***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: R and omly assigned streptokinase or heparin therapy was studied in 50 patients with deep vein thrombosis of less than 2 weeks ' duration .  Veno graphy was performed prior to therapy , after 3 days , and after 10 days . Two radiologists who were unaware of the patient 's therapy compiled a single average lytic score for each patient at each time interval . Lysis of venous thrombi was significantly greater with streptokinase than with heparin after 3 days , but not after 10 days of treatment . Lytic scores achieved with streptokinase were significantly better than those achieved with heparin therapy ( P < .01 ) in male patients who were symptomatic for 3 days or less . In females , regardless of the duration of symptoms , throm bolytic results obtained with streptokinase were not significantly different than results obtained with heparin Acute deep venous thrombosis ( DVT ) causes leg pain .  Elastic compression stockings ( ECS ) have potential to relieve DVT-related leg pain by diminishing the diameter of distended veins and increasing venous blood flow . It was our objective to determine whether ECS reduce leg pain in patients with acute DVT . We performed a secondary analysis of the SOX Trial , a multicentre r and omised placebo controlled trial of active ECS versus placebo ECS to prevent the post-thrombotic syndrome . The study was performed in 24 hospital centres in Canada and the U.S. and included 803 patients with a first episode of acute proximal DVT . Patients were r and omised to receive active ECS ( knee length , 30 - 40 mm Hg graduated pressure ) or placebo ECS ( manufactured to look identical to active ECS , but lacking therapeutic compression ) . Study outcome was leg pain severity assessed on an 11-point numerical pain rating scale ( 0 , no pain ; 10 , worst possible pain ) at baseline , 14 , 30 and 60 days after r and omisation . Mean age was 55 years and 60 % were male . In active ECS patients ( n=409 ) , mean ( SD ) pain severity at baseline and at 60 days were 5.18 ( 3.29 ) and 1.39 ( 2.19 ) , respectively , and in placebo ECS patients ( n=394 ) were 5.38 ( 3.29 ) and 1.13 ( 1.86 ) , respectively . There were no significant differences in pain scores between groups at any assessment point , and no evidence for subgroup interaction by age , sex or anatomical extent of DVT . Results were similar in an analysis restricted to patients who reported wearing stockings every day . In conclusion , ECS do not reduce leg pain in patients with acute proximal DVT Because of its fibrinolytic action , streptokinase is believed to reduce the severity of the postthrombotic syndrome in patients with deep vein thrombosis . A prospect i ve and a retrospective study have been undertaken in an attempt to determine when this therapy is useful for patients with deep vein thrombosis . The prospect i ve study included 15 patients with deep vein thrombosis : 5 were treated in the hospital with streptokinase and heparin and 5 only with heparin , 5 were treated at home with only phenprocoumon .  All the patients received oral anticoagulant therapy for at least 6 months . Three to four months after the acute episode , phlebography and venous pressure measurements were carried out . Streptokinase appeared to give the best results but with more side-effects . In the retrospective study , 51 patients who had had deep vein thrombosis in 1969 were reexamined 31 - 47 months later . It was found that more than 50 % of the patients with a thrombosis in the femoral and /or iliac vein developed a severe postthrombotic syndrome , in contrast to only 9 % of those with a thrombosis in the popliteal vein or lower . It is recommended , on the basis of both the prospect i ve and the retrospective study , that patients with a thrombosis in the femoral and /or iliac vein should be treated with either heparin or streptokinase during the early stage . It is probable that streptokinase will significantly decrease the frequency and severity of the postthrombotic syndrome in these patients in particular , although this has not yet been proven Objective The purpose of this r and omized study was to evaluate the influence of immediate multilayer compression b and ages before application of elastic stockings in the acute phase of deep-vein thrombosis ( DVT ) on development of the post-thrombotic syndrome ( PTS ) . Methods Sixty-nine patients with acute symptomatic DVT were r and omized to immediate b and aging ( n = 34 ) or no b and aging ( n = 35 ) . After reduction of edema sized-to-fit elastic stockings were applied in all patients after 7–14 days . Follow-up visits and non-invasive examinations were planned after 7 , 30 and 90 days and 1 year . Venous outflow resistance ( VOR ) was measured by strain gauge plethysmography . Thrombosis score ( TS ) and reflux were measured by duplex scanning . After one year patients were evaluated for clinical PTS using both the clinical scale of the CEAP classification and the Villalta score . Results Improvement of clinical symptoms and decrease of leg circumference was better on day 7 in the b and aging group , but after 1 and 3 months clinical symptoms had improved equally in both groups . In 7 patients in the no-b and aging group a b and age was applied after all because of persistent edema after 10 days . There were no differences in VOR , TS and reflux . Using the CEAP classification the incidence of PTS was 39 % in patients with b and ages and 42 % in patients without b and ages ( RR 0.91 , 95 % CI 0.50–1.66 ) . Using the Villalta score the incidence of PTS was resp . 29 and 33 % ( RR 0.87 , 95 % CI 0.41–1.8 ) . There was no difference in severity of PTS . Conclusion Immediate multilayer compression b and aging in the acute phase of DVT is effective in reducing edema and complaints in the first week , but has no effect on thrombus regression , valve incompetence and the development of clinical PTS after 1 year Fibrinolytic treatment of acute deep vein thrombosis ( DVT ) of the leg with high-dose streptokinase ( SK ) ( 100,000 U/h ) in 39 cases , or low-dose SK ( approx 10,000 U/h ) in combination with low-dose heparin in 41 cases , was studied in a prospect i ve r and omized trial . The degree of thrombolysis was similar in both groups and did not correlate with age or size of the thrombus or with fibrinogen level . The degree of late recanalization was also similar in both groups . There were however significantly more patients with postthrombotic changes  in the low-dose group than in the high-dose group after a mean follow-up time of 31 and 38 months respectively . In the low-dose group 2 intracranial hemorrhages occurred ( one was fatal ) and one patient died of pulmonary embolism , but there were significantly less allergic side effects to SK .  