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Query: UMLS:C0149871 (deep vein thrombosis)
 12,364 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thromboembolism following total hip arthroplasty is a common complication that may result in significant morbidity and mortality. Despite this, optimal prophylactic regimen is controversial. We investigated the efficacy of a comprehensive approach encompassing the use of aspirin, intermittent compression devices ('foot pumps'), and early mobilization in a cohort of 200 consecutive patients after non-cemented total hip replacements. The surgical procedures were carried out under epidural anesthesia in most cases (91%). All patients were allowed full weight bearing and received ambulation training starting on the first post-operative day. Ankle-high pneumatic boots ('foot pumps') and aspirin (325 mg p.o./qd) were used immediately after surgery. The presence of deep vein thrombosis was determined with the routine use of venous duplex scans on post-operative day number 5 to 10 (mean 6.8). The duration of the follow-up was 3 months. No patients were lost to follow-up. Four distal DVT's (2%) were detected in three patients. None of the patients developed symptomatic pulmonary embolism during the follow-up period. There were no major wound complications. Venous thromboembolic disease after hip replacement surgery is largely associated with postoperative immobilization and venous stasis. It is the authors' opinion that a prevention strategy should include mechanical as well as pharmacological measures. The concomitant use of epidural anesthesia, "foot pumps", aspirin and early full weight bearing ambulation may be effective in further reducing the incidence of DVT after surgery.
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PMID:Prevention of thromboembolic disease after non-cemented hip arthroplasty. A multimodal approach. 1205 Sep 97

Debate continues about whether and to what extent travel predisposes to venous thrombosis and pulmonary embolism (PE). Almost certainly, the strength of any association was greatly exaggerated in recent press reports. Conclusions from case-control studies vary, with some finding no excess of recent travel among patients with venous thromboembolism and others reporting a two-four fold excess. The strongest evidence that prolonged air travel predisposes to thrombosis comes from the travel history of people who present with PE immediately after landing. Two independent analyses suggest that the risk of early embolism increases exponentially with travel times beyond 6 hours and may reach 1:200,000 passengers traveling for more than 12 hours. The most likely explanation is venous stasis in the legs from prolonged sitting, and there is evidence (preliminary and controversial) that elastic support stockings may prevent deep vein thrombosis in people who travel long-distances. There is an urgent need for more and better studies to define the absolute hazard from travel-related thrombosis and the personal risk factors that may contribute. Without these, it is difficult to give a balanced account to people who intend to travel or to consider definitive prevention trials. Case reports suggest that in most cases, travel-related thrombosis has affected people who were also at risk because of previous thrombosis, recent injury, or other predispositions. This makes it sensible to target such "at risk" people with advice about hazards and precautions, at least until formal study validates some other approach.
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PMID:Travel and venous thrombosis. 1217 38

A large number of trials have shown that many patients with venous thromboembolism can be treated as outpatients by using low molecular weight heparin. However, the amount of physical activity is neither mentioned in the study protocols nor in the instruction brochures, which are given to the patients. In most institutions, the fear of dislodging clots by ambulation is more common than the consideration of thrombus propagation and of recurrence; therefore, bed rest is recommended at least for the initial stage. There have been two randomized trials showing that bed rest as a part of the initial treatment of patients with deep vein thrombosis (DVT) is not able to substantially reduce the incidence of pulmonary emboli detected by repeat lung scanning. In one study performed in patients with proximal DVT, it could be demonstrated that leg compression and walking exercises are able to reduce edema and pain more rapidly and more effectively than bed rest. Progression of the thrombus size assessed by an independent Duplex examiner was statistically significantly greater in those patients confined to bed when compared with ambulatory patients with compression therapy. By counteracting against venous stasis, walking exercises and compression therapy have an important impact on the clinical outcome and should therefore be addressed in future studies.
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PMID:Bed rest versus ambulation in the initial treatment of patients with proximal deep vein thrombosis. 1217 41

In last month's BJPB, Agnes Arnold discussed the pathophysiology of deep vein thrombosis and suggested ways that the risk could be reduced, particularly with respect to DVTs resulting from endothelial damage in surgery. In this, the second of a two-part series, Agnes continues by looking at hypercoagulability of blood and venous stasis and the impact of these conditions on the risk of DVT.
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PMID:DVT prophylaxis in the perioperative setting. 1236 Jul 82

