title: Hemodynamic Tandem Intracranial Lesions on Magnetic Resonance Angiography in Patients Undergoing Carotid Endarterectomy.
abstract: Hemodynamic tandem intracranial lesions (TILs) on intracranial magnetic resonance angiography, which develop flow dependently, have been overlooked clinically in patients undergoing carotid endarterectomy. As they represent severe baseline hemodynamic compromise at the segment, they may be associated with distinctive clinical outcomes.
  
  
  
  We assessed 304 consecutive carotid endarterectomy cases treated over 3 years. Included cases had both preoperative and postoperative intracranial 3-dimensional time-of-flight magnetic resonance angiography, of which signal intensities are flow dependent, and postoperative diffusion-weighted imaging (≤3 days following carotid endarterectomy). Preoperative TILs in the ipsilateral intracranial arteries were evaluated by the presence of nonexclusive components: focal stenosis (>50%), diffuse stenosis (>50%), and decreased signal intensities (>50%). The components showing postoperative normalization were considered hemodynamic. TILs with hemodynamic components were defined as hemodynamic TILs, while others as consistent TILs. Baseline characteristics and postoperative outcomes were analyzed among 3 groups: no TILs, consistent TILs, and hemodynamic TILs. Preoperative TILs were identified in 104 (34.2%) cases; 54 (17.8%) had hemodynamic components. Diffuse stenosis and decreased signal intensities were usually reversed postoperatively. Patients with hemodynamic TILs tended to have severe proximal carotid stenosis and recent strokes (≤14 days). For the outcome, hemodynamic TILs were independently associated with the advent of postoperative ischemic lesions on diffusion-weighted imaging (odds ratio: 2.50; 95% CI, 1.20-5.20).
  
  
  
  In patients undergoing carotid endarterectomy, a significant number of preoperative TILs demonstrated hemodynamic components, which were reversed postoperatively. The presence of such components was distinctively associated with the postoperative incidence of new ischemic lesions.
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan, Seoul, Korea.
authors.forename: Eun-Jae
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Department of Surgery, Asan Medical Center, University of Ulsan, Seoul, Korea.
authors.forename: Yong-Pil
authors.initials: YP
authors.lastname: Cho
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan, Seoul, Korea.
authors.forename: Sang-Hun
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Clinical Research Center, Asan Medical Center, University of Ulsan, Seoul, Korea.
authors.forename: Ji Sung
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan, Seoul, Korea.
authors.forename: Hyo Jung
authors.initials: HJ
authors.lastname: Nam
authors.affiliation: Department of Neurology, KyungHee University, Seoul, Korea.
authors.forename: Bum Joon
authors.initials: BJ
authors.lastname: Kim
authors.affiliation: Department of Surgery, Asan Medical Center, University of Ulsan, Seoul, Korea.
authors.forename: Tae-Won
authors.initials: TW
authors.lastname: Kwon
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan, Seoul, Korea.
authors.forename: Dong-Wha
authors.initials: DW
authors.lastname: Kang
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan, Seoul, Korea.
authors.forename: Jong S
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Department of Neurology, Asan Medical Center, University of Ulsan, Seoul, Korea sukwon@amc.seoul.kr.
authors.forename: Sun U
authors.initials: SU
authors.lastname: Kwon
mesh_terms: D000368:Aged; D002545:Brain Ischemia / Q000453:epidemiology*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery; D002560:Cerebrovascular Circulation; D015897:Comorbidity; D003251:Constriction, Pathologic; D038524:Diffusion Magnetic Resonance Imaging; D016894:Endarterectomy, Carotid; D005260:Female; D006439:Hemodynamics; D006801:Humans; D021621:Imaging, Three-Dimensional; D020765:Intracranial Arterial Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*; D056910:Republic of Korea / Q000453:epidemiology; D020521:Stroke / Q000453:epidemiology*; D016896:Treatment Outcome; D018608:Ultrasonography, Doppler
keywords: carotid endarterectomy; complication; intracranial stenosis; magnetic resonance angiography