Medial Hypoxia and Adventitial Vasa Vasorum Remodeling in Human Ascending Aortic Aneurysm

Aim. To describe a rare occurrence of ﬁbromuscular vasa vasorum dysplasia of the aortic aneurysm wall.Materials and methods. Surgical material from the ascending aortic aneurysm wall was examined. Longitudinal strips of the aortic wall were excised for histological examination with subsequent 24-h ﬁxation in 10% buffered formalin. A histological isopropanol assay was performed with an automated Logos microwave tissue processor (Milestone, Italy) with subsequent sample embedding into parafﬁn. Sections were obtained with a rotary microtome (Leica, Germany). Staining was performed with haematoxylin-eosin, van Gieson’s picrofuchsin, orcein for elastic ﬁbres, Hotchkiss’ PAS reaction with alcian blue for glycosaminoglycans. Histological and histochemical properties of the aortic wall were studied and imaged with a Leica DM 1000 microscope (Germany) equipped with a camera ICC50 E at magniﬁcations 40x, 100x, 200x, 400x.Results. The conducted histological examination of the aortic aneurysm wall revealed most pronounced changes in media and adventitia layers. Elastic ﬁbres in media were swollen, homogeneous, crimped, with pronounced dystrophic and necrobiotic changes in smooth myocytes. Regions of compromised cells and elastic ﬁbres in media contained pockets of alcian-positive glycosaminoglycans. Speciﬁc changes were revealed in adventitia vasa vasorum in the form of a pronounced wall thickening and lumen narrowing due to dysplastic ﬁbromuscular tissues.Conclusion. A rare form of ﬁbromuscular dysplasia of the vasa vasorum of the ascending aortic aneurysm wall observed in a 43 years-old woman demonstrated the morbid morphology of smooth myocytes, as well as ﬁbrous collagenous and elastic structures. The described features were likely associated with the aortic wall trophic structure and aneurysm morphogenesis.

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Features of Morphogenesis of Aortic Aneurysms on the Background of Hypertension and Associated Risk Factors

Ukrainian journal of cardiovascular surgery ◽

10.30702/ujcvs/21.4306/z022062-066/091.8 ◽

2021 ◽

pp. 62-66

Author(s):

V. Zakharova ◽

O. Rudenko ◽

V. Kravchenko

Keyword(s):

Risk Factors ◽

Aortic Aneurysm ◽

Aortic Wall ◽

Elevated Pressure ◽

Aortic Aneurysms ◽

Vasa Vasorum ◽

Morphological Examination ◽

Ascending Aortic Aneurysm ◽

The Media ◽

Associated Risk Factors

The aim. To investigate the role of hypertension and associated risk factors in the formation of aortic aneurysms. Material and methods. Retrospective analysis of 196 case histories of patients who were successively operated on for ascending aortic aneurysm at the National Amosov Institute of cardiovascular surgery. The history was analyzed, the duration and degree of hypertension were recorded, as well as other factors that may have influenced the development of ascending aortic aneurysm in some way. A pathomorphological examination of fragments of the aortic wall that were excised during the operation was performed. Out of all 294 examined patients operated for ascending aortic aneurysm, hypertension was reported in 196 (66.7%) patients. The incidence of ascending aortic aneurysm positively correlated with the duration of hypertension. The ma-jority of patients (118 [60.2%]) had signs of hypertension for more than five years. Additional ethiopathogenetic fac-tors were identified in patients with ascending aortic aneurysm and hypertension, with atherosclerosis ranking first (66 [33.6%]). The next factors that demonstrated the same incidence were the inflammatory process in the aorta and AV, and smoking: 45 cases each (22.9%). Then, in descending order, were: xenobiotics exposure (43 [21.9%]), rheumatic stenosis of AV (40 [20.4%]), chest injury (33 [16.8%]), dysplasia of AV (28 [14.3%]), alcohol abuse (13 [6.6%]), Marfan syndrome (9 [4.6%]), other (8 [4.1%]). The results of comparison of the history and pathomorphological findings allowed to develop a scheme of ascending aortic aneurysm pathogenesis in hypertension. The scheme of ascending aortic aneurysm pathogenesis in hypertension is discussed in the work. The results of morphological examination show that hypertension is associated with the dam-age to the aortic endothelium, which leads to fibromuscular proliferation of the intima with subsequent hypoxic damage to the inner layer of the media. Hypoxic damage to the media, which is associated with vasa vasorum remodeling due to hypertension, is also observed in the subventricular layer. Weakening of the aortic wall at elevated pressure causes dila-tation of the aorta, i.e. the formation of an aortic aneurysm. This process may be exacerbated by additional factors, with atherosclerosis being the most common (33.6%)

