How to predict and diagnose postthrombotic syndrome

Postthrombotic syndrome (PTS) is the most frequent complication of deep vein thrombosis (DVT). From 20% to 50% of the patients will develop PTS after DVT, and from 5% to 10%, severe PTS. PTS is diagnosed on clinical grounds, based on the presence of signs and symptoms of venous insufficiency in the leg ipsilateral to DVT. The Villalta scale, a clinical scale that incorporates venous symptoms and signs, is a recommended standard for the diagnosis of PTS. Identifying which patients are at high risk of developing PTS would help improve the management of patients with DVT and allow physicians to provide patients with individualized information on their expected prognosis. Clinical predictors of PTS have been progressively characterized, but the ability to predict which patient with DVT is likely to develop PTS remains limited. A number of risk factors for PTS have been identified; of these, proximal location of DVT and a previous ipsilateral DVT are the most important. This review discusses the knowledge gained over the last decade on the diagnosis and predictors of PTS.  

Effectiveness of compression stockings to prevent the post-thrombotic syndrome (the SOX Trial and Bio-SOX biomarker substudy): a randomized controlled trial

Background

Post thrombotic syndrome (PTS) is a burdensome and costly complication of deep venous thrombosis (DVT) that develops in 20–40% of patients within 1–2 years after symptomatic DVT. Affected patients have chronic leg pain and swelling and may develop ulcers. Venous valve disruption from the thrombus itself or thrombus-associated mediators of inflammation is considered to be a key initiating event for the development of venous hypertension that often underlies PTS. As existing treatments for PTS are extremely limited, strategies that focus on preventing the development of PTS in patients with DVT are more likely to be effective and cost-effective in reducing its burden. Elastic compression stockings (ECS) could be helpful in preventing PTS; however, data on their effectiveness are scarce and conflicting.

Methods/Design

The SOX Trial is a randomized, allocation concealed, double-blind multicenter clinical trial. The objective of the study is to evaluate ECS to prevent PTS. A total of 800 patients with proximal DVT will be randomized to one of 2 treatment groups: ECS or placebo (inactive) stockings worn on the DVT-affected leg daily for 2 years. The primary outcome is the incidence of PTS during follow-up. Secondary outcomes are severity of PTS, venous thromboembolism (VTE) recurrence, death from VTE, quality of life and cost-effectiveness. Outcomes will be evaluated during 6 clinic visits and 2 telephone follow ups. At baseline, 1 and 6 months, blood samples will be obtained to evaluate the role of inflammatory mediators and genetic markers of thrombophilia in the development of PTS (Bio-SOX substudy).

Discussion

The SOX Trial will be the largest study and the first with a placebo control to evaluate the effectiveness of ECS to prevent PTS. It is designed to provide definitive data on the effects of ECS on the occurrence and severity of PTS, as well as DVT recurrence, cost-effectiveness and quality of life. This study will also prospectively evaluate the predictive role of biomarkers that are reflective of putative underlying pathophysiological mechanisms in the development of clinical PTS. As such, our results will impact directly on the care of patients with DVT.

Trial Registration

NCT00143598 and ISRCTN71334751

A thrombolytic regimen for high-risk deep venous thrombosis may substantially reduce the risk of postthrombotic syndrome in children

Important predictors of adverse outcomes of thrombosis in children, including postthrombotic syndrome (PTS), have recently been identified. Given this knowledge and the encouraging preliminary pediatric experience with systemic thrombolysis, we sought to retrospectively analyze our institutional experience with a thrombolytic regimen versus standard anticoagulation for acute, occlusive deep venous thrombosis (DVT) of the proximal lower extremities in children in whom plasma factor VIII activity and/or D-dimer concentration were elevated at diagnosis, from within a longitudinal pediatric cohort. Nine children who underwent the thrombolytic regimen and 13 who received standard anticoagulation alone were followed from time of diagnosis with serial clinical evaluation and standardized PTS outcome assessments conducted in uniform fashion. The thrombolytic regimen was associated with a markedly decreased odds of PTS at 18 to 24 months compared with standard anticoagulation alone, which persisted after adjustment for significant covariates of age and lag time to therapy (odds ratio [OR] = 0.018, 95% confidence interval [CI] = < 0.001-0.483; P = .02). Major bleeding developed in 1 child, clinically judged as not directly related to thrombolysis for DVT. These findings suggest that the use of a thrombolysis regimen may safely and substantially reduce the risk of PTS in children with occlusive lower-extremity acute DVT, providing the basis for a future clinical trial.

Late results of catheter-directed recombinant tissue plasminogen activator fibrinolytic therapy of iliofemoral deep venous thrombosis

PURPOSE

To evaluate the efficacy of catheter-directed low-dose recombinant tissue-type plasminogen activator infusion in the treatment of iliofemoral deep venous thrombosis and prevention of post-thrombotic syndrome.

METHOD

Eighteen patients (out of 260 evaluated) with acute iliofemoral deep venous thrombosis and no previous evidence of venous insufficiency were prospectively selected for thrombolytic therapy. Catheter-directed low-dose recombinant tissue-type plasminogen activator (1 mg/h) was infused into the thrombotic segments.