External pneumatic compression (EPC) devices prevent lower extremity deep venous thrombosis (DVT) by reducing stasis. There is a widely held belief that they also enhance endogenous fibrinolysis; however, recent studies of tissue plasminogen activator (the primary activator of fibrinolysis) and plasminogen activator inhibitor-1 (the primary inhibitor of fibrinolysis) failed to confirm this. The hypothesis of this study was that EPC devices increase the level of urokinase plasminogen activator (uPA), a second activator of fibrinolysis. This was a prospective trial in which 44 subjects who underwent major abdominal surgery were randomized to receive unfractionated heparin injections, thigh-length sequential EPC devices, or both for DVT prophylaxis. Prophylaxis was begun immediately before surgical incision and continued until postoperative day 5 or discharge. Venous blood samples were collected from an antecubital vein for measurement of systemic uPA levels and from the common femoral vein for measurement of regional uPA levels. Samples were collected the day before surgery, after induction of anesthesia but before surgical incision, and on postoperative days 1, 3, and 5. uPA levels (ng/mL) were measured with an enzyme-linked immunoassay. Baseline uPA levels (0.41 to 0.56 ng/mL; P >.05, analysis of variance with repeated measures) were similar among the three groups. uPA levels did not change after surgery in systemic or regional blood samples in any group. There were no significant differences in systemic or regional uPA levels in the groups treated with EPC devices relative to those treated with heparin at any time point (P >.05, analysis of variance with repeated measures). Enhancement of fibrinolysis with EPC devices remains unproven; the findings reported here suggest that effective DVT prophylaxis can only be assured when the devices are used in a manner that reduces venous stasis.
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PMID:External pneumatic compression does not increase urokinase plasminogen activator after abdominal surgery. 1242 1

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are distinct but related aspects of the same dynamic disease process known as venous thromboembolism (VTE). An estimated 200,000 new cases occur in the United States every year, including 94,000 with PE, resulting in an incidence of 23 per 100,000 patients per year-cases. Without treatment, pulmonary embolism is associated with a mortality rate of approximately 30%, causing nearly 50,000 deaths per year. Moreover, based on post-mortem studies, two-thirds of the patients with pulmonary emboli remain undiagnosed. Clinically, PE may present as (1) isolated dyspnea, (2) pleuritic pain and/or hemoptysis, and (3) circulatory collapse. However, clinical history and examination can be notoriously misleading in reaching a diagnosis. A number of acquired etiologic risk factors (predispositions) are associated with a tendency to develop VTE. These include increasing age, immobilization, surgery, trauma, hospital or nursing home confinement, malignancy, neurologic disease with extremity paresis, as well as certain types of oral contraception and hormone replacement therapy. In addition, a variety of genetic risk factors, such as factor V Leiden, protein S or C deficiency have also been identified. However, in at least half of the instances, no predisposing factors can be identified (idiopathic PE). In the majority of cases thromboemboli originate in the deep veins of the calf or pelvis. The pathogenic conditions for VTE comprise a triad of factors and include (1) venous stasis, (2) hypercoagulable states, and (3) vascular endothelium injury. Occlusion of pulmonary arteries has variable and transient clinical and pathophysiologic consequences, involving both mechanical and reflex effects of vascular occlusion with a consecutive perfusion defect as well as the release of vasoactive and other inflammatory mediators. The objectives of this article are to present an overview of the etiologic and pathogenic factors promoting VTE as well as the pathophysiologic and inflammatory processes following PE.
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PMID:Principle mechanisms underlying venous thromboembolism: epidemiology, risk factors, pathophysiology and pathogenesis. 1258 87

Venous thromboembolism is a common and potentially lethal disease. Patients who have pulmonary embolism are at especially high risk for death. Death owing to pulmonary embolism is independent of other comorbid conditions (e.g., cancer, chronic heart disease, or lung disease). Sudden death is often the first clinical manifestation. Only a reduction in the incidence of venous thromboembolism can reduce sudden death owing to pulmonary embolism and venous stasis syndrome owing to deep vein thrombosis. The incidence of venous thromboembolism has been relatively constant since about 1980. Improvement in the incidence of venous thromboembolism will require better recognition of persons at risk, improved estimates of the magnitude of risk, the avoidance of risk exposure when possible, more widespread use of safe and effective prophylaxis when risk is unavoidable, and targeting of prophylaxis to those persons who will benefit most. Recognition of venous thromboembolism as a multifactorial disease with genetic and genetic-environmental interaction has provided significant insights into its epidemiology and offers the possibility of improved identification of persons at risk for incident and recurrent venous thromboembolism.
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PMID:Risk factors for venous thromboembolism. 1268 52

