title: A new self-convertible inferior vena cava filter: experimental in-vitro and in-vivo evaluation.
abstract: OBJECTIVE
  To evaluate using in-vitro and in-vivo models the feasibility and capture efficiency of a new self-convertible inferior vena cava filter (SCF), equipped with a biodegradable self-converting switch.
  
  
  METHODS
  Capture rates were tested in an in-vitro flow model for simulated supine and upright positions with clot diameters of 3 mm and 5 mm and tube diameters of 22 mm, 25 mm, and 28 mm. In the in-vivo study, five filters were implanted in five adult dogs. Venography was performed after the procedure every 2 weeks until filter conversion.
  
  
  RESULTS
  All filters were successfully implanted and completely converted with a mean trapping efficiency of 75.5% in the in-vivo study. The SCF was most efficient at 92% in the upright orientation with 5-mm clots and a 22-mm caval diameter. All five filters exhibited successful delivery and conversion in vitro. The SCFs were manually manufactured without barbs or hooks, and because of this feature, migration occurred.
  
  
  CONCLUSIONS
  The SCF is feasible and highly efficient and converts itself successfully. Evaluation is planned of future prototypes with appropriate modifications for risk of migration of the filter.
authors.affiliation: Department of Vascular Surgery, XuanWu Hospital, Capital Medical University, Changchun Street 45#, Beijing 100053, People's Republic of China.
authors.forename: XiXiang
authors.initials: X
authors.lastname: Gao
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Bing
authors.initials: B
authors.lastname: Chen
authors.forename: HengXi
authors.initials: H
authors.lastname: Yu
authors.forename: JianXin
authors.initials: J
authors.lastname: Li
authors.forename: ShuWen
authors.initials: S
authors.lastname: Zhang
authors.forename: ZengGuo
authors.initials: Z
authors.lastname: Feng
authors.forename: Lin
authors.initials: L
authors.lastname: Ye
authors.forename: Jian
authors.initials: J
authors.lastname: Han
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D002405:Catheterization, Central Venous / Q000009:adverse effects / Q000295:instrumentation*; D004285:Dogs; D005240:Feasibility Studies; D005548:Foreign-Body Migration / Q000209:etiology; D006801:Humans; D008422:Materials Testing; D023421:Models, Animal; D010690:Phlebography; D010865:Pilot Projects; D011474:Prosthesis Design; D013997:Time Factors; D016306:Vena Cava Filters / Q000009:adverse effects; D014682:Vena Cava, Inferior / Q000000981:diagnostic imaging; D020246:Venous Thrombosis / Q000628:therapy*