Compensatory effects of grade Ⅰ compensatory circulation on hemodynamics in the distal occlusion of internal carotid artery / 中国综合临床

ABSTRACT

Objective To analyze the hemodynamic changes of cerebral arterial collateral circulation and distal perfusion of cerebral arteries after external carotid artery occlusion (EICAO).Methods Ninety-six patients with EICAO were selected as the case group,of which 46 cases of left EICAO (group A),50 cases of right EICAO (group B) and 30 normal volunteers were selected as the control group.Color Doppler ultrasonography (TCD) was used to detect peak systolic velocity (Vs) in the middle cerebral artery (MCA),end diastolic velocity (Vd),mean blood flow velocity (Vm),pulsatility index (PI),hemodynamic parameters of arteries,and opening rate of grade Ⅰ anterior communicating artery (ACOA) and posterior communicating artery (PCOA).Results There were significant differences in Vs,Vm,Vd,and PI among group A,B and C (F =56.046,31.027,39.283,18.614,49.658,24.992,15.035,22.069,P＜ 0.001).The Vs,Vd,Vm,and PI of the left MCA in the group A were significantly lower than those of the left side in the control group (P＜0.01);the Vs,Vd,Vm,and PI of the right MCA in the group B were significantly lower than those of the right side in the control group (P＜0.01).In group A and B,the open rate of simple ACOA in the stage Ⅰ collateral circulation was 26.09％ and 30.00％.The open rate of PCOA alone was 23.91％ and 36.00％,respectively,and the concurrent opening rate of ACOA and PCOA was 36.96％ and 30.00％,respectively,There was no significant difference in the open rate of grade Ⅰ collateral circulation among the three types of blood vessels (x2 =0.223,2.881,0.808,P=0.637,0.090,0.369).The incidence of cerebral infarction at the MCA donor site in the group A was 60.87％ on the left side and 8.70％ on the right side.The data of the left side was significantly higher than that of the right side (x2 =57.165,P＜0.001).The incidence of cerebral infarction at the MCA in the group B was 14.00％ on the left side and 60.00％ on the right side,and the data of the fight side was significantly higher than that of the left side (x2 =43.436,P＜ 0.001).Conclusion Although there is a higher grade Ⅰ collateral circulation opening rate in patients with EICAO,the MCA blood supply area of the distal internal carotid artery is still in a state of low blood flow perfusion,and the incidence of cerebral infarction is also high,so opening the grade Ⅰ collateral circulation does not completely reduce the risk of cerebral infarction in these patients,and these patients are still at high risk of cerebral infarction.