ObjectiveTo evaluate the effectiveness and safety of the additional catheter-directed thrombolysis (CDT) and conventional treatment (CT) for treatment primary deep vein thrombosis. MethodsDatabases such as CNKI, WanFang Data, Pubmed, EMBASE.com, Medline, CBM, CSJD, CJFD, and the Cochrane Library were electronically searched from the date of their establishment to 30 June, 2013, and the relevant literatures and conference proceedings were also manually searched to include randomized controlled trials (RCTs) on comparison of additional CDT versus CT for primary deep vein thrombosis. Two reviewers independently screened studies according to the inclusion and exclusion criteria, extracted data, and accessed the methodological quality of the included studies. Then the meta-analysis was performed by using RevMan 5.1 software. Publication bias was assessed by STATA software. A meta-regression model was used to describe between study variability. ResultsTwo RCTs including 3 literatures contain 224 patients reporting data on safety and efficacy of CDT versus CT were included. There were no publication bias (Begg'S test, Z=1.02. P > 0.05;Egger'S test, t=0.98, P > 0.05). The results of meta-analysis showed that:in 6 months after surgery iliofemoral vein patency rate of CDT group was higher than that of CT group (OR=3.62, 95% CI:1.51-8.64, P=0.004), in 6 months after surgery CDT group with a lower rate than CT group of the iliofemoral vein occlusion and (or)venous reflux rate (OR=0.24, 95% CI:0.11-0.53, P=0.000), and the incidence rate of PTS in 24 months after surgery in CTD group was less than that of CT group (OR=0.55, 95% CI:0.31-0.96, P=0.040). There were no statistically significant of the major complications after surgery between CDT group and CT group (OR=1.34, 95% CI:0.12-15.69, P=0.810). But the incidence rates of minor complications and total complications after surgery in CT group were lower than those of CDT group (OR=13.67, 95% CI:4.08-45.83, P < 0.00 01 and OR=11.67, 95% CI:4.40-30.99, P < 0.000 01). ConclusionsCDT is a effective and positive way to treat early deep venous thrombosis especially in terms of the patency of vascular and prevent the occlusion and PTS. Due to the limitation of the included studies, large sample size, multicenter, and high quality studies are needed to verify the above conclusion, such as the ATTRACT Study. The intracavitary therapy could be applied to clinic combining individual conditions of patients.