Lipid uptake in synthetic vascular prostheses explanted from humans.

Previous in vivo studies in humans and dogs have revealed an atherosclerosis-like phenomenon in which lipid penetration within arterial prosthesis wall was observed. The primary goal of the present study was therefore to investigate the occurrence of this lipid retention in ePTFE prostheses implanted in humans and therefore identify potential risk factors related to this phenomenon. Lipid uptake in 367 ePTFE microporous vascular prostheses explanted from humans was studied using Fourier transform infrared spectroscopy. The assignment of the infrared absorption features clearly revealed the presence of strongly bonded unsaturated fatty acids to the microporous structure of the prostheses. A one-way ANOVA statistical analysis showed that the lipid uptake in the synthetic vascular prostheses depended on the duration of implantation of the prosthesis and on the sex of the patient. A two-way ANOVA showed that a relationship existed between the estimated lipid uptake and the internal diameter of the prosthesis. These results confirm that the lipid uptake phenomenon depends on some clinical factors related either to the patients or to the prostheses' morphological parameters.