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Immuno-Pathologic Basis of COVID-19 and the Management of Mild and Moderate Cases
Published in Srijan Goswami, Chiranjeeb Dey, COVID-19 and SARS-CoV-2, 2022
Debdeep Dasgupta, Srijan Goswami, Chiranjeeb Dey
Thrombosis refers to the formation of blood clots inside a blood vessel; the clot formed is termed a thrombus. Thrombus prevents the normal circulation of blood to concerned organs. The formation of blood clot or coagulation is the body's first line of defense against bleeding. Embolism, also known as thromboembolism, represents blockage in one of the arteries of the body due to a blood clot that has broken off from another location in the body (embolus) and traveled through the bloodstream to lodge in a small blood vessel (Cecil et al., 2012; Kumar et al., 2014; Hall, 2015; McPhee et al., 2021).
Complications of inferior vena cava filters
Published in Sachinder Singh Hans, Mark F. Conrad, Vascular and Endovascular Complications, 2021
Matthew T. Major, Paul G. Bove, Graham W. Long
Inferior vena cava thrombosis after IVC filter placement is reported in 2–30% of patients. Symptoms include bilateral lower extremity pain and edema; renal failure may occur if thrombus extends above the level of the renal veins. The risk of PE is also increased if the thrombus extends above the filter with recurrent pulmonary embolism occurring in 1–7%. The cause of filter thrombosis may be related to the patient's initial risk factors for thrombosis or the presence of foreign material within the body with progressive accumulation of thrombus on the struts. There is also the possibility of an entrapped, mobile thrombus within the filter rather the formation of new thrombus caused by the filter. There is no statistical difference in IVC thrombosis between patients with and without malignancy, although patients with metastatic disease may be at increased risk of recurrent PE despite filter placement. Rates of recurrent PE for patients with metastatic disease are reported at 10.4%, compared to 2.3% in those with non-metastatic malignancy. Tumor subtype (carcinoma vs sarcoma) does not appear to influence the likelihood of thrombotic complications.5
Practical guide for deep venous patency and obstruction
Published in Joseph A. Zygmunt, Venous Ultrasound, 2020
Venous thrombus is typically broken down into three different age categories: acute, age-indeterminate, and chronic (Table 5.3). Acute thrombus appears hypoechoic and spongy and is the most at risk for traveling to the lungs and causing a pulmonary embolism; therefore, it is typically treated more aggressively (Figure 5.18). Chronic thrombus is usually bright and organized, sometimes looking like strands or ropes, and has a much lower risk of embolizing (Figure 5.19). An age-indeterminate thrombus, like the name suggests, is a mix of both acute and chronic characteristics and is typically treated similarly to an acute thrombus (Figure 5.20). As previously mentioned, if there is thrombus present, additional longitudinal and transverse images may help the interpreting physician in determining the age of a clot [10,19]. If a thrombus appears to be mobile, this should always be considered an acute clot despite any chronic characteristics of the thrombus [16].
Symptomatic arterial thrombosis associated with novel coronavirus disease 2019 (COVID-19): report of two cases
Published in Acta Chirurgica Belgica, 2023
Nicolas De Hous, Paul Hollering, Ruth Van Looveren, Tu Tran, Dominik De Roover, Sven Vercauteren
The second patient presented with bilateral acute limb ischemia due to thrombosis of the right popliteal artery and left tibioperoneal trunk. The mainstay of treatment was bilateral intra-arterial thrombolysis because the ischemia was viable and the concomitant severe respiratory infection made the patient unsuitable for surgery. In this case, there are several factors that may have contributed to thrombus formation. In contrast to the first patient, the angiogram did show signs of mild underlying atherosclerosis in both femoral and popliteal arteries, indicating that this patient was more vulnerable to thrombotic complications associated with COVID-19. Secondly, the COVID-19 infection manifested as overt pneumonia accompanied by severe inflammation and a high D-dimer level (8.04 µg/mL) on admission. Several studies indicate that severe COVID-19 infections are associated with higher D-dimer levels, reflecting a more pronounced hypercoagulable state [17,18]. The hypercoagulable state and thrombotic risk were also reflected by the presence of lupus anticoagulant antibodies in this patient [11–13].
Relationship between intracoronary thrombus burden and systemic immune-inflammation index in patients with ST-segment elevation myocardial infarction
Published in Acta Cardiologica, 2023
Abdullah Kadir Dolu, Orhan Karayiğit, Can Ozkan, Muhammet Cihat Çelik, Macit Kalçık
Complete thrombotic occlusion of a major coronary artery due to rupture of atherosclerotic plaque constitutes the principal mechanism underlying ST-segment elevation myocardial infarction (STEMI). Clinical studies have shown that high peri-procedural intracoronary thrombus burden is a strong predictor for adverse consequences, including stent thrombosis, myocardial infarction, and mortality [1–3]. Inflammation has been a pivotal role in the pathogenesis of intracoronary thrombus formation. Recently, inflammation components have become a significant target in preventing cardiovascular diseases and many studies have tested the efficacy of anti-inflammatory treatments in acute myocardial infarction [4,5]. Although many invasive and pharmacological treatment strategies have been developed, thrombus management is still complex and inadequate. Therefore, identifying inflammatory predictors of intracoronary thrombus burden may contribute to the research of new pharmacological treatment procedures of STEMI.
Numerical study of the effect of LVAD inflow cannula positioning on thrombosis risk
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Ge He, Lu Han, Jiafeng Zhang, Aakash Shah, David J. Kaczorowski, Bartley P. Griffith, Zhongjun Wu
Thrombus formation is a complicated biological process that is involved with blood flow dynamics, property of blood and wall property. There is no universal standard for assessing the potential of thrombus formation in the LV cavity or devices. In this study, the risk of thrombosis was based on two previously proposed metrics: low shear rate (Dintenfass 1964) and low velocity magnitude (Chivukula et al. 2018). More specifically, the flow regions with velocity magnitude of less than 0.005 m/s and shear rate of less than 60/s were assumed to be where a thrombus is most likely to occur. Because the flow field around the LVAD IC is the field of interest, a wedge area (Figure 2b) covering the region from the LV apex to the top of LVAD IC was selected and its volume for each simulation case was slightly adjusted to ensure that the four cases have the same volume of the wedge area. The thrombosis risk for the four cases are calculated based on this wedge volume.