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Lipid uptake in expanded polytetrafluoroethylene vascular grafts
P Vermette1, D Mantovani, R Guidoin
1Department of Chemical Engineering, Laval University, and Centre Hospitalier Universitaire de Québec, Québec, Canada.
Journal of Vascular Surgery
|September 16, 1998
Summary
Lipid infiltration into expanded polytetrafluoroethylene (ePTFE) vascular grafts increases prosthesis permeability over time. This lipid uptake, driven by transmural pressure and exposure duration, contributes to graft failure mechanisms.
Area of Science:
- Biomaterials Science
- Vascular Surgery
- Medical Device Engineering
Background:
- Vascular prosthesis failure is linked to atherosclerotic processes and abnormal lipid infiltration.
- Expanded polytetrafluoroethylene (ePTFE) grafts are susceptible to lipid uptake, potentially affecting their long-term function.
Purpose of the Study:
- To investigate the in vitro lipid uptake in ePTFE vascular grafts.
- To determine the effect of time and pressure on the permeability of ePTFE prostheses.
Main Methods:
- Water permeability tests were conducted under dynamic flow and varying hydrostatic pressures.
- Lipid uptake was simulated using a phosphatidylcholine suspension within ePTFE prostheses under different pressures and flow rates for extended durations.
Main Results:
- Water permeability increased significantly with higher hydrostatic pressures and exposure times.
- Lipid uptake led to fluid convection through the prosthesis wall, forming preferential pathways.
- Infrared spectroscopy confirmed that lipid accumulation depended on transmural pressure and exposure duration.
Conclusions:
- Increased prosthesis permeability may result from dilatation and plastic deformation.
- Lipid uptake in ePTFE grafts is an aggressive kinetic process influenced by mechanical factors.