Venous thromboembolism (VTE) is a common disease with a myriad of presentation. It is often difficult to diagnosis with symptoms which are shared with many other disorders. Because of the overlap in symptomatology with other pathologies it is both commonly overlooked when present and commonly considered when absent. The threshold for investigating suspected VTE has dropped over time, in part due to a greater awareness of the disease among clinicians, but also because of the greater availability of diagnostic tests which are both accurate at positively diagnosing VTE and are patient friendly. This has resulted in a mushrooming of the number of diagnostic tests being performed for suspected VTE in radiology departments. As such radiology provides a window into the disease in a way that no other speciality can. All branches of medicine having their share of VTE patients but radiology provides a unique opportunity to study VTE patients as, no matter from which speciality they arise when the disease is suspected, they will almost inevitably end up undergoing a definitive radiological test. There is much still to learn about VTE however developments in modern imaging and computerised databases have advanced our understanding of this common disease. The window that radiology provides into VTE has contributed towards those advances.

Background: Pulmonary embolism (PE) accounts for almost 40% of perioperative deaths after bariatric surgery. Placement of prophylactic inferior vena cava (IVC) filter before bariatric surgery to improve outcomes has shown varied results. We performed a meta-analysis to evaluate postoperative outcomes associated with the preoperative placement of IVC filters in these patients. Methods: A systematic review was conducted by three investigators independently in PubMed, EMBASE, the Web of Science and Scopus until February 28, 2013. Our search was restricted to studies in adult patients undergoing bariatric surgery with and without IVC filters. Primary outcomes were postoperative deep vein thrombosis (DVT), pulmonary embolism (PE), and postoperative mortality. Meta-analysis used random effects models to account for heterogeneity, and Sidik-Jonkman method to account for scarcity of outcomes and studies. Associations are shown as Relative Risks (RR) and 95% Confidence Intervals (CI). Results: Seven observational studies were identified (n=102,767), with weighted average incidences of DVT (0.9%), PE (1.6%), and mortality (1.0%) for a follow-up ranging from 3 weeks to 3 months. Use of IVC filters was associated with an approximately 3-fold higher risk of DVT and death that was nominally significant for the former outcome, but not the latter (RR 2.81, 95%CI 1.33-5.97, p=0.007; and RR 3.27, 95% CI 0.78-13.64, p=0.1, respectively); there was no difference in the risk of PE (RR 1.02, 95%CI 0.31-3.77, p=0.9). Moderate to high heterogeneity of effects was noted across studies. Conclusions: Placement of IVC filter before bariatric surgery is associated with higher risk of postoperative DVT and mortality. A similar risk of PE in patients with and without IVC filter placement cannot exclude a benefit, given the potential large imbalance in risk at baseline. Randomized trials are needed before IVC placement can be recommended. / Revisión por pares

Diana.sobieraj@hhchealth.org / Objective To systematically review the literature and to quantitatively evaluate the efficacy and safety of extended pharmacologic treatment of venous thromboembolism (VTE) through network meta-analysis (NMA). Methods A systematic literature search (MEDLINE, Embase, Cochrane CENTRAL, through September 2014) and searching of reference lists of included studies and relevant reviews was conducted to identify randomized controlled trials of patients who completed initial anticoagulant treatment for VTE and then randomized for the extension study; compared extension of anticoagulant treatment to placebo or active control; and reported at least one outcome of interest (VTE or a composite of major bleeding or clinically relevant non-major bleeding). A random-effects Frequentist approach to NMA was used to calculate relative risks with 95% confidence intervals. Results Ten trials (n=11,079) were included. Risk of bias (assessed with the Cochrane tool) was low in most domains assessed across the included trials. Apixaban (2.5mg and 5mg), dabigatran, rivaroxaban, idraparinux and vitamin K antagonists (VKA) each significantly reduced the risk of VTE recurrence compared to placebo, ranging from a 73% reduction with idraparinux to 86% with VKAs. With exception of idraparinux, all active therapies significantly reduced VTE recurrence risk versus aspirin, ranging from a 73% reduction with either apixaban 2.5mg or rivaroxaban to 80% with VKAs. Apixaban and aspirin were the only therapies that did not increase composite bleeding risk significantly compared to placebo. All active therapies except aspirin increased risk of composite bleeding by 2 to 4-fold compared to apixaban 2.5mg, with no difference found between the two apixaban doses. Conclusion Extended treatment of VTE is a reasonable approach to provide continued protection from VTE recurrence although bleeding risk is variable across therapeutic options. Our results indicate that apixaban, dabigatran, rivaroxaban, idraparinux and VKAs all reduced VTE recurrence when compared to placebo. Apixaban appears to have a more favorable safety profile compared to other therapies. / Revisión por pares

