Color Doppler flow imaging feature of compensatory collateral circles via ophthalmic artery in patients with internal carotid artery occlusion

Abstract

Objective To investigate color Doppler flow imaging features of the ophthalmic artery,external carotid artery,which is known the secondary compensatory collateral circle,in patients with unilateral internal carotid artery occlusion.Methods A total of 42 patients with unilateral internal carotid artery occlusion were enrolled,and ipsilateral and contralateral ophthalmic artery,external carotid artery were examined by color Doppler flow imaging,prospectively,peak systolic velocity,pulsatility index and resistance index were analyzed and compared with findings of control group.Results In the 42 cases with internal carotid artery occlusion,the compensatory collateral circle was observed by the external carotid artery and ophthalmic branches,through their communicating arteries in 40 (95.2％) cases of chronic occlusion.Compared with the contralateral side,the ophthalmic arteries were characterized by retrograde blood flow,peak backward shifting,increase of diameter [(1.91 ± 0.53) mm vs (1.69 ± 0.34) mm,P =0.009] and peak systolic velocity [(43.41 ± 27.28) cm/s vs (29.91 ± 14.16) cm/s,P =0.003],reduced pulsatility index (1.18 ± 0.49 vs 1.69 ± 0.73,P =0.000) and resistance index (0.65 ± 0.26 vs 0.75 ±0.12,P =0.000),and prolonged acceleration time [(147.71 ± 56.16)ms vs (51.80 ± 7.81)ms,P =0.000].Ophthalmic arteries had antegrade blood flow with a decrease of peak systolic velocity and resistance in another two cases of acute thrombosis of ICA.Conclusions External-ophthalmic-internal carotid artery passway is another compensatory collateral circle for the chronic occlusion,but only by ipsilateral and contralateral internal carotid artery circle,for acute thrombosis. Key words: Ultrasonography, Doppler, color; Carotid artery, internal; Ophthalmic artery; Collateral circulation