Isolated left lower extremity swelling secondary to left iliac vein compression was first described by McMurrich in 1908, and defined anatomically by May and Thurner in 1957 and clinically by Cockett and Thomas in 1965. The left iliac vein is usually located posterior to the right iliac artery and can be compressed between the artery and the fifth lumbar vertebrae. Symptoms include left lower extremity edema, pain, varicosities, venous stasis changes, and deep venous thrombosis. Evaluation of these patients historically included a venous duplex scan to rule out deep venous thrombosis and an abdominal computed tomography scan to rule out pelvic mass. This paper describes the use of magnetic resonance imaging and venography in the evaluation of patients with isolated left lower extremity swelling. A retrospective analysis of a series of 24 patients who presented with symptomatic left lower extremity edema was performed. Infrainguinal deep venous thrombosis and valvular reflux was evaluated by duplex scan. The presence of suprainguinal deep venous thrombosis and pelvic mass was evaluated by magnetic resonance imaging. Magnetic resonance imaging was used to define the anatomic characteristics of the May-Thurner syndrome. Patients identified with the syndrome were treated either conservatively with lower extremity compression and elevation or with angioplasty and stenting. Follow-up of this subset of patients was performed with clinical assessment of the resolution of their symptomatic lower extremity edema as well as quality of life assessments via phone interviews. Twenty-four patients were evaluated for isolated left lower extremity swelling. Seven patients had positive results on duplex scans for deep venous thrombosis. Magnetic resonance imaging results demonstrated 1/24 (4%) had a pelvic mass compressing the iliac vein; 2/24 (8%) patients had iliac vein thrombosis; 1/24 (4%) patients with a history of deep venous thrombosis demonstrated a long stenotic segment of the left iliac vein unrelated to its association with the right iliac artery; 9/24 patients (37%) had anatomic evidence of May-Thurner syndrome; and 2/24 patients (8%) had isolated left lower extremity swelling of unknown etiology. Five patients diagnosed with May-Thurner syndrome were treated conservatively with compression stockings and leg elevation. Four patients with May-Thurner syndrome underwent iliac vein angioplasty and stenting. Technical success was 100%. On clinical follow-up, the patients with May-Thurner syndrome have had improvement/resolution of their symptoms. There have been no complications from either therapy. May-Thurner syndrome is a clinical entity of left iliac vein compression by the right iliac artery, resulting in isolated left lower extremity swelling and may be a precipitating factor for iliofemoral deep venous thrombosis. Magnetic resonance imaging is the best modality for diagnosis of this entity as it can rule out the presence of pelvic masses and deep venous thrombosis while simultaneously demonstrating the anatomy characteristic of this syndrome.
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PMID:Magnetic resonance venography in the diagnosis and management of May-Thurner syndrome. 1270 25

Anomalies of the inferior vena cava theoretically favor venous stasis and development of deep vein thrombosis. We report two cases of repeated deep vein thrombosis in patients with embryologic and acquired anomalies of the inferior vena cava, in which hypercoagulability syndrome was ruled out.
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PMID:Embryologic and acquired anomalies of the inferior vena cava with recurrent deep vein thrombosis. 1271 13

Sequential compression devices are used to reduce venous stasis and deep venous thrombosis after joint replacement. Thigh-length, calf-length, and foot compression devices were compared in using ultrasonography after unilateral knee arthroplasty. Simulated muscle activity via active ankle motion was also evaluated. Blood flow volume and velocity were recorded above and below the saphenous vein bifurcation, the division of the superficial and deep systems, allowing evaluation of each. Volume and velocity increased in the superficial and deep systems with all devices. A control group was evaluated to determine differences related to age and surgery. The devices performed similarly in the volunteers. However, active motion performed better than any device. Thus, unlike young, healthy patients, muscle activity alone in the operative population was unreliable in increasing blood flow. Thigh-length, calf-length, and foot compression devices are are effective at increasing femoral blood flow volume and velocity in the deep and superficial venous systems after total knee arthroplasty.
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PMID:Effect of external sequential compression devices on femoral venous blood flow. 1274 80


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