Medium term follow-up of phrenic nerve transfer to the posterior division of lower trunk to recover elbow and finger extension in patients with brachial plexus root avulsion

Objective To observe effect of phrenic nerve transter to the posterior division ot lower trunk (PDLT) for recovering elbow and finger extension in patients with brachial plexus root avulsion.Methods From June 2005 to December 2008,43 patients with brachial plexus root avulsion were treated with phrenic nerve transfer to PDLT to recover elbow and finger extension.There were 36 males and 7 females,aged from 4 to 44 years (average,23.5±9.9 years).The interval from injury to operation ranged from 1 to 12months (average,3.7±1.9 months).There were 32 cases of total nerve roots avulsion,5 cases of middle and lower trunk avulsion accompanied with upper trunk normal or partial injury,and 6 cases of C6 to T1 nerve root avulsion accompanied with C5 nerve root rupture or partial injury.The normal function of the phrenic nerve in the injured side should be proved preoperatively by radiographic and electromyographic examination.The entire brachial plexus in injured side was exposed through the combined incision.The posterior division of lower trunk was identified and severed as proximal as possible,and the posterior cord and radial nerve were dissociated distally until to the level of midpoint of humerus.Then the branches of the posterior cord except the radial nerve were sectioned.Direct anastomosis of the phrenic nerve and PDLT was performed in 33 patients,and indirect anastomosis through bridge grafting using sural nerve was performed in remaining 10 cases.Results All patients were followed up for 36 to 73 months (average,39.7±7.l months).The percentage of muscle strength ≥grade 3 in elbow,finger and thumb extension was 81.6％,41.9％ and 39.5％,respectively.Conclusion Satisfactory functional recovery of elbow extension had been achieved after the phrenic nerve transfer to the PDLT in patients with brachial nerve root avulsion injury,however,the functional recovery of finger and thumb extension was not as satisfactory as anticipated. Key words: Brachial plexus; Wounds and injuries; Phrenic nerve; Radial nerve