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Critical Care (London, England) May 2022Venous return is the flow of blood from the systemic venous network towards the right heart. At steady state, venous return equals cardiac output, as the venous and... (Review)
Review
Venous return is the flow of blood from the systemic venous network towards the right heart. At steady state, venous return equals cardiac output, as the venous and arterial systems operate in series. However, unlike the arterial one, the venous network is a capacitive system with a high compliance. It includes a part of unstressed blood, which is a reservoir that can be recruited via sympathetic endogenous or exogenous stimulation. Guyton's model describes the three determinants of venous return: the mean systemic filling pressure, the right atrial pressure and the resistance to venous return. Recently, new methods have been developed to explore such determinants at the bedside. In this narrative review, after a reminder about Guyton's model and current methods used to investigate it, we emphasize how Guyton's physiology helps understand the effects on cardiac output of common treatments used in critically ill patients.
Topics: Blood Pressure; Cardiac Output; Heart; Humans; Models, Cardiovascular; Vascular Resistance; Veins
PubMed: 35610620
DOI: 10.1186/s13054-022-04024-x -
Diagnostic and Interventional Radiology... Jan 2022Abernethy malformation is a rare condition in which portomesenteric blood bypasses the liver and drains into the systemic vein through a partial or complete shunt. It is... (Review)
Review
Abernethy malformation is a rare condition in which portomesenteric blood bypasses the liver and drains into the systemic vein through a partial or complete shunt. It is categorised into two types on the basis of the shunt pattern between the portal vein and systemic vein. Abernethy malformation is associated with multiple congenital anomalies and acquired complications. A detailed understanding of anatomy and embryology is a prerequisite to interpret the imaging findings. Computed tomography and magnetic resonance angiography can delineate the shunt anatomy and evaluate the concomitant malformations. It is essential to differentiate Abernethy malformation from intrahepatic portosystemic shunts and acquired extrahepatic portosystemic shunts. Mild metabolic abnormalities are treated with dietary modifications and medical therapy. Definitive treatment is done in symptomatic patients. Generally, type I Abernethy patients undergo liver transplantation, and type II undergo shunt occlusion by surgery or transcatheter coiling.
Topics: Humans; Liver Neoplasms; Liver Transplantation; Portal Vein; Portasystemic Shunt, Surgical; Vascular Malformations
PubMed: 34914605
DOI: 10.5152/dir.2021.20474 -
Circulation Jul 2021Cellular diversity of the lung endothelium has not been systematically characterized in humans. We provide a reference atlas of human lung endothelial cells (ECs) to...
BACKGROUND
Cellular diversity of the lung endothelium has not been systematically characterized in humans. We provide a reference atlas of human lung endothelial cells (ECs) to facilitate a better understanding of the phenotypic diversity and composition of cells comprising the lung endothelium.
METHODS
We reprocessed human control single-cell RNA sequencing (scRNAseq) data from 6 datasets. EC populations were characterized through iterative clustering with subsequent differential expression analysis. Marker genes were validated by fluorescent microscopy and in situ hybridization. scRNAseq of primary lung ECs cultured in vitro was performed. The signaling network between different lung cell types was studied. For cross-species analysis or disease relevance, we applied the same methods to scRNAseq data obtained from mouse lungs or from human lungs with pulmonary hypertension.
RESULTS
Six lung scRNAseq datasets were reanalyzed and annotated to identify >15 000 vascular EC cells from 73 individuals. Differential expression analysis of EC revealed signatures corresponding to endothelial lineage, including panendothelial, panvascular, and subpopulation-specific marker gene sets. Beyond the broad cellular categories of lymphatic, capillary, arterial, and venous ECs, we found previously indistinguishable subpopulations; among venous EC, we identified 2 previously indistinguishable populations: pulmonary-venous ECs (COL15A1) localized to the lung parenchyma and systemic-venous ECs (COL15A1) localized to the airways and the visceral pleura; among capillary ECs, we confirmed their subclassification into recently discovered aerocytes characterized by , , and and general capillary EC. We confirmed that all 6 endothelial cell types, including the systemic-venous ECs and aerocytes, are present in mice and identified endothelial marker genes conserved in humans and mice. Ligand-receptor connectome analysis revealed important homeostatic crosstalk of EC with other lung resident cell types. scRNAseq of commercially available primary lung ECs demonstrated a loss of their native lung phenotype in culture. scRNAseq revealed that endothelial diversity is maintained in pulmonary hypertension. Our article is accompanied by an online data mining tool (www.LungEndothelialCellAtlas.com).