RESULTS

Effective fibrinolysis was achieved in 14 of 18 cases, with correlation between effective fibrinolysis and major/complete resolution of acute signs and symptoms (P <.01). There were no episodes of major complications. Four patients presented with early rethrombosis (1 to 8 weeks). Individuals were followed for a period up to 131 weeks (average, 85.2). The incidence of clinical signs and symptoms of venous insufficiency and duplex-scan findings of valvular reflux was significantly lower in the patients in which lytic therapy succeeded and patency was kept, compared with patients experiencing acute therapeutic failure or rethrombosis (P <.01).

CONCLUSIONS

Low-dose recombinant tissue-type plasminogen activator fibrinolytic therapy is safe and effective in the treatment of acute iliofemoral venous thrombosis. The late evolution as revealed clinically and by ultrasound was superior in patients for whom lytic therapy was effective.

New technology applications: thrombolysis of acute deep vein thrombosis

Treatment of deep vein thrombosis traditionally has focused on preventing the potentially life-threatening complication of pulmonary embolism rather than on removing or reducing the thrombus. Although treatment with anticoagulants may prevent thrombus propagation, the body's intrinsic thrombolytic system is left to attempt clot dissolution. Because this natural process is generally ineffective in its ability to fully recanalize a proximal vein, the risks of recurrent thrombosis as well as the disabling complication of postthrombotic syndrome increase. Moreover, the long-term consequences of postthrombotic syndrome include pain, disability, and, for many, a significant decrease in the quality of life. Recent technology using high-frequency, low-power ultrasound, or mechanical thrombectomy with catheter-directed delivery of a thrombolytic drug directly into the clot is available and showing promise. Nurses are caring for patients who receive endovascular interventions with lytic infusions. The nursing challenge is to provide safe and effective patient care.

Review on the value of graduated elastic compression stockings after deep vein thrombosis

Graduated elastic compression stockings (GECS) are commonly used in the primary prevention of deep vein thrombosis (DVT); however, their role in preventing recurrent DVT and also post-thrombotic syndrome is less well established. The aim of this review was to investigate the effect of GECS after DVT. A literature search was performed by two independent searchers in order to identify randomised controlled trials on the effect of GECS in preventing recurrent DVT and post-thrombotic syndrome. Four randomised trials, including 537 patients, were identified. Two of the studies demonstrated that below-knee GECS significantly reduced post-thrombotic syndrome during follow-up, while a smaller study showed equivocal results. GECS reduced the incidence of post-thrombotic syndrome from 54% to 25.2% [relative risk (RR) 0.47, 95% confidence interval (CI) 0.36-0.61] with the number needed to treat (NNT) being 4 (95% CI 2.7-5.0). The rate of recurrent asymptomatic DVT was also significantly reduced by GECS (RR 0.20, 95% CI 0.06-0.64; NNT 5); the reduction in symptomatic DVT was not significant (RR 0.79, 95% CI 0.50-1.26; NNT 34). In conclusion, there is level Ia evidence to suggest that GECS can significantly reduce the incidence of post-thrombotic syndrome (PTS) after DVT, and therefore these should be routinely prescribed. The evidence for recurrent DVT is less conclusive. Further research is needed towards standardising PTS diagnostic criteria and evaluating more effective preventive measures after DVT.

Frequency and determinants of the postthrombotic syndrome after venous thromboembolism

PURPOSE OF REVIEW

Postthrombotic syndrome (PTS) is the most common complication of deep venous thrombosis (DVT). Identifying which patients are at high risk of developing PTS would help improve the management of patients with DVT and allow physicians to provide patients with individualized information on their expected prognosis. This review discusses the knowledge gained from key studies over the last decade on the incidence and determinants of PTS, with special emphasis on published studies from the last 2 years.

RECENT FINDINGS

About a third to half of DVT patients will develop PTS, in most cases within 1-2 years of acute DVT. Important risk factors for PTS appear to be ipsilateral recurrence of DVT, poor quality of initial anticoagulation for the treatment of DVT and increased body mass index.

SUMMARY

Preventing DVT recurrence by providing adequate intensity and duration of anticoagulation for the initial DVT and using effective thromboprophylaxis in high-risk settings is likely to reduce the frequency of PTS. Despite some advances in identifying risk factors for PTS, however, it is still not possible to reliably predict an individual patient's risk of developing PTS after an episode of DVT. Further studies of clinical determinants and biological markers of increased risk of PTS are needed to ultimately improve long-term prognosis after DVT.

Compression with or without Early Ambulation in the Prevention of Post-thrombotic Syndrome: A Systematic Review

INTRODUCTION

The aim of this study was to assess whether there is enough evidence to suggest that compression with or without early ambulation after proximal DVT reduces the risk of post-thrombotic syndrome (PTS).

METHODS

Systematic review based on electronic and hand searching of the relevant literature.

RESULTS

Four randomized studies were identified and despite the fact that there was lack of uniformity in reporting standards all but one showed significant risk reduction of PTS using compression. No difference in recurrent thromboembolic events (DVT or pulmonary embolism) was observed between the compression and control group. In one study the early outcome from the combination of early ambulation with compression was faster reduction of swelling with better well-being without increased risk of PE compared to the control group. Pooled analysis of all studies showed that PTS developed in 24% (61/254) in the compression group and in 46% (110/239) in the control group (chi2=25.36, p=0.0001; OR: 0.37, 95%CI: 0.25, 0.54; RR: 0.52, 95%CI: 0.40, 0.67; and RRR: 0.48, 95%CI: 0.33, 0.60) with a 48% risk reduction from the use of compression.

