title: In vitro evaluation of a new autologous valve-stent for deep venous incompetence.
abstract: OBJECTIVE
  To report the results of in vitro hydrostatic bench testing of a new vein-stent combination to correct deep venous incompetence.
  
  
  METHODS
  Twelve valves were constructed from a modified Palmaz stent encased in a segment of great saphenous vein harvested from patients during routine varicose vein surgery. An in vitro flow circuit was set up to evaluate opening and closing pressures (in cm H(2)O), and the valve was subsequently subjected to repetitive cycles of increasing prograde flow and reflux pressures. Duplex scanning was used to evaluate valve closure time and detect any possible reflux.
  
  
  RESULTS
  The valve mechanism required only 1 to 3 cm H(2)O for opening and 2 to 4 cm H(2)O for closing. Prograde flow of up to 1000 mL/min passed easily through this valve, which remained competent with reflux pressures up to 180 cm H(2)O. Mean valve closure time was 0.15+/-0.07 seconds. Unligated side branches or damage from dissection impaired the competence of 3 valves.
  
  
  CONCLUSIONS
  This new vein-stent valve functions as a normal deep vein valve, requiring only minimal pressures for opening and closing. It allows high flow passage and still remains competent at high reflux pressures. This valve may provide a minimally invasive solution for the correction of deep venous incompetence using autologous material. Further in vivo evaluation will be mandatory.
authors.affiliation: Department of Surgery, Sint Franciscus Gasthuis, Klieweg 500, 3045 PM Rotterdam, The Netherlands.
authors.forename: Jim H
authors.initials: JH
authors.lastname: Geselschap
authors.forename: Jorrit M
authors.initials: JM
authors.lastname: van Zuiden
authors.forename: Irwin M
authors.initials: IM
authors.lastname: Toonder
authors.forename: Cees H A
authors.initials: CH
authors.lastname: Wittens
mesh_terms: D000800:Angioplasty, Balloon / Q000009:adverse effects / Q000379:methods*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000379:methods*; D019544:Equipment Failure Analysis; D006801:Humans; D006874:Hydrostatic Pressure; D007866:Leg / Q000098:blood supply; D008422:Materials Testing; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D011474:Prosthesis Design; D012501:Saphenous Vein / Q000000981:diagnostic imaging / Q000637:transplantation*; D015607:Stents / Q000009:adverse effects / Q000592:standards; D013997:Time Factors; D014182:Transplantation, Autologous / Q000379:methods; D018616:Ultrasonography, Doppler, Duplex; D014689:Venous Insufficiency / Q000000981:diagnostic imaging / Q000628:therapy*