Cerebral microembolism during carotid endarterectomy.
BACKGROUND
This study was designed to assess the intraoperative risk of cerebral microembolism, as detected by transcranial Doppler ultrasonography, during carotid endarterectomy.


METHODS
Thirty-six patients (37 procedures) with symptomatic (n = 35) or asymptomatic (n = 2) internal carotid artery origin stenosis(> 50%) were monitored continuously during carotid endarterectomy. Special instrumentation was used to detect high-intensity transient signals (HITS) in the middle cerebral artery on the carotid endarterectomy side. All HITS satisfied a priori established criteria.


RESULTS
The incidence of carotid endarterectomies with formed-element HITS increased at clamp release (23/37, P < 0.001) and shunt opening (7/11, P = 0.014), and during wound closure (13/22, P< 0.005) and shunting (5/11, P = 0.046). HITS with air microbubble characteristics were detected at clamp release (22/37, P < 0.001) and shunt opening (5/11, P = 0.025).


CONCLUSIONS
HITS do not occur randomly during carotid endarterectomy. Shunting, unclamping, and wound closure are high-risk periods.
Gavrilescu
T
T
Department of Neurology, Boston University School of Medicine, Massachusetts, USA.
Babikian
V L
VL
Cantelmo
N L
NL
Rosales
R
R
Pochay
V
V
Winter
M
M
D000368:Aged; D000369:Aged, 80 and over; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D002542:Intracranial Embolism and Thrombosis / Q000150:complications / Q000000981:diagnostic imaging*; D007431:Intraoperative Complications / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D018608:Ultrasonography, Doppler