title: Effects of carotid artery stenting on arterial geometry.
abstract: BACKGROUND
  The role of carotid artery stenting (CAS) for the treatment of carotid artery disease continues to evolve, despite higher stroke and restenosis risks for CAS compared with conventional open endarterectomy. Understanding the effects of CAS on arterial geometry, which strongly influence hemodynamics and wall mechanics, can assist in better stratifying the inherent risk of CAS to individual patients.
  
  
  METHODS
  Fifteen consecutive patients undergoing CAS had pre- and post-stenting CT angiograms. These images were used to reconstruct the 3-dimensional geometries of the bilateral carotid arteries from their origin to the skull base. Quantitative assessment of the carotid bifurcation angle, cross-sectional area, tortuosity and artery length, were compared pre- and post-stenting. Plaque volume and calcification were also measured. Mathematical models were devised to determine the mechanisms of CAS-induced geometric changes, and their mechanical and hemodynamic significances.
  
  
  RESULTS
  Major and moderate changes in arterial tortuosity and elongation were seen in 5 (33%) patients. Characteristics most associated with the development of CAS-induced geometric changes were stenoses located in the internal carotid artery distal to the carotid bulb, circumferential distribution of plaque, and plaque calcification. Modeling did not demonstrate substantial alterations in wall shear stress due to geometric changes, but did show considerable increases in arterial wall axial stress.
  
  
  CONCLUSIONS
  Carotid artery stenting can produce geometric changes to the artery that promote favorable conditions for complications and recurrent disease. Patients with circumferential, highly calcified plaques that are located relatively distal in the internal carotid artery are most likely to have post-stenting geometric changes.
authors.affiliation: Department of Surgery, University of Nebraska Medical Center, Omaha, NE 68198-5182, USA. Alexey.Kamenskiy@unmc.edu
authors.forename: Alexey V
authors.initials: AV
authors.lastname: Kamenskiy
authors.forename: Iraklis I
authors.initials: II
authors.lastname: Pipinos
authors.forename: Yuris A
authors.initials: YA
authors.lastname: Dzenis
authors.forename: Jai
authors.initials: J
authors.lastname: Bikhchandani
authors.forename: Prateek K
authors.initials: PK
authors.lastname: Gupta
authors.forename: Nick
authors.initials: N
authors.lastname: Phillips
authors.forename: Syed A Jaffar
authors.initials: SA
authors.lastname: Kazmi
authors.forename: Jason N
authors.initials: JN
authors.lastname: MacTaggart
mesh_terms: D000368:Aged; D002342:Carotid Artery, External / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D057510:Endovascular Procedures / Q000295:instrumentation*; D005500:Follow-Up Studies; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D015607:Stents; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
keywords: 3-dimensional; 3D; CAS; CCA; CEA; ECA; HMM-1; Hemodynamic Mathematical Model; ICA; NASCET; North American Symptomatic Carotid Endarterectomy Trial; PMM-II; Parametric Mathematical Model; WSS; carotid artery stenting; carotid endarterectomy; common carotid artery; external carotid artery; internal carotid artery; wall shear stress