The role of duplex scanning in the management of carotid artery disease

Abstract: Extracranial carotid artery disease, mainly due to atherosclerosis, is a common cause of stroke. The risk for future stroke can be reduced in selected patients by carotid endarterectomy (CEA). Duplex scanning has been increasingly used for diagnosis of carotid artery disease. The aim of this thesis was to assess the role of duplex scanning in the management of carotid artery disease by evaluating various methodological and clinical aspects of its use.Retrospective analysis of 4,548 carotid artery duplex scans demonstrated that different validated spectral Doppler criteria had a significant effect on the proportion of patients receiving a diagnosis of ?70% internal carotid artery (ICA) stenosis. The Doppler angle of insonation significantly affects velocity measurements and is important in differentiating 50-69% and ?70% ICA stenosis. Two hundred eighty seven consecutive carotid endarterectomies were analysed retrospectively. The perioperative major stroke/mortality rate was 2.2% in 229 operations with duplex scanning as the sole preoperative imaging modality. Early postoperative duplex scanning was technically feasible and a high ICA flow velocity after CEA was often transient. In 24 patients with spontaneous cervical artery dissections, four pathological flow patterns were identified: absence of flow, reduced flow, staccato flow and stenotic flow.Duplex scanning has important implications in the management of patients with extracranial carotid artery disease. However, duplex performance depends on correct application of the method and selection of appropriate criteria for the definition of disease. Duplex scanning can be reliably used to select patients for CEA. Moreover it is a useful diagnostic modality in the immediate postoperative period. Finally, it can be reliably used for diagnosis of spontaneous cervical artery dissections.