Hypothermic storage or organ culture?

Abstract

AbstractCurrently there are two storage practices for the cornea, both use liquids based on cell culture medium: the hypothermic storage at 2‐6°C, and organ culture at 30‐37°C. Hypothermic storage seems to offer donor tissues of good quality comparable to that obtained by organ culture, provided that the storage time is kept short. Indeed, according to the literature, the risk of primary graft failure increases significantly after storage longer than 7 days. Furthermore, corneas stored longer than 7 days display epithelial alterations that may hinder the surgical procedure or delay the full recovery of the graft. The organ culture storage method consists of a storage period in culture medium at 30‐37C°, and a shorter de‐swelling and transportation phase at 30‐37C° and room temperature in the same medium supplemented with 4‐8% dextran. Organ culture solutions contain fetal calf serum as a source of growth factors to limit endothelial cell loss. The serum must be obtained from prion‐free countries. A storage period of 30 days can be achieved without significant loss of endothelial cells. The endothelium shows reparative phenomena during storage. Organ culture offers a longer storage time, a less restricted donor supply on beforehand, corneal endothelium with a better defined quality, and a pre‐operative microbiologic control. Cultured corneas always display an epithelium made up of 2‐3 layers of viable cells. The 30 days storage period allows an efficient use of valuable donor tissue: planning of operations is easier, allowing sufficient time for the allocation. The disadvantages of this method are the relative technical complexity and the need for qualified staff to perform tissue culture and selection of the corneas. The studies comparing the effect of the storage methods on outcome demonstrate similar graft survival and post‐operative decline in endothelial cell density. Corneas stored by organ culture are at least comparable with those stored hypothermically for shorter periods.