Inferior Vena Cava Filters For The Prevention Of Pulmonary Embolism: A Systematic Review And Meta-analysis

Objective: To systematically evaluate the effects of inferior vena cava filters for the prevention of pulmonary embolism.Methods: Chinese Conference Data, Chinese Biomedical Database, Cochrane Central Register of Controlled Trials, Pubmed, English Medical Current Contents were searched up to March 2009, and the studies as references of eligible articles were also searched. Controlled clinical trials (CCTs) and randomised controlled trials (RCTs) that examined the efficacy of inferior vena cava filters in preventing PE were selected. According to including criteria, articles were evaluated (Shekelle PG, et al). Randomized control (RCTs) were assessed according to the Juni assessment. Software RevMan 4.2.8 was used to examin the heterogeneity of trials, and analysis the data using fixed or random effect model to pool the Odds Ratio and 95% CI. The funnel plot and fail-safe number were useful to discuss the publication bias.Results: 7 trials met all eligible criteria. One was RCT, the other were CCTs. The methodological quality was generally low. Results of Meta-analysis showed that compared with the control group, the occurrence of pulmonary embolism in short term and long term,the total mortality and mortality correlated with pulmonary embolism in short term in the inferior vena cava filters group decreased,and difference was shown statistically in two groups. The Odds Rate were OR=0.14, 95% CI [0.05, 0.37], P<0.0001; OR=0.34, 95% CI[0.19, 0.62], P=0.0004; OR=0.52, 95% CI [0.32, 0.82], P=0.005; OR=0.10, 95% CI [0.01, 0.78], P=0.03, respectively. Nevertheless, vena cava filters had no effect on the total mortality in long term, OR=0.92, 95% CI[0.68, 1.22], P =0.52, and the occurrence of deep vein thrombosis increased, OR=1.68, 95% CI [1.17, 2.39], P=0.004.Conclusions: Inferior vena cava filters reduced the occurrence of pulmonary embolism, the total mortality and mortality correlated with pulmonary embolism in short term. Nevertheless, inferior vena cava filters had no effect on the total mortality in long term, and increased the occurrence of deep-vein thrombosis Further study are needed to come to the affirmative conclusion due to the localization of the study.