Validation of known markers: Several partners are involved in the description of biomarkers of AAA evolution, including markers of fibrinolytic activity, of platelet activation and leukocyte activation. The interest of these markers will be extended to the follow-up of patients with small aneurysms, and patients treated by endograft. Since aortic dilation is associated with rheological disturbances we will extend the study of some of these markers to TAA.

Discovery of new markers (proteomics): In parallel, we will develop an open proteomic approach of the differential pattern of proteins released by the aneurismal wall and circulating cells. Human tissue, circulating cells, and tissue-conditioned media will be used to explore the differential pattern of proteins retained and released by normal and pathological aortic walls and circulating cells, analyzing separately the products of the thrombus, the media and the adventitia, and of circulating PMNs, monocyte/macrophages and progenitors.

Functional imaging: Aortic stiffness is also a predictor of aortic dissection and dilatation in patients with syndromic TAA, and local disturbance of flow velocity could be involved in aneurysm evolution (see biomechanics). Aortic stiffness can be assessed non-invasively at a regional level by distensibility and over a larger aortic segment by flow wave velocity.

Molecular imaging in AAA. We will investigate, as a direct application of the pathophysiological concepts, biological activity associated with aneuryrism progression by scintigraphy, MRI, PET Scan, Scanner. We will correlate images obtained with these techniques with results of morphological and biochemical analysis.

New tracers for protease imaging in aneurysm. Since proteolytic injury is the driving force of aneurysm progression, partners have recently shown the ability of ligands to visualize platelet retention and fibrinolytic activities in vivo in animal models and in vitro in human diseased tissues. We will develop new peptidic ligands for visualizing protease activities within aneurismal tissue.