Validation of Fenestrations Positioning by Numerical Simulation

Study Overview
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Brief Summary
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Fenestrated endovascular repair (FEVAR) is nowadays a recognized option to treat juxtarenal, pararenal or suprarenal abdominal aortic aneurysms in patients at high risk for conventional repair. The technique consists in deploying a custom-made stent-graft (SG) inside the patient aorta. Part of the customization involves cauterizing a hole in SG fabric and reinforcing it with a Nitinol stent ring, thereby creating a fenestration for each corresponding collateral artery. For this reason, preoperative planning is crucial to determine adequate positions of fenestrations, in order to obtain perfect alignment with the collateral arteries of the patient. Inadequate positioning may result in failure to catheterize a collateral artery and subsequent organ damage, increased catheterizing time, increased irradiation dose, endoleaks… The current process of fenestrations positioning for fenestrated anacondaTM SG involves: (i) anatomical measurements on patient preoperative CT-scan by case planners using dedicated sizing software; (ii) designing an initial custom device scheme with its positioned fenestrations, created by engineers with CAD software using the above cited measurements and (iii) validation of fenestrations position by in vitro testing using a SG prototype deployed inside a transparent anatomy model (3D-printed model of patient aorta and collateral arteries). The main limitations of this process are the costs and long SG delivery time.

Detailed Description
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The current process of fenestrations positioning for fenestrated anacondaTM SG involves: (i) anatomical measurements on patient preoperative CT-scan by case planners using dedicated sizing software; (ii) designing an initial custom device scheme with its positioned fenestrations, created by engineers with CAD software using the above cited measurements and (iii) validation of fenestrations position by in vitro testing using a SG prototype deployed inside a transparent anatomy model (3D-printed model of patient aorta and collateral arteries). The main limitations of this process are the costs and long SG delivery time. The goal of this study is to compare fenestrations positioning obtained by two different processes, the actual one at Vascutek and the one by numerical simulation performed by Predisurge company.

Official Title
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Validation of Fenestrations Positioning by Numerical Simulation in Fenestrated Endovascular Repair of Abdominal Aortic Aneurysms

Conditions
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Abdominal Aortic Aneurysms

Intervention / Treatment
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* Other: numerical simulation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: - abdominal aortic aneurysms suitable for treatment using Fenestrated AnacondaTM (Vascutek) device Exclusion Criteria: failure to generate an adequate FE model of patient arteries (no preoperative multidetector contrast-enhanced CT-scan available, preoperative CT-scan slice thickness greater than 1mm, preoperative CT-scan with artifacts) stent-graft setup implanted during the surgical procedure has been modified compared to preoperative planning patient refusing to participate to the study

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| abdominal aortic aneurysms treated by fenestrated endovascular<br>Patients have an abdominal aortic aneurysms treated by fenestrated endovascular anacondaTM of society Vascutek will be included. Predisurge society will perform numerical simulation. | Other: numerical simulation<br>* After patients have been treated by fenestrated endovascular of society Vascutek data will be collected by society Vascutek and send to Predisurge society. They will perform numerical simulation and compare with the method of Vascutek.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vascutek in vitro validation test and the numerical simulation | To compare Vascutek in vitro validation test and the numerical simulation (Predisurge). The proportion of fenestrations is less or equal to 2.5mm will be calculated. | Months: 18 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| initial and final stent-graft designs obtained from Vascutek | To study differences between initial and final stent-graft designs obtained from Vascutek process, the differences between L2 and L1 and C2 to C1 will be computed: L = for each fenestration, the longitudinal distance between centre of fenestration and top of fabric C = for each fenestration, circumferential angular distance between O° line and center of fenestration Current Vascutek protocol: Initial custom Stent Graft design, right before in vitro testing = L1 and C1 Final custom Stent Graft design, after in vitro tests and subsequent design changes =L2 and C2 | Months: 18 | 
| stent-graft designs obtained from simulation of deployment | To study differences between stent-graft designs obtained from simulation of deployment in the polymer model and from simulation of deployment in the patient, the differences between L4 and L3 and C4 to C3 will be computed: L = for each fenestration, the longitudinal distance between centre of fenestration and top of fabric C = for each fenestration, circumferential angular distance between O° line and center of fenestration Simulation for fenestration positioning: Initial custom Stent Graft design, right before in vitro testing = L3 and C3 Final custom Stent Graft design, after in vitro tests and subsequent design changes =L4 and C4 | Months: 18 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Endovascular, Fenestrated endovascular repair, numerical simulation