Search results for "blood vessel"
showing 10 items of 323 documents
Mid-term results of zone 0 thoracic endovascular aneurysm repair after ascending aorta wrapping and supra-aortic debranching in high-risk patients
2017
Objectives Surgical repair of aneurysmal disease involving the ascending aorta, aortic arch and eventually the descending aorta is generally associated with significant morbidity and mortality. A less invasive approach with the ascending wrapping technique (WT), supra-aortic vessel debranching (SADB) and thoracic endovascular aneurysm repair (TEVAR) in zone 0 was developed to reduce the associated risk in these patients. Methods During a 10-year period, consecutive patients treated by the ascending WT, SADB and TEVAR in zone 0 were included. All patients were considered at high risk for conventional surgery. Measured outcomes included perioperative deaths and morbidity, maximal aortic trans…
The pre-vascularisation of a collagen-chondroitin sulphate scaffold using human amniotic fluid-derived stem cells to enhance and stabilise endothelia…
2015
Abstract A major problem in tissue engineering (TE) is graft failure in vivo due to core degradation in in vitro engineered constructs designed to regenerate thick tissues such as bone. The integration of constructs post-implantation relies on the rapid formation of functional vasculature. A recent approach to overcome core degradation focuses on the creation of cell-based, pre-engineered vasculature formed within the TE construct in vitro , prior to implantation in vivo . The primary objective of this study was to investigate whether an amniotic fluid-derived stem cell (AFSC)–human umbilical vein endothelial cell (HUVEC) co-culture could be used to engineer in vitro vasculature in a collag…
The Role of Osteoprotegerin and Its Ligands in Vascular Function
2019
International audience; The superfamily of tumor necrosis factor (TNF) receptors includes osteoprotegerin (OPG) and its ligands, which are receptor activators of nuclear factor kappa-B ligand (RANKL) and TNF-related apoptosis-inducing ligand (TRAIL). The OPG/RANKL/RANK system plays an active role in pathological angiogenesis and inflammation as well as cell survival. It has been demonstrated that there is crosstalk between endothelial cells and osteoblasts during osteogenesis, thus establishing a connection between angiogenesis and osteogenesis. This OPG/RANKL/RANK/TRAIL system acts on specific cell surface receptors, which are then able to transmit their signals to other intracellular comp…
Endovascular treatment of large and wide aortic neck: case report and literature review
2017
Large (24–34 mm) and wide (≥35 mm) aortic necks are a contraindication to endovascular aneurysm repair (EVAR). A 63-year-old man, unfit for conventional surgery, presented a 79 mm abdominal aortic aneurysm with 36.5 mm aortic neck and a 62 mm right common iliac artery aneurysm. He was treated endovascularly with standard commercially available stent-graft using the so-called ‘funnel technique’; by placing a thoracic stent-graft inside a bifurcated device to achieve proximal sealing. The completion angiography and the 6 months follow-up with computed tomography showed no stent-graft migration, limb occlusion or endoleak. The literature review reported 179 cases of large aortic neck managed w…
Assessment of conduit artery vasomotion using photoplethysmography
2013
Vasomotion is a spontaneous oscillation of vascular tone. The phenomenon has been observed in small arterioles and capillaries as well as in the large conduit arteries. The layer of smooth muscle cells that surrounds a blood vessel can spontaneously and periodically change its tension and thereby the arterial wall stiffness also changes. As the understanding of the phenomenon is still rather obscure, researchers would benefit from a low-cost and reliable investigation technique such as photoplethysmography (PPG). PPG is an optical blood pulsation measurement technique that can offer substantial information about the arterial stiffness. The aims of this pilot study were to evaluate the usefu…
Nitric Oxide Opposes Myogenic Pressure Responses Predominantly in Large Arterioles In Vivo
1998
Abstract —A myogenic vasoconstriction may amplify the effects of circulating vasoconstrictors. In cremaster arterioles, the contribution of a myogenic component to the constriction on intravenous infusion of norepinephrine (NE) or angiotensin II (Ang II) was studied. Second, the role of endothelium-derived nitric oxide (NO) in the control of these myogenic constrictions and its site of action in the resistance vascular bed was investigated. In 30 anesthetized (pentobarbital) hamsters, the cremaster was prepared for intravital microscopy, and a pneumatic vessel occluder was placed around the aorta to vary blood pressure in the hindquarter of the animal. Intravenous infusion of NE (0.5 nmol/…
External Volume Expansion Increases Subcutaneous Thickness, Cell Proliferation, and Vascular Remodeling in a Murine Model
2012
Background Fat grafting is a powerful tool for soft-tissue reconstruction; however, the science behind recipient bed preparation has not been thoroughly explored. External volume expansion using suction before fat grafting has been used clinically to improve reliability and consistency of graft survival. The authors developed a murine model to investigate the underlying mechanism of external volume expansion. Methods The authors created an external volume expansion device using a soft-silicone dome connected to a vacuum source (25 mmHg) to treat the dorsum of mice, and the response was compared with treatment with an occlusive dressing. Treated areas were monitored with magnetic resonance i…
Preclinical carotid atherosclerosis enhances the global cardiovascular risk and increases the rate of cerebro- and cardiovascular events in a five-ye…
2009
AIM: To evaluate if the intima-media thickening (IMT) and asymptomatic carotid plaque (ACP), as expression of carotid preclinical atherosclerosis (pre-ATS), can provide further information on the global cardiovascular risk (GCVR). METHODS: We studied 454 asymptomatic subjects, with a cluster of risk factors (RF), and evaluated the incidence of a first cardiovascular (CV) event in a five-year follow-up. The subjects at admission were subdivided in three groups of risk. RESULTS: Events occurred in 38% of subjects at high risk, in 13% and 6% of subjects at intermediate and low risk (p<0.003). Among evaluated parameters, carotid pre-ATS was a predictive marker of CV events (OR 2.7, 95% IC 1.4-5…
Effects of sildenafil on human penile blood vessels.
2000
Abstract Objectives. To investigate the effects of sildenafil on human penile blood vessels and evaluate the interaction of sildenafil with neurogenic-mediated responses. Sildenafil is currently used in the treatment of erectile dysfunction. Methods. Penile dorsal arteries and deep dorsal veins were obtained from 14 multiorgan donors. Vascular rings were suspended in organ bath chambers, and the isometric tension was recorded. We then studied the effects of sildenafil on precontracted vessels and the neurogenic (noradrenergic and nitrergic) responses. Results. Sildenafil (10 −9 to 3 × 10 −6 M) caused concentration-dependent relaxation and amplified the relaxation induced by sodium nitroprus…
Obstructive uropathy following aortofemoral graft surgery.
1991
Fifty patients who had undergone aorto-bifemoral bypass with a bifurcated Dacron graft for aortoiliac arteriosclerotic obliteration were examined with real-time sectorial ultrasound to screen for the presence of hydronephrosis. Hydronephrosis was detected in only 1 case. The low incidence of this complication in our cases may be due to the fact that all our patients were explored at least 1 year after surgery. Some may have developed hydronephrosis early, but this may have resolved spontaneously during the first year after the operation, thus remaining undiagnosed. Pathogenic mechanisms suggested for the development of hydronephrosis and therapeutic approaches are discussed. We conclude tha…