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

Many investigators have reported about beneficial results with thrombolytic therapy in patients with acute pulmonary embolism. Streptokinase and urokinase have been used for more than 15 years, but the conditions of use of these agents still remain controversial. Optimal dosage and treatment schedule are still evolving. For streptokinase most investigators adopt a fixed dosage schedule: a loading dose of 250,000 units followed by a maintenance infusion of 100,000 units per hour for 24 to 72 hours. For urokinase numerous dosage regimens have been used such as: high dosage schedule 4,400 units per kilogram per hour for twelve to 24 hours with or without loading dose; moderate dosage 1,600 to 2,000 units per kilogram per hour for 24 hours and low dosage in bolus. With these treatments there is a trend to reduced in-hospital-mortality in massive pulmonary embolism; the early pulmonary revascularization and the hemodynamic improvement are higher than those noticed with heparin. These results are obtained with a minimum of complication essentially bleeding in 10 or 15%; most bleeding being located at puncture site. More recently, new thrombolytic agents have been used in acute pulmonary embolism. Only four studies have tested rt-PA which is effective and relatively safe, but the optimal dose regimens remain to be determined. Less information is available concerning Anisoylated Plasminogen Streptokinase Activator Complex (APSAC), the angiographic improvement seems to be rapid and important (50% on average) but the decrease of fibrinogen is important too and comparable with streptokinase. Considering the good results of thrombolytic treatment of acute submassive and massive pulmonary embolism, there is a doubt as to whether the pulmonary embolectomy has any place in the pulmonary embolism patients except in those with cardiac arrest. In the near future new thrombolytic drugs could be more efficient on pulmonary embolism and deep venous thrombosis, and thus the bleeding risk might be decreased.
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PMID:Thrombolytic treatment of acute pulmonary embolism. 250 Mar 88

A previously described bioimmunoassay for tissue-type plasminogen activator (t-PA) has been modified in terms of antibody concentration and conditions of incubation to achieve a sensitivity range of approximately 5-500 IU/L of t-PA. A similar assay has been developed for urinary-type plasminogen activator (U-PA), also known as urokinase (UK), achieving a sensitivity range of approximately 5-500 X 10(-1) IU/L. The direct sensitive t-PA assay has been demonstrated to be a quantitative alternative to the traditional semiquantitative euglobulin clot lysis time (ECLT) assay, with correlation coefficients of 0.967 and 0.914, depending on the laboratory where the ECLT was carried out. This assay has the added advantages of avoiding loss of t-PA or UK during the formation of the euglobulin fraction and of calibration in terms of International Standards for both t-PA and UK. With both these assays, it has been demonstrated that the enhanced fibrinolytic activity observed after exercise results from increased levels of t-PA while the level of UK in plasma remains unaltered. Free t-PA (10-60 IU/L) has been demonstrated in resting plasma, whereas the level of free UK activity was 50-100 IU/L. Venous occlusion of matched groups of subjects with and without deep venous thrombosis (DVT) showed a wide variation of response in t-PA levels in each group and no change in UK levels. There was no difference between the DVT and non-DVT groups, and this suggests that the notion of the "nonresponder" being more prone to thrombosis needs to be reexamined.
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PMID:Sensitive and direct assays for functionally active plasminogen activators (tissue-type and urokinase-type) in plasma. 250 7

The age of the thrombus is probably a very important determinant of the outcome of thrombolysis. The clinical potential for rapidly dissolving thrombi by thrombolytic therapy is considerable because restoration of the blood flow can rescue the jeopardized district served by the occluded vessel such as for myocardial infarction, deep vein thrombosis, arterial thrombosis, pulmonary embolism, and occlusion of retinal vessels. Defibrotide was effective against 3-, 7-, or 10-day-old thrombi; its ED50s were 32, 65, or 118 mg/kg-1 hour-1, respectively, suggesting that the age of the thrombus could play a role in the outcome of thrombolysis. A similar pattern was also shown for urokinase.
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PMID:Thrombolytic activity of defibrotide against old venous thrombi. 251 Mar