There were no cases of such serious side effects in the highdose group . Although low-dose SK has equal thrombolytic effect it seems inferior to high-dose SK , since it probably causes more severe hemorrhagic side-effects OBJECTIVE We evaluated the effect of long-term anticoagulant treatment ( enoxaparin vs coumarin ) in patients with deep venous thrombosis ( DVT ) as to incidence of post-thrombotic syndrome ( PTS ) and recurrent venous thromboembolism . We also analyzed the impact of thrombus regression after the anticoagulant treatment for these two outcomes . METHODS A prospect i ve study was design ed in which 165 patients with symptomatic , unilateral , first-episode DVT were r and omized to a long-term anticoagulant treatment with coumarin or enoxaparin during at least 3 months . The rate of thrombus regression was defined as the difference in Marder score after 3 months of treatment by venography . Follow-up was performed at 3 , 6 , and 12 months , and yearly thereafter for 5 years . Venous disease was related to pathologic severity of PTS according to the vali date d scale of Villalta as rated by a physician blinded to treatment . Recurrence of symptomatic venous thromboembolism was documented objective ly . RESULTS The 5-year follow-up period was completed for 100 patients  ( enoxaparin , 56 ; coumarin , 44 ) . A lesser incidence of PTS was observed in the enoxaparin group ( 39.3 % absent , 19.6 % severe ) than in the coumarin group ( 29.5 % absent , 29.5 % severe ) , although this difference was not statistically significant . The accumulated recurrence rate was 19.3 % with enoxaparin compared with 36.6 % with coumarin ( P = .02 ) . Although the mean Marder score was significantly improved in both groups ( 49.1 % for enoxaparin vs 24.0 % for coumarin ; P = .016 ) , a lower reduction in thrombus size was associated with higher clinical events of recurrence ( hazard ratio = 1.97 ; 95 % CI , 1.06 - 3.66 ; P = .032 ) . A significant inverse correlation was also found between the degree of thrombus regression at 3 months and the incidence at 5 years of PTS ( P = .007 ) . CONCLUSIONS Residual venous thrombosis is an important risk factor for recurrent thromboembolism and PTS . A greater reduction in thrombus size was associated with lesser clinical events of recurrence and consequently a lesser rate of PTS . However , despite a greater recanalization with enoxaparin , the incidence of PTS was similar between both treatment groups , probably because of the small sample size . Further investigations are needed to clarify the implication of the anticoagulant treatment in the severity of PTS BACKGROUND The influence of the duration of anticoagulant therapy after venous thromboembolism ( VTE ) on the long-term morbidity and mortality is unclear . AIM To investigate the long-term sequelae of VTE in patients r and omized to different duration of secondary prophylaxis . METHODS In a multicenter trial comparing secondary prophylaxis with vitamin K antagonists for 6 weeks or 6 months , we extended the originally planned 2 years follow-up to 10 years . The patients had annual visits and at the last visit clinical assessment of the post-thrombotic syndrome ( PTS ) was performed . Recurrent thromboembolism was adjudicated by a radiologist , blinded to treatment allocation . Causes of death were obtained from the Swedish Death Registry . RESULTS Of the 897 patients r and omized , 545 could be evaluated at the 10 years follow-up . The probability of developing severe PTS was 6 % and any sign of PTS was seen in 56.3 % of the evaluated patients . In multivariate analysis , old age and signs of impaired circulation at discharge from the hospital were independent risk factors at baseline for development of PTS after 10 years . Recurrent thromboembolism occurred in 29.1 % of the patients with a higher rate among males , older patients , those with permanent triggering risk factor - especially with venous insufficiency at baseline - signs of impaired venous circulation at discharge , proximal deep vein thrombosis , or pulmonary embolism . Death occurred in 28.5 % , which was a higher mortality than expected with a st and ardized incidence ratio ( SIR ) of 1.43 ( 95 % CI 1.28 - 1.58 ) , mainly because of a higher mortality than expected from cancer ( SIR 1.83 ; 95 % CI 1.44 - 2.23 ) or from myocardial infa rct ion or stroke ( SIR 1.28 ; 95 % CI 1.00 - 1.56 ) . The duration of anticoagulation  did not have a statistically significant effect on any of the long-term outcomes . CONCLUSION The morbidity and mortality during 10 years after the first episode of VTE is high and not reduced by extension of secondary prophylaxis from 6 weeks to 6 months . A strategy to reduce recurrence of VTE as well as mortality from arterial disease is needed BACKGROUND The efficacy and safety of anticoagulant treatment is not established for patients with acute symptomatic deep vein thrombosis ( DVT ) of the calf . We aim ed to assess whether therapeutic anticoagulation is superior to placebo in patients with symptomatic calf DVT . METHODS In this r and omised , double-blind , placebo-controlled trial , we enrolled low-risk out patients ( without active cancer or previous venous thromboembolic disease ) with a first acute symptomatic DVT in the calf from 23 university medical centres or community medical clinics in Canada , France , and Switzerl and . We r and omly assigned ( 1:1 ) patients to receive either the low-molecular-weight heparin nadroparin ( 171 UI/kg , subcutaneously , once a day ) or placebo ( saline 0·9 % , subcutaneously , once a day ) for 6 weeks ( 42 days ) . Central r and omisation was done using a computer-generated r and omisation list , stratified by study centre . R and om allocation sequences of variable block size were central ly determined by an independent research clinical centre . Study staff , patients , and outcome 
    Output:
    
We found insufficient evidence to assess whether compression or other interventions protect against venous ulceration .