title: Removal of the G2 filter: differences between implantation times greater and less than 180 days.
abstract: OBJECTIVE
  To investigate whether filters implanted for longer periods are more difficult or hazardous to remove.
  
  
  METHODS
  A retrospective review of G2 inferior vena cava filter removals was performed. Objective measures reflecting the difficulty of the removal procedure were evaluated for differences required to remove a filter with an implantation period greater or less than 180 days.
  
  
  RESULTS
  One hundred seventy of 174 G2 filters were successfully removed (97.7% success rate). There was no significant difference in the success rate (P = .86), total procedure time (P = .87), fluoroscopy time (P = .13), or contrast medium use (P = .22) required to remove filters implanted for more than 180 days compared to those implanted for a shorter period of time. There was no significant difference in the frequency of filter movement (P = .90), tilt (P = .87), and caval penetration (P = .41) between the two groups. Six filter fractures were observed, all with implantation times greater than 180 days.
  
  
  CONCLUSIONS
  The removal of a G2 filter that has been in place for more than 180 days can be performed as easily, as safely, and with a similar degree of success as one that has been in place for less time. Movement, tilt, and penetration are early events after implantation that may have an effect on successful filter removal.
authors.affiliation: Milton S. Hershey Medical Center, Penn State University College of Medicine, Hershey, Pennsylvania 17033, USA. flynch@psu.edu
authors.forename: Frank C
authors.initials: FC
authors.lastname: Lynch
authors.forename: Stephanie
authors.initials: S
authors.lastname: Kekulawela
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D019919:Prosthesis Implantation / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome; D016306:Vena Cava Filters; D055815:Young Adult