EXTRACRANIAL CAROTID-ARTERY FLOW MEASUREMENT DURING CAROTID ENDARTERECTOMY USING A DOPPLER ULTRASONOGRAPHIC FLOWMETER

A study was performed to evaluate immediate changes in carotid artery blood flow after carotid endarterectomy using a Doppler ultrasonograph ic flowmeter. Forty-seven consecutive patients aged 49-78 (median 64) years with symptomatic internal carotid artery (ICA) stenosis underwen t carotid endarterectomy. Volume flow, resistance and pulsatility inde x were measured in the common carotid artery (CCA) and ICA both before and after operation. ICA flow increased by 54 per cent (P<0.01) and r esistance decreased by 58 per cent (P=0.01). CCA flow rose by 17 per c ent (P=0.1) and resistance fell by 21 per cent (P=0.02). The pulsatili ty index did not change significantly. The Doppler ultrasonographic fl owmeter offers a simple, non-invasive and convenient means of improvin g understanding of the immediate haemodynamic effects of carotid endar terectomy. It is useful in everyday practice to confirm the adequacy o f endarterectomy, particularly in the absence of other methods of qual ity control. Duplex ultrasonography might still be necessary after sur gery if the flowmeter does not demonstrate an increase in flow compare d with the preoperative value.