Search results for "Thoracic aorta"
showing 10 items of 56 documents
Decreased bioavailability of nitric oxide in aorta from ovariectomized senescent mice. Role of cyclooxygenase.
2015
This study investigates the effects of aging and/or ovariectomy on vascular reactivity to thromboxane A2 (TXA2) receptor stimulation with U46619, and the modulation by nitric oxide (NO) and cyclooxygenase (COX) in aorta from female senescence-accelerated mice (SAMP8) and from senescence resistant mice (SAMR1). Five-month-old female SAMR1 and SAMP8 were divided into three groups: sham-operated, ovariectomized and ovariectomized plus estradiol. Twenty-eight days after surgery, thoracic aortic rings were mounted for isometric recording of tension and concentration-response curves for U46619 (10(-10)-3 × 10(-7) M) were performed in the absence and in the presence of the NO synthase inhibitor N(…
Patterns of ascending aortic dilatation and predictors of surgical replacement of the aorta: A comparison of bicuspid and tricuspid aortic valve pati…
2019
Abstract Background Predictors of thoracic aorta growth and early cardiac surgery in patients with bicuspid aortic valve are undefined. Our aim was to identify predictors of ascending aorta dilatation and cardiac surgery in patients with bicuspid aortic valve (BAV). Methods Forty-one patients with BAV were compared with 165 patients with tricuspid aortic valve (TAV). All patients had LV EF > 50%, normal LV dimensions, and similar degree of aortic root or ascending aorta dilatation at enrollment. Patients with more than mild aortic stenosis or regurgitation were excluded. A CT-scan was available on 76% of the population, and an echocardiogram was repeated every year for a median time of 4 ye…
Regulation of PDE5 expression in human aorta and thoracic aortic aneurysms
2019
AbstractAneurysms and dissections affecting thoracic aorta are associated with smooth muscle cell (SMC) dysfunction. NO/cGMP signaling pathway in smooth muscle cells has been shown to be affected in sporadic thoracic aortic aneurysms. We analyzed the mRNA levels of PDE5, a cGMP-hydrolyzing enzyme highly expressed in aortic SMCs, that regulates arterious vascular tone by lowering cGMP levels. We found that aortic tissue obtained from Marfan, tricuspid and bicuspid thoracic aneurysms expressed lower levels of PDE5 mRNA compared to control aortas. In particular, we found that affected aortas showed lower levels of all the PDE5A isoforms, compared to control aortas. Transfection of vascular SMC…
Restoration of perivascular adipose tissue function in diet-induced obese mice without changing bodyweight
2017
Background and Purpose We have recently shown that a reduced function of endothelial nitric oxide synthase (eNOS) in the perivascular adipose tissue (PVAT) contributes crucially to obesity-induced vascular dysfunction in mice. The current study was conducted to test the hypothesis that vascular dysfunction in obesity can be reversed by in vivo improvement of PVAT eNOS activity. Experimental Approach Male C57BL/6 J mice were fed a high-fat diet (HFD) for 22 weeks to induce obesity. During the last 4 weeks of HFD feeding, the obese mice were treated orally with the standardized Crataegus extract WS® 1442 which has been shown previously to improve eNOS activity. Key Results Diet-induced obesit…
Periscopes, chimneys, sandwich and VORTEC to facilitate abdominal and thoracoabdominal aortic aneurysm repair
2012
The VORTEC (VIABAHN open revascularization technique) and the chimney graft technique are tools with which to maintain or restore blood flow to the aortic branches and can be used intentionally or as a bailout procedure in open surgery or endovascular procedures. VORTEC is a stent graft-based vascular connection technique that achieves end-to-end anastomosis configuration; it is especially useful when the traditional suture technique proves (can be) cumbersome. It is also a speedy tool with virtually no blood flow interruption and no anastomotic bleeding, and patency rates compare favorably with sutured anastomosis. The chimney/periscope, as well as the sandwich graft technique (CHIMPES), i…
Effect of aneurysm on the mechanical dissection properties of the human ascending thoracic aorta
2012
Objectives: The acute dissection of an ascending thoracic aortic aneurysm (ATAA) represents a devastating separation of elastic layers occurring when the hemodynamic loads on the diseased wall exceed the adhesive strength between layers. At present, the mechanics underlying aortic dissection are largely unclear, and the biomechanical delamination properties of the aneurysmal aorta are not defined. Individuals with bicuspid aortic valve (BAV) are particularly predisposed to ascending aortic aneurysm formation, with a marked risk of aortic dissection. The purpose of this study was to evaluate and compare the dissection properties of nonaneurysmal and aneurysmal human ascending thoracic aorta …
Biomechanical implications of excessive endograft protrusion into the aortic arch after thoracic endovascular repair
2015
Endografts placed in the aorta for thoracic endovascular aortic repair (TEVAR) may determine malappositioning to the lesser curvature of the aortic wall, thus resulting in a devastating complication known as endograft collapse. This premature device failure commonly occurs in young individuals after TEVAR for traumatic aortic injuries as a result of applications outside the physical conditions for which the endograft was designed. In this study, an experimentally-calibrated fluid-structure interaction (FSI) model was developed to assess the hemodynamic and stress/strain distributions acting on the excessive protrusion extension (PE) of endografts deployed in four young patients underwent TE…
Ambulatory follow-up of aortic dissection by transesophageal two-dimensional and color-coded Doppler echocardiography.
1989
Follow-up of 18 patients with aortic dissection (five with type I, one with type II, 11 with type III dissection according to DeBakey) by transesophageal, two-dimensional and color-coded Doppler echocardiography showed a persistence of the false lumen in five of seven patients (71%) after surgery and in nine of 11 patients (82%) after medical therapy. In two patients treated with surgery, the dissected part of the aorta had been resected, whereas in two patients treated medically, a progressive and complete obliteration of the false lumen was observed. In the false lumen, thrombus formation was absent in four, localized in four, and progressive in six patients. Flow within the false lumen c…
Assessment of chronic aortic dissection: contribution of different ECG-gated breath-hold MRI techniques.
2004
Our objective was to evaluate the impact of different rapid MRI techniques for the assessment and follow-up of chronic aortic dissections.Fifty-three patients (41 postoperative Stanford type A, 12 type B dissections) were scanned at 1.5 T during a 3-year period. The study reviewed ECG-gated breath-hold black blood sequences and 3D contrast-enhanced MR angiography of the thoracic aorta supplemented by segmented cine and phase-contrast imaging as well as abdominal contrast-enhanced MR angiography. A retrospective separate analysis of black blood acquisitions and contrast-enhanced MR angiograms from a total of 72 examinations was performed by two radiologists to evaluate detection of intimal f…
Non-invasive diagnosis in a case of bronchopulmonary sequestration and proposal of diagnostic algorhythm
2008
The case of a 43-year-old woman with intralobar pulmonary sequestration, Pryce type one, is presented. The medical history was characterised by recurrent bronchopneumonia, productive cough with purulent sputum and hemoptysis in the last three years. Diagnosis was made by CT angiography: multiplanar, maximum intensity projection and volume rendering reconstructions were visualised. A volume reduction of middle and lower lobe with multiple cyst-like bronchiectasis was detected and no evident relationship with tracheobronchial tree was pointed out. Reconstructions aimed at evaluating bronchial structures demonstrated no patency of middle and lower lobar bronchi. The study carried out after con…