Aortic stent-graft placement by augmented angio-navigation – ANGIOVISION

The abdominal aortic aneurysm (AAA) is the most common aortic aneurysm. The endovascular treatment of AAA (EVAR - EndoVascular Aneurism Repair) has become an alternative therapy to conventional open surgery. It consists in the deployment of one or several stent-grafts, through intravascular ways, at their anchorage site, in order to re-channel the blood flow excluding thrombus. This procedure has a high success rate in the short term, has the advantage of reducing blood loss, intraoperative morbidity and duration of hospitalization. Even if the feedback is still insufficient and that many questions remain, the indication of endovascular procedures compared to open surgery is constantly increasing. Due to the interventional devices, imaging modalities and protocols used, this minimally invasive approach has inherent limitations that make it difficult and still needs to be reliable and secure.
These limits are related to complex anatomical configurations, the difficulty of realizing the minimally invasive gesture, the durability of treatment (need for secondary procedures in the medium and long term). The solutions proposed through this project state in the field of computer aided / interventions. This approach is however largely under-exploited (or even nonexistent) in the current practice of endovascular interventions, including EVAR procedures, while the main actors of this field agree to recognize the difficulties encountered during stent-graft placement. The challenge lies here in taking into account the deformable nature of soft tissues with complex issues related to the behavior of anatomical structures in the presence of endovascular material
Patient specific simulation of instrument/tissues interactions is even more complex than this issue is generally considered without integrating of the intra-operative component of the problem, for which observations showing the endovascular device interacting with tissues are available but paradoxically not exploited. Similarly such an approach does not operate optimally all available information at different stages of observation (pre-, intra-and post-surgery), it is surprising that the visual information returned to the practitioner during the intervention is limited to 2D fluoroscopic imaging. In this context, the Industrial Research project ANGIOVISION intends to contribute to the improvement of interventional procedures in terms of accuracy and optimization of the operating strategy.
As an alternative to the iterative procedures, the risks of failure or conversion, the proposed approach is part of computer aided surgery field in order to propose an operational solution for the tracking and precise control of stentgraft placement incorporating a realistic modeling of tools / tissues interactions. Based on existing and innovative tools for analyzing patient data, computer aided endovascular navigation and optimized numerical simulation, this project is positioned in the intra-operative side deliberately. It makes use of balanced and complementary patient-specific information available at different stages of observation (pre-, per-, intra-operative), in order to import in the operating room the decision making support and display it to the practitioner during the procedure, through an augmented reality interface.