Given the young age of our patient, it would be wise to first rule out a congenital malformative cause.

Marfan syndrome (and related) was mentioned first. However, it combines cardiovascular and skeletal signs, lens ectopia and pneumothorax [1,3]. which is not the case in our patient. However, the Ankylosing Spondylitis-Marfan combination was described by P. Fietta and P. Manganelli in a 46-year-old patient, who had complete Marfan syndrome [4].

The aneurysm of the ascending thoracic aorta is the result of an alteration of the media of the aorta which is reflected histologically by: a progressive decrease in smooth muscle cells replaced by areas of mucoid degeneration rich in vacuoles and in polysaccharides; disorganization and loss of elastic fibers in the extracellular matrix. These processes lead to weakening of the aortic wall, which in turn is responsible for its dilation [1].

Indeed, aneurysms affecting the ascending aorta, of degenerative origin, are not linked to atherosclerosis (unlike aneurysms of the abdominal aorta and the descending thoracic aorta) but rather to a genetic part. In addition, we know that the ascending and descending thoracic aortas, separated anatomically by the ligamentum arteriosum, are two very distinct entities. This observation seems to be based in part on the difference in their embryonic origin [1].

[Figure 1-5]

The presence of inflammation or suggestive symptoms should suggest the association of dilation of the ascending aorta with inflammatory disease. In the first ranks, we find the vasculitis of the large caliber arteries: Takayasu's disease, giant cell arteritis, Behçet's disease but also spondyloarthropathies, connectivitis and finally infectious diseases such as syphilis or tuberculosis [5]. Crohn's is associated with extraintestinal manifestations and other autoimmune pathologies much more frequently than ulcerative colitis. Physiopathologically, it is a vasculitis of the mesenteric arteries which is thought to cause ischemic lesions and multiple infarctions of the intestinal wall [6,7]. Recent studies have shown that patients with IBD have a moderately increased risk of cardiovascular complications (ischemic heart disease, stroke and mesenteric ischemia), with no difference to Crohn's disease and UC [8]. To date no description associating IBD and dilation of the ascending aorta has not been reported to our knowledge.

However, in a case reported by El Kouache in 2013 of Ankylosing Spondylitis (AS) complicated by dystrophic aneurysm of the ascending aorta, would be similar to ours in an inflammatory context. AS, an inflammatory disease, can be complicated by systemic manifestations, including inflammatory cardiovascular disease, especially aortic disease. The histology of this aortic involvement, reported by El Kouache, is characterized by an inflammatory infiltrate predominantly lymphocytic which involves the first 3 centimeters of the aortic root. This results in adventitial thickening, destruction and focal necrosis of the elastic tissue of the media as well as intimal proliferation. In this observation, the histological study of the aortic wall did not identify inflammatory changes but rather cystic degeneration with dissociation of the bundles of elastic fibers observed throughout the thickness of the media. The intima was little changed. This histological description suggests dystrophic involvement comparable to that seen in Marfan's disease, but this 47-year-old patient had no other diagnostic criteria for this syndrome. This observation therefore raises the question of a possible relationship between AS and the histological lesions of Marfan [9]. However, we excluded the diagnosis of Marfan in our patient.

Ridker et al. showed, for the first time in 2003, that circulating levels of ultrasensitive C-Reactive Protein (CRP) strongly correlated with the subsequent risk of CV complications in the general population [10].

Supported

Laplace's law states that the more the tension exerted on the wall increases, the more the diameter of the aneurysm increases leading to dilation of the aorta. Thus, the kinetic energy produced during turbulence has an important effect on the distribution of pressure on the sacciform wall. It is therefore considered to be an important factor in avresysmal dilation as well as its rupture [11].

According to the recommendations of various Cardiology Societies, only recommend surgery for diameters> 50-55 mm and favor medical treatment for a diameter <40 mm [11].

Thus, we put our patient on beta blockers, because they made it possible to decrease the progression of the aortic aneurysm, according to Laplace's law by negative inotropic and chronotropic effect, while improving life expectancy, recommended class I, B [1]. As for the ARS inhibitors, our patient presents blood pressure limits between 90 and 100 systoles, hence abstention. As for the statin, it would seem that it has a beneficial effect, in particular on its ascending portion, by reducing its speed of progression linked to its anti-inflammatory action (in vivo and in vitro, statins decrease the expression of metalloproteins which are involved in the dilation process) [1].

As for his Crohn's disease, he is put on methotrexate 25 mg 1 tab / day [2].

Clinico-biological and imaging monitoring is recommended every 12 months [1].