# Computer Aided Surgery: Application to Aortic Dissection

Wenyang Pan, Pascale Kulisa, Xavier Escriva, Benyebka Bou Said, Marine Menut, Patrick Lermusiaux, Antoine Millon

<figure><img src="image_1.png" /></figure>

## To cite this version:

Wenyang Pan, Pascale Kulisa, Xavier Escriva, Benyebka Bou Said, Marine Menut, et al., Computer Aided Surgery: Application to Aortic Dissection. Annals of Vascular Medicine & Research, 2020. [hal-03401756](https://hal.science/hal-03401756)

HAL Id: hal-03401756

https://hal.science/hal-03401756

Submitted on 25 Oct 2021

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_2.png" /></figure>
Original Article

# Computer Aided Surgery:
Application to Aortic Dissection

Wenyang Pan<fnref n="1" />*, Pascale Kulisa<fnref n="2" />, Xavier Escriva<fnref n="2" />, Benyebka Bou-Saïd<fnref n="1" />, Marine Menut<fnref n="3" />, Patrick Lermusiaux<fnref n="4" />, Antoine Millon<fnref n="4" />

*Corresponding author

Wenyang Pan, INSA de Lyon, 69100 Villeurbanne,
France, Tel: 33769040403; Email: wenyang.pan@insa-
lyon.fr

Submitted: 07 October 2020

Accepted: 29 October 2020

Published: 30 October 2020

ISSN: 2378-9344

Copyright

© 2020 Pan W, et al.

OPEN ACCESS

Keywords

* Cardiovascular diseases; Aortic dissection;
Hemodynamics; Fluid/Structure Interaction

Abstract

In cardiovascular disease, aortic dissection is relatively unknown and difficult to treat. Endovascular treatment seeks to obliterate the entrances to the false lumen with a stent. The currently available surgical tools for endovascular procedures are selected only from information based on medical imaging techniques. The images are carried out before the intervention and therefore do not consider the deformation of the vascular structure by the implementation of the prosthesis. While many biomechanical studies have been done on the endovascular treatment of aneurysms of the abdominal aorta, there are, however, very few such studies on aortic dissections. This paper aims to present a numerical tool, from the open-source software FOAM-Extend®, allowing for Multiphysics numerical simulations performing the fluid-structure coupling between the hemodynamics and the arterial deformation to assist in the planning process. And, in addition using Abaqus software we realize the placement of the surgical tools in a 'biomecano-faithful' model.

ABBREVIATIONS

CFD: Computational Fluid Dynamic; FSI: Fluid Structure
Interaction; WSS: Wall Shear Stress

INTRODUCTION

Cardiovascular diseases are the leading cause of mortality
in the industrialized world [1]. Among these diseases, aortic
dissection is relatively unknown and difficult to treat, with a
survival rate for most severe cases not exceeding 10%. This
pathology occurs when an injury leads to a localized tear of the
innermost layer of the aorta, called the entry port. It allows blood
to flow between the layers of the aortic wall, forcing the layers
apart and creating a false lumen. The dissection of these layers
may extend over a long portion of the thoracic and abdominal
aorta. There are several types of dissection classified according
to the Stanford Classification (Daily PO 1970). While type A
dissection is a clinical emergency and associated with high
mortality, type B dissection differs in that the surgeons must
choose the method of intervention. Type B is more conducive
to endovascular treatment, which seeks to obliterate the false
lumen entrance with a stent. Poor redistribution of flow can be
harmful to the patient's health, and the implementation of a stent
in the aortic cross-region has significant technical difficulties due
to the angulation and the extent of the diseased area. Surgical
planning for this procedure is based on medical imaging carried
out before the intervention [2]. Therefore, it does not consider
the deformation of the vascular structure during the operation,
which can lead to a bad sizing and poor positioning of the stent.
Looking at the literature, we found that Karmonik et al. [3],

have treated this problem, but they use nonrealistic boundary
conditions, and they suppose that the structure is rigid. Benfanti
et al. [4], have also considered a Newtonian flow when Menut et
al. [5], show that this hypothesis is rough. Chen et al. [6], work
concerns a non bio-faithful model. Qiao et al. [7], consider the
hemodynamic as two phase flow and neglect the shear thinning
effect and viscoelastic properties of blood as well. Alimohammadi
et al. [8], present interesting work but using non-personalized
data. Our aim is to develop a patient-specific numerical analysis,
which considers the wall distortion and Newtonian behavior of
the blood with realistic boundary condition and patient-specific
framework.

