P6503Impact of ascending aortic disease categories on the histopathological degenerative changes in relation to aorta dimensions

Abstract

Abstract Background Recently a consensus statement on surgical pathology of the aorta was published to improve pathological assessment of non-inflammatory aortic diseases. Purpose We used data of the ascending aorta surgical specimens for aneurysm or dissection to better understand the relationship between the histological medial degenerative changes (MDC) and aortic size assessed by computed tomography. Methods In this retrospective single center study we retrieved 719 ascending aorta surgical specimens from January 2010 until June 2018 and analyzed them according to the consensus statement and scored MDC [elastic fiber fragmentation and/or loss (EFFL), smooth muscle nuclei loss (SMNL), mucoid extracellular matrix accumulation (MEMA); intralamellar (I) or translamellar (T)] and measured medial wall thickness on correlation with imaging data and the status [thoracic aorta aneurysm (TAA), dissection (TAD), bicuspid aortic valve (BAV) or non-BAV]. Results We analyzed 517 patients with degenerative aortic diseases (mean age, 61 years) whose imaging data were obtained, with BAV in 203 (TAD 4%, TAA 96%) and with non-BAV in 314 (TAD 44%, TAA 56%). In TAA subset, scores of EFFL, SMNL and MEMA-T were lower in BAV than in non-BAV (p<0.01). Maximum aortic diameters averaged 50 mm in TAD and 53 mm in TAA. In relation to the aortic diameter, the scores of EFFL, SMNL and MEMA-T were more important in non-BAV subset than in BAV, and in TAD subset than in TAA particularly at the small aortic diameters (<50mm) (Figure). Independent predictors of aortic dissection included thicker medial wall (odds ratio [OR], 6.5; 95% confidence interval [CI], 2.6 to 17.6; p<0.0001) and greater SMNL (OR, 1.2; 95% CI, 1.1 to 1.3; p=0.003). Conclusions Non-BAV aortas were associated with higher scores of MDC than BAV aortas. Advanced MDC was correlated with increased aortic diameter in the ascending aortic diseases. However, in even smaller aortic diameters, MDC in patients with TAD was important.