Prediction of Cross-Clamp-Induced Cerebral Ischemia During Carotid Endarterectomy Using Arterial Blood Flow Assessment

Published:December 22, 2021DOI:


      • There is a continuing debate regarding the indications for an intraoperative shunt while performing carotid endarterectomy (CEA). Previous studies have determined these indications based on changes in monitored parameters after cross-clamping reflecting cerebral ischemia. The purpose of our study was to evaluate arterial blood flow (ABF) directly on the carotid artery (direct-ABF) as a potential predictor of cerebral ischemia prior to cross-clamping. The ABF ratio (ABF-internal carotid artery/ABF-common carotid artery) can be a useful predictor of ischemia before cross-clamping.



      Cross-clamping during carotid endarterectomy (CEA) is associated with the risk of cerebral ischemia. Various studies have evaluated different criteria for detecting cerebral ischemia, but difficulties arise when ischemic changes appear after the carotid artery is cross-clamped and incised. Here, we explored a parameter that can predict cerebral ischemia prior to cross-clamping during CEA using a blood-flow meter.


      The carotid arterial blood flow was measured directly (direct ABF) in the common carotid artery prior to cross-clamping. The anatomical information in preoperative magnetic resonance imaging, cerebral blood flow in xenon-enhanced computed tomography, and carotid peak systolic flow velocity by carotid echo from the skin surface were also evaluated. A decrease in the short-latency somatosensory evoked potentials (SSEP) during cross-clamping to insert a shunt was assessed, and a decrease in amplitude of ≥ 50% was considered an indicator for cerebral ischemia. Surgery was performed under general anesthesia, and a shunt was inserted in all cases.


      Of 156 CEA patients between April 2013 and March 2020, 30 had decreased SSEP during cross-clamping. The baseline characteristics and intra- and postoperative findings were not significantly different between patients with and without a decrease in SSEP. Among the evaluated parameters, only the direct-ABF ratio (ABF-internal carotid artery/ABF-common carotid artery) differed significantly between the 2 groups (P = 0.011). The direct-ABF ratio ≤ 0.58 was predictive of cerebral ischemia during CEA.


      Direct-ABF measurement with an ultrasonic blood-flow meter can be useful for predicting cerebral ischemia prior to carotid artery cross-clamping during CEA.


