title: [Evaluation of ultramicroporous expanded polytetrafluoroethylene mitral valve under pulsatile flow condition in vitro].
abstract: OBJECTIVE
  To test 25# and 27# ultramicroporous expanded polytetrafluo-roethylene mitral valve (UPMV) under pulsatile flow condition in vitro.
  
  
  METHODS
  Six 25# and six 27#UPMV were tested using TH-1200 HV Prosthesis Pulsatile Flow Tester in vitro at the cycling rate of 70 cycle/min, with the systolic pressure maintained at about 16 kPa (120 mmHg), diastolic pressure at 10.7 kPa (80 mmHg), and the percentage of mean forward flow at 35%. The stimulant cardiac output was maintained at 2, 3, 4, 5 and 6 L/min, respectively, for the testing.
  
  
  RESULTS
  The mean pressure difference for the 25#UPMV under stimulant cardiac output of 2, 3, 4, 5 and 6 L/min was 2.488-/+0.378, 4.427-/+0.240, 5.460-/+0.449, 6.776-/+0.391 and 8.327-/+0.490 mmHg, and its effective valvular orifice was 1.430-/+0.333, 1.993-/+0.208, 2.260-/+0.477, 3.204-/+0.174 and 3.652-/+0.158 cm(2), respectively. The regurgitant fraction of the 25#UPMV under each stimulant cardiac output was (5.731-/+0.643) %, (5.431-/+0.312) %, (5.059-/+0.708) %, (3.545-/+0.097) % and (2.615-/+0.125) %, respectively. The mean pressure difference of the 27#UPMV under each stimulant cardiac output was 1.618-/+0.497, 3.448-/+0.440, 4.825-/+0.434, 5.494-/+0.446 and 7.482-/+0.455 mmHg, effective valvular orifice was 1.773-/+0.364, 2.113-/+0.305, 2.409-/+0.295, 3.326-/+0.417 and 4.522-/+0.445 cm(2), and regurgitant fraction was (5.357-/+0.509) %, (5.407-/+0.110) %, (4.999-/+0.182) %, (4.010-/+0.254) % and (2.584-/+0.114)%, respectively.
  
  
  CONCLUSIONS
  The mean pressure difference, effective valvular orifice and regurgitant fraction of the UPMVs can measure up to the national criteria for artificial heart valve prosthesis of China.
authors.affiliation: Department of Cardiothoracic Surgery, 454 Hospital of PLA, Nanjing 210002, China. b.z.liang@163.com
authors.forename: Yong
authors.initials: Y
authors.lastname: Liang
authors.forename: Wu-jun
authors.initials: WJ
authors.lastname: Wang
authors.forename: Kai-can
authors.initials: KC
authors.lastname: Cai
authors.forename: Zhen-kang
authors.initials: ZK
authors.lastname: Wang
authors.forename: Hai-bo
authors.initials: HB
authors.lastname: Li
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D002302:Cardiac Output; D006350:Heart Valve Prosthesis / Q000592:standards; D019918:Heart Valve Prosthesis Implantation / Q000379:methods; D006353:Heart-Assist Devices / Q000592:standards*; D006801:Humans; D008422:Materials Testing / Q000379:methods; D008943:Mitral Valve; D011138:Polytetrafluoroethylene / Q000737:chemistry*; D016062:Porosity; D011673:Pulsatile Flow
chemical_list: D001672:Biocompatible Materials; D011138:Polytetrafluoroethylene