CONCLUSION

Despite the fact that compression with or without early ambulation appears to be safe and it is more often associated with a decreased rate of PTS, the four existing studies do not permit meaningful data comparison due to lack of uniformity in reporting standards.

The post-thrombotic syndrome: progress and pitfalls

The post-thrombotic syndrome (PTS) develops in up to one half of patients after symptomatic deep venous thrombosis (DVT) and is the most common complication of DVT. Typical features of PTS include chronic pain, swelling, heaviness, oedema and skin changes in the affected limb. In severe cases, venous ulcers may develop. The frequency of PTS is likely to be reduced by preventing DVT with the use of effective thromboprophylaxis in high-risk patients and settings and by minimising the risk of ipsilateral DVT recurrence. Use of compression stockings for 2 years after DVT appears to reduce the incidence and severity of PTS but issues remain regarding their use and effectiveness. Future research should focus on elucidating the pathophysiology and risk factors for PTS, assessing the safety and effectiveness of catheter-directed thrombolysis to prevent PTS and evaluating the optimal use of compression stockings to prevent and treat PTS. In addition, new therapies to treat PTS should be sought and evaluated.

A New Method for Aggressive Management of Deep Vein Thrombosis: Retrospective Study of the Power Pulse Technique

Failure to treat deep vein thrombosis (DVT) is associated with significant morbidity and mortality. Anticoagulation, although effective at preventing clot progression, is not able to prevent postthrombotic syndrome. Catheter-directed thrombolysis is a more aggressive alternative, with some small studies suggesting a better long-term outcome, but the associated risks are significant, and the treatment can require 2-3 days in a monitored setting. This report describes the power pulse technique, in which mechanical thrombectomy is combined with thrombolytic agents to maximize the effectiveness of the treatment and reduce the need for prolonged infusion and its associated risks. A 24-patient retrospective study showed complete thrombus removal (>90%) in 12 patients, substantial thrombus removal (50%-90%) in seven patients, and partial thrombus removal (<50%) in five patients. All 24 patients had resolution of presenting symptoms. Only two patients required blood transfusion, and one patient experienced temporary nephropathy.

A cost analysis of the treatment of patients with post-thrombotic syndrome in Brazil

INTRODUCTION

Post-thrombotic syndrome (PTS) occurs in 15-50% of patients with deep vein thrombosis (DVT), and is associated with substantial medical costs. This prospective observational study investigated the costs associated with the treatment of PTS in Brazil.

MATERIALS AND METHODS

A total of 157 patients diagnosed with PTS and with a history of DVT were recruited from nine centers in Brazil. The costs of investigations and treatment for PTS over a 1-year follow-up period were analyzed. Ninety patients were available for this analysis.

RESULTS

Of the 90 patients, 17 had mild-to-moderate PTS, and 73 had severe PTS. The patients with severe PTS tended to undergo more investigations and hospitalizations for PTS than those with mild-to-moderate PTS, although the differences between the two groups did not reach statistical significance. The mean annual cost of treating PTS in Brazilian Reais was 1214 R dollars (426 US dollars) for mild-to-moderate PTS and 3386 R dollars (1188 US dollars) for severe PTS. The difference was mainly due to significantly higher hospitalization costs in patients with severe PTS (704 R dollars/247 US dollars vs. 0 R dollars; p=0.044).

CONCLUSION

These results suggest that PTS imposes substantial demands on health care resources in Brazil. The implementation of effective thromboprophylactic strategies could significantly reduce the incidence of DVT, and hence of PTS, potentially resulting in significant cost savings.

[Clinical and functional results after transfemoral thrombectomy for iliofemoral deep venous thrombosis: a 5-year-follow-up]

PURPOSE

The optimal therapy of deep pelvic and leg venous thrombosis is still a matter of debate. The purpose of our study was to evaluate early and late results of iliofemoral thrombectomy with regard to the prevention of the development of a postthrombotic syndrome.

METHODS

Between 1996 and 2000, 57 patients underwent transfemoral venous thrombectomy for acute iliofemoral thrombosis. 30 patients were reexamined after a mean of 60.4 months. At follow-up, the patency of the venous segments as well as the development of reflux was investigated by duplex-ultrasound. Furthermore, clinical signs and symptoms of chronic venous insufficiency as well as the subjective satisfaction of the patients with the operation were recorded.

RESULTS

Postoperatively the veins of the lower leg were completely recanalized in 25 % of the cases, those of the thigh in 52.3 %. The patency rate at the level of the groin, the pelvis and the caval vein were 92.5, 86 and 100 %, respectively. At follow-up, the veins of the lower limb, the thigh and the pelvis were patent in 76.7 % each and in 73.3 % at groin-level. The caval vein was completely recanalized in all cases. Reflux occurred in 12 patients. 26.7 % of the patients showed no signs of a postthrombotic syndrome. 63.3 % had mild changes including dilated superficial veins and swelling tendency, and only in 10 % trophic skin changes were apparent. A healed or active ulceration did not occur in any case. Except one, all patients were satisfied with the results of the thrombectomy.

CONCLUSIONS

Transfemoral thrombectomy for acute iliofemoral venous thrombosis offers good early and late results in terms of preserving venous function and reducing symptoms of venous insufficiency. In our patient population, the development of a severe postthrombotic syndrome could be reduced effectively.

