gms | German Medical Science

Objectives/Interrogation: The use of processed nerve allograft (PNA) in peripheral nerve surgery is rapidly evolving. Favorable outcomes have been reported for PNA as compared to autograft in the upper and lower extremities, and cranial nerves, for gaps up to 70 mm. Yet, there is limited data on reconstruction of gaps greater than 70 mm. Autograft data is also limited in longer gaps, and shows mixed results. To evaluate the effects of PNA, we selected patients with insufficient donor nerves, to evaluate the use of allograft to reconstruct injuries with gaps greater than 70 mm. The objective was to evaluate early outcomes for PNA repair of injuries greater than 70 mm at an academic Level-1 trauma center.

Methods: Retrospective review of patients who underwent reconstruction with PNA greater than 70 mm was performed. All procedures were performed by fellowship trained hand surgeons. Functional recovery, Tinel's sign, and sensory tests were recorded for all postoperative follow-up visits. When possible, electromyogram testing (EMG), nerve conduction study (NCS) were obtained to quantify re-innervation. Acute and sub-acute nerve transfers were cataloged. Complications and revision procedures were also recorded.

Results and Conclusions: Ten patients were included in our study. Average age was 31 (range 21-41 years). Eight patients (80%) were male. Ninety percent of reconstruction were in the upper extremity with an average gap length after resection of 17 cm (7.5-36 cm). All patients had multiple connected allografts used during their reconstruction. Mean follow-up was 4 months. All patients showed signs of nerve regeneration through the PNA, and advancing Tinel's. Five patients had EMG/NCS studies, one of which had serial studies performed. Two patients showed return of activity in a motor unit of the reconstructed nerve. Seven patients underwent Semmes Weinstein testing, and demonstrated some return of sensibility in the nerve distribution. The two longer term follow up patients showed signs of motor return and increasing range-of-motion. No complications directly related to nerve reconstruction or revisions were observed.

All patients in our cohort have shown short-term improvement in strength, sensation, and functional outcomes after allograft reconstruction of nerve injuries with gaps greater than 70 mm. Quantitative assessment of recovery is ongoing but encouraging. Early data suggests that long-term follow-up may show the use of allograft in nerve gaps greater than 70 mm to be a promising reconstructive option.