title: Endovascular Repair of Abdominal Aortic Aneurysm: Follow-up with Noninvasive Vascular Elastography in a Canine Model.
abstract: OBJECTIVE
  To assess the ability of noninvasive vascular elastography (NIVE) to help characterize endoleaks and thrombus organization in a canine model of abdominal aortic aneurysm after endovascular aneurysm repair with stent-grafts, in comparison with computed tomography (CT) and pathologic examination findings.
  
  
  METHODS
  All protocols were approved by the Animal Care Committee in accordance with the guidelines of the Canadian Council of Animal Care. Stent-grafts were implanted in a group of 18 dogs with aneurysms created in the abdominal aorta. Type I endoleak was created in four aneurysms; type II endoleak, in 13 aneurysms; and no endoleak, in one aneurysm. Doppler ultrasonography and NIVE examinations were performed at baseline and at 1-week, 1-month, 3-month, and 6-month follow-up. Angiography, CT, and macroscopic tissue examination were performed at sacrifice. Strain values were computed by using the Lagrangian speckle model estimator. Areas of endoleak, solid organized thrombus, and fresh thrombus were identified and segmented by comparing the results of CT and macroscopic tissue examination. Strain values were compared by using the Wilcoxon rank-sum and Kruskal-Wallis tests.
  
  
  RESULTS
  All stent-grafts were successfully deployed, and endoleaks were clearly depicted in the last follow-up elastography examinations. Maximal axial strains over consecutive heart cycles in endoleak, organized thrombus, and fresh thrombus areas were 0.78% ± 0.22, 0.23% ± 0.02, 0.10% ± 0.04, respectively. Strain values were significantly different between endoleak and organized or fresh thrombus areas (P < .000) and between organized and fresh thrombus areas (P < .0002). No correlation was found between strain values and type of endoleak, sac pressure, endoleak size, and aneurysm size.
  
  
  CONCLUSIONS
  NIVE may be able to help characterize endoleak and thrombus organization, regardless of the size, pressure, and type of endoleak.
authors.affiliation: From the Department of Radiology, Radio-Oncology and Nuclear Medicine, and Institute of Biomedical Engineering, Université de Montréal, Montreal, Quebec, Canada (E.S., A.B., C.K., E.T., G.C., G.S.); Department of Radiology, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada (E.T., G.S.); Centre de Recherche de l'Université de Montréal, 900 rue Saint-Denis, Montreal, QC, Canada H2X 0A9 (E.S., A.B., S.L., C.K., H.H., E.T., I.S., M.H.R.C., G.C., G.S.); Laboratory of Biorheology and Medical Ultrasonics (E.S., A.B., M.H.R.C., G.C.) and Clinical Image Processing Laboratory (E.S., A.B., C.K., G.S.), Centre de Recherche de l'Université de Montréal, Montreal, Quebec, Canada; and Department of Mechanical Engineering, École de Technologie Supérieure, Montreal, Quebec, Canada (S.L.).
authors.forename: Eli
authors.initials: E
authors.lastname: Salloum
authors.affiliation: From the Department of Radiology, Radio-Oncology and Nuclear Medicine, and Institute of Biomedical Engineering, Université de Montréal, Montreal, Quebec, Canada (E.S., A.B., C.K., E.T., G.C., G.S.); Department of Radiology, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada (E.T., G.S.); Centre de Recherche de l'Université de Montréal, 900 rue Saint-Denis, Montreal, QC, Canada H2X 0A9 (E.S., A.B., S.L., C.K., H.H., E.T., I.S., M.H.R.C., G.C., G.S.); Laboratory of Biorheology and Medical Ultrasonics (E.S., A.B., M.H.R.C., G.C.) and Clinical Image Processing Laboratory (E.S., A.B., C.K., G.S.), Centre de Recherche de l'Université de Montréal, Montreal, Quebec, Canada; and Department of Mechanical Engineering, École de Technologie Supérieure, Montreal, Quebec, Canada (S.L.).
