The hemodynamic effects of internal-external collateral circulation for the common carotid artery

Objective To evaluate the hemodynamic changes of common carotid artery(CCA)and external carotid artery(ECA)with unilateral high-degree stenosis or occlusion of the internal carotid artery(ICA)after internal-external artery collateral circulation(IEACC)opening.Methods A total of 160 patients with 70%-99% of stenosis or occlusion of ICA distal to the CCA were enrolled in this study.The peak systolic velocity(PSV),end-diastolic velocity(EDV),mean velocity(MV),resistance index(RI)of CCA and ECA were detected by means of color duplex ultrasonography(CDU).The blood flow volume(BFV)was calculated after examination.We analyzed the hemodynamic parameters in the CCA with high-degree stenosis and occlusion of ICA.The external carotid artery difference was compared between healthy and affected side after IEACC opening.Results(1)After IEACC opening,either EDV or BFV increased in 70%-99% of stenosis and occlusion group(P0.001),while PSV、MV、RI showed no difference.(2)There was no difference for the hemodynamic parameter between 70%-99% of stenosis group and occlusion group with IEACC opening.(3)If IEACC did not open,the EDV and BFV of CCA decreased in ICA occlusion group compared to ICA 70%-99% stenosis group.The EDV10±6 cm/s,BFV488±180 ml/min of CCA indicated occlusion on the same side of ICA.(4)The PSV,EDV,MV of ECA increased and RI decreased in 70%-99% of stenosis and occlusion group(P0.001)after IEACC opening.We found PSV124±35 cm/s,EDV34±12 cm/s,MV64±18 cm/s,RI0.79±0.07 of ECA which indicated a IEACC opening on the same side of carotid.Conclusion Our results suggest that hemodynamic parameters of the CCA can be influenced by IEACC opening.The collateral circulation of intra and extra-cerebral blood flow will be helpful for improving the accuracy of ICA occlusion disease.