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2008. / Härtill 4 uppsatser.

Orientador: Heitor Moreno Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-19T02:49:22Z (GMT). No. of bitstreams: 1 Pereira_DanielJose_M.pdf: 8289618 bytes, checksum: f81b30485257dfeb1919e76b99cecc7d (MD5) Previous issue date: 2011 / Resumo: Introdução: estudos experimentais de embolia pulmonar (EP) são habitualmente realizados sob ventilação mecânica. Como a maioria dos pacientes com suspeita de EP adentra os Serviços de Emergência em respiração espontânea e em ar ambiente, estudos que medissem as variáveis hemodinâmicas, gasométricas e capnográficas, nestas condições, em muito contribuiriam para compreensão mais específica das alterações cardiopulmonares e gasométricas na fase aguda da doença. Observa-se que faltam na literatura estudos experimentais que avaliem animais em tais condições. Objetivo: o objetivo do presente estudo foi submeter à EP animais sob ventilação espontânea e sem oxigênio suplementar. A EP por coágulos autólogos foi induzida em seis porcos e os registros cardiorrespiratórios e gasométricos foram realizados no pré e pós-EP. O valor da pressão média de artéria pulmonar (PMAP) "quase fatal" foi previamente determinada. Resultados: a presença de choque obstrutivo agudo pôde ser evidenciada pelo aumento da PMAP (de 17,8±3,5 para 41,7±3,3mmHg) (P<0,0001) e pela queda do débito cardíaco (de 4,9±1,0 para 2,7±1,0L/min) (P<0,003). Consequentemente, a presença de acidose metabólica pode ser constatada (de 2,4±0,6 para 5,7±1,8mmol/L) (P<0,0001). Observou-se ainda a presença de hipoxemia (de 73,5±12,7 para 40,3±4,6mmHg) (P<0,0001), porém, a PaCO2 não variou (de 44,9±4,4 para 48,2±6,0mmHg) (NS). Houve expressivos aumentos, tanto para P(a-et)CO2 (de 4,8±2,8 para 37,2±5,8mmHg) quanto para a P(A-a)O2 (de 8,2±8,9 para 37,2±10,3mmHg) (P<0,0001). Como tentativa de compensação à acidose metabólica, evidenciou-se significativo aumento do volume minuto alveolar total (de 4,0±0,9 para 10,6±2,9L/min) (P<0,0001). Conclusão: neste modelo, a PMAP quase fatal foi de 2 a 2,5 vezes a PMAP basal e as variáveis capnográficas, associadas a gasometria arterial e venosa, mostraram-se eficazes em discriminar um quadro obstrutivo agudo / Abstract: Introduction: Experimental studies on pulmonary embolism (PE) are usually performed under mechanical ventilation. Most patients with suspicion of PE enter the Emergency Services in spontaneous breathing and environmental air. Thus, under these conditions, measurements of hemodynamic, gasometric and capnographic variables contribute largely to a more specific comprehension of cardiopulmonary and gasometric alterations in the acute phase of the disease. Studies which evaluated animals under conditions are lacking. Objective: This study aimed to submit animals under spontaneous ventilation and without supplemental oxygen to PE. PE was induced in six pigs using autologous blood clots, and cardiorespiratory and gasometric records were performed before and after PE. The values of "near fatal" mean pulmonary arterial pressure (MPAP) were previously determined. Results: The presence of obstructive shock could be evidenced by increased MPAP (from 17.8±3.5 to 41.7±3.3mmHg) (p<0.0001) and decreased cardiac output (from 4.9±1.0 to 2.7±1.0L/min) (p<0.003). Consequently, metabolic acidosis occurred (Lac art)(from 2.4±0.6 to 5.7±1.8mmol/L) (p<0.0001). It was observed hypoxemia (from 73.5±12.7 to 40.3±4.6mmHg) (p<0.0001); however, PaCO2 did not vary (from 44.9±4.4 to 48.2±6.0mmHg) (NS). There were significant increases in both P(a-et)CO2 (from 4.8±2.8 to 37.2±5.8mmHg) and P(A-a)O2 (from 8.2±8.9 to 37.2±10.3mmHg) (p<0.0001). There was also a significant increase in the total alveolar minute volume (from 4.0±0.9 to 10.6±2.9L/min) (p<0.0001). Conclusion: In this model, the near fatal MPAP was from 2 to 2.5 times the basal MPAP; and the capnographic variables, associated with arterial and venous gasometry, showed effective in discriminating an acute obstructive profile / Mestrado / Farmacologia / Mestre em Farmacologia

