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American Journal of Physiology. Cell... May 2022Elastin is a long-lived extracellular matrix protein that is organized into elastic fibers that provide elasticity to the arterial wall, allowing stretch and recoil with... (Review)
Review
Elastin is a long-lived extracellular matrix protein that is organized into elastic fibers that provide elasticity to the arterial wall, allowing stretch and recoil with each cardiac cycle. By forming lamellar units with smooth muscle cells, elastic fibers transduce tissue-level mechanics to cell-level changes through mechanobiological signaling. Altered amounts or assembly of elastic fibers leads to changes in arterial structure and mechanical behavior that compromise cardiovascular function. In particular, genetic mutations in the elastin gene () that reduce elastin protein levels are associated with focal arterial stenosis, or narrowing of the arterial lumen, such as that seen in supravalvular aortic stenosis and Williams-Beuren syndrome. Global reduction of levels in mice allows investigation of the tissue- and cell-level arterial mechanical changes and associated alterations in smooth muscle cell phenotype that may contribute to stenosis formation. A loxP-floxed allele in mice highlights cell type- and developmental origin-specific mechanobiological effects of reduced elastin amounts. production is required in distinct cell types for elastic layer formation in different parts of the mouse vasculature. deletion in smooth muscle cells from different developmental origins in the ascending aorta leads to characteristic patterns of vascular stenosis and neointima. Dissecting the mechanobiological signaling associated with local depletion and subsequent smooth muscle cell response may help develop new therapeutic interventions for elastin-related diseases.
Topics: Animals; Aorta; Arteries; Constriction, Pathologic; Elastin; Mice; Myocytes, Smooth Muscle
PubMed: 35196168
DOI: 10.1152/ajpcell.00448.2021 -
Science Advances Sep 2023RIPK1 is crucial in the inflammatory response. The process of vascular graft remodeling is also involved in endothelial inflammation, which can influence the behavior of...
RIPK1 is crucial in the inflammatory response. The process of vascular graft remodeling is also involved in endothelial inflammation, which can influence the behavior of smooth muscle cells. However, the role of endothelial RIPK1 in arterial bypass grafts remains unknown. Here, we established an arterial isograft mouse model in wild-type and endothelial RIPK1 conditional knockout mice. Progressive vascular remodeling and neointima formation occurred in the graft artery, showing SMC accumulation together with endothelial inflammatory adhesion molecule and cytokine expression. Endothelial RIPK1 knockout exacerbated graft stenosis by increasing secretion of N-Shh. Mechanistically, RIPK1 directly phosphorylated EEF1AKMT3 at Ser, inhibiting its methyltransferase activity and global protein synthesis, which further attenuated N-Shh translation and secretion. Consistently, treatment with the Hedgehog pathway inhibitor GDC0449 markedly alleviated RIPK1 knockout-induced graft stenosis. Our results demonstrated that endothelial RIPK1 played a protective role in arterial bypass graft vascular remodeling, highlighting that targeting Hedgehog pathway may be an attractive strategy for graft failure in the future.
Topics: Animals; Mice; Arteries; Arteriosclerosis; Coleoptera; Constriction, Pathologic; Hedgehog Proteins; Mice, Knockout; Vascular Remodeling
PubMed: 37647392
DOI: 10.1126/sciadv.adh8939 -
Radiographics : a Review Publication of... 2022Patients who have undergone liver transplant are now regularly seen in day-to-day radiology practice. All surgical techniques for liver transplant require arterial,... (Review)
Review
Patients who have undergone liver transplant are now regularly seen in day-to-day radiology practice. All surgical techniques for liver transplant require arterial, portal venous, hepatic venous and caval, and biliary anastomoses. This review is focused on the 10 "not to be missed" complications of liver transplant that affect the health and life of the graft and graft recipient. Arterial complications are the most common and devastating. Early hepatic artery thrombosis may be catastrophic because the biliary tree is solely dependent on the hepatic artery after transplant and collateral vessels have not yet formed. In contrast, delayed hepatic artery thrombosis may be more insidious as collateral arteries develop. US findings of delayed hepatic artery thrombosis may be similar to those of hepatic artery stenosis and celiac artery stenosis. Splenic artery steal syndrome is an increasingly recognized cause of graft ischemia. Venous complications are much less common. Hepatic venous and caval complications are notable for their increased incidence in living-donor and pediatric transplants. Biliary complications often result from arterial ischemia. Biliary cast syndrome is a notable example in which ischemic biliary mucosa sloughs into and obstructs the duct lumens. Neoplasms also may occur within the hepatic graft and may be due to recurrent malignancy, posttransplant lymphoproliferative disorder, or metastases. US is the initial imaging modality of choice, particularly in the acute postoperative setting. Further evaluation with contrast-enhanced US, CT, or MRI; catheter angiography; endoscopic retrograde cholangiopancreatography; and/or nuclear medicine studies is performed as needed. RSNA, 2022.
