How long can cryopreserved skin be stored to maintain adequate graft performance?

Skin graft preservation for the purpose of delayed application is still a b asic tool in burn treatment and plastic and reconstructive surgery. As the demand for skin allografts has increased the responsibility for processing, storage and evaluation of graft performance of preserved skin has become a n important issue of banking organizations. The present experiments were un dertaken to determine how long can cryopreserved cadaveric skin be stored t o maintain adequate graft performance? We applied a mouse recipient model, developed by us: Human cadaveric skin cryopreserved and stored for 5, 6 or 7 years was grafted on Balb/c mice, and primary take was evaluated by gross observation and predetermined histologic criteria after 7 days. The result s demonstrate that graft performance of cryopreserved skin decreased with t ime, as reflected in the lower percent of samples with high score of separa te histologic criteria after prolonged storage. Nevertheless, paired compar ison analysis between cryopreserved and fresh skin indicated that this decr ease was not significant for storage of 5 years; whereas it was highly sign ificant for 6 years of storage. Linear regression analysis indicated that t here was no correlation between the score of the histologic criteria and st orage period for upto 65 months. These results are in line with the paired comparison analysis. We feel that our in vivo model and analysis may be use d as an evaluation procedure for transplantation performance of banked skin . (C) 2001 Elsevier Science Ltd and ISBI. All rights reserved.