title: A prospective long-term study of 220 patients with a retrievable vena cava filter for secondary prevention of venous thromboembolism.
abstract: BACKGROUND
  The immediate and long-term clinical events associated with the placement and removal of a retrievable filter (ALN filter; ALN Implants Chirurgicaux; Ghisonaccia, France) remain largely unknown.
  
  
  METHODS
  This was a prospective cohort study with an 18-month follow-up. All consecutive patients scheduled for placement of an ALN filter between April 1999 and June 2005 in the Radiology Department of our hospital were included.
  
  
  RESULTS
  During the study period, placement of an ALN filter was indicated in 220 patients (mean age, 70.8 years), who were followed up for a median duration of 338.5 days (range, 1 to 561 days); 148 patients (67.3%) completed the 18-month follow-up. No patients were unavailable for follow-up. All patients had an acute or past venous thromboembolism. Main indications were recurrent venous thromboembolism despite adequate anticoagulation therapy (10.9%), transient bleeding event (21.8%), definitive contraindication for anticoagulant therapy (26.8%), or obligation to stop anticoagulant therapy due to major surgery, major trauma, or invasive procedure (37.7%). Filter insertion was successful in 98.6% of patients and resulted in an immediate complication in 11.8%. The median duration of filter implantation was 166 days (first to third quartiles, 34 to 478 days). Meanwhile, 17.0% (37 of 217 patients) had at least one venous thromboembolic event. Filter retrieval was attempted in 25.3% of patients after a median of 51 days (range, 6 to 352 days); removal was successful at the first attempt in 92.7% of patients.
  
  
  CONCLUSIONS
  The filter could be easily inserted and successfully removed up to 1 year after insertion. Its safety and efficacy in preventing pulmonary embolism should be properly assessed in a randomized study.
authors.affiliation: Thrombosis Research Group, CIC-EC, Clinical Pharmacology Department, University Hospital, Saint-Etienne, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Mismetti
authors.forename: Karine
authors.initials: K
authors.lastname: Rivron-Guillot
authors.forename: Sara
authors.initials: S
authors.lastname: Quenet
authors.forename: Hervé
authors.initials: H
authors.lastname: Décousus
authors.forename: Silvy
authors.initials: S
authors.lastname: Laporte
authors.forename: Magali
authors.initials: M
authors.lastname: Epinat
authors.forename: Fabrice Guy
authors.initials: FG
authors.lastname: Barral
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019917:Blood Vessel Prosthesis Implantation; D020878:Device Removal; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000517:prevention & control; D013193:Stainless Steel; D013923:Thromboembolism; D016896:Treatment Outcome; D016306:Vena Cava Filters; D020246:Venous Thrombosis / Q000517:prevention & control*
chemical_list: D013193:Stainless Steel