CONCLUSIONS
Our integrated analysis provides a comprehensive and well-crafted reference atlas of ECs in the normal lung and confirms and describes in detail previously unrecognized endothelial populations across a large number of humans and mice.
Topics: Biomarkers; Capillaries; Computational Biology; Databases, Genetic; Disease Susceptibility; Endothelial Cells; Gene Expression Profiling; High-Throughput Nucleotide Sequencing; Humans; Lung; Microcirculation; Organ Specificity; Pulmonary Artery; Pulmonary Veins; Single-Cell Analysis; Transcriptome
PubMed: 34030460
DOI: 10.1161/CIRCULATIONAHA.120.052318 -
RoFo : Fortschritte Auf Dem Gebiete Der... Feb 2022Portal vein thrombosis (PVT) is a rare but severe entity that can cause clinically significant sequela such as worsening portal hypertension or mesenteric ischemia.... (Review)
Review
BACKGROUND
Portal vein thrombosis (PVT) is a rare but severe entity that can cause clinically significant sequela such as worsening portal hypertension or mesenteric ischemia. Those cases refractory to medical management may be referred for endovascular intervention. Several technical considerations have been described in the literature, but a cohesive comparison of these multiple techniques is lacking.
METHODS
The purpose of this article is to review the diagnosis and endovascular management of PVT, including areas in which further research is warranted.
RESULTS
Cases of PVT can be readily diagnosed using ultrasound, computed tomography, or magnetic resonance imaging. Treatment often begins with systemic anticoagulation and endovascular interventions may be used in selected cases. Determining the optimal approach to accessing the portal venous system depends on the underlying disease and chronicity of the thrombus and the degree of occlusion. Once access to the portal venous system is established, catheter-directed therapy may be performed to achieve recanalization.
CONCLUSION
Despite the heterogeneity in patient presentation, cases of PVT can be readily diagnosed across several imaging modalities. Strategizing interventional approaches involves evaluation of the underlying disease and the chronicity of the thrombus.
KEY POINTS
· This review will enable interventionalists to establish a framework for treating portal vein thrombosis by identifying patient risk factors and thrombus characteristics that determine patient management.. · The unique risks and benefits for transhepatic, transsplenic, and transmesenteric approaches for establishing portal venous access will be discussed.. · Advantages and complications of thrombolysis, thrombectomy, and transjugular intrahepatic portosystemic shunt creation for treating portal vein thrombosis will be reviewed in detail based on our extensive institutional experience..
CITATION FORMAT
· Ju C, Li X, Gadani S et al. Portal Vein Thrombosis: Diagnosis and Endovascular Management. Fortschr Röntgenstr 2022; 194: 169 - 180.
Topics: Endovascular Procedures; Humans; Portal Vein; Portasystemic Shunt, Transjugular Intrahepatic; Thrombosis; Treatment Outcome
PubMed: 34649289
DOI: 10.1055/a-1642-0990 -
The Cochrane Database of Systematic... Apr 2022Patients with kidney failure require vascular access to receive maintenance haemodialysis (HD), which can be achieved by an arteriovenous fistula or a central venous... (Review)
Review
BACKGROUND
Patients with kidney failure require vascular access to receive maintenance haemodialysis (HD), which can be achieved by an arteriovenous fistula or a central venous catheter (CVC). CVC use is related to frequent complications such as venous stenosis and infection. Venous stenosis occurs mainly due to trauma caused by the entrance of the catheter into the venous lumen and repeated contact with the vein wall. A biofilm, a colony of irreversible adherent and self-sufficient micro-organisms embedded in a self-produced matrix of exopolysaccharides, is associated with the development of infections in patients with indwelling catheters. Despite its clinical relevance, the treatment of catheter-related bloodstream infections (CRBSIs) in patients receiving maintenance HD remains controversial, especially regarding catheter management. Antibiotic lock solutions may sterilise the catheter, treat the infection and prevent unnecessary catheter procedures. However, such treatment may also lead to antibiotic resistance or even clinical worsening in certain more virulent pathogens. Catheter removal and delayed replacement may remove the source of infection, improving infectious outcomes, but this approach may also increase vascular access stenosis, thrombosis or both, or even central vein access failure. Catheter guidewire exchange attempts to remove the source of infection while maintaining access to the same vein and, therefore, may improve clinical outcomes and preserve central veins for future access.
