X-ray diffraction of pig aortic valve grafts reveals that tanning enhances collagen fiber orientation, which subsequently diminishes after prolonged patient implantation, without evidence of calcification.
Answers are grounded in this paper and cite their sources.
Animal data on tanned porcine valves should not guide clinical practice; leaves open whether collagen orientation affects human bioprosthetic durability.
The study of collagen fibers by X-ray diffraction, utilizing semiquantitative indices for appraisal of "structuration" and "orientation" was applied to 30 aortic valve grafts. These grafts, of pig origin, were studied in the fresh state, after tanning with aldehydes, and after having been implanted in patients for at least 18 months. It was shown that the collagen fibers are preferentially orientated parallel to the transverse axis of the valve cusps, and that this arrangement, enhanced by tanning, had a tendency to disappear in the post-implantation samples. The structuration index which concerns the fibril network was also augmented by tanning, and was found a little high or slightly diminished in post-implantation cusps. Evidence for a new compound, probably fibrin, was found in the diffraction patterns of implanted cusps, but crystallized calcium was noticeably absent.
No takes yet. Share an insight, caveat, or question.
Huc et al. (1975) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: