title: In vitro development and evaluation of a polyacrylic acid-silicone device intended for gradual occlusion of portosystemic shunts in dogs and cats.
abstract: OBJECTIVE
  To develop a device intended for gradual venous occlusion over 4 to 6 weeks.
  
  
  METHODS
  Silicone tubing filled with various inorganic salt and polyacrylic acid (PAA) formulations and mounted within a polypropylene or polyether ether ketone (PEEK) outer ring.
  
  
  METHODS
  15 polypropylene prototype rings were initially filled with 1 of 5 formulations and placed in PBSS. In a second test, 10 polypropylene and 7 PEEK prototype rings were filled with 1 formulation and placed in PBSS. In a third test, 2 formulations were loaded into 6 PEEK rings each, placed in physiologic solution, and incubated. In all tests, ring luminal diameter, outer diameter, and luminal area were measured over 6 weeks.
  
  
  RESULTS
  In the first test, 2 formulations had the greatest changes in luminal area and diameter, and 1 of those had a greater linear swell rate than the other had. In the second test, 6 of 7 PEEK rings and 6 of 10 polypropylene rings closed to a luminal diamater < 1 mm within 6 weeks. Polypropylene rings had a greater increase in outer diameter than did PEEK rings between 4.5 and 6 weeks. In the third test, 11 of 12 PEEK rings gradually closed to a luminal diameter < 1 mm within 6 weeks.
  
  
  CONCLUSIONS
  A PAA and inorganic salt formulation in a prototype silicone and polymer ring resulted in gradual occlusion over 4 to 6 weeks in vitro. Prototype PEEK rings provided more reliable closure than did polypropylene rings.
authors.forename: Mandy L
authors.initials: ML
authors.lastname: Wallace
authors.forename: Gary W
authors.initials: GW
authors.lastname: Ellison
authors.forename: Christopher
authors.initials: C
authors.lastname: Batich
authors.forename: J Brad
authors.initials: JB
authors.lastname: Case
authors.forename: Stanley E
authors.initials: SE
authors.lastname: Kim
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D002371:Cat Diseases / Q000517:prevention & control*; D002415:Cats; D004283:Dog Diseases / Q000517:prevention & control*; D004285:Dogs; D004867:Equipment Design; D006975:Hypertension, Portal / Q000517:prevention & control / Q000662:veterinary*; D014656:Vascular Surgical Procedures / Q000295:instrumentation*
chemical_list: D001672:Biocompatible Materials