Histological regional analysis of the aortic root and thoracic ascending aorta: a complete analysis of aneurysms from root to arch

Abstract

Background Although aortic root and ascending aortic aneurysms are treated the same, they differ in embryological development and pathological processes. This study examines the microscopic structural differences between aortic root and ascending aortic aneurysms, correlating these features to the macroscopic pathophysiological processes. Methods We obtained surgical samples from ascending aortic aneurysms (n = 11), aortic root aneurysms (n = 3), and non-aneurysmal patients (n = 7), Aortic collagen and elastin content were examined via histological analysis, and immunohistochemistry techniques used to determine collagen I, III, and IV subtypes. Analysis was via observational features, and colour deconvolution quantification techniques. Results Elastin fiber disruption and fragmentation was the most extensive in the proximal aneurysmal regions. Medial fibrosis and collagen density increased in proximal aneurysmal regions and aortic root aneurysms (p < 0.005). Collagen I was seen in highest quantity in aortic root aneurysms. Collagen I content was greatest in the sinus tissue regions compared to the valvular and ostial regions (p < 0.005) Collagen III and IV quantification did not vary greatly. The most susceptible regions to ultrastructural changes in disease are the proximal ascending aorta and aortic root. Conclusions The aortic root differs histologically from the ascending aorta confirming its unique composition in aneurysm pathology. These findings should prompt further evaluation on the influence of this altered structure on function which could potentially guide clinical management.

Evaluation of the Value of Histological Examination for the Prediction of Genetic Thoracic Proximal Aortopathies

“…These histological findings also correspond to the results of other works [16]. In publications on histological examinations of TAAD, patients were assigned to different syndromes, although it usually remained unclear whether this diagnosis was made after human genetic examination or solely based on clinical and phenotypological aspects [17,18]. Among others, Waters et al [19] evaluated the structured histological nomenclature in TAAD and concluded that this can contribute to the differentiation of syndromic and non-syndromic aortopathy [20].…”

Successful surgical correction of ascending aortic dissection in a kidney transplant patient

“…Существование распространенного атеросклероза у пациента получило убедительное подтверждение при гистологическом исследовании почечной артерии первого трансплантата, удаленного участка грудной аорты, а также при КТ почечной артерии второго трансплантата. Известные структурные особенности стенки корня и восходящего отдела аорты также могли иметь значение для формирования расслоения в этой области [27].…”

Unveiling cellular and molecular aspects of ascending thoracic aortic aneurysms and dissections

“…In addition, mucoid ECM accumulation is a common pathologic finding in TAA and can serve as a marker for ECM degradation [ 72 ]. Furthermore, elastic fiber fragmentation has been reported to be greatest in the proximal aneurysmal ascending aorta compared to the middle or distal regions [ 197 ]. Furthermore, fibulin-4 (Fbln4), a component of elastic fibers essential for maintaining aortic wall integrity has been implicated in aneurysm formation.…”