gms | German Medical Science

Surgical therapy of traumatic plexus brachialis lesions is still a great challenge in the field of peripheral nerve surgery. This study aims at demonstrating the value of recording intraoperative nerve action potentials (NAPs) in order to facilitate the surgeon´s decision for or against grafting procedure.

From January 1991 until September 1999, 134 patients with traumatic plexus brachialis lesions underwent surgery at our department. Intraoperative recording of NAPs was done on 85 patients. In more recent years this has been done on almost every patient.

Surgical exploration could be performed on average 6.3 months post trauma. In every case the interval was long enough to exclude spontaneous recovery. With lesions in continuity, the decision whether to graft or just neurolyse was based on microscopic inspection, palpation and intraoperative electrophysiological exam. In cases of obtained reproducible NAPs, that could be recorded after stimulating proximal to the neuroma in continuity, and recording from a point distally, the procedure was restricted to external neurolysis (19 cases). Without a recordable NAP (66 cases) the nerve was grafted. 83 nerves interrupted in continuity required grafting, 67 cases with root avulsion necessitated various types of nerve transfers. Intraoperative recording of nerve action potentials reduced the number of indication for nerve grafting: In 22% of cases monitored with NAPs the procedure could be restricted to neurolysis, compared to 16% of cases that had neurolysis only in a patient group not monitored. Functional results neurolyzed patients are better in the NAP group: 60% of the monitored patients showed a grade 3 or better (Kline) postoperatively, non-monitored only 39%.

Recording nerve action potentials is a helpful method to detect axonotmetic lesions with good regenerative potential. Failure to record NAPs together with morphologcal signs of neuroma in continuity guides the surgeon to decide in favor of grafting.