OBJECTIVES
To assess the benefits and harms of different interventions for CRBSI treatment in patients receiving maintenance HD through a permanent CVC, such as systemic antibiotics alone or systemic antibiotics combined with either lock solutions or catheter guidewire exchange or catheter replacement.
SEARCH METHODS
We searched the Cochrane Kidney and Transplant Register of Studies up to 21 December 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register were identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov.
SELECTION CRITERIA
We included all randomised controlled trials (RCTs) and quasi-RCTs evaluating the management of CRBSI in permanent CVCs in people receiving maintenance HD.
DATA COLLECTION AND ANALYSIS
Two authors independently selected studies for inclusion, assessed their risk of bias, and performed data extraction. Results were expressed as risk ratios (RR) or hazard ratios (HR) for dichotomous outcomes and mean difference (MD) for continuous outcomes, with their 95% confidence intervals (CI). The certainty of the evidence was assessed using GRADE.
MAIN RESULTS
We identified two RCTs and one quasi-RCT that enrolled 760 participants addressing the treatment of CRBSIs in people (children and adults) receiving maintenance HD through CVC. No two studies compared the same interventions. The quasi-RCT compared two different lock solutions (tissue plasminogen activator (TPA) and heparin) with concurrent systemic antibiotics. One RCT compared systemic antibiotics alone and in association with an ethanol lock solution, and the other compared systemic antibiotics with different catheter management strategies (guidewire exchange versus removal and replacement). The overall certainty of the evidence was downgraded due to the small number of participants, high risk of bias in many domains, especially randomisation, allocation, and other sources of bias, and missing outcome data. It is uncertain whether an ethanol lock solution used with concurrent systemic antibiotics improved CRBSI eradication compared to systemic antibiotics alone (RR 1.61, 95% CI 1.16 to 2.23) because the certainty of this evidence is very low. There were no reported differences between the effects of TPA and heparin lock solutions on cure rates (RR 0.92, 95% CI 0.74 to 1.15) or between catheter guidewire exchange versus catheter removal with delayed replacement, expressed as catheter infection-free survival (HR 0.88, 95% CI 0.43 to 1.79). To date, no results are available comparing other interventions. Outcomes such as venous stenosis and/or thrombosis, antibiotic resistance, death, and adverse events were not reported.
AUTHORS' CONCLUSIONS
Currently, there is no available high certainty evidence to support one treatment over another for CRBSIs. The benefit of using ethanol lock treatment in combination with systemic antibiotics compared to systemic antibiotics alone for CRBSIs in patients receiving maintenance HD remains uncertain due to the very low certainty of the evidence. Hence, further RCTs to identify the benefits and harms of CRBSI treatment options are needed. Future studies should unify CRBSI and cure definitions and improve methodological design.
Topics: Adult; Catheter-Related Infections; Central Venous Catheters; Child; Heparin; Humans; Renal Dialysis; Sepsis
PubMed: 35363884
DOI: 10.1002/14651858.CD013554.pub2 -
Vascular Health and Risk Management 2022Kawasaki disease (KD), first reported as an acute febrile mucocutaneous lymph node syndrome, is a self-limiting vasculitis of unknown etiology. The most important aspect... (Review)
Review
Kawasaki disease (KD), first reported as an acute febrile mucocutaneous lymph node syndrome, is a self-limiting vasculitis of unknown etiology. The most important aspect of KD is the prevention of coronary artery lesion (CAL) because myocardial ischemia or infarction due to CAL might be lethal. In addition to the CAL, patients with KD develop systemic vasculitis, which indicates the presence of vascular endothelial damage. Studies assessing pulse wave velocity or percentage change in flow-mediated dilatation have shown that aortic stiffness is increased in patients with KD history. In contrast, the cardio-ankle vascular index, a novel parameter not affected by blood pressure, has not demonstrated increased aortic stiffness in patients with KD. Although many studies using various parameters have suggested a risk of atherosclerosis in patients with a history of KD, a few others have reported no significant differences between KD patients and controls. Therefore, it will be necessary to thoroughly understand the characteristics of each parameter, before evaluating the results of those studies, to understand systemic vascular dysfunction in these populations, and to manage their vascular health. Although it is controversial whether the risk of atherosclerosis in patients with KD is higher, those with CAL are thought to be at a high risk of atherosclerosis. Therefore, appropriate treatment to prevent CAL in the acute phase and subsequent regular follow-up is important. Here, we review the pathology, risk, and management of vascular disorders, especially systemic vascular disorders, in patients with KD history.
