Blood Flow in the Internal Carotid Artery With Common Carotid Artery-Occluding Lesions in Takayasu Arteritis

Abstract

The purpose of this study was to investigate carotid artery hemodynamics and blood flow involving external carotid artery (ECA) and internal carotid artery (ICA) patency in patients with Takayasu arteritis (TA). The common carotid artery (CCA), ECA, ICA, and vertebral artery (VA) were examined in 19 patients with TA involving ECA and ICA patency and in 19 healthy control participants. Bilateral carotid sonographic studies were performed with the use of 5- to 8-MHz linear transducers. Patency of the ECA and ICA was noted in 14 bilateral, 2 right-sided, and 3 left-sided CCA lesions. Flow in the ECA was retrograde, whereas flow in the ICA was directed cephalad and showed a low-frequency, damped waveform or even a veinlike waveform. The peak systolic velocity (PSV) of the ICA in the patients was significantly lower than that in the control participants (P < .001). A good correlation was observed in the PSV between the ECA and ICA (r = 0.77). The VA displayed normally directed flow, a significantly larger diameter, and a higher flow velocity (P < .001). Color duplex sonography can identify special features of TA with CCA-occluding lesions and permit quantification of carotid artery flow velocities and VA diameters both efficiently and practically.