Computer Aided Surgery (CAS) for Abdominal Aortic Aneurysm (AAA)

Transcription

1 Computer Aided Surgery (CAS) for Abdominal Aortic Aneurysm (AAA) Aurélien Dumenil Pierre Louat Thierry Marchal Michel Rochette 2009 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary

2 Outline Clinical Challenges for Abdominal Aortic Aneurysm (AAA) ANGIOVISION Project Patient Geometry Tuning between simulation results and per- operative data Benefits of Endovascular Simulation Next steps 2009 ANSYS, Inc. All rights reserved. 2 ANSYS, Inc. Proprietary

3 Clinical Challenges for Abdominal Aortic Aneurysm 2009 ANSYS, Inc. All rights reserved. 3 ANSYS, Inc. Proprietary

4 Abdominal Aortic otc Aneurysm Abdominal Aortic Aneurysm (AAA): a localized dilatation (ballooning) of aortic artery exceeding the normal diameter by more than 50 percent Prevalence: ~5% for Caucasian men aged d65+ 15,000 ruptures per year in US Rupture of the AAA occurs in 1-3% of men aged 65+, the mortality is 70-95% 2009 ANSYS, Inc. All rights reserved. 4 ANSYS, Inc. Proprietary

5 AAA Repair Open Surgery EndovascularTreatment Endovascular l treatment t t tis part of what tis called dminimally i Invasive i Treatment, t in principle less risky and more cost effective than traditional surgery; it also allows a much faster patient recovery which can return to active life quicker This solution is however more delicate. Although very promising, numerous doctors are still hesitant to widely adopt it because of various challenges described later ANSYS, Inc. All rights reserved. 5 ANSYS, Inc. Proprietary

6 ANGIOVISION Project 2009 ANSYS, Inc. All rights reserved. 6 ANSYS, Inc. Proprietary

7 ANGIOVISION GO SO Project ANGIOVISION French sponsored project to develop and validate a sophisticated i patient-specific ifi model aortic stent deployment and artery deformation From 01/2010 to 12/2012 ANGIOVISION Partners LTSI (Prime): Lab, Health Technologies and Signal Processing LAMCOS: Lab, Biomechanical expertise CIC-IT & HMN, Hospitals: (Pr Jean-Pierre Becquemin is the reference surgeon in France for AAA) THERENVA: SME, Computer Assisted Surgery Tools ANSYS France: Patient Specific FE Simulation 2009 ANSYS, Inc. All rights reserved. 7 ANSYS, Inc. Proprietary

8 Patient Segmented Data &G Geometrical ti lm Modeling 2009 ANSYS, Inc. All rights reserved. 8 ANSYS, Inc. Proprietary

9 Patient tsegmented e Data High quality segmented data, STL Format 2009 ANSYS, Inc. All rights reserved. 9 ANSYS, Inc. Proprietary

10 Patient tsegmented e Data Iliac and aortic arteries close to the spine Distance between artery and spine 2009 ANSYS, Inc. All rights reserved. 10 ANSYS, Inc. Proprietary

11 Patient tsegmented e Data Extraction of the vessel centerline Artery wall property (healthy (blue), calcified (white)) 2009 ANSYS, Inc. All rights reserved. 11 ANSYS, Inc. Proprietary

12 Generation of a Simplified Geometry Simplified geometry with centerline and circles 3D Simplified geometry More than 40 splines in normal plans along the centerline 2009 ANSYS, Inc. All rights reserved. 12 ANSYS, Inc. Proprietary

13 Simplified Geometry et yusing Splines Automated mesh from this simplified geometry Comparison between detailed geometry and simplified geometry 2009 ANSYS, Inc. All rights reserved. 13 ANSYS, Inc. Proprietary

14 Endovascular Simulation 2009 ANSYS, Inc. All rights reserved. 14 ANSYS, Inc. Proprietary

15 Endovascular a Treatment e t 1. Insert a flexible guidewire inside iliac artery y( (near hip) until a position above the AAA 2. Insert a flexible catheter around flexible guidewire 3. Take off flexible guidewire 4. Insert stiff guidewire (e.g. Lunderquist TM )inside flexible catheter 5. Take off flexible catheter 6. Insert stent tdelivery catheter t around stiff guidewire i 7. Deploy stent 8. Eventually another procedure to deploy a leg stent in the second iliac artery Our goal is to predict artery deformation and medical device deformation for the steps 4, 6 and 7 The first steps involving flexible devices do not deform the artery 2009 ANSYS, Inc. All rights reserved. 15 ANSYS, Inc. Proprietary