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Abstract 672: Histopathological Comparison of Ascending Aortic Aneurysm: Bicuspid versus Tricuspid Aortic Valve Patients

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.35.suppl_1.672 ◽

2015 ◽

Vol 35 (suppl_1) ◽

Author(s):

Hiroaki Osada ◽

Katsuaki Meshii ◽

Motoaki Ohnaka ◽

Naoki Kanemitsu ◽

Hiroyuki Nakajima ◽

...

Keyword(s):

Smooth Muscle ◽

Aortic Valve ◽

Aortic Aneurysm ◽

Smooth Muscle Cells ◽

Aortic Wall ◽

Vasa Vasorum ◽

Ascending Aortic Aneurysm ◽

Tricuspid Aortic Valve ◽

Group B ◽

Elastic Lamina

Introduction: The pathogenic mechanisms of ascending aortic aneurysm are not fully understood. The aim of this study was to identify the beginning of aortic wall dilatation based on histopathological evaluation by comparison of patients with bicuspid versus tricuspid aortic valves. Methods: Twenty-one patients (9 males, 12 females; mean age, 69±8.9 years) who underwent ascending aortic repair from 2008 to 2014 were divided into bicuspid aortic valve (n=8, Group B) and tricuspid aortic valve (n=13, Group T) subgroups. We compared the histopathological characteristics of the ascending aortic wall in these patients. Results: There were no significant differences between the two groups in age, sex, history of hypertension, and maximum diameter of the ascending aorta (Group B: 51.4±5.1 mm; Group T: 55.5±8.8 mm; p=0.247) at the time of operation. While all Group B cases exhibited aortic stenosis, there was only one case in Group T. Sclerosis or hypertrophy of the vasa vasorum was evident in both groups (Group B: 7 patients, 87.5%; Group T: 10 patients, 76.9%; p=1.000). Group B patients exhibited a much thinner aortic wall, resulting from frail smooth muscle cells of media, which induced a fragile thinner elastic lamina. The histopathological pattern of Group T was variable and included atheroma, inflammatory granulation tissue and a Marfan-like acid mucopolysaccharide pool, which produce severe fragmentation of elastic lamina. Conclusions: Degeneration of the vasa vasorum, which induces chronic ischemia or malnutrition of the aortic wall, is an important emerging substrate for the development of ascending aortic aneurysm. Bicuspid aortic valve patients exhibited congenital maldevelopment of the medial smooth muscle cells and elastic lamina. Tricuspid aortic valve patients exhibited severe fragmentation of elastic lamina, which induced by pathological changes including atheroma, inflammatory granuloma, and a Marfan-like acid mucopolysaccharide pool.

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Open Distal Anastomosis Technique for Ascending Aortic Aneurysm Repair without Cerebral Perfusion

The Heart Surgery Forum ◽

10.1532/hsf.1284 ◽

2015 ◽

Vol 18 (4) ◽

pp. 124

Author(s):

Mehmet Kaplan ◽

Bahar Temur ◽

Tolga Can ◽

Gunseli Abay ◽

Adlan Olsun ◽

...

