title: Evaluation by Magnetic Resonance Imaging of Silent Brain Infarcts in Preoperative and Postoperative Asymptomatic Carotid Surgery.
abstract: BACKGROUND
  To report the prevalence of silent brain infarcts (SBI) at magnetic resonance imaging (MRI) before and after surgery for asymptomatic high grade carotid stenosis.
  
  
  METHODS
  This is a single center retrospective observational study. Asymptomatic patients who underwent carotid endarterectomy between October 2012 and October 2014 were included. The preoperative assessment included a Doppler and a computed tomographic (CT) scan dating less than 3 months. A neurological examination was performed during the anesthesia consultation and in the 15 days before surgery. An MRI angiography was performed the day before and 3 days after surgery and was analyzed by an independent neuroradiologist. Preoperative analysis focused on the presence of ischemic events at MRI. The type of plaque, the supra aortic trunk lesions, and the quality of the circle of Willis were analyzed using Doppler and CT scanning. Postoperatively, we searched for signs of postoperative ischemic events at MRI.
  
  
  RESULTS
  Forty-one patients were included (85.4% of men), and the mean age was 72.4 ± 8.3 years. We noted 7 (17.1%) contralateral stenoses (>50%) and 2 (4.9%) contralateral thromboses, 6 (14.6%) vertebral stenoses, and 7 (17.1%) abnormalities of the circle of Willis. The morphological analysis described 6 unstable plaques including 4 ulcerated, 1 pseudodissection, and 1 intraplaque hemorrhage. Preoperatively, we noted the presence of 21 (51.2%) ischemic lesions including 9 (21.9%) multiple lacunar ischemic events and 12 (29.3%) silent arterial territory infarcts. Eversion was performed for all patients except for 6 (14.6%), for whom a bypass was necessary. No deaths or major complications were observed in the 30 postoperative days. Postoperatively, MRI showed 3 (7.3%) asymptomatic recent ischemic strokes, 1 ipsilateral middle cerebral artery (MCA) stroke, and 2 contralateral (cerebellar and MCA) strokes.
  
  
  CONCLUSIONS
  Patients with asymptomatic significant carotid stenosis show many preoperative SBI indicating a significant embolic risk. It is difficult to conclude about intraoperative embolic risk, but we hope that more data could demonstrate the importance of MRI for the preoperative evaluation of carotid plaques and brain parenchyma, to identify high-risk embolic patients.
authors.affiliation: Department of Vascular Surgery, Rennes University Hospital, Rennes, France. Electronic address: remy.pascot@gmail.com.
authors.forename: Remy
authors.initials: R
authors.lastname: Pascot
authors.affiliation: Department of Vascular Surgery, Rennes University Hospital, Rennes, France; INSERM, U1099, Rennes, France; Laboratory of Signal and Image Processing, University of Rennes 1, Rennes, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Daoudal
authors.affiliation: Department of Vascular Surgery, Rennes University Hospital, Rennes, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Cardon
authors.affiliation: Department of Anesthesia and Intensive Care, Rennes University Hospital, Rennes, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Godet
authors.affiliation: Department of Vascular Surgery, Rennes University Hospital, Rennes, France; INSERM, U1099, Rennes, France; Laboratory of Signal and Image Processing, University of Rennes 1, Rennes, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Lucas
authors.affiliation: Department of Vascular Surgery, Rennes University Hospital, Rennes, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Clochard
authors.affiliation: Department of Neuroradiology, Rennes University Hospital, Rennes, France.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Gauvrit
authors.affiliation: Department of Anesthesia and Intensive Care, Nantes University Hospital, Nantes, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Le Teurnier
authors.affiliation: Department of Vascular Surgery, Rennes University Hospital, Rennes, France; INSERM, U1099, Rennes, France; Laboratory of Signal and Image Processing, University of Rennes 1, Rennes, France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Kaladji
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D058070:Asymptomatic Diseases; D020520:Brain Infarction / Q000000981:diagnostic imaging* / Q000453:epidemiology; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000601:surgery*; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D020521:Stroke / Q000000981:diagnostic imaging* / Q000453:epidemiology; D013997:Time Factors; D016896:Treatment Outcome; D017585:Ultrasonography, Doppler, Transcranial