Embalming cadaveric upper limbs after freezing and thawing: a novel technique for maximizing body donor usage through fresh frozen and formalin-fixed preservation

Fresh frozen body donors are invaluable for surgical skills training sessions and medical research due to their realistic tissue quality. However, the potential for use as long-term teaching specimens is limited by soft-tissue deterioration following multiple freeze-thaw cycles. Embalming with the use of formalin achieves tissue fixation, thereby preventing tissue deterioration and enabling prolonged use of anatomical specimens. The purpose of this study was to determine whether fresh frozen upper limbs can be successfully embalmed for use as dissection and prosection resources in anatomical sciences education following one or more freeze-thaw cycles, thereby allowing for increased usage of an individual body donor. Four previously frozen left upper limbs were preserved using formalin fixation and were dissected 30 days following arterial embalming to determine whether adequate fixation could be achieved and whether the tissue quality could be maintained. The greatest number of freeze-thaw cycles evaluated in this study was six. To our knowledge, this is the first report in which specimens from fresh frozen human body donors have successfully been embalmed using formalin-fixation techniques following single or multiple freeze-thaw cycles. Following dissection of each upper limb, we conclude that formalin fixation after freezing and thawing is a viable preservation technique that can maintain a level of tissue quality suitable for educational dissection and prosection following use of the fresh frozen cadaver for surgical skills training sessions or medical research.