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        • Lee JH
        • Choi CG
        • Kim DK
        • et al.
        Relationship between circle of Willis morphology on 3D time-of-flight MR angiograms and transient ischemia during vascular clamping of the internal carotid artery during carotid endarterectomy.
        Am J Neuroradiol. 2004; 25: 558-564
        • Rutgers DR
        • Blankensteijn JD
        • van der Grond J.
        Preopeative MRA flow quantifiation in CEA patients:flow differences between patients who develop cerebral ischemia and patients who do not develop cerebral ischemia during cross-clamping of the cartoid artery.
        Stroke. 2000; 31: 3021-3028
        • Jonsson M
        • Lindström D
        • Wanhainen A
        • et al.
        Near infrared spectroscopy as a predictor for shunt requirement during carotid endarterectomy.
        Eur J Vasc Endovasc Surg. 2017; 53: 783-791
        • Nwachuku EL
        • Balzer JR
        • Yabes JG
        • et al.
        Diagnostic value of somatosensory evoked potential changes during carotid endarterectomy: A systematic review and meta-analysis.
        JAMA Neurol. 2015; 72: 73-80
        • Domenick Sridharan N
        • Thirumala P
        • Chaer R
        • et al.
        Predictors of cross-clamp-induced intraoperative monitoring changes during carotid endarterectomy using both electroencephalography and somatosensory evoked potentials.
        J Vasc Surg. 2018; 67: 191-198
        • Hiramatsu K
        • Shima T
        • Toyota A
        • et al.
        Usefulness of ultrasonologic examinations on microemboli and hemodynamics for the prevention of complications associated with carotid endarterectomy.
        J Stroke Cerebrovasc Dis. 2003; 12: 51-58
        • Bozzani A
        • Arici V
        • Ticozzelli G
        • et al.
        Intraoperative cerebral monitoring during carotid surgery: a narrative review.
        Ann Vasc Surg. 2021; : 1-9
        • Jaffer U
        • Normahani P
        • Harrop-Griffiths W
        • et al.
        Pre-operative methods to predict need for shunting during carotid endarterectomy.
        Int J Surg. 2015; 23: 5-11
        • North American Symptomatic Carotid Endarterectomy Trial Collaborators
        • Barnett HJM
        • Taylor DW
        • et al.
        Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis.
        N Engl J Med. 1991; 325: 445-453
        • Bagan P
        • Vidal R
        • Martinod E
        • et al.
        Cerebral ischemia during carotid artery cross-clamping : Predictive value of phase-contrast magnetic resonance imaging.
        Ann Vasc Surg. 2006; 20: 747-752
        • Guérit JM
        • Witdoeckt C
        • de Tourtchaninoff M
        • et al.
        Somatosensory evoked potential monitoring in carotid surgery. I. Relationships between qualitative SEP alterations and intraoperative events.
        Electroencephalogr Clin Neurophysiol. 1997; 104: 459-469
        • Schweiger H
        • Kamp HD
        • Dinkel M.
        Somatosensory-evoked potentials during carotid artery surgery: Experience in 400 operations.
        Surgery. 1991; 109: 602-609
        • Schwartz ML
        • Panetta TF
        • Kaplan BJ
        • et al.
        Somatosensory evoked potential monitoring during carotid surgery.
        Cardiovasc Surg. 1996; 4: 77-80
        • Beese U
        • Langer H
        • Lang W
        • et al.
        Comparison of near-infrared spectroscopy and somatosensory evoked potentials for the detection of cerebral ischemia during carotid endarterectomy.
        Stroke. 1998; 29: 2032-2037
        • Astarci P
        • Guerit JM
        • Robert A
        • et al.
        Stump pressure and somatosensory evoked potentials for predicting the use of shunt during carotid surgery.
        Ann Vasc Surg. 2007; 21: 312-317
        • Kordzadeh A
        • Abbassi OA
        • Prionidis I
        • et al.
        The role of carotid stump pressure in carotid endarterectomy: A systematic review and meta-analysis.
        Ann Vasc Dis. 2020; 13: 28-37
        • Wiske C
        • Arhuidese I
        • Malas M
        • et al.
        Comparing the efficacy of shunting approaches and cerebral monitoring during carotid endarterectomy using a national database.
        J Vasc Surg. 2018; 68: 416-425
        • Tan TW
        • Garcia-Toca M
        • Marcaccio EJ
        • et al.
        Predictors of shunt during carotid endarterectomy with routine electroencephalography monitoring.
        J Vasc Surg. 2009; 49: 1374-1378
        • Eckstein H-H
        • Eichbaum M
        • Klemm K
        • et al.
        Improvement of carotid blood flow after carotid endarterectomy—evaluation using intraoperative ultrasound flow measurement.
        Eur J Vasc Endovasc Surg. 2003; 25: 168-174
        • Kretz B
        • Abello N
        • Bouchot O
        • et al.
        Risk index for predicting shunt in carotid endarterectomy.
        Ann Vasc Surg. 2014; 28: 1204-1212
        • Friedell ML
        • Clark JM
        • Graham DA
        • et al.
        Cerebral oximetry does not correlate with electroencephalography and somatosensory evoked potentials in determining the need for shunting during carotid endarterectomy.
        J Vasc Surg. 2008; 48: 601-606
        • Pennekamp CWA
        • Van Laar PJ
        • Hendrikse J
        • et al.
        Incompleteness of the circle of Willis is related to EEG-based shunting during carotid endarterectomy.
        Eur J Vasc Endovasc Surg. 2013; 46: 631-637
        • Ishiguro T
        • Yoneyama T
        • Ishikawa T
        • et al.
        Perioperative and long-term outcomes of carotid endarterectomy for Japanese asymptomatic cervical carotid artery stenosis: A single institution study.
        Neurol Med Chir (Tokyo). 2015; 55: 830-837