authors.forename: Antony
authors.initials: A
authors.lastname: Bertrand-Grenier
authors.affiliation: From the Department of Radiology, Radio-Oncology and Nuclear Medicine, and Institute of Biomedical Engineering, Université de Montréal, Montreal, Quebec, Canada (E.S., A.B., C.K., E.T., G.C., G.S.); Department of Radiology, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada (E.T., G.S.); Centre de Recherche de l'Université de Montréal, 900 rue Saint-Denis, Montreal, QC, Canada H2X 0A9 (E.S., A.B., S.L., C.K., H.H., E.T., I.S., M.H.R.C., G.C., G.S.); Laboratory of Biorheology and Medical Ultrasonics (E.S., A.B., M.H.R.C., G.C.) and Clinical Image Processing Laboratory (E.S., A.B., C.K., G.S.), Centre de Recherche de l'Université de Montréal, Montreal, Quebec, Canada; and Department of Mechanical Engineering, École de Technologie Supérieure, Montreal, Quebec, Canada (S.L.).
authors.forename: Sophie
authors.initials: S
authors.lastname: Lerouge
authors.affiliation: From the Department of Radiology, Radio-Oncology and Nuclear Medicine, and Institute of Biomedical Engineering, Université de Montréal, Montreal, Quebec, Canada (E.S., A.B., C.K., E.T., G.C., G.S.); Department of Radiology, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada (E.T., G.S.); Centre de Recherche de l'Université de Montréal, 900 rue Saint-Denis, Montreal, QC, Canada H2X 0A9 (E.S., A.B., S.L., C.K., H.H., E.T., I.S., M.H.R.C., G.C., G.S.); Laboratory of Biorheology and Medical Ultrasonics (E.S., A.B., M.H.R.C., G.C.) and Clinical Image Processing Laboratory (E.S., A.B., C.K., G.S.), Centre de Recherche de l'Université de Montréal, Montreal, Quebec, Canada; and Department of Mechanical Engineering, École de Technologie Supérieure, Montreal, Quebec, Canada (S.L.).
authors.forename: Claude
authors.initials: C
authors.lastname: Kauffman
authors.affiliation: From the Department of Radiology, Radio-Oncology and Nuclear Medicine, and Institute of Biomedical Engineering, Université de Montréal, Montreal, Quebec, Canada (E.S., A.B., C.K., E.T., G.C., G.S.); Department of Radiology, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada (E.T., G.S.); Centre de Recherche de l'Université de Montréal, 900 rue Saint-Denis, Montreal, QC, Canada H2X 0A9 (E.S., A.B., S.L., C.K., H.H., E.T., I.S., M.H.R.C., G.C., G.S.); Laboratory of Biorheology and Medical Ultrasonics (E.S., A.B., M.H.R.C., G.C.) and Clinical Image Processing Laboratory (E.S., A.B., C.K., G.S.), Centre de Recherche de l'Université de Montréal, Montreal, Quebec, Canada; and Department of Mechanical Engineering, École de Technologie Supérieure, Montreal, Quebec, Canada (S.L.).
authors.forename: Hélène
authors.initials: H
authors.lastname: Héon
authors.affiliation: From the Department of Radiology, Radio-Oncology and Nuclear Medicine, and Institute of Biomedical Engineering, Université de Montréal, Montreal, Quebec, Canada (E.S., A.B., C.K., E.T., G.C., G.S.); Department of Radiology, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada (E.T., G.S.); Centre de Recherche de l'Université de Montréal, 900 rue Saint-Denis, Montreal, QC, Canada H2X 0A9 (E.S., A.B., S.L., C.K., H.H., E.T., I.S., M.H.R.C., G.C., G.S.); Laboratory of Biorheology and Medical Ultrasonics (E.S., A.B., M.H.R.C., G.C.) and Clinical Image Processing Laboratory (E.S., A.B., C.K., G.S.), Centre de Recherche de l'Université de Montréal, Montreal, Quebec, Canada; and Department of Mechanical Engineering, École de Technologie Supérieure, Montreal, Quebec, Canada (S.L.).
