title: Retrievable inferior vena cava filters in high-risk trauma and surgical patients: factors influencing successful removal.
abstract: BACKGROUND
  An Inferior vena cava filter (IVCF) provides prophylaxis against pulmonary embolism in patients that cannot be anticoagulated. A removable IVCF (R-IVCF) provides prophylaxis during a high-risk period while potentially eliminating long-term complications associated with a permanent IVCF. Factors influencing success of R-IVCF removal are ill-defined.
  
  
  METHODS
  The study was a retrospective review of a prospectively maintained patient registry comprising patients who received an R-IVCF (Bard Recovery and G2) at an academic level 1 trauma center. The influence of time in vivo, filter design, and filter head position on computed abdominal tomographic (CAT) scan (touching caval wall vs. free) on removal success was examined.
  
  
  RESULTS
  Ninety-two patients each received an R-IVCF. Thirty-nine patients underwent removal attempt and 30 R-IVCFs were removed. Time in vivo did not affect removal success (success: 228 +/- 104 days versus unsuccessful: 289 +/- 158 days, p = 0.18). Filter design impacted filter head position (Recovery: 43% touching versus G2: 6% touching, p = 0.023). Position of the filter head influenced removal success (touching: 50% success versus free: 88% success, p = 0.021).
  
  
  CONCLUSIONS
  Position of the filter head is the key determinant of removal success. Specific device designs may impact filter head position as was the case with the two designs in this analysis. Time in vivo does not affect removal success.
authors.affiliation: Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI 53792, USA.
authors.forename: Joshua L
authors.initials: JL
authors.lastname: Hermsen
authors.forename: Anna R
authors.initials: AR
authors.lastname: Ibele
authors.forename: Lee D
authors.initials: LD
authors.lastname: Faucher
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Nale
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Schurr
authors.forename: Kenneth A
authors.initials: KA
authors.lastname: Kudsk
mesh_terms: D000328:Adult; D020878:Device Removal; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019919:Prosthesis Implantation; D011655:Pulmonary Embolism / Q000209:etiology / Q000517:prevention & control*; D012042:Registries; D012189:Retrospective Studies; D013514:Surgical Procedures, Operative / Q000009:adverse effects*; D016306:Vena Cava Filters; D014682:Vena Cava, Inferior; D014947:Wounds and Injuries / Q000150:complications*