METODOLOGIE CRIOCONSERVATIVE E CONTROLLO DI QUALITA DI LEMBI DERMOEPIDERMICI

Skin banks that supply Burns Centres with allogenic dermoepidermal flaps were born later in Italy than in other countries because of law impediments that are now overcome. Scientific indications to the use of allogenic skin, known for a number of years, have found new evidence in the fact that allogenic dermoepidermal grafting is an essential operative step in promoting the good taking of autogenic cultured keratinocytes. The choice of cryopreservation is due both to law impediments to the use of fresh allografts and to the need of ameliorating standards of production, availability and distribution of the product. The role of the laboratory is pivotal for the correct management of the skin bank in controlling and directing all procedures. A delicate problem arisen during this study was that of quality controls: although there are no laws in this field, we believe that control of cryopreserved skin must be multiple and careful, in order to guarantee sterility and viability of the preserved tissues. During this study, three different methods of freezing were tried: that involving subsequent passages at decreasing temperatures has proved to be the best in preserving cellular viability. This was assessed after perfecting several methods to assess cells viability. Another relevant, and so far unsolved, problem is preoperative donor disinfection. From the study, it is clear that a high number of the flaps we analysed was contaminated from the beginning by different bacteria. For this reason, several methods for the disinfection of the operating field are being evaluated.