Topics: Atherosclerosis; Coronary Artery Disease; Coronary Vessels; Humans; Mucocutaneous Lymph Node Syndrome; Pulse Wave Analysis; Vascular Stiffness
PubMed: 35711626
DOI: 10.2147/VHRM.S291762 -
Arteriosclerosis, Thrombosis, and... Sep 2020Atherosclerosis is a systemic disease that involves multiple vascular beds. The pathological characteristics and clinical presentation, however, vary among the different... (Review)
Review
Atherosclerosis is a systemic disease that involves multiple vascular beds. The pathological characteristics and clinical presentation, however, vary among the different vascular territories. Acute coronary syndrome is a relatively common manifestation of coronary atherosclerotic disease, wherein the thrombosis occurs secondary to disruption (65%-75%) and erosion (25%-35%) of the fibrous caps of atheromatous plaques. The plaques associated with plaque rupture have large necrotic cores and thin and inflamed fibrous caps. However, the pathological manifestations of peripheral artery disease result from thrombosis regardless of the extent of atherosclerosis. Approximately 75% of peripheral arteries with significant stenosis demonstrate presence of thrombi, of which two-thirds have thrombi associated with insignificant atherosclerosis. The presence of obliterative thrombi in peripheral arteries of patients with critical limb ischemia in the absence of coronary artery-like lesions suggests a locally thrombogenic or remotely embolic basis of disease. Extensive calcification of the medial vascular layer is commonly observed. In this review, we have described and compared the pathological basis of coronary and peripheral artery disease in patients with acute coronary syndrome and critical limb ischemia. It is expected that pathogenetic characterization would allow for definition of strategic targets for superior management of peripheral artery disease.
Topics: Acute Coronary Syndrome; Arteries; Coronary Artery Disease; Coronary Vessels; Critical Illness; Disease Progression; Fibrinolytic Agents; Fibrosis; Humans; Ischemia; Peripheral Arterial Disease; Plaque, Atherosclerotic; Prognosis; Rupture, Spontaneous; Thrombosis
PubMed: 32673526
DOI: 10.1161/ATVBAHA.119.312864 -
Current Problems in Cardiology Dec 2022For almost 30 years, urgent revascularization termed primary percutaneous coronary intervention has been a cornerstone of modern care for acute myocardial infarction... (Review)
Review
For almost 30 years, urgent revascularization termed primary percutaneous coronary intervention has been a cornerstone of modern care for acute myocardial infarction (AMI). It lowers mortality and improved cardiovascular outcome compared to conservative therapy including thrombolysis. Reperfusion injury, which occurs after successful re-opening of the formerly occluded coronary artery, had been exploited as a potential therapeutic target. When revascularization became faster and primary percutaneous coronary intervention was successfully performed within 60-90 minutes of symptom onset, the interest in a potential additive effect of targeting reperfusion injury vanished. More recently, several meta-analyses indicated that limiting reperfusion injury prevents microvascular obstruction and reduces final infarct size, thereby lowering the probability of heart failure events and improving quality of life in AMI survivors. Here, we describe the current strategies to limit reperfusion injury and to improve post-AMI outcomes such as systemic or intracoronary hypothermia, left-ventricular unloading, intracoronary infusion of super-saturated oxygen, intermittent coronary sinus occlusion, and C-reactive protein apheresis.
Topics: Humans; Quality of Life; Myocardial Infarction; Percutaneous Coronary Intervention; Coronary Vessels; Reperfusion Injury
PubMed: 36108813
DOI: 10.1016/j.cpcardiol.2022.101398