Behavior of the Iliofemoral Segment

Peripheral artery diseases (PAD) are associated with an overall increased risk of mortality and morbidity, as a consequence of fatal or non-fatal vascular events, mainly due to the total or partial occlusion of the affected artery. Particularly, lower extremity occlusive arterial diseases remain a global concern, affecting more than 200 million people worldwide in 2015. Regarding the iliofemoral segment and, especially, the common femoral artery (CFA), conventional surgical approach (namely common femoral endarterectomy, CFE) is still as the gold standard despite its high morbidity rates mainly due to high rate of wound sepsis and autonomy loss . Endovascular procedures with CFA stenting have been introduced as a promising alternative for their multiple advantages such as shorter hospital stay and less perioperative complications. However, its acceptance among the vascular surgery community has been limited.

Endovascular stenting aims to reduce restenosis and improve the target lesion revascularization rates by the implementation of the stent at the level of the CFA. Nevertheless, fear of stent fracture due to hip mobility constitutes one of the main limitations to its implantation, despite the lack of widely accepted quantitative evidence of their relationship. Thus, this study aims to validate that the stresses and deformations on the iliofemoral segment during hip flexion are not a direct cause of stent fracture.

Numerical 3D models offer a non-invasive, inexpensive and personalized approach in the biomedical engineering field; thereby encouraging their use for the biomechanical study of different anatomical structures. These models are able to simulate the behavior and, additionally, quantify the forces, stresses and deformations of different organs and systems by implementing the information gathered in clinical measurements, diagnostic tests and imaging. 3D models can be reconstructed from computed tomography scans (CT scans). Specifically, CT angiography (CTA) images, offering high-quality and high-contrast images, facilitate the creation of numerical models of the vascular system (including the iliofemoral segment).

Our study will analyze the mechanical behavior of the iliofemoral segment by the creation of a numerical simulation to estimate the stresses and deformations at the level of the CFA during hip flexion. For this purpose, our project aims to use 3D models of this region reconstructed CT scans that are routinely performed preoperatively for PAD patients. Indeed CT scan are indicated for anatomical characterization of PAD lesions and guidance for optimal revascularization therapy.

The results of this study could be applied to the assessment of the treatment of lower extremities occlusive arterial diseases at the level of the CFA.


Eligibility Criteria:
Inclusion Criteria:

* Patient's age \> 65 years old
* Patient with Glomerular filtration rate \> 60ml/mn
* Patient affiliated to the French Health insurance system
* Patient with a preoperative duplex scan of the lower limbs
* Patient with an indication of CT scan with either diagnostic or preoperative purposes
* Patient referred for endovascular procedure (aortic or peripheral), with an indication of CTA comprising the CFA region, without significant lesions of the external iliac and common femoral arteries (control group) or patients referred for endovascular stenting of the common femoral artery (stent group)

Exclusion Criteria:

* Patient with significant below the knee arterial lesions according the duplex scan analysis
* Hip arthroplasty.
* Hip pain and stiffness caused by hip arthritis.
* Patient under guardianship
* Patient deprived of liberty
* Patient under court protection
* Patient objecting to the use of his/her data for this research