An X-ray photoelectron spectroscopy study of the external surface of explanted microporous polyurethane vascular prostheses.

XPS has been used to examine the external surfaces of microporous polyurethane vascular prostheses implanted for up to 6 months in dogs. The phenomena of bilirubin absorption and physical degradation were investigated, using three different chemical washes to clean the prostheses. Very little evidence for chemical change was found, indicating a predominant role for the mechanical or biochemical ablation of degraded material.