Pulmonary embolism can produce severe cardiopulmonary dysfunction characterized by pulmonary artery hypertension, right ventricular failure, and hypoxemia. The search for the source of a pulmonary embolus, by exploration of the veins of the lower limbs and the inferior vena cava should be systematically carried out in all cases of pulmonary embolus which are not immediately life-threatening to the patient. The treatment of deep vein thrombosis associated with pulmonary embolism with thrombolytic agents has been proposed and utilized for approximately 20 years. Although superior results have been claimed with thrombolytic agents, the use of this type of treatment remains limited to massive or sub-massive pulmonary embolism. Fibrinolytic agents with high specificity for fibrin in the thrombi and little systemic activation of the fibrinolytic system have been developed and tested in preliminary clinical trials of patients with acute pulmonary embolism. The largest published experience available has been with recombinant tissue plasminogen activator (rtPA). The acylated streptokinase-plasminogen complex (APSAC) and pro-urokinase also gave promising results. All these agents were accompanied by unexpectedly high incidence of systemic activation of the fibrinolytic system and by hemorrhagic complications with frequencies similar to those that follows the use of first generation products (urokinase and streptokinase). Hence, their superior clinical efficacy must be clearly proven before they are substituted for a more widely available and less expensive drug, such as streptokinase.
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PMID:Pathogenesis and management of acute pulmonary embolism. 251 49

Twenty cases of primary nephrotic syndrome were treated with urokinase at a dosage of 60,000 units per day for two successive weeks. The results showed that after treatment the concentrations of fibrinogen, urine FDP, alpha 2-plasma inhibitor and plasminogen were significantly decreased (P value less than 0.01, less than 0.01, less than 0.001, less than 0.005 respectively). The concentration of antithrombin III was significantly increased (P less than 0.05). It is suggested that the treatment obviously increased the fibrinolytic activity and improved the hypercoagulated state. The clinical data showed that in addition to decrease of proteinuria and obvious increase of urine volume, the clinical manifestations and laboratory parameters showed no significant difference. Further study on the dosage and indications of urokinase is needed and the activity of coagulation and fibrinolysis in patients with deep vein thrombosis of lower extremities was also discussed.
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PMID:[Primary nephrotic syndrome treated with urokinase--a report of 20 cases]. 258 15

The importance of the fibrinolytic treatment in deep venous thrombosis, to avoid the mortal pulmonary embolism, among other complications, is commented on. The results in 32 patients, presenting deep venous thrombosis and treated with loco-regional Urokinase, are presented. Author carries out some commentaries about surgical and medical treatment.
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PMID:[Loco-regional fibrinolysis with urokinase in the treatment of deep venous thromboses]. 261 Apr 1

The ability of streptokinase and urokinase to lyse intravascular fibrin-based clots is firmly established. However, there is a lack of enthusiasm for these agents because of serious haemorrhagic complications and a lack of controlled randomized studies indicating their efficacy. Thrombolytic therapy is suitable in only 15 per cent of patients with acute deep venous thrombosis. It restores the venous circulation to normal in up to 95 per cent of these patients if therapy is instituted within 5 days of the onset of symptoms. These patients have significantly fewer symptoms on follow-up than patients treated with heparin although the ability of thrombolytic therapy to preserve venous valvular function and to prevent the post-phlebitic syndrome is now in question. Thrombolytic therapy is as effective as heparin in preventing pulmonary embolism and may be superior in its treatment. Pulmonary haemodynamics are rapidly improved, diffusion capacity is restored and, although the evidence is inconclusive, long-term pulmonary hypertension may be prevented. Although the mortality rate is not decreased, controlled studies show that thrombolytic therapy may be beneficial in massive pulmonary embolism with clinical shock. Thrombolytic therapy is indicated for acute arterial and acute bypass graft occlusion when the surgical alternative is associated with a higher morbidity and mortality. Partial thrombolysis is achieved in up to 90 per cent of cases and the need for further therapeutic intervention is eliminated in one-third of the patients treated. New thrombolytic agents with greater specificity and potentially greater efficacy and fewer complications are being developed. Tissue plasminogen activator has been successfully used. Prourokinase, fibrin-seeking urokinase and acetylated streptokinase-plasminogen complex may expand the role of thrombolytic therapy in surgical practice.
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PMID:The role of thrombolytic therapy in surgical practice. 265 13

