BACKGROUND. Long nerve grafts are prone to chronic denervation, often resulting in unsatisfactory clinical outcomes. We aim to investigate if supercharge end-to-side (SETS) nerve transfers to a long nerve graft can potentially enhance nerve regeneration and functional outcomes.
METHODS. A reversed long nerve graft was interposed between C6 and musculocutaneous nerve in 48 rats. The motor nerves near the C6 proximally and the musculocutaneous nerve distally were chosen for SETS transfer to the long nerve graft. There were four groups: (A) nerve graft only, (B) proximal SETS transfer, (C) distal SETS transfer, and (D) proximal and distal double SETS transfers. A grooming test was assessed at 4, 8, 12, and 16 weeks postoperatively. Biceps weight, compound action potential amplitude (CMAP), tetanic contraction force, as well as histomorphometric analysis of the musculocutaneous nerve were evaluated at 16 weeks.
RESULTS. Long nerve grafts that received SETS transfers (Groups B, C, and D) showed superior results compared to the control group. Proximal SETS transfer had significantly better outcomes than distal SETS transfer in electrodiagnostic parameters, while double SETS transfer had the highest axonal count and biceps CMAP.
CONCLUSIONS. SETS transfers to long nerve grafts can effectively improve functional outcome and optimize nerve graft regeneration to the target nerve.

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