Predicting Post-TEVAR Endoleaks: A Pre-operative Hemodynamic Risk Factor from Patient-Specific Fluid-Structure...

Thoracic endovascular aortic repair (TEVAR) is a minimally invasive treatment for thoracic aortic pathologies, including thoracic aortic aneurysm (TAA). Computational simulations can provide valuable insights into TEVAR outcomes and complications before intervention. This proof-of-concept study proposes a novel risk factor R as a potential predictor of post-TEVAR type I and III endoleaks (ELs) using pre-TEVAR hemodynamic data.

Fluid-structure interaction (FSI) computational simulations are performed in ten pre-TEVAR patient-specific TAA cases, with known follow-up TEVAR outcomes. Hemodynamic drag forces acting on the aortic wall are quantified and used to define R, which combines parallel and perpendicular drag force components with aortic tortuosity. The patient cohort is divided into a calibration set, used to associate specific R values with three different risk levels, and a test set, used to preliminarily assess the agreement between the predictions derived from R and the post-TEVAR follow-up outcomes.

Based on the R values obtained for the calibration set, R $\le$ 0.33 is associated with low risk of EL formation, 0.33 < R $\le$ 0.67 with moderate risk, and R > 0.67 with high risk. Once it is applied to the test set, the risk factor is able to correctly identify a type I EL.

The risk factor proposed in this work is capable of identifying all the EL cases analyzed. This study represents a preliminary attempt to determine whether pre-TEVAR hemodynamics can effectively predict post-TEVAR complications and therefore aid clinicians in the pre-operative planning.