title: Predictors of hyperperfusion syndrome before and immediately after carotid artery stenting in single-photon emission computed tomography and transcranial color-coded real-time sonography studies.
abstract: BACKGROUND
  Hyperperfusion syndrome (HPS) is a critical complication after carotid artery stenting (CAS) and carotid endarterectomy (CEA).
  
  
  OBJECTIVE
  To identify predictors of HPS before and immediately after CAS.
  
  
  METHODS
  We analyzed patients who underwent elective CAS from 2005 to 2008, and underwent single-photon emission computed tomography (SPECT) and transcranial color-coded real-time sonography before and immediately after CAS. HPS was defined as post-CAS deteriorating neurological conditions with headache not secondary to cerebral ischemia. We assessed the measures of blood flow between the two cortical hemispheres by taking the ratio of cerebral blood flow (CBF) of the affected to unaffected hemisphere excluding any ischemic/infarcted areas (asymmetry index); the measures of blood flow within each cortical hemisphere by comparing the CBF in the affected cortical hemispheric area to the CBF in the ipsilateral cerebellar hemisphere (middle cerebral artery [MCA]-to-cerebellar activity ratio); cerebral vasoreactivity (CVR); MCA mean blood flow velocity in the affected hemisphere; and MCA mean blood flow velocity ratio (preoperative to postoperative).
  
  
  RESULTS
  Sixty-four patients were analyzed retrospectively. Nine patients presented with HPS. Logistic regression analysis showed that CVR (P<.01) and MCA mean blood flow velocity (P<.05) were the significant predictors among the pre-CAS variables, and that MCA mean blood flow velocity ratio (P<.05) and MCA-to-cerebellar activity ratio change (P<.05) were significant predictors among the post-CAS variables.
  
  
  CONCLUSIONS
  SPECT and transcranial color-coded real-time sonography studies are useful in predicting HPS.
authors.affiliation: Department of Stroke Treatment, Shonan Kamakura General Hospital, Kamakura City, Kanagawa 247-8533, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Iwata
authors.forename: Takahisa
authors.initials: T
authors.lastname: Mori
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tajiri
authors.forename: Masahito
authors.initials: M
authors.lastname: Nakazaki
mesh_terms: D000368:Aged; D001807:Blood Vessel Prosthesis / Q000706:statistics & numerical data; D016893:Carotid Stenosis / Q000453:epidemiology* / Q000601:surgery*; D002561:Cerebrovascular Disorders / Q000175:diagnosis / Q000453:epidemiology*; D015897:Comorbidity; D003199:Computer Systems; D004453:Echoencephalography / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology*; D018570:Risk Assessment; D012307:Risk Factors; D015607:Stents / Q000706:statistics & numerical data*; D015899:Tomography, Emission-Computed, Single-Photon / Q000706:statistics & numerical data*; D016896:Treatment Outcome; D018615:Ultrasonography, Doppler, Color / Q000706:statistics & numerical data*