16 Simulation of Stiff Guidewire Insert: Modeling the Cardiovascular Environment Artery wall thickness Iliac: 0.8mm Aorta: 1.5mm Youngs Modulus: 12 MPa Poisson: 0.49 Aorto-iliac structure geometrical movements constrained by surrounding abdominal structures Elastic support between aorta and spine Fixed support at introduction point Elastic support: link to second iliac Elastic support: link to internal femoral artery Stiff guidewire - Lunderquist 2009 ANSYS, Inc. All rights reserved. 16 ANSYS, Inc. Proprietary

17 Stiff Guidewire e Diameter: 1mm Length: mm Head: half sphere BC: Prescribed Displacement Linear Elastic Steel Poisson ratio: 0.3 Variable Youngs modulus: 0-40 mm: MPa mm: MPa mm: MPa mm: MPa mm: MPa >120mm: MPa 2009 ANSYS, Inc. All rights reserved. 17 ANSYS, Inc. Proprietary

18 Motion o Simulation uat Deformation of the second iliac and the aorta under the action of the stiff guide, Ddifferent view angles 2009 ANSYS, Inc. All rights reserved. 18 ANSYS, Inc. Proprietary

19 Artery Wall Stresses 2009 ANSYS, Inc. All rights reserved. 19 ANSYS, Inc. Proprietary

20 Per-operative e Data -Blue & yellow: artery centerline before endovascular treatment - Black/Red: guidewire - Green: First simulation (before tuning) X-ray using one single incidence 2009 ANSYS, Inc. All rights reserved. 20 ANSYS, Inc. Proprietary

21 Model Tuning - Yellow: artery centerline before endovascular treatment - Black/Red: guidewire - Green: simulation with tuning - Tuning Parameters: - Artery wall thickness - Second Iliac Link - Elastic support between upper aorta and spine - Hyperelastic material law (more flexible iliac artery) - More accurate artery geometry 2009 ANSYS, Inc. All rights reserved. 21 ANSYS, Inc. Proprietary

22 Necessary yclinical Output Transient progression of stiff wire : Nice to look at Time consuming Not really necessary for clinical purpose Valuable clinical information: Deformed arteries Induced stress Getting quick results to test various configurations and devices Solution Direct calculation of final position No transient modeling 2009 ANSYS, Inc. All rights reserved. 22 ANSYS, Inc. Proprietary

23 Direct Final Position to 2009 ANSYS, Inc. All rights reserved. 23 ANSYS, Inc. Proprietary

24 Comparison between the 2 End dresults Motion Simulation Direct Final Position Simulation Comparison (Black (transient), Green (Direct)) 2009 ANSYS, Inc. All rights reserved. 24 ANSYS, Inc. Proprietary

25 Blood Pressure e Simulation without blood pressure Simulation with blood pressure 2009 ANSYS, Inc. All rights reserved. 25 ANSYS, Inc. Proprietary

26 Endovascular Simulation: Its Value, its Future 2009 ANSYS, Inc. All rights reserved. 26 ANSYS, Inc. Proprietary

27 Benefits of Endovascular Simulation Clinical Applications Treatment Planning All treatment steps can be simulated using patient specific data Verification of stresses of the calcified artery parts during rigid guidewire insertion to control risk of rupture Surgeon Training on Patient Data Endovascular simulation as an education tool Interactive computation of artery deformation, stent deployment, stresses on artery wall, reaction forces Industrial Applications Design and certification of endovascular tools Virtual Experimentation and Virtual Planning Targeting Smart Products and Product Integrity Contribution to Virtual Human Laboratory (VHL) 2009 ANSYS, Inc. All rights reserved. 27 ANSYS, Inc. Proprietary

28 Conclusions cus o s& Next tsteps Automated process from patient specific data to personalized endovascular simulation Cohort of patients (20+) from our 2 hospitals (Rennes and Creteil) Fully automated process with segmentation, boundary conditions, simulation and visualization of results Simulation speed up and robustness Fine tuning between endovascular simulation and per-operative patient data Second incidence angle for a full 3D verification Validation on several patient data Adoption and deployment of this solution amongst leading biomedical companies 2009 ANSYS, Inc. All rights reserved. 28 ANSYS, Inc. Proprietary

29 Acknowledgement e CIC-IT & HMN Hospitals Treatment t of medical limages: LTSI Therenva Material lproperties: LAMCOS 2009 ANSYS, Inc. All rights reserved. 29 ANSYS, Inc. Proprietary

30 Thank you Insertion of medical devices along stiff wire 2009 ANSYS, Inc. All rights reserved. 30 ANSYS, Inc. Proprietary