title: Patency of external and internal carotid artery in the presence of an occluded common carotid artery: noninvasive evaluation with combined cerebrovascular Doppler examination and sequential computertomography.
abstract: The patency of the external carotid artery (ECA) and internal carotid artery (ICA) in the presence of an occlusion of the common carotid artery (CCA) was evaluated in 7 patients with a symptomatic CCA occlusion by the combined application of cerebrovascular Doppler examination (cv-Doppler) based on continuous-wave equipment and sequential computertomographic scans with intravenous bolus injection of contrast material (sequential CT-scans). Occlusion of the CCA was demonstrated by cv- Doppler and sequential CT-scans and confirmed by routine angiography. A patent ECA was found in all 7 patients by the combined method, but could not be demonstrated by routine angiography in one of these patients. A patent ICA was found in 2 patients by the combined method, while routine angiographic findings concerning the patency of the ICA were equivocal. An occluded ICA was found in 5 patients by the cv-Doppler-sequential CT-scans method, where routine angiographic findings also were equivocal. Operation to restore blood flow in the CCA was performed in 5 patients and successful in 3 patients in whom blood flow from the CCA to the ECA could be achieved in 2 patients, and to the ECA and ICA in one patient, as predicted by the combined cv-Doppler-sequential CT-scans method. Thus, the patency of the ICA in the presence of a CCA occlusion can be reliably evaluated by the combined diagnostic procedure. The method may help to decide for further diagnostic work-up, e.g., specific selective injections and projections in more than two plans during cerebral angiography, and/or successful surgical intervention in a given patient with a CCA occlusion, even if angiographic findings are equivocal.
mesh_terms: D000328:Adult; D002341:Carotid Artery Thrombosis / Q000175:diagnosis* / Q000209:etiology / Q000601:surgery; D002342:Carotid Artery, External / Q000000981:diagnostic imaging; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D003097:Collateral Circulation; D004691:Endarterectomy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography