Assessment of the aortic tunica media histological changes in relation with the cause of death.

Abstract

Aim: The authors set out to evaluate the correlations between three of the main morphological aortic parameters (elastic fibers - FE, collagen fibers - FCOL, and smooth muscle fibers - FM) and the cause of death.

Materials and methods: Study groups included 25 cases died of a vascular disease (V_P), 37 cases died of a non-vascular disease (NV_P) and 28 cases died of a violent/suspect non-pathological cause of death (V_Dth), the latter group representing also the control group. Four aortic cross-sections (base, arch, thoracic, and abdominal regions) were collected during autopsy from the selected cases, fixed in 10% buffered formalin and first of all photographed together with a calibrating ruler. Then, they were embedded in paraffin, sectioned off at 4 μm and stained with Hematoxylin-Eosin (HE) and Orcein. The obtained histological slides were transformed into virtual slides. Fibrillary components amounts were using a custom-made software, developed in MATLAB (MathWorks, USA). Statistical tools used were Pearson's correlation test, t-test (two-sample assuming equal variances) and one-way analysis of variance (ANOVA) test.

Results and discussions: The amounts of the three fibrillary components of the aortic tunica media had a synchronous variation in all aortic regions in each of the three groups, excepting FCOL in the group of patients died from vascular pathology, which presented only a trend of synchronous variation along the aorta. FE had their lowest values and FCOL had their highest values in patients died from vascular pathology. FCOL had always higher levels than FE in people died from any pathological condition, vascular or non-vascular. FM had always at least two times lower level than that of the other types of fibers, regardless of whether the person died due to a pathological condition or not.

Conclusions: The different pathological conditions causing death are influencing the fibrillary composition of aortic tunica media. Further studies are required to reveal other changes in the morphology of aortic wall in particular and vascular wall in general that could be related with different pathological conditions affecting the entire organism.