title: Retrievability and device-related complications of the G2 filter: a retrospective study of 139 filter retrievals.
abstract: OBJECTIVE
  To evaluate the retrievability and safety of the G2 filter.
  
  
  METHODS
  A retrospective study of all G2 filter retrievals at a single institution was conducted. Hospital records and imaging studies were reviewed for complications, and factors affecting retrieval were analyzed.
  
  
  RESULTS
  From 2005 to 2009, a total of 139 patients presented for retrieval of their G2 filter, and 131 pairs of pre- and post-placement cavagrams and 39 computed tomography scans were available for analysis. The following findings were recorded: limb penetration (n = 33), tilt greater than 15° (n = 22), local migration greater than 2 cm (n = 17), retained thrombus within the filter (n = 16), deformity (n = 10), inferior vena cava (IVC) occlusion (n = 3), fracture (n = 2), and pulmonary embolism breakthrough (n = 2). A total of 118 filters were removed, with a mean indwelling time of 131.8 days (range, 3-602 d). Indwell time (< 90, 90-180, or > 180 d) did not affect retrieval (P = .4). There were 21 filters (15.1%) left in situ as a result of severe tilt (n = 9), significant thrombus in the filter (n = 5), IVC occlusion (n = 3), filter incorporation into the caval wall (n = 3), or lack of central venous access (n = 1). There was a strong relationship between penetration and caudal migration (P < .0001). Severe tilt was associated with prolonged fluoroscopic times for retrieval (P = .003).
  
  
  CONCLUSIONS
  The majority of G2 filters can be removed without difficulty. The most common factor affecting retrieval was severe tilting. The indwelling time had no impact on retrieval. G2 filter-related complications were frequent but most, including fractures, were clinically insignificant.
authors.affiliation: Imaging Institute, Section of Interventional Radiology, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Zhu
authors.forename: Matthew D B S
authors.initials: MD
authors.lastname: Tam
authors.forename: John
authors.initials: J
authors.lastname: Bartholomew
authors.forename: James S
authors.initials: JS
authors.lastname: Newman
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Sands
authors.forename: Weiping
authors.initials: W
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D002681:China; D020878:Device Removal; D005260:Female; D005548:Foreign-Body Migration / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010690:Phlebography / Q000379:methods; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging / Q000209:etiology / Q000517:prevention & control*; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D016306:Vena Cava Filters / Q000009:adverse effects*; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging; D020246:Venous Thrombosis / Q000150:complications / Q000000981:diagnostic imaging / Q000628:therapy*; D055815:Young Adult