• Masakazu Kobayashi, Kuniaki Ogasawara, Kenji Yoshida, Makoto Sasaki, Hiroki Kuroda, Taro Suzuki, Yoshitaka Kubo, Shunrou Fujiwara, and Akira Ogawa.
• Department of Neurosurgery, Iwate Medical University, Morioka, Japan.
• Neurosurgery. 2011 Aug 1;69(2):301-7.

BackgroundLow blood flow velocity in the middle cerebral artery (MCA) correlates with the development of postoperative cerebral ischemic lesions related to generation of microemboli during dissection of carotid arteries in carotid endarterectomy (CEA).ObjectiveThe purpose of this prospectively controlled trial was to determine whether increased mean blood flow velocity in the MCA by intentional hypertension during carotid dissection in CEA prevented postoperative development of new cerebral ischemic lesions caused by intraoperative microemboli.MethodsPatients with ipsilateral internal carotid artery stenosis (>70%) underwent CEA under transcranial Doppler monitoring of mean blood flow velocity and microembolic signals in the ipsilateral MCA. Attempts were made to keep systolic blood pressure during carotid dissection between -10% and +10% of the preoperative value (controls, n = 65) or above a +10% increase (intentional hypertension group, n = 65).ResultsIncidence of new ischemic lesions on postoperative diffusion-weighted magnetic resonance imaging was significantly lower in the intentional hypertension group both for all patients (controls, 15.4%; intentional hypertension group, 3.1%; P = .03) and in a subgroup of 37 patients showing microembolic signals during carotid dissection (controls, 52.6%; intentional hypertension group, 11.1%; P = .013). Logistic regression analysis demonstrated the absence of intentional hyperperfusion (95% confidence interval: 1.77-100.00; P = .012) and high number of microembolic signals (95% confidence interval: 1.00-1.62; P = .05) during carotid dissection were significant independent predictors of the postoperative development of new ischemic lesions on diffusion-weighted magnetic resonance imaging.ConclusionIncreased MCA mean blood flow velocity by intentional hypertension during dissection of the carotid artery in CEA prevents the postoperative development of new cerebral ischemic lesions caused by intraoperative microemboli.

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