The quality of evidence is downgraded by imprecise results (few patients and outcome events).
A Cochrane review included 17 studies with a total of 1 103 subjects. Studies were carried out from 1969 to 2009 to assess the effects of thrombolytic therapy and anticoagulation versus anticoagulation alone in the management of people with acute deep vein thrombosis (DVT) of the lower limb. A cut-off of 21 days from onset of symptoms was used. Systemic, loco-regional and catheter-directed thrombolysis (CDT) were included. The majority of trials assessed systemic thrombolysis, with streptokinase the most common agent used.
Complete clot lysis occurred significantly more often in the treatment group (any thrombolysis) in early follow up (RR 4.91, 95% CI 1.66 to 14.53, statistical heterogeneity I2=62%; 8 studies, n=592), and at intermediate follow up (table ). A similar effect was also seen for any degree of improvement in venous patency (RR 2.48, 95% CI 1.35 to 4.57, statistical heterogeneity I2=77%; 9 studies, n=421). Significantly less post-thrombotic syndrome occurred in those receiving thrombolysis (NNTB=5 for intermediate and NNTB=4 for late follow-up). Leg ulceration was reduced, but not significally, the data were limited by small numbers (RR 0.87, 95% CI 0.16 to 4.73; 4 studies, n=342).
Those receiving thrombolysis had significantly more bleeding complications. Three strokes occurred in the treatment group, all in trials conducted pre-1990, and none in the control group. There was no significant effect on mortality detected in either early (RR 0.76, 95% CI 0.31 to 1.89; 9 studies, n=529) or intermediate (RR 0.96, 95% CI 0.27 to 3.43; 2 studies, n=289) follow up. Data on occurrence of pulmonary embolism (PE) and recurrent DVT were inconclusive)"?>.
| Outcome | Follow-up after treatment | Relative effect (95% CI) | Assumed risk - Control | Corresponding risk - Any thrombolysis (95% CI) | Participants (studies) |
|---|---|---|---|---|---|
| *statistical heterogeneity I2=70%; **statistical heterogeneity I2=59% | |||||
| Complete clot lysis (intermediate) | 6 months to under 5 years | RR 2.44 (1.4 to 4.27)* | 325 per 1000 | 793 per 1000 (455 to 1000) | 630 (7 studies) |
| Bleeding (early) | up to 1 month | RR 2.23 (1.41 to 3.52) | 43 per 1000 | 96 per 1000 (61 to 152) | 1 103 (17 studies) |
| Post-thrombotic syndrome (intermediate) | 6 months to under 5 years | RR 0.66 (0.53 to 0.81)** | 658 per 1000 | 434 per 1000 (348 to 533) | 306 (3 studies) |
| Post-thrombotic syndrome (late) | 5 years | RR 0.58 (0.45 to 0.77) | 673 per 1000 | 390 per 1000 (303 to 518) | 211 (2 studies) |
)."?> Systemic thrombolysis and catheter-directed thrombolysis (CDT) had similar levels of effectiveness. Studies of CDT included 2 trials in femoral and iliofemoral DVT, and results from these (table ) were consistent with those from studies of systemic thrombolysis in DVT at other levels of occlusion.
| Outcome | Follow-up after treatment | Relative effect (95% CI) | Assumed risk - Control | Corresponding risk - Any thrombolysis (95% CI) | Participants (studies) |
|---|---|---|---|---|---|
| *statistical heterogeneity I2=82% | |||||
| Complete clot lysis (intermediate) | 6 months to under 5 years | RR 2.52 (0.52 to 12.17)* | 58 (of 116) patients treated with standard anticoagulation had complete clot lysis compared to 81 (of 108) in the CDT group | 224 (2 studies) | |
| Bleeding (early) | up to 1 month | RR 7.69 (0.40 to 146.90) | Cannot define risk as no events reported in the standard anticoagulation group | 224 (2 studies) | |
| Post-thrombotic syndrome (intermediate) | 6 months to under 5 years | RR 0.74 (0.55 to 1.00) | 556 per 1000 | 411 per 1000 (306 to 556) | 189 (1 study) |
| Post-thrombotic syndrome (late) | 5 years | RR 0.60 (0.45 to 0.79) | 708 per 1000 | 425 per 1000 (319 to 559) | 176 (1 study) |
Patients with extensive thromboses, for example iliofemoral, may have the most to gain in terms of preserving venous function, and patient selection is important to reduce the risk of complications. It is not possible to determine the optimum treatment regime in terms of agent, dose and route of administration from this review.