Clinical implication of orbital ultrasound monitoring during selective cerebral perfusion.
BACKGROUND
We evaluated clinical relevance of orbital ultrasound (OUS) monitoring to neurological events in aortic surgery associated with selective cerebral perfusion (SCP).


METHODS
In 24 consecutive cases, blood flow was monitored at central retinal artery (CRA) and retrobulbar vessels. The threshold perfusion pressure for detecting CRA flow in the color Doppler mode (BPt) was determined in individual eyes.


RESULTS
The BPt ranged from 25 to 71 mm Hg. Events (infarction, anisocoria, delirium) occurred in 8 cases. Infarction occurred in all 3 cases when retrobulbar flow was severely impaired for 40 minutes or longer, while none of the remaining 21 cases had infarction (p = 0.0005). Among the latter cases, perfusion pressure was below BPt for longer than 100 minutes in all 5 cases with events, and in 5 of 16 cases without events (p = 0.0124). No significant difference was found in age, duration of cardiopulmonary bypass, SCP, and circulatory arrest, and duration of blood pressure below 50 mm Hg.


CONCLUSIONS
Sustained hypoperfusion detected with OUS monitoring is related to an occurrence of neurological events.
Orihashi
K
K
First Department of Surgery, Hiroshima University School of Medicine, Japan. ka-ori@mcai.med.hiroshima-u.ac.jp
Matsuura
Y
Y
Sueda
T
T
Shikata
H
H
Watari
M
M
Okada
K
K
D000368:Aged; D000784:Aortic Dissection / Q000000981:diagnostic imaging / Q000601:surgery*; D017545:Aortic Aneurysm, Thoracic / Q000000981:diagnostic imaging / Q000601:surgery*; D001783:Blood Flow Velocity / Q000502:physiology; D001921:Brain / Q000098:blood supply*; D002545:Brain Ischemia / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009915:Orbit / Q000098:blood supply*; D012016:Reference Values; D012161:Retinal Artery / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D018615:Ultrasonography, Doppler, Color; D017585:Ultrasonography, Doppler, Transcranial