Inflammatory aortic aneurysms comprise a minor subset of aortic aneurysms. Although they are mostly seen in the infrarenal abdominal aorta, there have been cases reported where it occurs in the thoracic aorta as well. Connery et al. described the first inflammatory aneurysm of the ascending aortic in 1994.3 Since then, only twelve other case studies have been reported, most of which consisted of individuals over the age of 54 or with related inflammatory diseases.1, 4 Other studies have described incidental findings of aortitis upon retrospective pathology reviews of aortic surgical specimens, however, the severity of inflammation in this case is incomparable.5 Also, most cases consisted of elderly individuals with related comorbid diseases including giant cell arteritis and other rheumatologic diseases. A severely inflamed ascending aortic aneurysm with the inflammation extending into the LAD in a young female with no related co-morbid diseases is a medical phenomenon that has never been documented.
The cause of inflammatory aortic aneurysms is still unclear. Inflammatory diseases of the aorta are thought to be either infectious or non-infectious. Because of the negative bacterial, fungal and treponemal stains, the infectious forms are ruled out in our patient. The role of a viral infection involving SARS CoV-2 was postulated but also found to be noncontributory. The differential diagnosis for a non-infectious aortitis could be due to an autoimmune response against atherosclerosis.6 Being that this inflammatory process occurred in the occluded LAD as well, it could be postulated that our patient had an autoimmune reaction against the atherosclerotic plaques. Further studies to diagnose an underlying inflammatory, rheumatologic, or autoimmune etiology are required to expound on this phenomenon. Other noninfectious inflammatory diseases have been postulated to be the underlying cause of thoracic aortitis including Takayasu arteritis, granulomatosis with polyangiitis and sarcoidosis.7 Some studies have reported IgG4-related sclerosing disease is involved in thoracic aortitis.5 However, some authors contend the elevated IgG4 levels are an incidental finding and don’t contribute to the diagnosis due to the inadequate serologic correlation.7
Preoperative diagnosis was difficult because CT could not differentiate an inflammatory aneurysm from an intramural hemorrhage. This drawback is also demonstrated in our literature search where six of the thirteen cases were preoperatively diagnosed with an intramural hemorrhage. Furthermore, only two of the thirteen cases had accurate preoperative diagnoses of an inflammatory aortic aneurysm.1, 4 Echocardiogram is also unable to correctly identify this disease due to the echocardiographic similarities of an aortic wall with inflammation, atherosclerosis, and a thrombosed false lumen.1 The final diagnosis is presumed by the gross appearance during the operation and confirmed by pathologic evaluation of the tissue. Therefore, an inflammatory aortic aneurysm should be considered preoperatively when there is an abnormal dilated aortic aneurysm with a severely thick wall. At the time of surgery, an inflammatory aneurysm is suspected when there is inflammatory thickening of the aortic wall and excessive adherence to surrounding structures. The histopathologic evaluation of inflammatory aortic aneurysms confirms the diagnosis and typically shows inflammatory lymphoplasmacytic infiltration with destruction of the media.
In summary, we described the case of an inflammatory aneurysm of the ascending aorta with comparable inflammation of the LAD in a young female patient who underwent successful surgical treatment. The underlying etiology of severe inflammatory ascending aortic aneurysms with lymphoplasmacytic infiltration and media destruction without contributory diseases remains uncertain and still open for debate. There is a high surgical mortality (16%) of the inflammatory subtype compared to elective repair of ascending aortic aneurysms.1 More advanced preoperative imaging is needed to unmask this diagnosis as it is questioned whether this fragile inflammatory aneurysm requires surgery at earlier stages compared to its non-inflammatory counterparts.