Topics: Child; Constriction, Pathologic; Hepatic Artery; Humans; Ischemia; Liver; Liver Diseases; Liver Transplantation; Living Donors; Postoperative Complications; Retrospective Studies; Thrombosis; Vascular Diseases
PubMed: 35245104
DOI: 10.1148/rg.210108 -
VASA. Zeitschrift Fur Gefasskrankheiten Nov 2015Dealing with vascular compression syndromes is one of the most challenging tasks in Vascular Medicine practice. This heterogeneous group of disorders is characterised by... (Review)
Review
Dealing with vascular compression syndromes is one of the most challenging tasks in Vascular Medicine practice. This heterogeneous group of disorders is characterised by external compression of primarily healthy arteries and/or veins as well as accompanying nerval structures, carrying the risk of subsequent structural vessel wall and nerve damage. Vascular compression syndromes may severely impair health-related quality of life in affected individuals who are typically young and otherwise healthy. The diagnostic approach has not been standardised for any of the vascular compression syndromes. Moreover, some degree of positional external compression of blood vessels such as the subclavian and popliteal vessels or the celiac trunk can be found in a significant proportion of healthy individuals. This implies important difficulties in differentiating physiological from pathological findings of clinical examination and diagnostic imaging with provocative manoeuvres. The level of evidence on which treatment decisions regarding surgical decompression with or without revascularisation can be relied on is generally poor, mostly coming from retrospective single centre studies. Proper patient selection is critical in order to avoid overtreatment in patients without a clear association between vascular compression and clinical symptoms. With a focus on the thoracic outlet-syndrome, the median arcuate ligament syndrome and the popliteal entrapment syndrome, the present article gives a selective literature review on compression syndromes from an interdisciplinary vascular point of view.
Topics: Arterial Occlusive Diseases; Celiac Artery; Constriction, Pathologic; Diagnostic Imaging; Humans; Median Arcuate Ligament Syndrome; Popliteal Artery; Predictive Value of Tests; Prognosis; Risk Factors; Thoracic Outlet Syndrome
PubMed: 26515219
DOI: 10.1024/0301-1526/a000465 -
Journal of Visceral Surgery Apr 2021Arterial blood flow to the organs of the upper abdomen is provided by the celiac axis (CA) and the superior mesenteric artery (SMA) that communicate between each other...
Arterial blood flow to the organs of the upper abdomen is provided by the celiac axis (CA) and the superior mesenteric artery (SMA) that communicate between each other via the gastro-duodenal artery, the anterior and posterior pancreatico-duodenal arcades, the branches of the dorsal pancreatic artery and inconsistently, though a supplementary arcade that connects the CA and the SMA (arcade of Bühler). Celiac axis stenosis may or may not have a hemodynamic impact on the splanchnic circulation. Hemodynamically significant CA stenosis can be asymptomatic, or symptomatic with variables clinical consequences. Management depends on whether the mechanism of stenosis is extrinsic or intrinsic. When upper gastrointestinal interventional radiology or surgery is indicated, stenosis can pose technical difficulties or create severe ischemia requiring good understanding of this entity in the planning of operative steps and adapted management. Management of CA stenosis is therefore multidisciplinary and may involve interventional radiologists, gastrointestinal surgeons, vascular surgeons as well as medical physicians. Even though the prevalence of CA stenosis is relatively low (between 5 and 10%) and irrespective of its etiology, surgeons, radiologists and physicians must be aware of it because it can intervene in the management of upper gastrointestinal disease. It must be sought, and treatment must be adapted to each particular situation to avoid potentially severe complications.
Topics: Celiac Artery; Constriction, Pathologic; Gastrointestinal Diseases; Hepatic Artery; Humans; Mesenteric Artery, Superior
PubMed: 33191149
DOI: 10.1016/j.jviscsurg.2020.10.005 -
Vascular Medicine (London, England) Feb 2021
Topics: Celiac Artery; Chronic Disease; Constriction, Pathologic; Humans; Ischemia; Mesenteric Arteries; Mesenteric Artery, Superior; Mesenteric Ischemia; Mesenteric Vascular Occlusion; Stents
PubMed: 33357138
DOI: 10.1177/1358863X20979734 -
Magnetic Resonance Imaging Dec 2022Intracranial atherosclerotic stenosis of a major intracranial artery is the common cause of ischemic stroke. We evaluate the feasibility of using deep learning to... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND AND OBJECTIVES
Intracranial atherosclerotic stenosis of a major intracranial artery is the common cause of ischemic stroke. We evaluate the feasibility of using deep learning to automatically detect intracranial arterial steno-occlusive lesions from time-of-flight magnetic resonance angiography.
METHODS
In a retrospective study, magnetic resonance images with radiological reports of intracranial arterial stenosis and occlusion were extracted. The images were randomly divided into a training set and a test set. The manual annotation of lesions with a bounding box labeled "moderate stenosis," "severe stenosis," "occlusion," and "absence of signal" was considered as ground truth. A deep learning algorithm based on you only look once version 5 (YOLOv5) detection model was developed with the training set, and its sensitivity and positive predictive values to detect lesions were evaluated in the test set.
