title: Angioscopy for experimental evaluation of optional IVC filters.
abstract: OBJECTIVE
  To demonstrate the feasibility of direct angioscopic visualization of an optional inferior vena cava (IVC) filter in situ and during retrieval.
  
  
  METHODS
  Angioscopy was used for direct visualization of optional IVC filters in six sheep. Cavograms were obtained before the filters were retrieved. After successful filter retrieval, segmental IVC perfusion was performed to evaluate filter retrieval-related damage to the IVC wall. Therefore, all branch vessels were ligated before the IVC segment was flushed with normal saline solution until it was fully distended. Then, the inflow was terminated and the IVC segment observed for deflation. Subsequently, the IVC was harvested en bloc, dissected, and inspected macroscopically.
  
  
  RESULTS
  The visibility of IVC filters at angioscopy was excellent. During the retrieval procedure, filter collapse and retraction into the sheath were clearly demonstrated. Angioscopy provided additional information to that obtained with cavography, demonstrating adherent material in three filters. Three filters in place for more than 2 months could not be retrieved because the filter legs were incorporated into the IVC wall. After filter retrieval, there was no perforation at segmental IVC perfusion. At macroscopic inspection of the IVC lumen, a small piece of detached endothelium was found in one animal.
  
  
  CONCLUSIONS
  Angioscopy enabled the direct evaluation of optional IVC filters in situ and during retrieval. Compared with cavography, angioscopy provided additional information about the filter in situ and the retrieval procedure. Future applications of this technique could include studies of filter migration, compression, and clot-trapping efficacy.
authors.affiliation: Dotter Interventional Institute, Oregon Health & Sciences University, L-342, 3181 SW Sam Jackson Park Rd, Portland, OR 7239-3098, USA. hoppeh@ohsu.edu
authors.forename: Hanno
authors.initials: H
authors.lastname: Hoppe
authors.forename: Barry T
authors.initials: BT
authors.lastname: Uchida
authors.forename: Dusan
authors.initials: D
authors.lastname: Pavcnik
authors.forename: Man Deuk
authors.initials: MD
authors.lastname: Kim
authors.forename: Won Kyu
authors.initials: WK
authors.lastname: Park
authors.forename: Luiz O
authors.initials: LO
authors.lastname: Correa
authors.forename: John A
authors.initials: JA
authors.lastname: Kaufman
authors.forename: Frederick S
authors.initials: FS
authors.lastname: Keller
authors.forename: Josef
authors.initials: J
authors.lastname: Rösch
mesh_terms: D017546:Angioscopy; D000818:Animals; D020878:Device Removal; D004730:Endothelium, Vascular / Q000473:pathology; D005240:Feasibility Studies; D005260:Female; D023421:Models, Animal; D010477:Perfusion / Q000379:methods; D010690:Phlebography / Q000379:methods; D012756:Sheep; D016306:Vena Cava Filters; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000601:surgery