On the validation of patient-specific numerical simulations of the TEVAR procedure

Abstract

The Thoracic Endovascular Aortic Repair (TEVAR) is becoming the first choice to treat thoracic aortic pathologies (e.g., aneurysms, ulcerations, and dissections) in a minimally invasive way. It consists of placing a self-expandable stent-graft into the pathological region to recreate a more physiological condition. When computational models are used in this clinical context to predict procedural results, their credibility should be validated and verified. This works applies a validated finite element methodology to four patient-specific anatomies. Different sizes of a commercial stent-graft model are recreated, and the TEVAR simulation results are validated by comparing them to post-operative Computed Tomography images. Errors between simulation and segmentation are lower than 10% for the stent struts opening area. This study also evaluates and discusses numerical quantities (contact pressures, device-to-vessel distances, and stress distributions) associated with potential TEVAR complications such as device migration and bird beak phenomenon. This work aims at demonstrating how a fully validated methodology is useful for clinicians to identify the best treatment for the patient before the intervention to avoid device-related complications.