Doppler ultrasound monitoring for detection of microembolic signals in peripheral arteries

Abstract

Objective: to use Doppler ultrasound to detect peripheral microemboluation. Methods: standard Transcranial Doppler equipment was used to peripheral detect peripheral embolic high intensity transient signals (HITSs) in a pig model following injection of microparticles and atheroma, and in 23 patients who underwent open repair of an abdominal aortic aneurysm (AAA), six patients with blue toe syndrome and 10 age matched healthy subjects. Results: the pig study showed increasing signal intensity with particle size. Particles of 100 (n = 24), 200 (n = 17), and 400 μm (n = 31) elicited 14, 25, 33 dB signals, respectively (p < 0.05). During AAA surgery, the intensity (median) of HITSs before clamping (n = 226) and after declamping (n = 1216) were 14, and 20 dB, respectively (p < 0.001). Quite a few HITSs were detected after surgery. In patients with blue toe syndrome, a total of 63 HITSs could be detected, and the frequency of HITSs (median: 5.72/30 min) was significantly higher than that in patients with AAA before surgery (0.065/30 min) (p < 0.001). Conclusions: Doppler ultrasound technique may be a clinically useful test to guide the treatment of patients at risk of distal atheroembolic events. © 2002 Elsevier Science Ltd. All rights reserved.