title: Preoperative cervical carotid artery contrast-enhanced ultrasound findings are associated with development of microembolic signals on transcranial Doppler during carotid exposure in endarterectomy.
abstract: Emboli from the surgical site during exposure of the carotid arteries cause new cerebral ischemic lesions or neurological deficits after carotid endarterectomy (CEA). The purpose of the present study was to determine whether preoperative contrast-enhanced ultrasound findings of the cervical carotid arteries are associated with the development of microembolic signals (MES) on transcranial Doppler, during exposure of the arteries in CEA, and to compare the predictive accuracy of contrast-enhanced ultrasound findings with that of gray-scale median (GSM).
  
  
  
  Seventy patients with internal carotid artery stenosis (≥70%) underwent preoperative cervical carotid artery ultrasound and CEA under transcranial Doppler monitoring of MES in the ipsilateral middle cerebral artery. Maximally enhanced intensities on the intraplaque and lumen time-intensity curves, respectively, were obtained from contrast-enhanced ultrasonography data, and the ratio of the maximal intensity (EIp) of the intraplaque curve to that (EIl) of the lumen curve was calculated. The GSM value of the plaque was also measured.
  
  
  
  The area under the receiver operating characteristic curve to discriminate between the presence and absence of MES during exposure of the carotid arteries was significantly greater for EIp/EIlthan for GSM (p = 0.0108). Multivariate statistical analysis demonstrated that only EIp/EIlwas significantly associated with the development of MES during exposure of the carotid arteries (p = 0.0002).
  
  
  
  Preoperative contrast-enhanced ultrasound findings of the cervical carotid arteries are associated with development of MES on transcranial Doppler during exposure of the arteries in CEA, and the predictive accuracy of contrast-enhanced ultrasound is greater than that of GSM.
authors.affiliation: Department of Neurosurgery, Iwate Medical University School of Medicine, Morioka, Japan.
authors.forename: Kohki
authors.initials: K
authors.lastname: Oikawa
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University School of Medicine, Morioka, Japan.
authors.forename: Tadayoshi
authors.initials: T
authors.lastname: Kato
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University School of Medicine, Morioka, Japan.
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Oura
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University School of Medicine, Morioka, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Narumi
authors.affiliation: Division of Ultrahigh Field MRI, Institute for Biomedical Sciences, Iwate Medical University School of Medicine, Morioka, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Sasaki
authors.affiliation: Department of Neurosurgery, Iwate Medical University School of Medicine, Morioka, Japan.
authors.forename: Shunrou
authors.initials: S
authors.lastname: Fujiwara
authors.affiliation: Department of Neurosurgery, Iwate Medical University School of Medicine, Morioka, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: Department of Neurosurgery, Iwate Medical University School of Medicine, Morioka, Japan.
authors.forename: Yoshiyasu
authors.initials: Y
authors.lastname: Matsumoto
authors.affiliation: Department of Neurosurgery, Iwate Medical University School of Medicine, Morioka, Japan.
authors.forename: Jun-Ichi
authors.initials: JI
authors.lastname: Nomura
authors.affiliation: Department of Neurosurgery, Iwate Medical University School of Medicine, Morioka, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Department of Neurology and Gerontology, Iwate Medical University School of Medicine, Morioka, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Terayama
authors.affiliation: Department of Neurosurgery, Iwate Medical University School of Medicine, Morioka, Japan. Electronic address: kuogasa@iwate-med.ac.jp.
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Ogasawara
mesh_terms: D000368:Aged; D000792:Angiography; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging* / Q000601:surgery; D016893:Carotid Stenosis / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D003287:Contrast Media / Q000494:pharmacology; D016894:Endarterectomy, Carotid / Q000009:adverse effects*; D005260:Female; D005290:Ferric Compounds / Q000494:pharmacology; D005500:Follow-Up Studies; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000175:diagnosis* / Q000209:etiology; D007501:Iron / Q000494:pharmacology; D008297:Male; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D010087:Oxides / Q000494:pharmacology; D011300:Preoperative Care / Q000379:methods*; D011446:Prospective Studies; D012372:ROC Curve; D013997:Time Factors; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds; D010087:Oxides; C069727:Sonazoid; D007501:Iron
keywords: Carotid endarterectomy; Contrast enhancement; Microembolic signals; Ultrasound