gms | German Medical Science

Objectives/Interrogation: Nerve reconstruction is an essential part of limb salvage. Processed nerve allograft (PNA) utilization is a growing component of limb salvage. Revisions to limb salvage can unfortunately be a necessary multi-step process. Nerve banking has been proposed as a means of preserving sacrificed nerve autografts in the past, however no study has evaluated the banking of nerve allografts. We present the histological assessment of banking nerve allograft by burying it within a patient's muscle during revision limb salvage.

Methods: We performed a retrospective review of patients that underwent PNA reconstruction of peripheral nerve injuries who had complications necessitating take down of previously placed graft. PNA was salvaged by burying their graft within the patient's own muscle. The histopathology of the in situ banked nerve graft after storage in the patients muscle was qualitatively compared to the histopathology of the nerve graft before original implantation.

Results and Conclusions: Two patients were included in our case series. Patient 1 had a right ulnar nerve injury from a gunshot wound. He underwent ulnar nerve reconstruction using PNA. Five days post-operatively, the patient had wound necrosis in the region of the reconstructed nerve. The graft removed from the original reconstruction was implanted in the intact triceps muscle. Two weeks after banking, the patient underwent revision ulnar nerve reconstruction and the banked allografts were removed for evaluation. Patient 2 had a brachial plexus injury secondary to a motor vehicle collision. The patient underwent significant brachial plexus reconstruction with PNA. Twelve days post-operatively, the patient sustained an unsalvageable vascular complication and underwent amputation. The Graft was salvaged and implanted into the pectoralis major muscle. Two days post-amputation, patient underwent TMR and banked grafts were removed for evaluation. Histologic analysis of the in situ banked graft as compared to nerve graft pre-implantation reveals good structural preservation, presence of Schwann cells, and no signs of cellular infiltration from rejection or reaction.

We present a novel technique of nerve allograft banking within intact muscle tissue. Histopathologic slides showed no qualitative difference between pre-implantation and salvaged allograft. This study suggests that acellular nerve allografts are safe and retain adequate integrity after in situ muscle banking.