title: Pilot in vivo study of an absorbable polydioxanone vena cava filter.
abstract: OBJECTIVE
  The objectives of this study were to evaluate tensile strength retention of polydioxanone as a function of time in a swine venous system and to assess the feasibility of an absorbable inferior vena cava (IVC) filter made from polydioxanone in a pilot swine study.
  
  
  METHODS
  Twenty strands (60 cm each) of size 1 polydioxanone absorbable suture (Ethicon, Somerville, NJ) were placed in the central venous system of domestic swine. Strands were harvested at weekly intervals during 10 weeks for tensile strength testing. Results were compared with control samples obtained from an in vitro engineered circulation system containing sodium phosphate buffer solution. Three IVC filters braided from polydioxanone suture were also catheter deployed in three swine to assess absorbable IVC filter feasibility.
  
  
  RESULTS
  Polydioxanone retained 82% tensile strength in vitro vs 79% in vivo at 35 days (P > .22), the desired prophylactic duration. For IVC filters made from polydioxanone, technical success of placement was achieved in all three filters deployed (100%). Autologous thrombus deployed inferior to the filter remained trapped in the filter until thrombus resorption, with no evidence of pulmonary emboli on follow-up computed tomography. There were no instances of caval penetration, filter-induced IVC thrombosis, filter migration, or tilt >15 degrees with imaging and clinical follow-up carried out to 32 weeks.
  
  
  CONCLUSIONS
  Strength retention of polydioxanone suture placed in the venous system of swine is similar to earlier in vitro studies out to 10 weeks (P > .06 for all weeks) and is more than sufficient (8.20 ± 0.37 kg mean load at break for size 1) to trap thrombus. Pilot animal study suggests that an absorbable polydioxanone IVC filter can be catheter deployed to capture and to hold iatrogenically administered autologous thrombus through resorption.
authors.affiliation: Department of Orthopedic Surgery, Baylor College of Medicine, Houston, Tex. Electronic address: mitcheggers@yahoo.com.
authors.forename: Mitchell D
authors.initials: MD
authors.lastname: Eggers
authors.affiliation: Department of Veterinary Medicine and Surgery, University of Texas MD Anderson Cancer Center, Houston, Tex.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: McArthur
authors.affiliation: Department of Interventional Radiology, University of Texas MD Anderson Cancer Center, Houston, Tex.
authors.forename: Tomas A
authors.initials: TA
authors.lastname: Figueira
authors.affiliation: Department of Interventional Radiology, University of Texas MD Anderson Cancer Center, Houston, Tex.
authors.forename: Mohamed E
authors.initials: ME
authors.lastname: Abdelsalam
authors.affiliation: Department of Interventional Radiology, University of Texas MD Anderson Cancer Center, Houston, Tex.
authors.forename: Katherine P
authors.initials: KP
authors.lastname: Dixon
authors.affiliation: Department of Veterinary Medicine and Surgery, University of Texas MD Anderson Cancer Center, Houston, Tex.
authors.forename: Laura R
authors.initials: LR
authors.lastname: Pageon
authors.affiliation: Department of Interventional Radiology, University of Texas MD Anderson Cancer Center, Houston, Tex.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Wallace
authors.affiliation: Department of Interventional Radiology, University of Texas MD Anderson Cancer Center, Houston, Tex.
authors.forename: Steven Y
authors.initials: SY
authors.lastname: Huang
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D005500:Follow-Up Studies; D010865:Pilot Projects; D016687:Polydioxanone; D011655:Pulmonary Embolism / Q000517:prevention & control*; D013552:Swine; D013718:Tensile Strength; D016306:Vena Cava Filters; D014682:Vena Cava, Inferior; D020246:Venous Thrombosis
chemical_list: D016687:Polydioxanone