title: Dilation of the Internal Carotid Artery at the Entrance to the Carotid Canal following Carotid Artery Stenting Predicts Postprocedural Hyperperfusion.
abstract: OBJECTIVE
  Ischemic stroke and hyperperfusion (HP) are the most frequent and important complications in carotid artery stenosis surgery. Carotid artery stenting (CAS) has replaced carotid endarterectomy in high medical risk patients. Prior to CAS, initial angiographic findings disclose a small caliber internal carotid artery (IC) due to stenosis, but after the stenosis is relieved, the diameter of the IC becomes enlarged. We investigated whether a change in the IC diameter was related to ischemic complication and HP using cerebral blood flow single photon emission computed tomography (SPECT).
  
  
  METHODS
  From February 2008 to December 2009 we consecutively performed 39 CAS on 35 patients. We retrospectively analyzed the relationship between changes at the level before the entry to the petrous bone canal of the IC and stenosis of the etiological artery, improvement in stenosis, HP and postintervention diffusion-weighted image high-intensity lesions. Statistical analyses comprised Wilcoxon/Kruskal-Wallis analysis, analysis of variance and a multivariate logistic analysis.
  
  
  RESULTS
  A total of 9 cases showed HP in SPECT. Severity of IC stenosis and change in the IC at the level before the entry to the petrous bone canal were related with statistical significance to HP. Other factors did not correlate with HP.
  
  
  CONCLUSIONS
  Procedure-related dilation of the IC at the level before the entry to the petrous bone canal occurred due to release of the etiological stenosis. This finding can also support the prediction of HP.
authors.affiliation: Department of Neurosurgery, Hirosaki University School of Medicine, Hirosaki, Towada, Japan.
authors.forename: Norihito
authors.initials: N
authors.lastname: Shimamura
authors.affiliation: Department of Neurosurgery, Kuroishi Hospital, Kuroishi, Towada, Japan.
authors.forename: Tomoshige
authors.initials: T
authors.lastname: Kikkawa
authors.affiliation: Towada City General Hospital, Towada, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Hatanaka
authors.affiliation: Department of Neurosurgery, Hirosaki University School of Medicine, Hirosaki, Towada, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Naraoka
authors.affiliation: Department of Neurosurgery, Hirosaki University School of Medicine, Hirosaki, Towada, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Munakata
authors.affiliation: Department of Neurosurgery, Hirosaki University School of Medicine, Hirosaki, Towada, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ohkuma
keywords: Carotid artery stenting; Dilation; Hyperperfusion; Internal carotid artery; Single photon emission computed tomography