MATERIALS AND METHODS

Fluid-structure interaction without prosthesis

Based on the results of studies already carried out and MRI
scans of an affected patient, a numerical FSI model was developed.
FSI modeling is often used in the study of cardiovascular
medicine [9]. Two different methodologies are usually used to
solve the system, which are Monolithic and Partitioned methods
(Michler et al. 2004). For this study, from the numerical point
of view, we used the partitioned approach. Computational Fluid
Dynamic simulations of blood flow in a type B aortic dissection
were performed. Navier-Stokes equations for an incompressible
fluid were solved using the OpenFOAM® solver. Rigid wall and
laminar flow were considered in a first step. In a second step, the
inverse method was used to identify the mechanical properties
of the artery and thanks to a Mooney Rivlin model we consider
the deformability of the structure [8]. A simplification is made

<footnote n="1">¹LaMCoS, INSA de Lyon, UMR5259, University of Lyon, 69100 Villeurbanne, France</footnote>

<footnote n="2">²Univ Lyon, INSA de Lyon, École Centrale de Lyon, UCBL1, CNRS, LMFA, UMR 5509, F-69621, Villeurbanne, France</footnote>

<footnote n="3">³CISTEN, 66 Bd. Niels Bohr, 69603 Villeurbanne, France</footnote>

<footnote n="4">⁴Hôpital Louis Pradel HCL 59 Boulevard Pinel, 69500 Bron</footnote>
<figure><img src="image_3.png" /></figure>

for these preliminary calculations by considering isotropic and
elastic media [8,9]. The three-element Windkessel model was
applied to account for flow resistance encountered by the blood
and a Poiseuille velocity profile at the inlet was based on a clinical
data of the patient pulsatile flow rate [9]. It has been established
[9] that the systolic part can be simplified by considering a
Newtonian fluid and a laminar regime hypothesis. The structure
was fixed at the entrance and outlet. In the numerical simulation,
several calculations were performed using OpenFOAM® software
during several cardiac cycles to guarantee the convergence.
In FOAM-Extend®, the solver to realize the FSI simulation uses
strong coupling with the partitioned approach.

Simulation of tools insertion

Modeling the tools' insertion is a non-linear numerical
problem, mainly due to numerous contacts between deformable,
tortuous, heterogeneous bodies, and large deformations of
complex materials such as arterial tissue. For this study, the
Abaqus® software with an explicit diagram is used for the
numerical calculations. According to [10], an implicit analysis
leads to several months' calculation times, linked mainly to the
evaluation and costly inversion of the stiffness matrix. Compared
to an implicit method, an explicit temporal integration scheme
leads to more reasonable calculation times and guarantees
more robustness in terms of numerical stability (better contact
management). With Abaqus® we treat the complex contact
between the aorta and the surgical tools. Next, we show the
results of numerical simulations performed only in structural
calculations, without considering the hemodynamic effects on
the wall.

As for the simulation of fluid-structure interaction, it
is necessary in the case of tools insertion to firstly create a
numerical bio-faithful model. Next, we hypothesize an elastic
behavior with Young's modulus of 4.66Mpa and Poisson's ratio
of 0.45 for the dissection. The rest of the aorta is modeled with
an elastic behavior with Young's modulus of 3Mpa and Poisson's
ratio of 0.45 [8]. In addition, we used from previous work [11]
the mechanical properties of the tools. The modeling of the
environment surrounding aorta tissue is rarely studied in the
literature. But, in the context of the study of Menut [10-13], which
has chosen to model the areas of attachment of the aorta at the
level of the spine by springs whose stiffness allows them to get as
close as possible to intraoperative aortic deformation (Figure 2).

RESULTS AND DISCUSSION

We did a whole completely cardiac cycle for two simulations
with different Young modulus values of the structure. Figure 1
shows the results of FSI simulation at systolic pressure with a
Young modulus of the structure at 30 GPa, which can represent
a highly calcified wall. The obtained result in terms of pressure
is higher than those obtained in the literature [8] because of
different factors: patient-specific data and realistic boundary
conditions.

Simulation of tools insertion

Figure 3 shows that firstly the rigid guide inserts in the

<figure><img src="image_4.png" /><figcaption>**Figure 1** FSI simulation at systolic pressure with a Young modulus of the structure at 30 GPa (Left: fluid pressure; Center: solid displacement; Right: WSS.</figcaption></figure>

<figure><img src="image_5.png" /><figcaption>**Figure 2** FSI simulation at systolic pressure with a Young modulus of the structure at 300MPa (Left: fluid pressure; Center: solid displacement; Right: WSS.</figcaption></figure>

aorta to lead the rest of the surgical tools inserted in the aorta.
Numerical simulations of catheter rise begin after insertion of the
rigid guide.

