Effect of Ipsilateral C7 Nerve Root Transfer on Restoration of Rat Upper Trunk Muscle and Nerve Function After Brachial Plexus Root Avulsion

The effects of ipsilateral cervical nerve root transfer on the restoration of the rat upper trunk muscle and nerve brachial plexus root avulsion were studied. After simulated root avulsion of the upper trunk brachial plexus, 120 rats were randomly divided into 4 groups: (A) ipsilateral C7 root transfer group; (B) Oberlin group; (C) phrenic nerve group; and (D) no axillary nerve restoration group. At 3, 6, and 12 weeks postoperatively, Ochiai score, Barth feet overreaching test, Terzis grooming test, and indices of neurotization were determined in 10 rats from each group. Twelve weeks postoperatively, nearly all the behavioral, neuroelectrophysiological, and histological outcomes of the axillary nerve and deltoid muscle and some of the indices of musculocutaneous nerve and biceps brachii function in the ipsilateral C7 group were superior to those in the other 3 groups. No significant difference was found between the ipsilateral C7 group and the other 3 groups in recovery rate of wet biceps muscle weight. No significant difference was found between the ipsilateral C7 group and the Oberlin group in the recovery of the axillary nerve compound muscle action potential and biceps brachii cell size. No significant difference was found between the ipsilateral C7 group and the phrenic nerve and no axillary nerve restoration groups in amplitude recovery rate of musculocutaneous nerve compound muscle action potential. No significant difference was found between the ipsilateral C7 and the Oberlin groups in the early recovery of musculocutaneous nerve compound muscle action potential, but recovery was significantly better in the ipsilateral C7 group at 12 weeks. Ipsilateral C7 root transfer can improve the quality of restoration of muscle and nerve function in the rat upper trunk after brachial plexus root avulsion.