title: IVC filter tilt and asymmetry: comparison of the over-the-wire stainless-steel and titanium Greenfield IVC filters.
abstract: OBJECTIVE
  A comparison of tilting, caval coverage, asymmetry, and insertion problems with the over-the-wire stainless-steel and titanium versions of the Greenfield filter.
  
  
  METHODS
  The study compared 104 stainless-steel and 141 titanium Greenfield inferior vena cava (IVC) filter insertions. The angle the sheath and deployed filter made relative to the cava, as well as filter strut distribution, were determined from spot films. The proportionate caval coverage was computed from the cavogram (anteroposterior projection). Mean filter tilts, subgrouped by insertion site, and caval coverage were compared with the Student t test, whereas strut patterns were analyzed with a contingency table.
  
  
  RESULTS
  The filter caval and sheath caval angles correlated. The filter caval angles varied with insertion site, but were lowest with a right jugular approach. Caval coverage was identical with both designs. The stainless-steel version resulted in a more uniform distribution of struts in comparison with the titanium version. The incidence of insertion problems was not significantly different between the filter types.
  
  
  CONCLUSIONS
  While IVC filter tilting was not improved with the newer design, the pattern of struts was more uniformly symmetric with the stainless-steel device. The right jugular insertion site was associated with the lowest filter caval angles and the most symmetric pattern of struts.
authors.affiliation: UCSD Medical Center, Department of Radiology, San Diego, CA 92103-8756, USA.
authors.forename: T B
authors.initials: TB
authors.lastname: Kinney
authors.forename: S C
authors.initials: SC
authors.lastname: Rose
authors.forename: K E
authors.initials: KE
authors.lastname: Weingarten
authors.forename: K
authors.initials: K
authors.lastname: Valji
authors.forename: S B
authors.initials: SB
authors.lastname: Oglevie
authors.forename: A C
authors.initials: AC
authors.lastname: Roberts
mesh_terms: D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015641:Radiography, Interventional; D012189:Retrospective Studies; D013193:Stainless Steel; D014025:Titanium; D016306:Vena Cava Filters; D014682:Vena Cava, Inferior
chemical_list: D013193:Stainless Steel; D014025:Titanium