2017 年 67 巻 2-4 号 p. 158-165
Background: Retrievable inferior vena cava (IVC) filter devices have been developed to overcome the
long-term complications of permanent filters. It is of interest to evaluate the retrievability of retrievable IVC filters
and how safely the IVC filters indwelled for a long period of time can be retrieved. We reviewed a group of 44
patients, who were selected for ALN retrievable filter implantation and reviewed the indications, efficacy as well as
Material and Methods: 300 venous thromboembolism (VTE) patients were treated in our institution between 2003 and 2014. IVC filters were inserted in 84 cases (28%) and 44 of 84 patients received ALN retrievable filter implantation. We retrospectively reviewed the indications, efficacy and complications of 44 patients with ALN filters. Results: All 44 patients had deep vein thrombosis (DVT) and 39 patients (88.6%) also had pulmonary embolism (PE). The most frequent associated risk factor for DVT was cancer (n=19). The filter was implanted for a median duration of 708.8 days (range 68-1717). While the filter was in place, at least one venous thromboembolic event occurred in 4.5% (2 of 44 patients）. Filter retrieval was attempted in 8 patients (18.2%) after a median period of 271.9 days (range 79 - 559）. Filter retrievals were successful in all cases.
Conclusion: This study showed the efficacy of ALN filter. It also demonstrated the safety of retrieval after a long-term placement.