With progressive occlusion of a coronary main artery, some anastomotic vessels are recruited in order to supply blood to the ischemic region. This collateral circulation is an important factor in the preservation of the myocardium until reperfusion of the area at risk. An accurate estimation of collateral flow is crucial in surgical bypass planning as it alters the blood flow distribution in the coronary network and can influence the outcome of a given treatment for a given patient. The evaluation of collateral flow is frequently achieved using an index based on pressure measurements. It is named Collateral Flow Index (CFI) and defined as: (P(w)-P(v))/(P(ao)-P(v)), where P(w) is the pressure distal to the thrombosis, P(ao) the aortic pressure and P(v) the central venous pressure. We propose here another index, that is more sensitive to the P(w) value and could thus describe the role of collateral flow with more precision. We illustrate this idea using some clinical pressure measurements in patients with severe coronary disease (stenoses on the left branches and total occlusion of the right coronary artery).
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http://dx.doi.org/10.1016/j.mehy.2012.05.004 | DOI Listing |
Iran J Med Sci
December 2024
Neonatology Research Center, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
Background: Inadequate pulmonary blood flow in tetralogy of Fallot (TOF) can lead to the development of major aortopulmonary collateral arteries (MAPCA), which interferes with surgical repair. The present study evaluated the features of MAPCAs among patients with TOF and their treatment approaches. Besides, perioperative parameters and mortality rates of our TOF patients with and without MAPCA were compared.
View Article and Find Full Text PDFFront Neurol
January 2025
Department of Neurology and Institute of Neurology of First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou, China.
Introduction: Hemorrhagic transformation (HT) is a severe complication in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO) after endovascular treatment (EVT). We hypothesize that asymmetry of the internal cerebral veins (ICVs) on baseline CT angiogram (CTA) may serve as an adjunctive predictor of HT.
Methods: We conducted a study on consecutive AIS-LVO patients from November 2020 to April 2022.
Front Bioeng Biotechnol
January 2025
Department of General Surgery, The First Affiliated Hospital of Anhui Medical University, Hefei, China.
Iliac Vein Compression Syndrome (IVCS) is a common risk factor for deep vein thrombosis in the lower extremities. The objective of this study was to investigate whether employing a porous medium model to simulate the compressed region of an iliac vein could improve the reliability and accuracy of Computational Fluid Dynamics (CFD) analysis outcomes of IVCS. Pre-operative Computed Tomography (CT) scan images of patients with IVCS were utilized to reconstruct models illustrating both the compression and collateral circulation of the iliac vein.
View Article and Find Full Text PDFACS Synth Biol
January 2025
Department of Chemical and Biomolecular Engineering (BK21 Four), Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
We herein developed an ultrasensitive and rapid strategy to identify genomic nucleic acids by integrating a clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 13a (Cas13a) into our recently developed isothermal technique, nicking and extension chain reaction system-based amplification (NESBA) reaction. In this technique, named CESBA, the NESBA reaction isothermally produces a large amount of RNA amplicons from the initial target genomic RNA (gRNA). The RNA amplicons bind to the crispr RNA (crRNA) and activate the collateral cleavage activity of Cas13a, which would then cleave the reporter probe nearby, consequently producing the final signals.
View Article and Find Full Text PDFAJNR Am J Neuroradiol
January 2025
From the Department of Radiology, Medical Physics (MML, TJC), Department of Interventional Radiology (NS, GAC), Department of Surgery and Large Animal Studies (MAN), and the Department of Statistics (MG), University of Chicago, Chicago, IL, USA; Department of Anesthesiology (SPR), University of Illinois, Chicago, IL, USA; Department of Radiology (MSS), University of Massachusetts Chan Medical School, Worcester, MA, USA; Department of Radiology, Biomedical Engineering and Imaging Institute (Current affiliation MML), Icahn School of Medicine at Mount Sinai, New York, NY, USA; Mount Carmel Health Systems (Current affiliation GAC), Columbus, OH, USA.
Background And Purpose: In acute ischemic stroke, the amount of "local" CBF distal to the occlusion, i.e. all blood flow within a region whether supplied antegrade or delayed and dispersed through the collateral network, may contain valuable information regarding infarct growth rate and treatment response.
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