Relation between quality of anticoagulant treatment and the development of the postthrombotic syndrome

BACKGROUND

About 30% of patients with an episode of adequately treated deep venous thrombosis (DVT) develop the postthrombotic syndrome (PTS) within 2 years. During treatment with vitamin K antagonists (VKA) patients spend only 60% of time between an International Normalized Ratio (INR) of 2.0 and 3.0. We hypothesized that patients who spend a large amount of their time beneath this range will have an increased risk of the PTS.

OBJECTIVE

To investigate the relation between the quality of anticoagulant therapy with VKA and the risk of the development of the PTS.

METHODS

The time spent beneath the therapeutic range was calculated for patients with a first episode of DVT, who were treated with VKA for at least 3 months. At follow-up assessments for a maximum of 5 years, presence and severity of signs and symptoms of PTS were recorded.

RESULTS

A total of 244 patients, with a median duration of follow-up of 4.9 years were included for analysis. Of these, 81 patients (33%) developed the PTS. The multivariate model showed that patients who spend more than 50% of their time beneath an INR level of 2.0 are at higher risk for PTS [odds ratio (OR): 2.71, 95% CI: 1.44-5.10].

CONCLUSIONS

Low quality treatment with VKA, which is a common condition, is related to the occurrence of the PTS in patients with DVT. Strategies aimed at improving the quality of long-term anticoagulation might have the potential to reduce the incidence of this complication.

Cost consequence analysis of fondaparinux versus enoxaparin in the prevention of venous thromboembolism after major orthopaedic surgery in Belgium

Fondaparinux, a selective inhibitor of activated factor X, has been shown to reduce further the risk of venous thromboembolism (VTE) in major orthopaedic surgery compared to the low molecular weight heparin enoxaparin, when both were applied for 7 days after surgery. To compare the expected costs and clinical outcomes of fondaparinux with enoxaparin applied for 7 days after surgery, we conducted a cost-consequence analysis in patients undergoing major orthopaedic surgery, i.e. total hip replacement, total knee replacement and hip fracture repair. Our decision model included endpoints relevant in routine clinical practice and the natural history of VTE over a long term period of 5 years. Costs for prevention, diagnosis and treatment of VTE and its complications were estimated from the Belgian health care payer perspective. Analyses were conducted for different time horizons and for the three indications, separately, and then combined. Overall, our results indicated that the initial investment in fondaparinux (cost per day: 10.39 euros versus 3.74 euros for enoxaparin) was soon compensated by savings due to avoided VTE events, with cost neutrality being achieved after 90 days and further savings being incurred over longer time periods mainly due to avoided post-thrombotic syndromes. These findings were most pronounced in patients undergoing hip fracture repair. Sensitivity analyses showed these findings to be robust for the three indications separately, and combined. We conclude that our analysis of health and economic consequences over a long term period, demonstrates the value for money of fondaparinux versus enoxaparin for the prevention of VTE events after total hip replacement, total knee replacement and hip fracture repair.

Below-knee elastic compression stockings to prevent the post-thrombotic syndrome: a randomized, controlled trial

BACKGROUND

Because only limited evidence suggests that elastic stockings prevent the post-thrombotic syndrome in patients with symptomatic deep venous thrombosis (DVT), these stockings are not widely used.

OBJECTIVE

To evaluate the efficacy of compression elastic stockings for prevention of the post-thrombotic syndrome in patients with proximal DVT.

DESIGN

Randomized, controlled clinical trial.

SETTING

University hospital.

PATIENTS

180 consecutive patients with a first episode of symptomatic proximal DVT who received conventional anticoagulant treatment.

INTERVENTIONS

Before discharge, patients were randomly assigned to wear or not wear below-knee compression elastic stockings (30 to 40 mm Hg at the ankle) for 2 years. Follow-up was performed for up to 5 years.

MEASUREMENTS

The presence and severity of the post-thrombotic syndrome were scored by using a standardized scale.

RESULTS

Post-thrombotic sequelae developed in 44 of 90 controls (severe in 10) and in 23 of 90 patients wearing elastic stockings (severe in 3). All but 1 event developed in the first 2 years. The cumulative incidence of the post-thrombotic syndrome in the control group versus the elastic stockings group was 40.0% (95% CI, 29.9% to 50.1%) versus 21.1% (CI, 12.7% to 29.5%) after 6 months, 46.7% (CI, 36.4% to 57.0%) versus 22.2% (CI, 13.8% to 30.7%) after 1 year, and 49.1% (CI, 38.7% to 59.4%) versus 24.5% (CI, 15.6% to 33.4%) after 2 years. After adjustment for baseline characteristics, the hazard ratio for the post-thrombotic syndrome in the elastic stockings group compared with controls was 0.49 (CI, 0.29 to 0.84; P = 0.011).

LIMITATIONS

This study lacked a double-blind design.

CONCLUSIONS

Post-thrombotic sequelae develop in almost half of patients with proximal DVT. Below-knee compression elastic stockings reduce this rate by approximately 50%.

Non-pharmaceutical measures for prevention of post-thrombotic syndrome

BACKGROUND

Post-thrombotic syndrome (PTS) is a long-term complication of deep vein thrombosis (DVT) characterised by chronic pain, swelling and skin changes in the affected limb. One in every three patients with DVT will develop post-thrombotic complications within five years.

OBJECTIVES

To determine the relative effectiveness of, and the rate of complications using non-pharmaceutical interventions in patients with DVT in the prevention of PTS.

SEARCH STRATEGY

The reviewers searched the Cochrane Peripheral Vascular Diseases Group Specialised Trials Register (last searched January 2003), and the Cochrane Central Register of Controlled Trials (CENTRAL) (last searched Issue 4, 2002). In addition, hand searching of non-listed journals and personal communications with researchers was undertaken.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of non-pharmaceutical interventions, such as bandaging and elastic stockings in patients with clinically confirmed DVT. The primary outcome was the occurrence of PTS. There was no restriction on date or language. One reviewer (DNK) identified and assessed titles and abstracts for relevance. This was verified independently by a second reviewer (RS).

DATA COLLECTION AND ANALYSIS

Data extraction was undertaken independently by two reviewers (DNK, RS), using data extraction sheets.

MAIN RESULTS

Three RCTs that evaluated compression therapy were identified. Two studies compared elastic compression stockings with a pressure of 30-40 mm Hg at the ankle with no intervention applied directly after an episode of DVT. The other small study compared elastic compression stockings (pressure 20-30 mm Hg) with stockings that were one to two sizes too large in patients one year after DVT. Overall, in the treatment group at two years, the use of elastic compression stockings was associated with a highly statistically significant reduction in the incidence of PTS with odds ratio (OR) 0.31 (95% confidence interval (CI) 0.20 to 0.48). In addition, the incidence of severe PTS was reduced from OR 0.39 (95% CI 0.20 to 0.76). In another RCT that considered the first nine days post DVT, no difference in the incidence of pulmonary embolism and size of thrombus in the femoral vein was found. A statistically significant reduction (p <0.05) was found in pain, swelling and clinical scores, favouring the compression group.

REVIEWER'S CONCLUSIONS

There is substantial evidence that elastic compression stockings reduce the occurrence of PTS after DVT. No serious adverse effects were mentioned in the studies. Hence, elastic compression stockings should be added to the treatment of DVT to prevent the development of post-thrombotic syndrome.

Thrombolytic therapy for acute deep vein thrombosis and the venous registry

Randomized clinical trials have defined anticoagulation with unfractionated or low molecular weight heparin followed by warfarin as standard therapy for acute deep venous thrombosis (DVT). Such treatment is highly effective in preventing recurrent venous thromboembolism, but provides imperfect protection against development of the postthrombotic syndrome. By restoring venous patency and preserving valvular function, catheter-directed thrombolytic therapy potentially affords an improved long-term outcome in selected patients with DVT. A national venous registry, compiling data from 63 participating centers, was established to collect data regarding the technical details of the procedure and early outcome. Data from the registry have established the optimal technical approach and patient population. An antegrade catheter-directed approach using urokinase in patients with acute iliofemoral DVT of less than 10 days duration and no prior history of DVT may achieve complete lysis in 65% of patients. Analysis of the clinical outcome is pending, but early results suggest improved valve function and fewer symptoms at 1 year in patients with complete thrombolysis. These promising data should serve as the basis for future randomized trials of catheter-directed thrombolysis for the treatment of acute DVT.

Quality-of-life improvement using thrombolytic therapy for iliofemoral deep venous thrombosis

Patients with iliofemoral deep venous thrombosis suffer the most severe postthrombotic morbidity. Techniques that effectively remove thrombus from the venous system eliminate venous obstruction and potentially preserve valvular function. This will likely reduce or avoid the postthrombotic syndrome and improve long-term quality of life. To evaluate whether catheter-directed thrombolysis is associated with improved quality of life compared with anticoagulation alone and whether outcome in the thrombolysis group is related to lytic success, 98 patients with iliofemoral deep venous thrombosis who were treated at least 6 months earlier were identified and queried with a validated health-related quality-of-life questionnaire. Sixty-eight patients were identified through the Venous Registry (a national, multicenter venous registry) and were treated with catheter-directed thrombolysis with urokinase, and 30 patients were identified by means of medical record review and were treated with anticoagulation alone. All patients were candidates for thrombolysis; however, the treatment decision was made according to physician preference. The two treatment groups did not differ significantly in average time between the reference hospitalization and first contact. No difference was found in physical functioning and well-being between the groups before the development of deep venous thrombosis. Following treatment, patients receiving catheter-directed thrombolysis reported better overall physical functioning, less stigma, less health distress, and fewer postthrombotic symptoms compared to those patients treated with anticoagulation alone. Within the thrombolysis group, successful lysis correlated with health-related quality of life. Catheter-directed thrombolysis for the management of patients with iliofemoral deep venous thrombosis significantly improves health-related quality of life compared to similar patients treated with anticoagulation alone. Improved quality of life is related to successful thrombolysis. These data offer a compelling argument for a prospective randomized study.

Treatment and management of acute venous thromboembolic disease

Venous thromboembolic (VTE) disease consists of deep vein thrombosis and/or pulmonary embolism. Either low molecular weight heparin given subcutaneously or unfractionated heparin administered intravenously are used for the initial treatment. Simultaneously, warfarin therapy is initiated. Thrombolytic therapy plays a limited role. Following the initial heparin treatment, anticoagulation clinics provide an excellent means of monitoring the oral anticoagulation. Patient education is important and patients should be well versed in the basic features of oral anticoagulation. The duration of oral anticoagulation is dependent on a number of factors including the presence of inherited risk factors, bleeding risk and patient reliability. Residual thrombus in the affected vein may indicate the need for prolonged anticoagulation. The low intensity oral anticoagulation (INR 1.5-2.0) is useful in preventing recurrent thrombosis following the initial treatment period with full intensity oral anticoagulation.

[Role of plasminogen activators in the treatment of deep venous thrombosis]

In deep vein thrombosis, thrombolytic agents can improve vein patency more rapidly than conventional anticoagulant therapy. The clinical benefit of thrombolytic use would be a reduction in the incidence and severity of the postthrombotic syndrome and limb salvage in "phlegmatia caerulea". A literature review suggests that streptokinase and rt-PA do better than heparin regarding vein patency. A clinical benefit on postthrombotic syndrome can only be suggested by available evidence. The risk of major bleeding is increased by thrombolytic agents as compared with heparin. Mortality for cerebral bleeding is about 0.5%. Currently, thrombolytic therapy is only recommended for limb salvage in phlegmatia caerulea.

Prevention and treatment of postphlebitic syndrome: results of a 3-part study

BACKGROUND

The true incidence of postphlebitic syndrome (PPS) following proximal deep venous thrombosis (DVT) and the efficacy of graduated compression stockings in preventing and treating PPS are unknown.

METHODS

A 3-part study of 202 patients evaluated 1 year after proximal DVT: 2 randomized placebo-controlled trials of stockings and 1 prospective cohort of untreated patients. Patients were evaluated for PPS, using a standardized questionnaire, and for venous valvular incompetence, using photoplethysmography and venous Doppler. They were enrolled in study 1 or study 2 if they did not have symptomatic PPS and did not have or had venous valvular incompetence, respectively, and into study 3 if they had symptomatic PPS. Study 1 patients were left untreated and followed up for development of PPS every 6 months for a mean of 55 months. Study 2 patients were randomized to a below-knee stocking (20-30 mm Hg) or a matched placebo stocking, and followed up for development of PPS every 6 months for a mean of 57 months. Study 3 patients were randomized to an active stocking (30-40 mm Hg) or a matched placebo stocking and followed up every 3 months for treatment failure, defined a priori.

RESULTS

In study 1, 6 (5.0%) of 120 patients were categorized as treatment failures, a rate similar to placebo-treated study 2 patients (P =.10). In study 2, 0 (0%) of 24 active and 1 (4.3%) of 23 placebo-treated patients were categorized as treatment failures (P =.49). In study 3, 11 (61.1%) of 18 active and 10 (58.8%) of 17 placebo-treated patients were categorized as treatment failures (P>.99).

CONCLUSIONS

Most patients do not have PPS 1 year after proximal DVT, and do not require stockings. We failed to show a benefit of stockings in patients with PPS, but the small numbers preclude definitive conclusions.

The effects of heparin and oral anticoagulants on thrombus propagation and prevention of the postphlebitic syndrome: a critical review of the literature

Based on a comprehensive literature search, this report aims to examine the effects of heparin and oral anticoagulants on thrombus propagation and prevention of the postphlebitic syndrome. The effects on recurrence of thromboembolic disease have not been addressed. It is concluded that published reports of serial venograms and ultrasound examinations of patients treated with conventional anticoagulant therapy for deep venous thrombosis show either no change or thrombus extension in the first few months in approximately 50% of cases. Approximately two thirds of patients will have damage to the venous valves, leading to incompetence or other hemodynamic changes. More than one third of patients so treated may have oedema, leg pain, or other severe symptoms on long-term follow-up. The consistency with which these outcomes have been observed, particularly in many large, recent, prospective trials, adds to the credibility of these figures. The results of prospective controlled trials have failed uniformly to show any significant local benefits of anticoagulant therapy for deep vein thrombosis compared with other treatments or placebo. There does not seem to be any convincing evidence that heparin exerts a favorable influence on pulmonary embolism in situ or on portal vein thrombosis. Use of anticoagulant therapy to limit thrombus propagation therefore cannot be said to be "evidence based." These generally poor outcomes with regard to postphlebitic complications should lead to an active exploration of alternative methods of management. Substantial uncertainties surrounding many fundamental aspects of the treatment of this disease remain, and further placebo-controlled trials are needed.

[Value of compression therapy in treatment of deep venous thrombosis]

Therapy in the acute phase of deep vein thrombosis aims to prevent the longitudinal growth of the thrombus as well as the life-threatening complication of pulmonary embolism. Compression therapy is part of all revascularisative and conservative treatment strategies, but hardly mentioned in most of the literature. Clinical efficacy of a sufficient compression therapy in patients with acute deep vein thrombosis is marked by a quick ease of subjective complaints as well as a reduction of the edema. The long-term risk of deep vein thrombosis, the postthrombotic syndrome, is avoidable by the use of compression therapy. Clinical studies about the effectiveness in relation to the length of the thrombus and the incidence of pulmonary embolism are missing as well as studies about the selection of the best compression material. Recently compression pressures were experimentally measured between long and short stretch bandages and the skin in order to select bandage material. It can be concluded that long stretch bandages can be used in the treatment of acute phlebothrombosis in mobile out-patients. Short stretch bandages should be used in immobile patients in order to avoid high pressures between the skin and the bandages. Compression stockings (Class III) represent an equivalent alternative to compression bandages after the resolution of edema.

[Therapy of deep leg vein thrombosis. When is surgical therapy indicated?]

In spite of quite a few clinical trials the benefit of venous thrombectomy is seen controversially. The primary objectives of treating venous thrombosis are survival rate, prevention of pulmonary embolism and of postthrombotic syndrome. We report our experience with 47 patients who underwent venous thrombectomy. The mortality rate was 0%. We did not observe clinically relevant pulmonary embolism. After two years 90% of thrombectomised veins were patent. The mortality rates given in the literature of conservative treatment with heparin and following oral anticoagulation are 0.4 to 1.6%. Fibrinolysis shows mortality rates of 1 to 2.4, and thrombectomy of 3.8%, respectively. Venous thrombectomy is an effective treatment to prevent pulmonary embolism. In our own experience we saw no clinically significant pulmonary event. The danger of embolism rises with the proximity of the venous thrombus. Therefore those patients may have the greatest potential benefit from thrombectomy who present with a mobile inguinal thrombus or a thrombus in the iliac vein. So far there are no statistically sufficient data to support the indication of thrombectomy to prevent a postthrombotic syndrome.

Treatment of venous thrombo-embolism

Clinically suspected deep vein thrombosis (DVT) or pulmonary thromboembolism (PE) should be initially treated with heparin, and an objective diagnosis obtained. In pregnancy, heparin is usually continued until delivery, following which warfarin is substituted. In the absence of pregnancy, warfarin is substituted and usually continued for 3 months after a first thrombo-embolic event. Low molecular weight heparins are increasingly preferred to unfractionated heparin in non-pregnant patients with acute DVT, because of efficacy when given by daily subcutaneous injection without routine monitoring of coagulation assays, greater efficacy, and lower risks of major bleeding and of mortality. Unfractionated heparin requires monitoring by the APTT (target ratio 1.5-2.5), and warfarin requires monitoring by the International Normalized Ratio (INR) of the prothrombin time (target ratio 2.0-3.0). Graduated elastic compression stockings reduce post-thrombotic leg symptoms after DVT. Secondary prevention is important in future high risk situations.

Randomised trial of effect of compression stockings in patients with symptomatic proximal-vein thrombosis

BACKGROUND

Post-thrombotic syndrome varies from mild oedema to incapacitating swelling with pain and ulceration. We investigated the rate of post-thrombotic syndrome after a first episode of deep-vein thrombosis and assessed the preventive effect of direct application of a sized-to-fit graded compression stocking.

METHODS

Patients with a first episode of venogram-proven proximal deep-vein thrombosis were randomly assigned no stockings (the control group) or made-to-measure graded compression elastic stockings for at least 2 years. Post-thrombotic syndrome was assessed with a standard scoring system that combined clinical characteristics and objective leg measurements. Patients were assessed every 3 months during the first 2 years, and every 6 months thereafter for at least 5 years. The cumulative incidence of mild-to-moderate post-thrombotic syndrome was the primary outcome measure.

FINDINGS

Of the 315 consecutive outpatients considered for inclusion, 44 were excluded and 77 did not consent to take part. 194 patients were randomly assigned compression stockings (n = 96) or no stockings (n = 98). The median follow-up was 76 months (range 60-96) in both groups. Mild-to-moderate post-thrombotic syndrome (score > or = 3 plus one clinical sign) occurred in 19 (20%) patients in the stocking group and in 46 (47%) control-group patients (p < 0.001). 11 (11%) patients in the stocking group developed severe post-thrombotic syndrome (score > or = 4), compared with 23 (23%) patients in the control group (p < 0.001). In both groups, most cases of post-thrombotic syndrome occurred within 24 months of the acute thrombotic event.

INTERPRETATION

About 60% of patients with a first episode of proximal deep-vein thrombosis develop post-thrombotic syndrome within 2 years. A sized-to-fit compression stocking reduced this rate by about 50%.

Automated computer interviews to elicit utilities: potential applications in the treatment of deep venous thrombosis

OBJECTIVE

To assess the practicality of an automated computer interview as a method to assess preferences for use in decision making. To assess preferences for outcomes of deep vein thrombosis (DVT) and its treatment.

STUDY DESIGN

A multimedia program was developed to train subjects in the use of different preference assessment methods, presented descriptions of mild post-thrombotic syndrome (PTS), severe PTS and stroke and elicited subject preferences for these health states. This instrument was used to measure preferences in 30 community volunteers and 30 internal medicine physicians. We then assessed the validity of subject responses and calculated the number of quality-adjusted life years (QALYs) for each individual for each alternative.

RESULTS

All subjects completed the computerized survey instrument without assistance. Subjects generally responded positively to the program, with volunteers and physicians reporting similar preferences. Approximately 26.5% of volunteers and physicians had preferences that would be consistent with the use of thrombolysis. Individualization of therapy would lead to the most QALYs.

CONCLUSIONS

Utilization of computerized survey instruments to elicit patient preferences appears to be a practical and valid approach to individualize therapy. Application of this method suggests that there may be many patients with DVT for whom treatment with a thrombolytic drug would be optimal.

Results of venous thrombectomy in the treatment of deep vein thrombosis

Despite the infrequent use in the United States, venous thrombectomy seems to have a beneficial effect in carefully selected patients with acute iliofemoral thrombosis. The final decision to proceed with venous thrombectomy should be based on a balanced analysis of two factors--the characteristics of the thrombus and the characteristics of the patient. First, the diagnosis of acute deep vein thrombosis must be unequivocally established preoperatively. Accurate anatomic localization is usually achieved with venography, but duplex Doppler examination may be sufficient in selected instances. Second, the distribution of thromboses should be determined. Venous thrombectomy should be considered only in instances of deep vein thrombosis involving the iliofemoral venous segment. Thrombectomy for venous thrombosis below the inguinal ligament has not been consistently beneficial. Third, the age of the thrombus should be estimated. This can usually be accomplished though a careful analysis of the clinical history, but may be corroborated by duplex Doppler or venographic features of the thrombus. Venous thrombectomy should rarely be attempted if the age of the thrombus is thought to be greater than 72 hours. Unfortunately, in many instances the clinical history substantially underestimates the actual age of the underlying thrombus. Fourth, patient characteristics must be assessed preoperatively. While venous thrombectomy can usually be accomplished using local anesthesia, substantial shifts in fluid and acid base balance may be poorly tolerated by elderly, frail patients. In the setting of widespread metastatic disease, rethrombosis rates may be too high to justify thrombectomy in some patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[Venous thromboembolic disease]

Prevention and treatment of venous thrombosis and pulmonary embolism have improved dramatically in the last few years owing to: 1) better control of the coumarin activity with the International Normalized Ratio system; 2) appearance on the market of the low-weight molecular heparins and enlargement of their field of prescription; 3) indications of thrombolysis in severe pulmonary embolism; 4) availability of inferior vena cava filters, effective in preventing recurrent pulmonary embolism.

[Thrombolysis in deep venous thrombosis: critical review]

Thrombolytic treatment of deep vein thrombosis remains controversial. It has never been demonstrated that the late postthrombotic syndrome may be diminished by the faster dissolution of the clots induced by streptokinase or urokinase. On the other hand are the hemorrhagic side effects associated with thrombolysis well described (lethality of 0.6%). Thrombolysis should be performed preferably under controlled conditions of a clinical study. It is indicated only in young patients with symptoms for less than 7 days of a first thrombosis. Initial results from second generation fibrinolytic substances such as rt-PA (alteplase) do not change this view drastically.

[Thrombolysis with rt-PA in children with arterial and venous thromboses--a new therapy concept]

Thrombolytic therapy usually used for thrombosis in the adult has been administered as a therapeutic regiment in pediatric patients (parental consent was sought prior to the treatment with rt-PA). We report our experience with rt-PA in 17 children and adolescents suffering from arterial (n = 4) or venous thrombosis (n = 13) due to local rhabdomyosarcoma, acute lymphoblastic leukemia, chronic myeloblastosis, sickle cell anaemia, parenteral nutrition, haemolytic uremic syndrome, central arterial and venous catheters and septicemia Thrombotic diseases have been diagnosed by Doppler ultrasound, computed tomography, angiography and phlebography. Rt-PA therapy was started immediately after diagnostic procedures had been performed. Rt-PA dose varied from 0.2 mg as a single dose to 0.8 mg/kg bw/d over a three day period in children local thrombolysis was performed. In patients requiring systemic thrombolytic therapy rt-PA was administered from 0.8 mg/kg bw/d in three days to 2.0 mg/kg bw/d over a whole period of three weeks in both groups during thrombolysis low dose heparin was added. When rt-PA infusion was terminated heparin (70 IU - 400 IU/kg bw/d) was administered for 7 to 14 days in order to prevent reocclusion. Later prophylaxis with coumarin derivatives in venous thrombosis and antiplatelet agents in arterial occlusive diseases was performed. In no patient did we see a decrease of fibrinogen and plasminogen during rt-PA therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

[Treatment of distal venous thrombosis of the lower extremity with "moderated" doses of heparin]

The effectiveness of a therapeutic protocol, using 15,000 to 22,500 IU/day of heparin by subcutaneous injection, to treat the distal postoperative vein thrombosis on the lower limb, was evaluated. The study was made on 427 patients, which were analyzed by the Fibrinogen I125 marked accumulation test, to give an early diagnostic and follow-up of their thrombosis (thrombus lysis, stabilization or expansion). Treatment made, showed its efficacy preventing from proximal expansion, as well as avoiding pulmonary embolism and postphlebitic syndrome. Its cost is lower than other therapeutic option's costs, and it doesn't extend the hospital stay.

Thrombectomy for acute deep vein thrombosis: prevention of postthrombotic syndrome

Ninety-six limbs of 89 patients with acute deep vein thrombosis of the lower extremity were followed for 1 to 18 years. In the thrombectomy group (43 limbs), the cumulative incidence of pigmentation at the 15th year was 15%, but no stasis ulcers occurred throughout the follow-up period. In the conservative treatment group (53 limbs), the cumulative incidence of pigmentation at the 15th year was 41%, and that of stasis ulceration was 27%. Fogarty thrombectomy restricted below the pelvic vein spur and removal of thrombi in the leg veins by manual milking is sufficient to relieve early morbidity, preserve venous valve function, and promote intrapelvic collateral circulation. Preservation of venous valves in the femoropopliteal region is a key to the prevention of postthrombotic syndrome. Thrombectomy within 5 days of the onset of symptoms is recommended for patients with iliofemoropopliteal venous thrombosis.