Aortic Dissection Risk from Intramural Structure – ADRIS

Aortic dissection is one of the most prevalent catastrophic cardiovascular events. The ADRIS (Aortic Dissection Risk from Intramural Structure) project aims to estimate the risk of type A aortic dissection for a given patient from both the intramural structure and circulating biomarkers, obtained from medical images and a blood sample. We assume that dissection is a biomechanical process, initiated within the medial lamellae. It is determined by acute stressors (arterial pressure) and wall frailty, evidenced by pre-existing micro-defects which can be correlated to specific biomarkers.
ADRIS proposes a four-step approach: characterise, understand, model and predict. Indeed, we first aim to establish a rupture risk criterion by conducting mechanical tests on fresh ex-vivo human tissue obtained from at-risk patients. Ground-truth rupture data (critical dissection pressure and tissue strength) will be characterised, as well as its mechanical and morphological properties.
Then, in order to understand how the distribution of pre-existing structural and compositional micro-defects affects the onset of dissection in human diseased tissue, we will perform in-situ dissection experiments using synchrotron X-ray tomography. This will allow direct observation of the initiation sites and dissection mechanisms at the scale of medial lamellae.
Based on these results, a multi-scale numerical biomechanical model of the dissection process within the wall will be developed and validated using synchrotron experiments. This model will be able to provide a probabilistic estimate of the pressure at which a dissection would occur based on the microstructure and composition of the aortic wall.
Blood samples and residual arterial tissue from the same patients will also be analysed for AD-specific circulating and intramural biomarkers using proteomics and lipidomics, to establish correlations with mechanical parameters and predict the density and type of intramural defects.
By integrating these findings into a computational model of the aorta, we will identify key determinants of dissection that will be incorporated into a clinical score for predicting aortic dissection. This score, using anatomical and mechanical parameters derived from clinically-available data, will be used to help clinicians make monitoring or treatment decisions.
These approaches are based on the team's insights, experience and previous work. The ADRIS project will significantly improve the understanding of the pathogenesis of aortic dissection by sequentially linking biochemical processes, intramural micro-defects and damage mechanics of the aorta. It also has the potential to impact the clinical field by providing novel assessment capabilities and guiding technological developments in medical imaging.