title: Computational Fluid Dynamics and Aortic Thrombus Formation Following Thoracic Endovascular Aortic Repair.
abstract: BACKGROUND
  We present the possible utility of computational fluid dynamics in the assessment of thrombus formation and virtual surgical planning illustrated in a patient with aortic thrombus in a kinked ascending aortic graft following thoracic endovascular aortic repair.
  
  
  METHODS
  A patient-specific three-dimensional model was built from computed tomography. Additionally, we modeled 3 virtual aortic interventions to assess their effect on thrombosis potential: (1) open surgical repair, (2) conformable endografting, and (3) single-branched endografting. Flow waveforms were extracted from echocardiography and used for the simulations. We used the computational index termed platelet activation potential (PLAP) representing accumulated shear rates of fluid particles within a fluid domain to assess thrombosis potential.
  
  
  RESULTS
  The baseline model revealed high PLAP in the entire arch (119.8 ± 42.5), with significantly larger PLAP at the thrombus location (125.4 ± 41.2, p < 0.001). Surgical repair showed a 37% PLAP reduction at the thrombus location (78.6 ± 25.3, p < 0.001) and a 24% reduction in the arch (91.6 ± 28.9, p < 0.001). Single-branched endografting reduced PLAP in the thrombus region by 20% (99.7 ± 24.6, p < 0.001) and by 14% in the arch (103.8 ± 26.1, p < 0.001), whereas a more conformable endograft did not have a profound effect, resulting in a modest 4% PLAP increase (130.6 ± 43.7, p < 0.001) in the thrombus region relative to the baseline case.
  
  
  CONCLUSIONS
  Regions of high PLAP were associated with aortic thrombus. Aortic repair resolved pathologic flow patterns, reducing PLAP. Branched endografting also relieved complex flow patterns reducing PLAP. Computational fluid dynamics may assist in the prediction of aortic thrombus formation in hemodynamically complex cases and help guide repair strategies.
authors.affiliation: Department of Surgery, University of Michigan, Ann Arbor, Michigan, USA; Thoracic Aortic Research Center, Vascular Surgery, Policlinico San Donato IRCCS, University of Milan, Italy.
authors.forename: Foeke J H
authors.initials: FJH
authors.lastname: Nauta
authors.affiliation: Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Lau
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering, King's College London, London, United Kingdom.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Arthurs
authors.affiliation: Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Kim A
authors.initials: KA
authors.lastname: Eagle
authors.affiliation: Department of Radiology, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Williams
authors.affiliation: Thoracic Aortic Research Center, Vascular Surgery, Policlinico San Donato IRCCS, University of Milan, Italy.
authors.forename: Santi
authors.initials: S
authors.lastname: Trimarchi
authors.affiliation: Department of Cardiac Surgery, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Himanshu J
authors.initials: HJ
authors.lastname: Patel
authors.affiliation: Department of Surgery, University of Michigan, Ann Arbor, Michigan, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA. Electronic address: figueroc@med.umich.edu.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Figueroa
mesh_terms: D000368:Aged; D001011:Aorta / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D001014:Aortic Aneurysm / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery; D057510:Endovascular Procedures / Q000009:adverse effects*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008955:Models, Cardiovascular; D013927:Thrombosis / Q000209:etiology / Q000503:physiopathology*; D014057:Tomography, X-Ray Computed