Doppler ultrasound monitoring for detection of microembolic signals in peripheral arteries.
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 microm (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 20dB, 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: 5.72/30min) was significantly higher than that in patients with AAA before surgery (0.065/30min) (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.
Kudo
T
T
Department of Surgery, Division of Vascular Surgery, Tokyo Medical and Dental University, School of Medicine, Tokyo, Japan.
Inoue
Y
Y
Sugano
N
N
Iwai
T
T
D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D017544:Aortic Aneurysm, Abdominal / Q000601:surgery*; D018438:Blue Toe Syndrome / Q000150:complications / Q000000981:diagnostic imaging*; D004617:Embolism / Q000000981:diagnostic imaging* / Q000209:etiology; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008875:Middle Aged; D023421:Models, Animal; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging*; D013552:Swine; D018608:Ultrasonography, Doppler