Thrombolysis for acute deep vein thrombosis.
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.


OBJECTIVE
To determine the efficacy and safety of thrombolysis for DVT.


METHODS
Publications describing randomised controlled trials (RCTs) of thrombolysis versus anticoagulation for acute DVT were sought through electronic searches of the Cochrane Peripheral Vascular Diseases trials register (last searched April 2004) and the Cochrane Central Register of Controlled Trials (CENTRAL) (last searched The Cochrane Library Issue 2, 2004). Additional trials were identified by reviewing reference lists of papers. There were no restrictions for language.


METHODS
RCTs examining thrombolysis versus anticoagulation for acute DVT and/or calf vein thrombosis were considered.


METHODS
One reviewer (LIW) selected trials, extracted data and assessed study quality, with checking at all stages by the other reviewer (MPA). Where required, additional information was sought from trialists.


RESULTS
Twelve studies were included. Complete clot lysis occurred significantly more often in the treatment group in early follow up, (relative risk (RR) 0.24; 95% confidence interval (CI) 0.07 to 0.82), and in late follow up, (RR 0.37; 95 % CI 0.25 to 0.54). 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 0.43; 95 % CI 0.06 to 3.17)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.


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.
Watson
L I
LI
Cochrane PVD Group, University of Edinburgh, Dept of Public Health Sciences, Teviot Place, Edinburgh, UK, EH3 9AG. lorna.watson@isd.csa.scot.nhs.uk
Armon
M P
MP
D006801:Humans; D016032:Randomized Controlled Trials as Topic; D015912:Thrombolytic Therapy / Q000009:adverse effects / Q000379:methods*; D020246:Venous Thrombosis / Q000188:drug therapy*