An infarct is an area which has lost its blood supply due to obstruction, thrombosis or embolism. It is the third leading cause of death in the Western world, following non-cerebral cardiovascular disease and cancer. This research study focused on determining the infarct prevalence according to age, sex and brain areas most affected by infarcts. The prevalence of different infarct types was also determined. Brain MRI statistics were obtained from a Private Radiology practice in Pretoria for a 13-month period. A total of 1844 brain MRI examinations were evaluated, of which 299 patients presented with infarcts. Their age and sex were noted and their individual reports were obtained to record the anatomical structures and brain lobes that were infarcted. The infarct types were also noted. Diffusion-weighted images were used to measure new infarcts, while FLAIR images were used to measure old infarcts. Results showed an overall incidence of 16.10% and vascular structures accounted for 26.63% of these. Most infarcts were new (56.80%) and mainly affected patients aged 70–79 years (31.36%). Normal cerebral infarcts (72.49%) and embolic infarcts (14.50%) were the most common. The parietal lobe (34.91%) and right middle cerebral artery (11.54%) presented with the most infarcts. The right hemisphere (34.91%) presented with slight infarct predominance, but this was not significant when compared to the left (31.95%) hemisphere (Chi square p>0.05). No significant difference was found concerning the overall male to female ratio (Chi square p>0.05). Females aged 18–39 years of age presented with three times more infarcts than their male counterparts. This may possibly be due to their use of oral contraceptives and pregnancy, which increases the risk of thrombosis and embolism. Females over 80 years also presented with higher infarct prevalence, which is expected, since men die at earlier ages due to other co-morbidities such as cancer. / Dissertation (MSc)--University of Pretoria, 2009. / Anatomy / MSc / Unrestricted

