ENDOSIM is a research project in the field of predictive simulation and computer-aided medical interventions (CAMI). It focuses on the treatment of aortic aneurisms and valvular stenoses. In a previous ANR TecSan project (ANGIOVISION, ended in February 2013), the partners of the ENDOSIM project have developed operative assistance tools using augmented angio-navigation for the treatment of abdominal aortic aneurysms (AAA). The results demonstrated, on more than 20 patients, the accuracy of the patient-specific simulation approach. Based on these developments and results, the team aims to move forward and tackle the problem of predictive planning, in order to maximize the accuracy and reliability of two complex endovascular procedures: • the implantation of fenestrated stent-grafts for the treatment of thoraco-abdominal aneurysms, • the endovascular implantation of cardiac valves for the treatment of aortic stenoses. For these two minimally invasive procedures, atheromatous plaques are sources of numerous, unsolved so far, difficulties among which: navigability issues in the vicinity of the lesions, risk of plaque rupture due to ancillary contacts, complexity for positioning the device on the lesion site, brittleness of the vasculature, crushing of the native valves… These issues currently constitute a major obstacle for a more massive use of endovascular techniques. The goal of ENDOSIM is to develop the first predictive endovascular surgery planning software in the world. This will lead to optimize the pre-operative planning and to secure per-operative navigation, through the following points: • tool navigability estimation from the patient’s imaging data, • improvement of the pre-operative device sizing reliability, • pre-operative prediction of the device positioning and per-operative visualization, • decision-making help for patient eligibility and device selection. In order to reach these objectives, the novel approach featured in ENDOSIM relies upon the joint use of image analysis techniques and biomechanical numerical simulation techniques, both being patient-specific and predictive. The scientific breakthroughs of ENDOSIM comprise mainly accurate and predictive patient-specific simulations of the endovascular ancillary insertion and device deployment. These simulations will be based on pre-operative imaging data and validated using per- and post-operative data on a group of atheromatous patients. The prediction of the risk of surgery-induced injury at the atheromatous sites is also very original. The numerical simulations developed through the project will be systematically enhanced and validated thanks to 3D imaging data obtained on real patients with the per-operative multi-incidence equipment of the TherA-Image platform. From a clinical point of view, the benefits of the ENDOSIM project will relate to securing the surgical planning thanks to simulations based on pre-operative data and improved positioning accuracy thanks augmented navigation tools. This should allow a more massive use of endovascular treatments and hence make the most of these minimally invasive procedures for the patients. From the industrial point of view, ENDOSIM will lead Therenva® (French leader in endovascular surgery software) to market the first predictive endovascular planning software solution. This will also be complemented by a visualization system for per-operative assistance. The close partnership with Ansys® (worldwide leader in numerical simulation) will promote a widespread adoption of Therenva® software solutions by endovascular device companies, as a first step, and by the worldwide clinical community as a second step.