title: Accurate detection of stent-graft migration in a pulsatile aortic model using Roentgen stereophotogrammetric analysis.
abstract: OBJECTIVE
  To evaluate the feasibility and accuracy of Roentgen stereophotogrammetric analysis (RSA) versus computed tomography (CT) for detecting stent-graft migration in an in vitro pulsatile circulation model and to study the feasibility of a nitinol endovascular clip (NEC) as an aortic wall reference marker for RSA.
  
  
  METHODS
  An aortic model with stent-graft was constructed and connected to an artificial circulation with a physiological flow and pressure profile. Tantalum markers and NECs were used as aortic reference markers for RSA analysis. Stent-graft migrations were measured during pulsatile circulation with RSA and CT. CT images acquired with 64 x 0.5-mm beam collimation were analyzed with Vitrea postprocessing software using a standard clinical protocol and central lumen line reconstruction. RSA in the model with the circulation switched off was used as the reference standard to determine stent-graft migration. The measurement errors of RSA and CT were determined during pulsatile circulation.
  
  
  RESULTS
  The mean measurement error +/- standard deviation (maximum) of RSA during pulsatile circulation using the tantalum markers was -0.5+/-0.16 (0.7) mm. Using the NEC, the mean (maximum) measurement error was -0.4+/-0.25 (1.1) mm. The mean (maximum) measurement error of CT was -1.1+/-1.17 (2.8) mm.
  
  
  CONCLUSIONS
  RSA is an accurate and feasible tool to measure stent-graft migration in a pulsatile environment. Migration measurement with RSA was more accurate than CT in this experimental setup. The nitinol clip tested in this study is potentially feasible as an aortic reference marker in patients after endovascular repair.
authors.affiliation: Departments of Surgery (Division of Vascular Surgery), Leiden University Medical Center, Leiden, The Netherlands. o.koning@jbz.nl
authors.forename: Olivier H J
authors.initials: OH
authors.lastname: Koning
authors.forename: Eric H
authors.initials: EH
authors.lastname: Garling
authors.forename: Jan-Willem
authors.initials: JW
authors.lastname: Hinnen
authors.forename: Lucia J M
authors.initials: LJ
authors.lastname: Kroft
authors.forename: Edwin
authors.initials: E
authors.lastname: van der Linden
authors.forename: Jaap F
authors.initials: JF
authors.lastname: Hamming
authors.forename: Edward R
authors.initials: ER
authors.lastname: Valstar
authors.forename: J Hajo
authors.initials: JH
authors.lastname: van Bockel
mesh_terms: D000497:Alloys; D000818:Animals; D001013:Aorta, Thoracic / Q000503:physiopathology / Q000601:surgery*; D001027:Aortography / Q000379:methods; D001794:Blood Pressure; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects*; D004867:Equipment Design; D005240:Feasibility Studies; D005548:Foreign-Body Migration / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000209:etiology; D006801:Humans; D021621:Imaging, Three-Dimensional; D008955:Models, Cardiovascular; D010780:Photogrammetry / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D011673:Pulsatile Flow; D011857:Radiographic Image Interpretation, Computer-Assisted; D011859:Radiography / Q000379:methods; D012016:Reference Values; D015203:Reproducibility of Results; D015607:Stents; D013525:Surgical Instruments; D013552:Swine; D013635:Tantalum; D014057:Tomography, X-Ray Computed
chemical_list: D000497:Alloys; C013616:nitinol; D013635:Tantalum