RESULTS
A dataset of 200 examinations consisted of a total of 411 lesions-242 moderate stenoses, 84 severe stenoses, 70 occlusions, and 15 absence of signal. The magnetic resonance images contained 291 lesions in the training set and 120 lesions in the test set. The sensitivity and positive predictive values were 64.2 and 83.7%, respectively. The detection sensitivity in relation to the location was greatest in the internal carotid artery (86.2%).
CONCLUSIONS
Applying deep learning algorithms in the automated detection of intracranial arterial steno-occlusive lesions from time-of-flight magnetic resonance angiography is feasible and has great potential.
Topics: Humans; Carotid Artery, Internal; Carotid Stenosis; Constriction, Pathologic; Deep Learning; Magnetic Resonance Angiography; Retrospective Studies
PubMed: 36174873
DOI: 10.1016/j.mri.2022.09.006 -
Vascular Medicine (London, England) Dec 2022This study aims to evaluate changes in the arterial spectral Doppler waveform in a canine artery stenosis model.
INTRODUCTION
This study aims to evaluate changes in the arterial spectral Doppler waveform in a canine artery stenosis model.
METHODS
Canine femoral artery stenosis models were established in 12 beagle dogs. Doppler waveforms were recorded in the femoral artery preoperatively and postoperatively in the femoral artery and at the ankle after formation of a 50%, 70%, and 90% stenosis or occlusion. Major descriptors for arterial Doppler waveform were used to analyse waveforms.
RESULTS
The proportion of multiphasic waveforms proximal to a moderate stenosis decreased compared to normal baseline, although the difference was not statistically significant, whereas the decreases at the stenosis, distal to the stenosis, and at the ankle were significant ( < 0.05). The decreases in arteries with a more severe stenosis or occlusion were significant at all locations ( < 0.05). The proportion of high resistive waveforms decreased significantly at the ankle in the arteries with a moderate stenosis (50%) ( = 0.002), but the decreases proximal to, at, and distal to the stenosis were not significant. The decreases were significant at all locations in the arteries with a more severe stenosis ( < 0.05). The decrease was significant at the ankle in the arteries with an occlusion ( < 0.001) but not significant pre, at, and post an occlusion.
CONCLUSIONS
Phasicity and resistance of Doppler waveforms alter in canine femoral arteries with a stenosis. Phasicity change seems more sensitive in response to an arterial stenosis than resistance change. Additional information on arterial resistance could be obtained using end-diastolic ratios, resistive indices, and potentially end-systolic notch velocity measurements.
Topics: Humans; Animals; Dogs; Femoral Artery; Constriction, Pathologic
PubMed: 36000474
DOI: 10.1177/1358863X221117608 -
European Radiology Jun 2022• TOF MRA is very important in the evaluation of cerebrovascular stenosis, and a novel evaluation system can further enhance its strengths.• This evaluation system...
• TOF MRA is very important in the evaluation of cerebrovascular stenosis, and a novel evaluation system can further enhance its strengths.• This evaluation system is more accurate based on the fact that cerebral vascular stenosis alters hemodynamics and leads to different imaging presentations.
Topics: Arteries; Cerebral Angiography; Constriction, Pathologic; Humans; Magnetic Resonance Angiography
PubMed: 35076760
DOI: 10.1007/s00330-021-08521-5 -
Annals of Biomedical Engineering Jun 2023In order to study the influence of different vascular stenosis rates and stent-to-artery ratios on the fatigue strength and reliability of lower limb arterial stents,... (Review)
Review
In order to study the influence of different vascular stenosis rates and stent-to-artery ratios on the fatigue strength and reliability of lower limb arterial stents, numerical simulation was conducted for the fatigue strength of complete SE stents under pulsating loads using a finite element method. Then, fracture mechanics and conditional probability theory were adopted for mathematical modeling, whereby analyzing the crack growth rate and reliability with stents of different thickness (0.12, 0.15, and 0.18 mm) at different vascular stenosis rates (30, 50, and 70%) and stent-to-artery ratios (80, 85, and 90%). The study found: all three stents of different thickness failed to meet 10-year service life at three vascular stenosis rates; all three stents of different thickness met 10-year service life at three stent-to-artery ratios. With increased vascular stenosis rate, the elastic strain of stents was increased, while the fatigue strength was decreased; with increased stent-to-artery ratio, the elastic strain of the stent was increased, while the reliability of the stent was reduced. After the stent with an initial crack was implanted into the vessel, the crack length underwent non-linear growth with increased pulsating cyclic loads. When the pulsating load reached 3 × 10, the growth rate of the crack on the stent surface increased exponentially, leading to a rapid decrease in reliability. Vascular stenosis rate, stent release ratio, and support thickness have significant effects on crack length propagation rate and reliability. Determining the influence of vascular stenosis rate and stent-to-artery ratio on the fatigue strength and reliability of stents provides a valuable reference for evaluating the fracture failure rate and safety of stents.
Topics: Humans; Constriction, Pathologic; Reproducibility of Results; Stress, Mechanical; Finite Element Analysis; Stents; Arteries; Prosthesis Design
PubMed: 36939956
DOI: 10.1007/s10439-023-03165-6