Is carotid duplex scanning sufficient as the sole investigation prior to carotid endarterectomy?

Carotid endarterectomy (CEA) is the accepted treatment for certain patients who have had, or who are at risk of having, a stroke if they have a significant narrowing of the internal carotid artery. Rapid and accurate classification of the degree of stenosis is important as the benefit of surgery is highly dependent on this. The aim of this study was to assess whether the addition of angiography to duplex scanning resulted in a change in patient management in a unit where duplex scanning was used as the sole imaging investigation prior to CEA. The study population consisted of 64 patients with significant internal carotid artery stenosis on duplex scanning who were suitable for, and wished to be considered for, CEA. All patients underwent an angiogram. In this study 9 (14%) patients did not proceed to surgery on the basis of angiography and in a further 11 (17%) patients insufficient views of the distal vessel were obtained on duplex scanning. Three of these patients had extensive disease which excluded surgery. One patient experienced a transient ischaemic attack (TIA) at the time of angiography. In conclusion, this audit has highlighted the limitations in performing duplex scanning alone, and the costs that this can incur on the patient who may undergo an unnecessary operation. We cannot recommend duplex scanning as the sole investigation prior to CEA. There is need to evaluate the role of additional non-invasive carotid imaging such as magnetic resonance angiography or CT angiography in the assessment of these patients.