Experimental study of phrenic nerve transfer for treatment of brachial plexus root avulsion

OBJECTIVE: To investigate the effects of neurorrhaphy, nerve grafting and nerve implantation in phrenic nerve transfer for treatment of brachial plexus root avulsion. METHODS: One hundred and eighty Sprague-Dawley rats were divided into three groups: the neurorrhaphy group, the nerve grafting group and the nerve implantation group. Evaluations such as motor nerve latency, amplitude of compound actional potentials, muscle weight, cross sectional areas of muscle fibers and myelinated axons, and muscle function were performed at 1, 2, 3, 4, 5 and 6 months postoperatively. All data were analyzed by the Student-Newman Keuls test in SAS software. RESULTS: Variable recovery in each group was found at different postoperative intervals. At six months after operation, the following results were observed in descending superiority: neurorrhaphy > nerve grafting > nerve implantation. Nerve implantation demonstrated the function recovery was 75.76%. CONCLUSIONS: This study demonstrates that neurorrhaphy is statistically superior to nerve grafting and nerve grafting superior to nerve implantation, and also confirms the validity of phrenic nerve implantation. But when no reparable distal nerve stump is available, nerve implantation is an effective method in phrenic nerve transfer for brachial plexus root avulsion to some extent.