Intraoperative microemboli and low middle cerebral artery blood flow velocity are additive in predicting development of cerebral ischemic events after carotid endarterectomy.
OBJECTIVE
Microemboli generated during dissection of the carotid arteries in patients undergoing carotid endarterectomy result in postoperative cerebral ischemic events. The purpose of this study was to determine whether these events correlate with middle cerebral artery blood flow velocity.


METHODS
One hundred sixty-three patients with ipsilateral internal carotid artery stenosis (>70%) underwent carotid endarterectomy under transcranial Doppler monitoring of mean blood flow velocity and microembolic signals in the ipsilateral middle cerebral artery.


RESULTS
Logistic regression analysis of several variables demonstrated that only middle cerebral artery mean blood flow velocity during carotid dissection was significantly associated with new postoperative neurological deficits in patients with microembolic signals during carotid dissection (95% CI, 1.069 to 1.528; P=0.0072). The combination of low middle cerebral artery mean blood flow velocity (<or=28 cm/s) and microembolic signals >or=10 during carotid dissection resulted in improved specificity and positive predictive value for the development of new postoperative neurological deficits when compared with either criterion used alone.


CONCLUSIONS
Intraoperative microemboli and low middle cerebral artery mean blood flow velocity are additive in predicting the development of cerebral ischemic events after carotid endarterectomy.
Ogasawara
Kuniaki
K
Department of Neurosurgery, School of Medicine, Iwate Medical University, Morioka, Japan. kuogasa@iwate-med.ac.jp
Suga
Yasunori
Y
Sasaki
Makoto
M
Chida
Kohei
K
Kobayashi
Masakazu
M
Yoshida
Kenji
K
Otawara
Yasunari
Y
Ogawa
Akira
A
D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D002545:Brain Ischemia / Q000209:etiology*; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D006801:Humans; D020766:Intracranial Embolism / Q000150:complications / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000473:pathology / Q000502:physiology; D017585:Ultrasonography, Doppler, Transcranial