Editor's Choice - Fluid-Structure Interaction Simulations of Aortic Dissection with Bench Validation.
BACKGROUND
The blood flow and stresses in the flap in aortic dissections are not well understood. Validated fluid-structure interaction (FSI) simulations of the interactions between the blood flow and the flap will provide insight into the dynamics of aortic dissections and may lead to developments of novel therapeutic approaches.


METHODS
A coupled, two-way blood flow and flap wall computational model was developed. The Arbitrary Lagrange-Eulerian method was used, which allowed the fluid mesh to deform. Inflow velocity waveforms from a pulse duplicator system were used in the simulations.


RESULTS
The velocities for true lumen (TL) and false lumen (FL) were not significantly different between bench and simulation. The dynamics of the TL % cross-sectional area (CSA) during the cycle was similar between the bench and computational simulations, with the TL %CSA being most reduced near peak systole of the cycle. The experimental distal measurements had significantly lower velocities, likely due to the spatially heterogeneous flow distally. The conservation of mass and validity of simulations were confirmed. Additionally, regions of stress concentrations were found on the flap leading edge, towards the corners, and through the entire vessel wall. The pressure gradient across the FL results in a net force on the flap.


CONCLUSIONS
The FSI flow velocities in the TL and the FL as well as the dynamics of the CSA during the cardiac cycle were validated by bench experiments. The validated FSI model may provide insights into aortic dissection including the stresses on the dissection flap and related flow disturbance, which may be subdued by novel therapeutic approaches. Simulations of more realistic human aortic dissections and the effects of current therapeutic approaches such as stent-graft can be developed in the future using the validated computational platform provided in the present study.
California Medical Innovations Institute, San Diego, CA, USA.
H Y
HY
Chen
California Medical Innovations Institute, San Diego, CA, USA.
S V
SV
Peelukhana
3DT Holdings LLC, San Diego, CA, USA.
Z C
ZC
Berwick
Research Engineering, Cook Medical, Bloomington, IN, USA.
J
J
Kratzberg
Research Engineering, Cook Medical, Bloomington, IN, USA.
J F
JF
Krieger
Research Engineering, Cook Medical, Bloomington, IN, USA.
B
B
Roeder
Research Engineering, Cook Medical, Bloomington, IN, USA.
S
S
Chambers
California Medical Innovations Institute, San Diego, CA, USA; 3DT Holdings LLC, San Diego, CA, USA. Electronic address: gkassab@iupui.edu.
G S
GS
Kassab
D000784:Aortic Dissection / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D000818:Animals; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D017545:Aortic Aneurysm, Thoracic / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D001783:Blood Flow Velocity; D003196:Computer Graphics; D003198:Computer Simulation; D004108:Dilatation, Pathologic; D006439:Hemodynamics; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008955:Models, Cardiovascular; D012039:Regional Blood Flow; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D034421:Sus scrofa; D018617:Ultrasonography, Doppler, Pulsed
Aortic dissection; Fluid–structure interaction; Validation