Doppler ultrasound in aortic dissections: a study of cephalic and peripheral arteries

We investigated the role of continuous-wave Doppler ultrasound in predicting the presence of an aortic dissection prospectively in 28 patients whose diagnosis was confirmed either by arteriography or surgery (26 cases) or at autopsy (two cases). We hypothesized that dissections, by creating two channels for flow, would produce velocity disturbances detectable in accessible arteries such as the carotid, brachial, and femoral arteries. Of the 28 patients, 20 had Type I, two Type II, and six Type III dissections. Two abnormalities of the Doppler signals were found: in 18 of Type I dissections, notching was found in the systolic upslope of the velocity tracing from those arteries that were either involved in or distal to the dissection sites. Notching was much less frequent for Type II and III dissections: only one patient with Type II and two patients with Type III dissections showed notching. In addition diastolic backflow with marked aortic valvular insufficiency was present. Notching in brachiocephalic artery continuous-wave Doppler signals appears to have a high positive predictive value for Type I dissections.