Evaluation of blood flow velocity changes in middle cerebral artery from contralateral transorbital approach as the alternative method of monitoring during carotid surgery in patients with no temporal acoustic "window".
BACKGROUND
We evaluated the possibility of utilising the transorbital approach for middle cerebral artery (MCA) blood flow velocity monitoring as the alternative method of intraoperative evaluation of cerebral ischaemia risk in patients with no temporal acoustic "window".


METHODS
We insonated the MCA from contralateral, transorbital approach at a depth ranging from 68 to 80 mm. Ten patients with no temporal window (group A) undergoing carotid surgery were examined intraoperatively by means of this method.


RESULTS
For comparison a reference group of 15 patients with temporal acoustic windows present (group B) was established. In this group, the simultaneous (double) records of MCA blood flow velocity changes from transtemporal and transorbital approaches during carotid endarterectomy (CEA) were conducted. Mean blood flow velocity (Vmean) was recorded after anaesthesia, during a 120-sec clamp test, after shunt insertion (if necessary), immediately after and 5 min after clamp release.


CONCLUSIONS
We would recommend transorbital Doppler monitoring as a method of choice when the transtemporal approach is not possible. Although quite difficult, this method appears to be safe and reliable in the intraoperative evaluation of patients at risk of cerebral ischaemia.
Staszkiewicz
W
W
Department of Vascular Surgery CMKP, Warsaw, Poland.
Antepowicz
W
W
Madycki
G
G
Dabek
P
P
Gabrusiewicz
A
A
D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D016022:Case-Control Studies; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging* / Q000502:physiology; D016343:Monitoring, Intraoperative / Q000379:methods*; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*