Keyword(s):

Aortic Aneurysm ◽

Cerebral Perfusion ◽

Circulatory Arrest ◽

Deep Hypothermic Circulatory Arrest ◽

Hypothermic Circulatory Arrest ◽

Distal Anastomosis ◽

Ascending Aortic Aneurysm ◽

Aortic Aneurysm Surgery ◽

Aneurysm Repair ◽

Aortic Aneurysm Repair

Background: This study aimed to report the outcomes of patients who underwent proximal thoracic aortic aneurysm surgery with open distal anastomosis technique but without cerebral perfusion, instead under deep hypothermic circulatory arrest.Methods: Thirty patients (21 male, 9 female) who underwent ascending aortic aneurysm repair with open distal anastomosis technique were included. The average age was 60.2±11.7 years. Operations were performed under deep hypothermic circulatory arrest and the cannulation for cardiopulmonary bypass was first done over the aneurysmatic segment and then moved over the graft. Intraoperative and early postoperative mortality and morbidity outcomes were reported.Results: Average duration of cardiopulmonary bypass and cross-clamps were 210.8±43 and 154.9±35.4 minutes, respectively. Average duration of total circulatory arrest was 25.2±2.4 minutes. There was one hospital death (3.3%) due to chronic obstructive pulmonary disease at postoperative day 22. No neurological dysfunction was observed during the postoperative period.Conclusion: These results demonstrate that open distal anastomosis under less than 30 minutes of deep hypothermic circulatory arrest without antegrade or retrograde cerebral perfusion and cannulation of the aneurysmatic segment is a safe and reliable procedure in patients undergoing proximal thoracic aortic aneurysm surgery.

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Epigenetic Profiling Identifies Novel Genes for Ascending Aortic Aneurysm Formation with Bicuspid Aortic Valves

The Heart Surgery Forum ◽

10.1532/hsf.1247 ◽

2015 ◽

Vol 18 (4) ◽

pp. 134 ◽

Cited By ~ 12

Author(s):

Asad A Shah

Keyword(s):

Gene Expression ◽

Aortic Aneurysm ◽

Methylation Status ◽

Aortic Aneurysms ◽

Aortic Valves ◽

Ascending Aortic Aneurysm ◽

Novel Genes ◽

Aneurysm Formation ◽

Aortic Replacement ◽

Bicuspid Aortic Valves

Background: Bicuspid aortic valves predispose to ascending aortic aneurysms, but the mechanisms underlying this aortopathy remain incompletely characterized. We sought to identify epigenetic pathways predisposing to aneurysm formation in bicuspid patients.Methods: Ascending aortic aneurysm tissue samples were collected at the time of aortic replacement in subjects with bicuspid and trileaflet aortic valves. Genome-wide DNA methylation status was determined on DNA from tissue using the Illumina 450K methylation chip, and gene expression was profiled on the same samples using Illumina Whole-Genome DASL arrays. Gene methylation and expression were compared between bicuspid and trileaflet individuals using an unadjusted Wilcoxon rank sum test. Results: Twenty-seven probes in 9 genes showed significant differential methylation and expression (P<5.5x10-4). The top gene was protein tyrosine phosphatase, non-receptor type 22 (PTPN22), which was hypermethylated (delta beta range: +15.4 to +16.0%) and underexpressed (log 2 gene expression intensity: bicuspid 5.1 vs. trileaflet 7.9, P=2x10-5) in bicuspid patients, as compared to tricuspid patients. Numerous genes involved in cardiovascular development were also differentially methylated, but not differentially expressed, including ACTA2 (4 probes, delta beta range: -10.0 to -22.9%), which when mutated causes the syndrome of familial thoracic aortic aneurysms and dissectionsConclusions: Using an integrated, unbiased genomic approach, we have identified novel genes associated with ascending aortic aneurysms in patients with bicuspid aortic valves, modulated through epigenetic mechanisms. The top gene was PTPN22, which is involved in T-cell receptor signaling and associated with various immune disorders. These differences highlight novel potential mechanisms of aneurysm development in the bicuspid population.

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