The relationship between Willis circle and collateral circulation with brain symptom in severe stenosis at internal carotid artery
HUI Pin jing,CHEN Mou sen,LIU Chun feng,et al. (The First Affiliated Hospital of Soochow University,Suzhou 215006,China)
Objective Using transcranial Doppler(TCD) ultrasonography to evaluate the patients with severe stenosis at internal carotid artery (ICA) and analyze the relationship between circle of Willis collateral circulation and clinical manifestation. Methods 34 cases with severe stenosis at ICA were devided into symptomatic and asymptomatic groups (18 of them had been admitted to MRA). The patterns of collateral circulation,flow velocities(Vm),pulsatility index(PI) and spectral waveforms of the MCA distal were also assessed. Results There were three patterns of collateral circulation:Anterior communicating artery (ACOA),Posterior communicating artery (PCOA) and Ophthalmic artery (OA). Among them,in asympotomatic group,88.9% of cases were in ACOA pattern,whose MCA Vm of stenosis was 59.1±8.7cm/s. In sympotomatic group 50% was ACOA and there was no collateral circulation in 4 cases. The Vm of MCA at stenosis side was decreased compared with normal control (48.6±7.3cm/s,P0.001). Blunted Doppler flow waveforms (reduced systolic flow velocity and pulsatility) of the MCA inferred to reflect hemodynamic impairment. Conclusion TCD can detect the changes of circle of Willis collateral circulation in patients with severe extracranial ICA. It is suggested that searching for circle of Willis collateral circulation is significant to evaluate severe extracranial ICA.
【CateGory Index】： R743