Clinical study of direct coaptation of phrenic nerve harvested in mediastinum with posterior division of lower trunk to recover finger extension with brachial plexus root avulsion

Objective To find out a new effective method of nerve transfer to reconstruct the function of finger extension in patient suffered brachial plexus root avulsion.Methods The length of phrenic nerve was enlongated by harvested in the mediastinum.The entire brachial plexus of injuried side was exposed through the combined incision superior and inferior to the clavicle and the clavicle was osteotomied.The posterior division of lower trunk was identified and severed as proximal as possible,direct anastomosis of phrenic nerve with posterior division of lower trunk was performed.From Jun.2005 to Mar.2007,12 patients including 10 males and 2 females with brachial plexus nerve root avulsion were performed with this procedure,11 cases with total nerve roots avulsion and 1 cases with middle and lower trunk avulsion,the average age was 28 years with a range of 6 to 39 years.The interval from injury to operation ranged from 2 to 11 months with a mean of 6 months.The normal function of the phrenic nerve on the injuried side should be proved preoperatively by chest radiographic and electromyography examination.Results The length of phrenic nerve harvested from the mediastinum was elongated 3～7cm,with an average of 4cm.All the cases were successfully performed by the direct coaptation of phrenic nerve with posterior division of lower trunk.3 cases were followed up more than 12 months after operation,the muscle strength of extensor digitorum was M2 in 2 cases and newborn potential appeaed in the muscle of extensor digitorum in another case.Conclusion The direct coaptation of the phrenic nerve harvested in the mediastinum with the posterior division of lower trunk to recover the extension of finger in patient with brachial plexus injury was feasibile.