COLD-PRESERVED NERVE ALLOGRAFTS - CHANGES IN BASEMENT-MEMBRANE, VIABILITY, IMMUNOGENICITY, AND REGENERATION

Rat sciatic nerve graft segments were harvested and pretreated by eith er placement in the University of Wisconsin Cold Storage Solution at 5 degrees C and storage from 1 to 26 weeks, or repeatedly freezing (-40 degrees C) and thawing (20 degrees C), Following pretreatment, grafts were transplanted as either syngeneic or allogeneic nerve grafts. Sto rage and freeze-thawing did not affect the Schwann cell basal lamina o r laminin distribution of the peripheral nerve. Graft cell viability d ecreased with increasing time of storage, with some viable cells detec table even after 3 weeks of storage. Freeze-thawed grafts were not via ble. Increasing time of storage led to decreasing immune response and graft rejection, but improved regeneration. Freeze-thawed and 26-week stored allografts were nonimmunogenic and rejection was not seen, but regeneration was delayed compared to autografts. Graft storage may bec ome a useful adjunct to clinical nerve allografting to permit elective scheduling of surgery, provide greater time for preoperative tissue t esting, and possibly blunt the immune response. (C) 1998 John Wiley & Sons, Inc.