Preservation of Vein Allograft Viability during Long-Term Storage

Abstract

Background: The aim of this study was to compare the vein allograft viability following cryopreservation with that remaining after prolonged refrigerated storage. Materials and Methods: Great saphenous vein biopsies had been cryopreserved, and the samples were divided into two matched groups and stored in tissue culture medium for 42 days at +4°C, either with or without regular medium replacement. Each vein allograft was biopsied and assayed for viability every third day by the methyltetrazolium reduction assay. Viability indexes of vein allografts harvested from brain-dead multi-organ donors and from cadavers whose warm ischemic periods were maximally 24 h were also compared. Results: Vein allografts stored for 42 days at +4°C showed a similar viability (58.9 ± 1.2%) to that of cryopreserved veins (59.7 ± 2.3%). This was true even when cryopreserved and thawed allografts were subjected to 3 days of post-thaw incubation under presumably favorable conditions (58.7 ± 1.6%). There was no viability index difference between the samples with medium replaced and not replaced and the specimens harvested from two different donor groups. Conclusions: Long-term storage of vein allografts at +4°C is a valuable option for regular banking practice. Sufficient amounts can be procured from cadavers similar to tissue donors.

A novel method for long-lasting preservation of arterial grafts

“…Other methods include cold ischemia storage (+4°C) [27,28] and preservation in glutaral dehyde [29]. Currently, experimental studies with glycerol and polyphenol for vessels preservation are being M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 11 carried out [30][31][32][33].…”

Successful Human Vascular Reconstructions with Long-Term Refrigerated Venous Homografts

“…Long-term storage of vein allografts in tissue culture medium at 4 ° C could provide grafts with the same viability for 6 weeks when compared to those that have been cryopreserved [15] . It is important to note that large amounts of vein allografts can be procured from cadavers with ischemic time of maximally 24 h similar to the tissue donors.…”

“…It is important to note that large amounts of vein allografts can be procured from cadavers with ischemic time of maximally 24 h similar to the tissue donors. After more than 24 h, the viability indexes of veins dramatically decrease so that they are not available for transplantation purposes [15] .…”

“…Even the attempt to improve the survival of cryopreserved veins by allowing favorable tissue culture conditions following cryoinjury did not result in improved survival [15] . Experience in liver and kidney transplant surgery shows that vessels supplying a transplant rarely become thrombosed or aneurysmal even during follow-up periods of 20 years or longer.…”

“…These grafts were stored in saline solution containing antibiotics (chloramphenicol and amphotericin) for up to 3 weeks. The allografts were examined under aseptic conditions for wall quality and diameter measurement and were ready for use after 10-21 days [14] Previously, we have confirmed that vein allografts that had been stored at 4 ° C for up to 42 days in tissue culture medium showed excellent viability, better than cryopreserved samples [15] . Over the past 3 years we introduced this technique into our clinical practice.…”