Ex Vivo Hydrodynamic Assessment of Expanded Polytetrafluoroethylene Trileaflet Pulmonary Valves.

Handmade trileaflet valves using expanded polytetrafluorethylene (ePTFE) have been considered a viable option for pulmonary valve replacement. Studies have performed ex vivo testing of adult sized valves, data on pediatric-sized ePTFE valves is limited. Our aim was to evaluate pediatric-sized ePTFE valves and ovine tissue valves as comparison to assess performance. Trileaflet valves were constructed using 0.1 mm ePTFE Gore-Tex membrane ranging from 14 to 20 mm in size and sutured into Hemashield conduits. Ovine pulmonary valves were harvested and ranged from 14 to 20 mm. Valves were tested under pediatric pulmonary conditions using a hydrodynamic tester. Regurgitation fraction (RF%), closing volume (CV%), closing volume duration (CVd, second), effective orifice area (EOA, cm2), and peak pressure (PMax, mm Hg), and mean pressure (PMean, mm Hg) were measured. All valves reached goal cardiac output with mild regurgitation. Ovine pulmonary valves had significantly lower RF% than ePTFE valves (14 mm: 4.1 vs. 9.4%; 16 mm: 5.6 vs. 13.8%; 18 mm: 3.5 vs. 9.8%; 20 mm: 5.4% vs. 14.4%; p < 0.05, Table 3). Peak pressure was not significantly different between ovine versus ePTFE groups (14 mm: 37 vs. 24 mm Hg; 16 mm: 27 vs. 27 mm Hg; 18 mm: 26 vs. 27 mm Hg; 20 mm: 13 vs. 12 mm Hg). Expanded polytetrafluorethylene valves offer a viable option for pulmonary valve replacement given mild RF%, and comparable PMax. Further work is needed to understand the interplay between leaflet design and function.