Study on repairing high ulnar nerve injury by low end-to-side anastomosis of superficial branch of radial nerve

doi:10.3969/j.issn.1674-3806.2014.03.05

Abstract：Objective To explore the histological changes in intrinsic muscle and the neuropathological changes in anastomosis during repairing high ulnar nerve injury ( above the elbow ) at the first stage using sensory nerve transferring by experiments conducted with animals .Methods Six adult male macaques were included in the experiment and the upper limbs were studied , with the 12 limbs randomized into 3 groups ( 4 limbs in each group ) . Group A(experimental group):The ulnar nerve was cut at the upper segment of the upper limb , with end-to-end an-astomosis followed .The superficial branch of radial nerve was cut at the distal end and the end-to-side anastomosis was performed by transferring the superficial branch of radial nerve to the wrist segment ( fenestration was made in the outer membrane).Group B(control group):3 cm of the ulnar nerve was cut at the upper segment of the upper limb and folding ligation was made from both ends .Treatment at the wrist segment was the same as in group A .Group C ( Control group ):Treatment at the unlar nerve of the upper was the same as in group A .But no transferring was made at the wrist segment .The atrophy of intrinsic muscle controlled by ulnar nerve was observed after surgery .The intrin-sic muscle at the end-to-side anastomosis , neural stem distal to end-to-side anastomosis and hypothenar muscle were collected at 1M, 3M, 6M and 12M after surgery and the tissues collected were made into sections to observe the changes under microscope .Results The intrinsic muscle of the macaques in group A restored autonomic activity 12 months after surgery and no obvious atrophy in intrinsic muscle of the operated side was observed .Atrophy in intrinsic muscle of the operated side was observed in group B and group C , but with more obvious atrophy observed in group C.Histological observation revealed that the number and density of nerve fibres increased as the time went on in group A.While in group B, the number and density of nerve fibres kept stable after increase to certain degree , but no necrosis was observed .In group C, the number of nerve fibres decreased significantly as time went on .The number of muscle fibres also decreased significantly and besides atrophy , hyalinization , interstitial hemorrhage and formation of granulation tissue were observed in most muscle fibres .Conclusion Sensory nerve transferring is effective in preven-ting atrophy , degeneration and fibrosis of intrinsic muscle and provides favourite situation for the regeneration and growth of ulnar nerve after repairing for high injury .