Cerebral ischemia during carotid artery cross-clamping: predictive value of phase-contrast magnetic resonance imaging.
The goal of this prospective study was to determine the utility of preoperative cerebral magnetic resonance imaging (MRI) in predicting cerebral ischemia during carotid artery cross-clamping for endarterectomy. Between January 2000 and December 2003, a total of 121 patients (95 men, 26 women) underwent three-dimensional phase-contrast MRI to assess collateral function prior to carotid endarterectomy. During regional anesthesia, patients were monitored to detect ischemic events and their timing in relation to cross-clamping and to determine mean intraoperative arterial pressure. These findings were then correlated with the collateral variations observed in the circle of Willis on preoperative MRI. Patients were classified into three groups according to neurological tolerance: normal tolerance (n = 106), immediate severe deficit (n = 9), and late deficit associated with arterial hypotension (n = 6). In the second group, a significant correlation was found between the absence of collateral circulation and neurological deficit (p < .0001). These results indicated that three-dimensional phase-contrast MRI is useful for predicting cerebral ischemia during carotid cross-clamping and selecting indications for shunting. Absence of visible collaterals of the circle of Willis on MRI is significantly predictive of early ischemia and an indication for systematic shunt placement.
Bagan
Patrick
P
Service de Chirurgie, Thoracique et Vasculaire, Avicenne University Hospital Center, Bobigny, France. patrick.bagan@egp.ap-hop-paris.fr
Vidal
Renaud
R
Martinod
Emmanuel
E
Destable
Marie-Dominique
MD
Tremblay
Bruno
B
Dumas
Jean Luc
JL
Azorin
Jacques F
JF
D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D002545:Brain Ischemia / Q000209:etiology*; D002340:Carotid Artery Diseases / Q000503:physiopathology* / Q000601:surgery; D002533:Cerebral Angiography / Q000379:methods*; D002560:Cerebrovascular Circulation; D002941:Circle of Willis / Q000503:physiopathology; D003097:Collateral Circulation; D003250:Constriction; D016894:Endarterectomy, Carotid / Q000009:adverse effects* / Q000379:methods; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000209:etiology; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods*; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors