Thrombolysis for acute deep vein thrombosis

Watson L, Armon MP

Bookmark this:

more ...

Email this page

Summary

Thrombolysis for treatment of acute deep vein thrombosis

Deep vein thrombosis (DVT) occurs when a blood clot forms in a leg vein. The clot can break up and move to the lungs, leading to a potentially serious blockage in blood flow (pulmonary embolism). Because of the damage to the leg vein, post-thrombotic syndrome may develop any time over the next couple of years. Symptoms include leg pain, swelling, skin pigmentation and leg ulcers leading to loss of mobility. Anticoagulants are the standard treatment for DVT or a clot in a calf vein. These thin the blood to reduce further clots forming and prevent pulmonary embolism; yet post-thrombotic syndrome can still develop. Thrombolysis breaks down the blood clot. For DVT, drugs such as streptokinase, urokinase and tissue plasminogen activator are infused into a vein in the arm or foot or, in some cases, directly at the clot using a catheter and X-ray control. Bleeding complications, stroke or intracerebral haemorrhage are potential adverse events for both treatments.

The present review showed that thrombolysis may have advantages over standard anticoagulation treatment. Thrombolysis effectively dissolved the clot so that complete clot lysis occurred more often with thrombolysis than with standard anticoagulant therapy. Blood flow in the affected vein (venous patency) was also better maintained. Two trials (101 participants) continued for over six months and found that fewer people developed post-thrombotic syndrome when treated with thrombolysis, 48% compared with 65% in the standard anticoagulation treatment group (number needed to treat six).

The review results are based on 12 controlled trials that randomized a total of 668 people with acute DVT (within 14 days of onset of symptoms) or calf vein thrombosis to receive thrombolysis or anticoagulant treatment. Trials were carried out principally in the USA, Scandinavia, Germany and the UK. All trials included men and women and the age range was 18 to 75 with a preponderance of older adults. Those receiving thrombolysis had significantly more bleeding complications than with standard anticoagulation (10% versus 8%). Most bleeding episodes and deaths occurred in the earlier studies. Use of strict eligibility criteria has improved the safety and acceptability of this treatment.

This is a Cochrane review abstract and plain language summary, prepared and maintained by The Cochrane Collaboration, currently published in The Cochrane Database of Systematic Reviews 2010 Issue 1, Copyright © 2010 The Cochrane Collaboration. Published by John Wiley and Sons, Ltd.. The full text of the review is available in The Cochrane Library (ISSN 1464-780X).
This record should be cited as: Watson L, Armon MP. Thrombolysis for acute deep vein thrombosis. Cochrane Database of Systematic Reviews 2004, Issue 3. Art. No.: CD002783. DOI: 10.1002/14651858.CD002783.pub2.

This version first published online: October 18. 2004
Last assessed as up-to-date: October 07. 2007

Abstract

Background

Standard treatment for deep vein thrombosis (DVT) aims to reduce immediate complications. Use of thrombolysis or clot dissolving drugs could reduce the long-term complications of post-thrombotic syndrome (pain, swelling, skin discolouration, or venous ulceration) in the affected leg.

Objectives

To determine the efficacy and safety of thrombolysis for DVT.

Search strategy

The Cochrane Peripheral Vascular Diseases Group searched for randomised controlled trials (RCTs) in their Specialised Register (last searched October 2007) and the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (last searched Issue 3, 2007). Additional trials were identified by reviewing reference lists of papers. There were no restrictions for language.

Selection criteria

RCTs examining thrombolysis versus anticoagulation for acute DVT or calf vein thrombosis or both were considered.

Data collection and analysis

One review author (LIW) selected trials, extracted data and assessed study quality, with checking at all stages by the other review author (MPA). If necessary we sought additional information from trialists.

Main results

Twelve studies with over 700 people were included. Complete clot lysis occurred significantly more often in the treatment group in early follow up, (Risk Ratio (RR) 4.14; 95% confidence interval (CI) 1.22 to 14.01), and in late follow up, (RR 2.71; 95% CI 1.84 to 3.99). A similar effect was also seen for any degree of improvement in venous patency. Significantly less post-thrombotic syndrome occurred in those receiving thrombolysis, (RR 0.66; 95% CI 0.47 to 0.94). Leg ulceration was reduced although the data were limited by small numbers, (RR 0.53; 95% CI 0.12 to 2.43). Venous function was improved at late follow up, but not significantly (RR 2.33; 95% CI 0.32 to 17.27)
Out of 668 patients, those receiving thrombolysis had significantly more bleeding complications, (RR 1.73; 95% CI 1.04 to 2.88). Two strokes occurred in the treatment group (RR 1.70; 95% CI 0.21 to 13.70). The incidence of bleeding appears to have reduced over time with the introduction of stricter selection criteria. There was no significant effect on mortality detected in either early or late follow up. Data on occurrence of pulmonary embolism (PE) and recurrent DVT were inconclusive.

Authors' conclusions

Thrombolysis appears to offer advantages in terms of reducing post-thrombotic syndrome and maintaining venous patency after DVT. Use of strict eligibility criteria has improved the safety and acceptability of this treatment. The optimum drug, dose and route of administration have yet to be determined.

top of page | contact us | about this site | disclaimer | privacy