In vitro study of trileaflet polytetrafluoroethylene conduit and its valve-in-valve transformation

Te I. Chang, Kang Hong Hsu, Chi Wen Luo, Jen Hong Yen, Po Chien Lu, Chung I. Chang

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


OBJECTIVES: Handmade trileaflet expanded polytetrafluoroethylene valved conduit developed using the flip-over method has been tailored for pulmonary valve reconstruction with satisfactory outcomes. We investigated the in vitro performance of the valve design in a mock circulatory system with various conduit sizes. In our study, the design was transformed into a transcatheter stent graft system which could fit in original valved conduits in a valve-in-valve fashion. METHODS: Five different sizes of valved polytetrafluoroethylene vascular grafts (16, 18, 20, 22 and 24 mm) were mounted onto a mock circulatory system with a prism window for direct leaflets motion observation. Transvalvular pressure gradients were recorded using pressure transducers. Mean and instant flows were determined via a rotameter and a flowmeter. Similar flip-over trileaflet valve design was then carried out in 3 available stent graft sizes (23, 26 and 28.5 mm, Gore aortic extender), which were deployed inside the valved conduits. RESULTS: Peak pressure gradient across 5 different sized graft valves, in their appropriate flow setting (2.0, 2.5 and 5.0 l/min), ranged from 4.7 to 13.2 mmHg. No significant valve regurgitation was noted (regurgitant fraction: 1.6-4.9%) in all valve sizes and combinations. Three sizes of the trileaflet-valved stent grafts were implanted in the 4 sizes of valved conduits except for the 16-mm conduit. Peak pressure gradient increase after valved-stent graft-in-valved-conduit setting was <10 mmHg in all 4 conduits. CONCLUSIONS: The study showed excellent in vitro performance of trileaflet polytetrafluoroethylene valved conduits. Its valved stent graft transformation provided data which may serve as a reference for transcatheter valve-in-valve research in the future.

Original languageEnglish
Pages (from-to)408-416
Number of pages9
JournalInteractive Cardiovascular and Thoracic Surgery
Issue number3
Publication statusPublished - Mar 1 2020


  • Extended polytetrafluoroethylene valve
  • Handmade trileaflet expanded polytetrafluoroethylene valved conduit
  • Pulmonary valve replacement
  • Trileaflet expanded polytetrafluoroethylene valved stent graft
  • Valve-in-valve

ASJC Scopus subject areas

  • Surgery
  • Pulmonary and Respiratory Medicine
  • Cardiology and Cardiovascular Medicine


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