ILT thickness appeared to be associated with VSMCs apoptosis and elastin degradation and was positively associated with MMP-2 concentrations in the underlying wall. This suggests that ILT thickness affects AAA wall stability and might contribute to AAA growth and rupture. ILT thickness was not correlated with markers of lipid oxidation.

A bdominal aortic aneurysm (AAA) is an abnormal focal dilation of the aortic wall that affects 5% of men aged 60 years. The risk of aortic rupture increases with AAA size, and AAA rupture is associated with a 80% to 90% mortality rate.1 Currently, the only treatment option for AAA is open or endovascular surgery; however, there is significant interest in developing medical therapies to limit AAA growth and rupture. [2][3][4] Osteoprotegerin (OPG) is a secreted glycoprotein member of the tumor necrosis factor receptor superfamily.5 It acts as a decoy receptor for receptor activator of nuclear factor kB ligand (RANKL) and tumor necrosis factorrelated apoptosis-inducing ligand.6 Cells described to secrete OPG include osteoblasts, endothelial cells, human aortic vascular smooth muscle cells (VSMCs), dendritic cells, lymphocytes, and plasma cells. [7][8][9] OPG is a key regulator of bone remodeling 5,10 but has also been implicated in tumorigenesis, immunologic pathways, and vascular diseases. 6,7,[11][12][13][14][15] The precise role of OPG in vascular disease is currently controversial.Evidence from animal studies suggests that OPG prevents arterial calcification and stabilizes plaque formation. 16,17 However, clinical studies have associated serum OPG concentrations with the presence and progression of cardiovascular disease. [18][19][20][21] Circulating OPG concentrations have also been reported to be higher in patients with AAA and positively associated with AAA progression. 4,22 In vitro experiments have suggested that OPG stimulates matrix metalloprotease (MMP) secretion from human monocytes and VSMCs, and that OPG secretion is downregulated by irbesartan. 4 These data suggest a potential role of OPG in AAA; however, currently we are aware of no studies that have reported the concentration of OPG in human AAA biopsies.The aim of this study was to assess the concentration of OPG in a large number of AAA biopsies and assess whether OPG expression was related to markers of AAA severity. We hypothesized that OPG is locally produced in vessel walls of patients with AAA disease and is associated with markers of aortic proteolysis. Osteoprotegerin is Associated With Aneurysm diameter and Proteolysis in Abdominal Aortic Aneurysm disease Patient inclusionIn this study, consecutive patients undergoing open repair of intact or ruptured AAA were included. The indications for intervention were based on current guidelines and included the following: AAA diameter exceeding 55 mm for males, AAA diameters between 50 and 55 mm for females, rapidly expanding aortic diameters (5 mm in 6 months with a minimum diameter of 40 mm), saccular aneurysms, symptoms attributable to AAA and AAA rupture. 1,24 Patients with AAA diameters between 50 and 55 mm were selected for surgery based on the clinical judgment of the surgeon and in consultation with the patient. Open repair was performed in patients in whom AAAs were not anatomically suited for endovascular repair. Patients with terminal malignancies or severe dementia were excluded ...

IntroductionExtracranial carotid artery aneurysms (ECAA) are rare but may be accompanied with significant morbidity. Previous studies mostly focused on diagnostic imaging and treatment. In contrast, the pathophysiological mechanisms and natural course of ECAA are largely unknown. Understanding the pathophysiological background may add to prediction of risk for adverse outcome and need for surgical exclusion. The aim of this study was to investigate the histopathological characteristics of ECAA in patients who underwent complete surgical ECAA resection.Material and MethodsFrom March 2004 till June 2013, 13 patients were treated with open ECAA repair. During surgery the aneurysm sac was resected and processed for standardized histological analysis. Sections were stained with routine hematoxylin and eosin and special stains to detect elastin, collagen, different types of inflammatory cells, vascular smooth muscle cells and endothelial cells.ResultsHistopathological characterization revealed two distinct categories: dissection (abrupt interruption of the media; n = 3) and degeneration (general loss of elastin fibers in the media; n = 10). In the degenerative samples the elastin fibers in the media were fragmented and were partly absent. Inflammatory cells were observed in the vessel wall of the aneurysms.ConclusionHistological analysis in this small sample size revealed dissection and degeneration as the two distinct underlying mechanisms in ECAA formation.