Clinical experience with thrombolytics in non-coronary disorders is limited to the plasminogen activators streptokinase, urokinase and alteplase; therapeutic trials with anistreplase (APSAC) are almost, and with saruplase completely, limited to acute myocardial infarction. In terms of thrombus clearance, thrombolytic drugs are superior to heparin in patients with recent deep vein thrombosis in the pelvis or lower limbs. In aggregate, thrombi younger than 8 days are lysed in approximately 60% of patients treated with streptokinase, urokinase or alteplase. The results of studies assessing the subsequent development of the postphlebitic syndrome are conflicting, but most suggest that thrombolytic therapy can reduce symptoms of chronic venous insufficiency. Currently, the combination of systemic thrombolytic drugs followed by heparin is recommended for patients with acute major pulmonary embolism who are haemodynamically unstable. Streptokinase, urokinase and alteplase have all been shown to accelerate the lysis of pulmonary emboli and to decrease pulmonary vascular obstruction and pulmonary hypertension. Systemic venous or intrapulmonary infusions of alteplase offers the same benefit in terms of angiographic and haemodynamic improvement. A short infusion of 100 mg alteplase over 2 hours seems to be superior to a 24-hour infusion of urokinase. None of the thrombolytic trials in pulmonary embolism have been large enough to demonstrate a reduction in mortality. It is now generally accepted that, unless contraindicated, thrombolytic therapy is the front-line treatment for patients with massive pulmonary embolism and major haemodynamic disturbance. The local treatment of acute arterial occlusion in limb arteries results in rapid clearing of the artery in 67% of patients treated with streptokinase; the corresponding success rates for urokinase and alteplase are 81% and 88 to 94%, respectively. The main question appears to be the identification of patients in whom local thrombolysis is the treatment of choice, as opposed to established therapeutic modalities. Thrombolytic treatment following a major ischaemic stroke is hazardous, although clinical improvement has been noted in a minority of patients with recanalised cerebral arteries. The safety and efficacy of thrombolytic treatment remains unproven for this indication, and its use must be restricted to experimental protocols. Thrombolytic treatment in retinal artery or vein occlusion has, in practice, been abandoned.
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PMID:Use of thrombolytic drugs in non-coronary disorders. 268 38

Between October 1982 and July 1984 systemic thrombolysis was carried out in 10 patients (5 males and 5 females aged 19 to 66 years) with massive pulmonary embolism (PE). Mean thrombolytic treatment duration was 77 hours. The main fibrinolytic agent used (9 cases) was streptokinase. Sequential treatment with streptokinase and urokinase was given to 2 patients and urokinase alone to one. 5 patients received porcine plasmin additionally, and one patient BRL 26921 (streptokinase-plasminogen complex) and human plasminogen. Pulmonary arterial pressures were recorded serially. Pulmonary angiograms were obtained before, occasionally during and after thrombolysis. Pulmonary arterial pressures (systolic: p less than 0.01, diastolic: p less than 0.05, mean: p less than 0.01, paired t-test, two tailed) and pulmonary angiograms (p less than 0.001, paired t-test, two tailed) all showed significant improvement. Thrombolytic treatment had to be discontinued in two patients due to side effects. Patients with the most recent PE showed the best response. Patients with recurrent PE and preexisting pulmonary hypertension showed no improvement. In PE without deep vein thrombosis (DVT), treatment duration of up to three days seems to be appropriate. In PE with concomitant DVT the treatment should be prolonged to achieve complete lysis of thrombi.
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PMID:[Fibrinolysis therapy in massive lung embolism. Experiences in 10 patients 1982-1984]. 293

The efficacy of fibrinolysis in deep venous thrombosis (DVT) depends on the age and organization of the thrombus as well as its localization. Up to now, indication for lysis therapy is defined according to the duration of clinical symptoms (less than 7 days). Our lysis results in urokinase therapy (n = 87) with high-dose and long-term regimen (mean 7.8 days), however, have shown no correlation between the duration of clinical symptoms (up to six weeks) and lysis efficacy (p less than 0.05). Therefore phlebographic criteria were established to allow the differentiation of fibrinolytic therapy depending on the site of the thrombus, its localization and the formation of collateral veins. In order to determine the state of thrombus organization, we used a new ultrasound Duplex system device (ARTIS, 7.5 Mhz, Picker International). In vivo experiments with induced thrombosis in human vena saphena magna demonstrate that echodensity of thrombi in ultrasound starts at the 11th-15th day. These findings are in good agreement with pathological studies of thrombus formation. Recent results of 24 patients with DVT indicate that echodensity of thrombus in ultrasound correlates with the course of organization and the efficacy of later lysis therapy.
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PMID:Thrombus formation in deep venous thrombosis. A clinical approach to diagnosis and control of lysis efficacy. 305 31


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