INTRODUCTION: Pulmonary embolism (PE) is a major cause of mortality during pregnancy. It is estimated that about 20% of maternal deaths in north america are due to PE. A lung V/Q study in a standard (non-gravid) patient typically consists of a low dosage ventilation study followed by a higher dosage perfusion study. In some centers however, perfusion-only imaging, without accompanying ventilation imaging has been employed. In this method, a several-fold lower dose of radioactivity is used. Perfusion-only imaging has multiple advantages. In addition to reduction of radiation dose to the mother and the fetus, there is decreased cost to the health-care system as well as improved patient convenience and shortened hospital workflow. OBJECTIVES: The present study aimed at assessing the negative predictive value (among other diagnostic accuracy measures) of perfusion-only imaging in a large group of pregnant patients with suspected pulmonary embolism. METHODS: This study was a retrospective cohort study of the entire pregnant patients with suspected PE who underwent V/Q scan at The Ottawa Hospital and their V/Q scans were available in the PACS system. After acquiring REB approval, a comprehensive search in the PACS (Picture Archiving and Communication System) was conducted to find pregnant patients who were assessed for PE in our division since 2004 (the earliest date the V/Q images were available in our system). A statistical consultation was made before the initiation of data collection and at the time of data analysis. All patients who met the inclusion criteria were included. Initially a nuclear medicine resident with 2 years of experience read all the perfusion- only images. The PISAPED criteria were used for image interpretation. Then the results were compared against the reports made by nuclear medicine staffs that were available to us in our electronic system and a final interpretation was made after such comparison. The follow-up clinical notes were used as the gold standard to make a final diagnosis of PE. Finally, diagnostic accuracy measures were calculated. RESULTS: A total of 364 patients were included. Mean maternal age at the time of lung V/Q scan was 30.3 years-old (SD=5.8) ranging from 16 to 51 years-old. From a total of 362 lung perfusion scans, 316/362 (87.3%) scans interpreted as normal, 17/362 (4.7%) scans were interpreted as high probability and 29/362 (8.0%) scans were interpreted as non-diagnostic. Pulmonary embolism was diagnosed in a total of 15 patients directly after performing lung scan. None of the patients with normal perfusion-only scans were diagnosed later with PE, proving a negative predictive value of 100%. The sensitivity and specificity of perfusion-only imaging after including the non-diagnostic studies were 100% (100% to 100%) and 99.1% (88.1% to 94.1%), respectively with a negative predictive value of 100% (100% to 100%) and a positive predictive value of 32.6% (19.1% to 46.2%). Conclusion: The results of the current study show that perfusion-only imaging has a very high negative predictive value for PE in pregnant population and therefore can exclude PE with a very high degree of accuracy.

Pulmonary embolism (PE) is a common clinical problem affecting 600,000 patients per year in the United States. Although the diagnosis can be easily confirmed by imaging techniques, such as computed tomographic angiography of the chest, the identification of underlying mechanism leading to PE is important for appropriate duration of anticoagulation, and prevention of subsequent episodes. The differential diagnosis of underlying mechanism is broad and must include careful review of medication history. Drug-related thromboembolic disease can be easily missed and may have catastrophic consequences. The identification of the culprit drug is important for prevention of subsequent episodes and choosing appropriate duration of anticoagulation. We report a case of a middle-aged man who developed PE after administration of intravenous immunoglobulin.

Venous thromboembolism (VTE) is a chronic illness that affects nearly 10 million people every year worldwide. Anticoagulant therapy with direct oral anticoagulants is the mainstay of treatment for patients with VTE, and should be continued for at least 3-6 months. Thereafter, a decision should be made to discontinue anticoagulation or continue it indefinitely. This decision is most challenging for patients with a first unprovoked VTE because of uncertainty in estimates for the long-term benefits (e.g., reduction in recurrent VTE) and harms (e.g., increase in major bleeding) of extended anticoagulation, and the trade-offs between them. The overarching aim of this doctoral thesis was to address these key evidence gaps that are pertinent to making decisions regarding the duration of anticoagulation for patients with a first unprovoked VTE. The first three studies of this thesis synthesized contemporary and reliable estimates for the long-term risks and consequences of recurrent VTE and major bleeding, with and without extended anticoagulation (parameters that can influence the clinical and cost-effectiveness of discontinuing versus continuing anticoagulation indefinitely). Broadly, these systematic reviews and meta-analyses found that: 1) the long-term risks and consequences of major bleeding during extended anticoagulation are considerable, particularly with vitamin K antagonists as well as in older patients, patients using antiplatelet therapy, and in patients with kidney disease, a history of bleeding, or anemia; and 2) the long-term risks of recurrent VTE during extended anticoagulation and major bleeding after discontinuing anticoagulation are reassuringly low but not negligible. The fourth study incorporated the synthesized evidence to compare the lifetime clinical benefits, harms, and costs of discontinuing versus continuing anticoagulation indefinitely. This decision analytic modelling study showed that indefinite anticoagulation is unlikely to either result in a net clinical benefit or be cost-effective in all (i.e., unselected) patients with a first unprovoked VTE. Findings from this thesis can serve to impact clinical practice and health policy by informing patient prognosis to guide shared decision-making regarding the duration of treatment for unprovoked VTE, and informing future research to ultimately identify which patients should receive anticoagulation indefinitely in order to maximize health benefits for the available healthcare resources.