Abstract 17677: Elevated Wall Shear Stress Assessed by Computational Fluid Dynamics Simulations is a Risk Factor for Retrograde Aortic Type-A Dissection
Introduction: Retrograde aortic type-A dissections (RTAD) represent a known complication in patients with aortic type-B dissections. The aim of this study was to identify functional and hemodynamic risk factors for occurrence of RTAD by means of computational fluid dynamics simulations.
Hypothesis: Hemodynamic conditions, in particular elevated WSS, in patients with type B dissections are risk factors for occurrence of RTAD.
Methods: Computed tomographic angiography (CTA) images of 10 patients with a type-B dissections, who subsequently developed a RTAD were retrospectively analyzed. The patients in the control group (n = 10) did not have any further vascular events after the initial type-B dissection. Computational meshes were created from 3D surface models of the aortic lumen derived from contrast-enhanced CTA datasets. For both groups, pressures, velocity magnitudes and wall shear stresses were quantified at the location of the future RTAD entry tear (immediately distal to the origin of the left subclavian artery) and the surrounded area.
Results: WSS at the area of the future entry tear was significantly elevated compared to the surrounding wall (14.53 Pa vs. 5.15 Pa, p < 0.001), (Fig.1) and significantly higher in the RTAD group than in the control group (5.90 Pa, p < 0.002). Pressures and velocity magnitudes were elevated at the entry tear (28.70 mmHg, 0.63 m/s) compared to the aortic arch (26.63 mmHg, 0.50 m/s) as well as to the control group (26.27 mmHg, 0.62 m/s).
Conclusion: Increased WSS is associated with the occurrence of RTAD. Our results merit the design for a prospective study to confirm that WSS is a risk factor for the occurrence of RTAD and to validate the results which could be achieved by measuring the time-varying 3D velocity field in the ascending aorta using 4D-phase contrast MRI.
Author Disclosures: A.K. Osswald: None. C. Karmonik: None. J.R. Anderson: None. F. Rengier: None. M. Karck: None. K. Kallenbach: None. D. Kotelis: None. S. Partovi: None. D. Boeckler: None. A. Ruhparwar: None.
- © 2016 by American Heart Association, Inc.