Aneurysms - Diagnosis and Personalized Treatment

Aortic aneurysms consist of a localized dilatation of the aorta resulting from compromised structural integrity and are characterized by a diameter increase of at least 50% compared to a reference diameter. When left untreated, aneurysms tend to progressively enlarge, with an increased risk of catastrophic events, i.e. rupture or dissection. Given the dangers and expenses related to surgery, risk stratification is crucial. The current criterion provides a rough estimate of the rupture risk of aneurysms; however, it has been shown that adverse events can occur in aneurysms not meeting the surgery criteria, while a large aneurysm may remain stable for the patient's lifetime. We propose a biomechanics-based approach, in which the peak wall stress is calculated and compared to the aneurysm wall strength. CT scanning, uniaxial tensile testing, planar biaxial tensile testing, microstructural analysis and finite element modeling are needed to retrospectively estimate patient-specific vales for peak wall stress and wall strength. Our current research is directed at correlating these retrospective findings to non-invasive patient parameters (general patient health parameters as well as compliance estimates from time-resolved CT scanning), such that a prospective risk index can be defined.