Overview of safety issues concerning the preparation and processing of soft-tissue allografts

With the increasing use of allograft tissue and the recent infections found in patients undergoing surgical procedures, the current practices that prepare grafts for implantation must be examined. Initially, most tissue banks harvest allografts aseptically. There are many steps in the different techniques of preparation and processing of allograft tissue. Before allograft tissue is ready for clinical use, it undergoes specific disinfection methods, according to the individual tissue bank's specific process. Tissue banks use in-process bactericidal and virucidal steps via physical cleaning, chemical treatments, or application of irradiation to the allografts (or some combination thereof). Gamma irradiation may also be used as a terminal processing method to reach an assurance of sterility after the allograft has been packaged. Because of the allograft toxicity potential, the use of ethylene oxide as a final tissue sterilization measure is really nonexistent. The role of the Food and Drug Administration and American Association of Tissue Banks in allograft tissue handling is presented, as well as the new rules that regulate tissue banks and affect their processing methods.