Not rarely aortitis is firstly identified in thoracic aorta aneurysm/dissection specimens only by histopathology in the absence of clinical evidence of systemic inflammatory disease emphasizing the importance of histology for the diagnosis of aortitis. Regardless of the improvement of the pathological assessment of aortic diseases by the recent consensus statements on surgical pathology of the aorta, histology can be confusing since medial degenerative changes (MDC) can be prominent in a background where inflammation is sometimes limited. This raises the question of the role of aging or other degenerative process versus the role of inflammation in the damage to aorta wall.
In this study, besides inflammation, we evaluated aorta samples from aortitis cases focusing on the histological scoring of MDC. In this retrospective single center study, we retrieved 719 cases of ascending aorta aneurysms or dissections operated on from January 2010 until June 2018. MDC (elastic fiber fragmentation and/or loss, smooth muscle nuclei loss, mucoid extracellular matrix accumulation intralemellar or translamellar) were estimated using a scoring system derived from that of the consensus statement. Noninfectious aortitis group versus age-matched non-inflammatory degenerative aortic disease group were compared.
Noninfectious aortitis was pathologically diagnosed in 62 patients (8.6%). Among the 62 noninfectious aortitis patients, 47 patients (75.8%) had aortitis identified pathologically prior to the clinical diagnosis. Higher MDC scores were observed at all aortic sizes in aortitis group versus non-aortitis group, especially for elastic fiber damage and smooth muscle cell loss.
Aortitis is remarkably associated with severe damage to the aorta wall resulting in advanced MDC scores. Inflammatory process is responsible for higher MDC in the aorta wall than aging or other degenerative process.