CONCLUSION

The characterization of blood behavior with the deformability
of the arterial wall is a first step into the surgical procedure
simulation. Numerical predictions will allow the surgical team
to choose surgical tools and stent and identify its most suitable
positioning for each patient. With these calculations, it was
possible to obtain the information concerning the flow around
aortic dissection and compare different cases to find an effective
method on the stent position in the aorta. This research project
aims to develop a numerical tool to predict the consequences of
these changes in flow, hence assisting in the surgical planning
process. In the next future, we will perform the numerical
simulation for the stent deployment to compare with the clinical
images to validate our simulations, which we will present in the
future.
<figure><img src="image_6.png" /><figcaption>Figure 3 Movements observed on the aorta according to the simulation of tool insertion.</figcaption></figure>

## ACKNOWLEDGEMENTS

This work is supported by the China Scholarship Council.

## REFERENCES

1. OMS. 2016. Rapport sur la situation mondiale des maladies non transmissibles. 2015.

2. Daily PO, Trueblood HW, Stinson EB, Wuerflein RD, Shumway NE. Management of acute aortic dissections. Ann Thorac Surg. 1970; 10: 237-247.

3. Anne Amblard, Hélène Walter-Le Berre, Benyebka Bou-Saïd, Michel Brunet. Analysis of type I endoleaks in a stented abdominal aortic aneurysm. Med Eng Phy. 2009; 31: 27-33.

4. C Karmonik, J Bismuth, D J Shah, M G Davies, D Purdy, A B Lumsden. Computational Study of Haemodynamic Effects of Entry- and Exit-Tear Coverage in a DeBakey Type III Aortic Dissection: Technical Report. Eur J Vasc Endovasc Surg. 2011; 42: 172-177.

5. Mirko Bonfanti, Stavroula Balabani, John P Greenwood, Sapna Puppala, Shervanthi Homer-Vanniasinkam, Vanessa Díaz-Zuccarini, et al. Computational tools for clinical support: a multi-scale compliant model for haemodynamic simulations in an aortic dissection based on multi-modal imaging data. J R Soc Interface. 2017; 14: 20170632.

6. M Chen. Chirurgie endovasculaire virtuelle pour patient-spécique: application au traitement de l'anévrisme de l'aorte thoracique. Thesis. INSA Lyon. 2016.

7. H Y Chen, S V Peelukhana, Z C Berwick, J Kratzberg, J F Krieger, B Roeder, et al. Editor's choice-fluid-structure interaction simulations of aortic dissection with bench validation. Eur J Vasc Endovasc Surg. 2016; 52: 589-595.

8. Qiao Y, Zeng Y, Ding Y, Fan J, Luo K, Zhu T. Numerical simulation of two-phase non-Newtonian blood flow with fluid-structure interaction in aortic dissection. Comput Methods Biomech Biomed Engin. 2019; 22: 620-630.

9. Mona Alimohammadi, Joseph M Sherwood, Morad Karimpour, Obiekezie Agu, Stavroula Balabani, Vanessa Díaz-Zuccarini. Aortic dissection simulation models for clinical support: fluid-structure interaction vs. rigid wall models. Biomed Eng Online. 2015; 14: 34.

10. M Hirschhorn, V Tchantchaleishvili, R Stevens, J Rossanoe, A Throckmorton. Fluid-structure interaction modelingin cardiovascular medicine-A systematic review 2017-2019. Med Eng Phy. 2020.

11. C Michler, S Hulsho, E Van Brummelen, R. de Borst. A monolithic approach to fluid-structure interaction. Computers & Fluids. 2004; 33: 839-848.

12. Amblard A, B Bou-Saïd. Modelling the blood flow in an aorta; the MPTT and Modified MPTT models. Tribol Interf Eng Series. 2005; 48: 381-387.

13. Marine Menut, Benyebka Bou-Said, Helene Walter-Le Berre, Philippe Vézin, Leila Ben Boubaker. Characterization of the Mechanical Properties of the Human Aortic Arch Using an Expansion Method. J Vasc Med Surg. 2015; 3: 4.

## Cite this article

Pan W, Kulisa P, Escriva X, Bou-Saïd B, Menut M, et al. (2020) Computer Aided Surgery: Application to Aortic Dissection. Ann Vasc Med Res 7(5): 1120.