Screening for Thoracic Aortic Aneurysm Among a Cohort of Patients With a Degenerative Abdominal Aortic Aneurysm

Overview

Many publications deal with the natural history of aortic aneurysms in literature. Except for connective tissue disorders as Marfan or Loeys-Dietz syndrome, aortic aneurysms are a complex multifactorial disease with genetic and environmental risk factors. Susceptibility loci identified in thoracic aortic aneurysms (TAA) and abdominal aortic aneurysms (AAA) do not overlap, suggesting that different genetic risk factors contribute to these two forms of aneuryms. With a higher prevalence correlated to ageing (5%), AAA is usually presented as the degenerative form of the disease. However, a recent epidemiologic study by Olsson et al. has revealed an increasing incidence of thoracic aortic disease among older individuals (70+/-12 years) with 60% of aneurysmal rupture or dissection at diagnosis, and a 1.7 :1 male-to-female ratio compared to 6:1 in AAA. From this current knowledge arises the concept of diffuse or plurisegmental degenerative aneurysmal aortic disease, poorly explored so far. As regards to the prevention policy, there is a consensus statement in which ultrasonography screening for AAA is recommended for all individuals aged \> 60 years (particularly in men who have ever smoked) and for those aged \> 50 years with family history of AAA. Nevertheless, screening for a concomittant thoracic location of the disease (except thoracoabdominal aneurysm) is not yet required, whereas it could change the prognosis of the patients and influence their management.

Through the constitution of a multicentric prospective cohort of patients with infra-renal AAA (n=450), the investigators aimed to determine the prevalence of a concomitant TAA, and the epidemiologic, clinical, biological and genetic factors related to this aortic phenotype. Therefore, the investigators postulate for a prevalence of the AAA-TAA association inferior or equal to 15%. By the use of an innovating software (AMIRA) to analyse scans, the investigators will perform reproductive measurements of segmental diameters from a segmental aortic volumetric numerized imaging, and describe the different thoracic aortic phenotypes associated with AAA, including the form (TAA, penetrating ulcer, dolichoaorta …) and the location of the disease.