Relationship between collateral circulation and clinical manifestation after severe stenosis or occlusion of in-ternal carotid artery

Objective To explore the relationship between collateral circulation and clinical manifestation after severe stenosis or occlusion of internal carotid artery. Methods According to the clinical manifestation, 78 cases of ICA stenosis or occlusion confirmed by digital subtraction angiography(DSA) were divided into two groups: asymptomatic group(n=31) and symptomatic group(n=47). Collateral circulation pathway in circle of Willis and the mean flow velocity of the middle cerebral arteries(MVMCA) were measured by Transcranial Doppler Ultrasonography(TCD). The correlation of the types of intracranial collateral circulation and clinical manifestation was analyzed. Results ① The collateral circulation opening rate of severe stenosis or occlusion of internal carotid artery in 78 cases of patients was 70.5%(55/78). The collateral patency rate(27/31, 87.1% of patients) was higher in asymptomatic group than in the symptomatic group(28/ 47, 59.6% of patients)(P 0.01). ② Collateral patency of anterior communicating artery(ACoA)in asymptomatic group(24/31, 77.4% of patients) was higher than that in symptomatic group(20/47, 42.6% of patients)(P0.01). Collateral patency of ophthalmic artery(OA) in symptomatic group(21/47, 44.7% of patients) was higher than that in asymptomatic group(6/31, 19.4% of patients)(P0.05). The opening rate of ACoA was significantly higher than that of either the posterior communicating artery(PCoA) or OA collateral circulation in asymptomatic group(P0.05). ③ The mean flow veloci-ty of the affected side middle cerebral arteries(MVMCA) in asymptomatic group(51.58±12.36cm/s) was significantly higher than that in symptomatic group(32.23±10.31cm/s)(P0.01). Conclusion The clinical manifestation is closely related to arterial circle of Willis collateral circulation opening after severe stenosis or occlusion of internal carotid artery and collateral patency of anterior communicating artery is the major collateral supply vessel.