title: Accordion effect during carotid artery stenting: report of two cases and review of the literature.
abstract: BACKGROUND
  The term "accordion effect" is used to describe a mechanical distortion of tortuous arteries mimicking spasm or dissection. This phenomenon has been reported in patients undergoing percutaneous coronary intervention. To our knowledge, this is the first documentation of the accordion effect during carotid artery intervention.
  
  
  METHODS
  Two patients who developed the accordion effect during carotid artery stenting (CAS) are described.
  
  
  RESULTS
  Angiograms obtained just after CAS showed a stenosing lesion with wall irregularity at the distal part of the stent. This lesion disappeared and tortuosity of the internal carotid artery developed after withdrawing the guidewire until its floppy segment rested equally on the lesion. In another patient, the lesion did not disappear completely until the guiding catheter had been withdrawn to the proximal portion of the common carotid artery. We conclude that these stenosing lesions reflected the accordion effect.
  
  
  CONCLUSIONS
  It is essential to differentiate the accordion effect from dissection, spasm, and thrombosis because the management is importantly different. We report our findings and present a review of the literature.
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, 1-1-1 Zokumyoin, Chikushino, Fukuoka, 8188502, Japan. kazekawa@xb3.so-net.ne.jp
authors.forename: Masanori
authors.initials: M
authors.lastname: Tsutsumi
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kazekawa
authors.forename: Masanari
authors.initials: M
authors.lastname: Onizuka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Aikawa
authors.forename: Minoru
authors.initials: M
authors.lastname: Iko
authors.forename: Tomonobu
authors.initials: T
authors.lastname: Kodama
authors.forename: Kouhei
authors.initials: K
authors.lastname: Nii
authors.forename: Shuko
authors.initials: S
authors.lastname: Matsubara
authors.forename: Housei
authors.initials: H
authors.lastname: Etou
authors.forename: Akira
authors.initials: A
authors.lastname: Tanaka
mesh_terms: D000368:Aged; D000800:Angioplasty, Balloon / Q000009:adverse effects*; D002343:Carotid Artery, Internal; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000628:therapy*; D005260:Female; D006801:Humans; D007431:Intraoperative Complications; D008297:Male; D011859:Radiography; D015607:Stents