns of infarction occurring equally frequent. CT was normal in two-thirds of 83 low-grade ICA-stenoses, whereas 14% showed microangiopathic brain lesions. We conclude that (1) asymptomatic ICA stenoses should not be operated on, as long as they are not of very high degree and (2) even symptomatic ICA stenoses should not undergo endarterectomy, if the patient's stroke was due to lacunar infarctions of typical site and size.