Development of postoperative internal carotid artery occlusion due to the presence of risk factors.

Postoperative internal carotid artery (ICA) occlusion is a rare condition with few data on the risk factors. The aim of the study was to analyze risk factors and ischemic symptomatology in patients with postoperative ICA occlusion. During one year period, 33 patients with postoperative ICA occlusion were examined at Cerebrovascular Laboratory. Medical history, clinical findings and atherosclerosis risk factors were compared with data on 33 patients with satisfactory postoperative finding. Student's t-test was used on data comparison (P < 0.05). In 31 of 33 patients, ICA occlusion was recorded on the first postoperative examination, 3 months after carotid endarterectomy (18 right and 15 left). In 8 patients, combined occlusion of the common carotid artery and ICA was found (4 right, 4 left). One patient ICA developed occlusion during the first and third postoperative year each. Clinically, three patients presented with ischemic symptoms (one stroke and two transitory ischemic attacks (TIA)). The following risk factors were present in the group with postoperative ICA occlusion: hypertension in 18, smoking in 10, hyperlipidemia in 8, diabetes mellitus in 9, history of stroke in 13, TIA in 3, heart attack in 4 and coronary disease in 3 patients; the respective figures in the control group were as follows: 25, 11, 16, 7, 7, 3, 4 and 3. There was no significant between-group difference in the presence of risk factors. Study results suggested that postoperative ICA occlusion was not caused by atherosclerosis risk factors but by perioperative complications.