['The aim of this study was to investigate whether the introduction of routine transcranial Doppler (TCD) ultrasonography during carotid endarterectomy reduces the incidence of microembolization by altering operative technique.', 'The number and nature of microemboli detected during the first 75 consecutive carotid endarterectomies performed with TCD monitoring during 1992-1993 (group 1) were compared with those in a similar series of 75 consecutive patients undergoing carotid endarterectomy in 1995 (group 2), after substantial experience (210 patients) with TCD monitoring. Emboli were classified as either particulate or gaseous.', 'In patients with evidence of particulate emboli during the dissection phase of the operation, the total number of particulate emboli fell significantly in patients in group 2 (P = 0.019). Similarly, in patients in whom microembolization was detected on immediate opening of the shunt, the total number of microemboli also fell significantly in group 2 (P = 0.003). Overall, the median (95 per cent confidence interval) number of particulate emboli detected during the entire procedure fell significantly from 21 (16-29) in group 1 to 9 (7-14) in group 2 (P = 0.0008).'] Does experience with transcranial Doppler monitoring reduce the incidence of particulate embolization during carotid endarterectomy?