Key result
Freezing heart valves over 4 years irreversibly deforms collagen, potentially reducing post-implantation durability.
Why the study?
Does prolonged freezing alter the structural integrity of heart valves compared to fresh valves?
Does prolonged freezing alter the structural integrity of heart valves compared to fresh valves?
Allogeneic heart valves should ideally be implanted within 5 years of freezing to avoid structural collagen degradation that may predispose to calcification.
Answers are grounded in this paper and cite their sources.
May warrant limiting cryopreserved valve storage to 5 years; leaves open human durability validation.
Studies were conducted on valves from a valve bank, frozen for up to 19 years. Obtained results were compared to studies of fresh, non-frozen valves. Stereomicroscopy, polarized light microscopy, scanning microscopy and X-ray diffractometry were used in the studies. It was determined that the structures of valve leaflets after prolonged freezing time (4-5 years) do not return to their initial, pre-frozen state. Changes in the structures after freezing time of over 5 years may, when the valves are implemented, favor faster damage processes, including calcification. Hence it appears beneficial to only implant valves that have been frozen for less than 5 years.
No takes yet. Share an insight, caveat, or question.
M. Pawlikowski (2019) studied Heart valve allografts (n=21). Prolonged freezing vs. Fresh valves and valves frozen for 4-5 years was evaluated on Structural deformation of collagen fibers and water binding changes.
Synapse has enriched 10 related papers. Consider them for comparative context: