Objective To summarize the probability of pulmonary embolism （PE） induced by lower extremity deep venous thrombosis （DVT） and investigate the role of vena cava filter （VCF） in preventing from PE. Methods The clinical data of 1 058 patients with lower extremity DVT from January 2005 to January 2012 were analyzed retrospectively. Results The PE rate was 3.21% （34/1 058） and the death rate was 1.42% （15/1 058） in 1 058 patients with lower extremity DVT. The VCF was implanted in 171 of 1 058 patients. The VCFs of 151 patients were implanted from femoral vein， 20 patients were implanted from jugular vein. The PE rates were 3.61% （32/887） and 1.17% （2/171） and the death rates were 1.69% （15/887） and 0 （0/171） in patients without VCF and with VCF， respectively. Both of them occurred in the first ten days. PE could keep as long as 35 d. The PE rate and death rate in the patients without VCF were significantly higher than those in the patients with VCF （P＜0.01）. The PE rates and death rates in both lower extremities DVT were higher than those in patients with the right and left ones （P＜0.05）， which in the right lower extremity were higher than those in the left one （P＜0.05）. The PE rate and death rate in the patients with lower extremity DVT combined with vena cava thrombosis were significantly higher than those in the patients with central type （P＜0.05）， which in the central type were significantly higher than those in the peripheral type （P＜0.05）， there were no significant differences between peripheral type and mixed pattern. The follow-up time was from 1 month to 7 years with （39±19） months， the patency rate of VCF was 98.7%. There were no filter migration， declination， and failure of expansion. Conclusions VCF can prevent from PE effectively， but the indications must be controlled.
Objective To explore the therapeutic effect of catheter-directed thrombolysis combined with vena cava filter on deep venous thrombosis (DVT) of lower extremity.Methods The clinical data of 65 patients with DVT of lower extremities from January 2008 to August 2009 were analyzed retrospectively, whose course of diseases were not more than 7 d and clinical type included central type and mixed type. Thirty-two cases were treated with catheter-directed thrombolysis combined with vena cava filter, while administrating treatment of anticoagulation and activating blood circulation to dissipate blood stasis, which were named as study group. Thirty-three cases were treated traditionally with thrombolysis, anticoagulation, and activating blood circulation to dissipate blood stasis, which were named as control group. The course of therapy was continued 10-14 d, then the efficacy in two groups patients was evaluated. Results It was (7.35±1.42) cm that circumference difference before treatment between affected extremties and unaffected extremties in study group, which of 3, 7, and 14 d after treatment was (4.21±1.12) cm， (2.87±0.98) cm, and (1.22±1.02) cm, respectively. Circumference difference between before and after treatment had significant difference in study group (Plt;0.01). It was (6.97±1.27) cm that circumference difference before treatment between affected extremties and unaffected extremties in control group, which of 3, 7, and 14 d after treatment was (5.72±1.31) cm, (4.58±0.88) cm, and (3.18±1.24) cm, respectively. Circumference difference between before treatment and 3, 7, and 14 d after treatment had significant difference in control group (Plt;0.05 or Plt;0.01). Circumference difference before treatment in two groups had no significant difference (Pgt;0.05). Circumference difference after treatment at different time points in two groups was significantly different, respectively (Plt;0.01). Circumference difference after treatment at different time points in study group was significantly less than that in control group, respectively (Plt;0.01). After 14 d, complete recanalization rate （71.88%, 23/32） and cure rate (71.88%, 23/32) of iliofemoral vein in study group were significant higher than that (36.36%, 12/33) in control group (Plt;0.01). No pulmonary embolism occurred. Conclusion In terms of ideal therapy targets of DVT of lower extremity, the catheterdirected thrombolysis combined with vena cava filter is obviously superior to traditional thrombolysis treatment.