Search results for "Tunica Media"

Potential Functional Significance of Brain-Type and Muscle-Type Nitric Oxide Synthase I Expressed in Adventitia and Media of Rat Aorta

1999

Abstract —Skeletal muscle and myocardium express μNOS I, an elongated splice variant of neuronal-type nitric oxide (NO) synthase (NOS I), and NOS III, endothelial-type NO synthase, respectively. This study was designed to elucidate whether vascular smooth muscle also contains a constitutively expressed NO synthase isoform. In the rat, μNOS I contains an insert of 102 nucleotides after nucleotide 2865 of the cDNA, yielding a protein of 164 kd. Reverse transcription-polymerase chain reaction with primers flanking this insert and with insert-specific primers indicated that endothelium-denuded rat aorta expresses both brain-type NOS I and μNOS I. RNase protection analyses with an antisense RNA…

Fiber Micro-Architecture in the Longitudinal-Radial and Circumferential-Radial Planes of Ascending Thoracic Aortic Aneurysm Media.

2013

It was recently demonstrated by our group that the delamination strength of ascending thoracic aortic aneurysms (ATAA) was lower than that of control (CTRL, non-aneurysmal) ascending thoracic aorta (ATA), and the reduced strength was more pronounced among bicuspid (BAV) vs. tricuspid aortic valve (TAV) patients, suggesting a different risk of aortic dissection for BAV patients. We hypothesized that aortic valve morphologic phenotype predicts fiber micro-architectural anomalies in ATA. To test the hypothesis, we characterized the micro-architecture in the longitudinal-radial (Z-RAD) and circumferential-radial (Θ-RAD) planes of human ATA tissue that was artificially dissected medially. The ou…

Combining Sirolimus-eluting Stents and External Irradiation in Cholesterol-fed Rabbits Increased Incomplete Stent Apposition and Decreased Re-endothe…

2009

Restenosis after the implantation of a drug-eluting stent or after vascular irradiation therapy shares similar physiopathological mechanisms. No experimental data are currently available on vascular wall behavior after external irradiation on arteries stented with sirolimus-eluting stents (SES). Ten New Zealand white rabbits received a 0.5% cholesterol-enriched chow for 1 month. Bilateral iliac artery stent implantation was then performed with an SES (Cypher; Cordis Corp). The animals were randomized into either an irradiated group (I, 2 Gy external x-ray irradiation, n = 5) or a control group (C, n = 5). The cholesterol-enriched chow was continued for 1 additional month after stent implant…

Biomechanical properties and histomorphometric features of aortic tissue in patients with or without bicuspid aortic valve

2020

Background We sought to investigate and compare biomechanical properties and histomorphometric findings of thoracic ascending aorta aneurysm (TAA) tissue from patients with bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) in order to clarify mechanisms underlying differences in the clinical course. Methods Circumferential sections of TAA tissue in patients with BAV (BAV-TAA) and TAV (TAV-TAA) were obtained during surgery and used for biomechanical tests and histomorphometrical analysis. Results In BAV-TAA, we observed biomechanical higher peak stress and lower Young modulus values compared with TAV-TAA wall. The right lateral longitudinal region seemed to be the most fragile zon…

Radiologic and Intraoperative Finding of Intimal Tear in Type A Intramural Hematoma of the Aorta

2019

AbstractAortic intramural hematoma (IMH) is described as “dissection without intimal tear” due to rhexis of vasa vasorum, which results in bleeding within the tunica media in the absence of intimal disruption or blood flow communication. The aim of our study is to validate perioperative evidence of intimal entry tear in IMH patients and to suggest that this entity may represent a part of a disease and not a separate disease.

Asymptomatic Carotid Lesion as a Marker of Future Cerebrovascular and Cardiovascular Events

2003

Cystic Medial Necrosis of the Internal Thoracic Artery:Case Report

1996

In an internal thoracic artery intended as a graft in coronary angioplasty, multiple intramural haematomas impeded blood flow and consequently precluded use of the artery as a free graft. The cause was found to be cystic medical necrosis of the internal thoracic artery. A good result was obtained with three single aorto-coronary venous bypass grafts.

Evidence of intimal tear in type A intramural hematoma of the aorta: A case series

2017

Highlights • We report two cases of type A intramural hematoma of the aorta. • We found radiological and intraoperative evidence of an intimal tear. • This finding supports the hypotesis that IMH belong to “aortic dissection” disease.

Resistance of the internal mammary artery to restenosis: a histomorphologic study of various porcine arteries.

2007

<i>Background/Aims:</i> Restenosis after percutaneous transluminal angioplasty (PTA) of the internal mammary artery (IMA) grafts is much less pronounced than in other arteries and venous grafts. The aim of the study was to test whether various arteries respond differently to dilatation. <i>Methods:</i> PTA of the IMA, carotid, renal and circumflex coronary (RCx) arteries was performed in 9 pigs (balloon to artery ratio of 1:1.5). After 8 weeks, angiography was repeated and vessels prepared for histological analysis. Immunohistochemical staining was done to examine proliferative activity (Ki67) and to identify the vasa vasorum of the adventitia (F VIII-RA). <i>R…