authors.forename: Eric
authors.initials: E
authors.lastname: Therasse
authors.affiliation: From the Department of Radiology, Radio-Oncology and Nuclear Medicine, and Institute of Biomedical Engineering, Université de Montréal, Montreal, Quebec, Canada (E.S., A.B., C.K., E.T., G.C., G.S.); Department of Radiology, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada (E.T., G.S.); Centre de Recherche de l'Université de Montréal, 900 rue Saint-Denis, Montreal, QC, Canada H2X 0A9 (E.S., A.B., S.L., C.K., H.H., E.T., I.S., M.H.R.C., G.C., G.S.); Laboratory of Biorheology and Medical Ultrasonics (E.S., A.B., M.H.R.C., G.C.) and Clinical Image Processing Laboratory (E.S., A.B., C.K., G.S.), Centre de Recherche de l'Université de Montréal, Montreal, Quebec, Canada; and Department of Mechanical Engineering, École de Technologie Supérieure, Montreal, Quebec, Canada (S.L.).
authors.forename: Igor
authors.initials: I
authors.lastname: Salazkin
authors.affiliation: From the Department of Radiology, Radio-Oncology and Nuclear Medicine, and Institute of Biomedical Engineering, Université de Montréal, Montreal, Quebec, Canada (E.S., A.B., C.K., E.T., G.C., G.S.); Department of Radiology, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada (E.T., G.S.); Centre de Recherche de l'Université de Montréal, 900 rue Saint-Denis, Montreal, QC, Canada H2X 0A9 (E.S., A.B., S.L., C.K., H.H., E.T., I.S., M.H.R.C., G.C., G.S.); Laboratory of Biorheology and Medical Ultrasonics (E.S., A.B., M.H.R.C., G.C.) and Clinical Image Processing Laboratory (E.S., A.B., C.K., G.S.), Centre de Recherche de l'Université de Montréal, Montreal, Quebec, Canada; and Department of Mechanical Engineering, École de Technologie Supérieure, Montreal, Quebec, Canada (S.L.).
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Roy Cardinal
authors.affiliation: From the Department of Radiology, Radio-Oncology and Nuclear Medicine, and Institute of Biomedical Engineering, Université de Montréal, Montreal, Quebec, Canada (E.S., A.B., C.K., E.T., G.C., G.S.); Department of Radiology, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada (E.T., G.S.); Centre de Recherche de l'Université de Montréal, 900 rue Saint-Denis, Montreal, QC, Canada H2X 0A9 (E.S., A.B., S.L., C.K., H.H., E.T., I.S., M.H.R.C., G.C., G.S.); Laboratory of Biorheology and Medical Ultrasonics (E.S., A.B., M.H.R.C., G.C.) and Clinical Image Processing Laboratory (E.S., A.B., C.K., G.S.), Centre de Recherche de l'Université de Montréal, Montreal, Quebec, Canada; and Department of Mechanical Engineering, École de Technologie Supérieure, Montreal, Quebec, Canada (S.L.).
authors.forename: Guy
authors.initials: G
authors.lastname: Cloutier
authors.affiliation: From the Department of Radiology, Radio-Oncology and Nuclear Medicine, and Institute of Biomedical Engineering, Université de Montréal, Montreal, Quebec, Canada (E.S., A.B., C.K., E.T., G.C., G.S.); Department of Radiology, Centre Hospitalier de l'Université de Montréal, Montreal, Quebec, Canada (E.T., G.S.); Centre de Recherche de l'Université de Montréal, 900 rue Saint-Denis, Montreal, QC, Canada H2X 0A9 (E.S., A.B., S.L., C.K., H.H., E.T., I.S., M.H.R.C., G.C., G.S.); Laboratory of Biorheology and Medical Ultrasonics (E.S., A.B., M.H.R.C., G.C.) and Clinical Image Processing Laboratory (E.S., A.B., C.K., G.S.), Centre de Recherche de l'Université de Montréal, Montreal, Quebec, Canada; and Department of Mechanical Engineering, École de Technologie Supérieure, Montreal, Quebec, Canada (S.L.).
authors.forename: Gilles
authors.initials: G
authors.lastname: Soulez
mesh_terms: D015901:Angiography, Digital Subtraction; D000818:Animals; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging* / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation; D003287:Contrast Media; D004195:Disease Models, Animal; D004285:Dogs; D054459:Elasticity Imaging Techniques; D057510:Endovascular Procedures; D005260:Female; D015607:Stents; D014057:Tomography, X-Ray Computed; D018608:Ultrasonography, Doppler
chemical_list: D003287:Contrast Media