gms | German Medical Science

Objective: The cC7 transfer is an established technique and has gained increasing importance in plexus surgery. To minimize possible deficits an electrophysiological examination of the healthy arm is crucial.

Method: By analyzing retrospectively 5 patients with cC7 transfers, the electrophysiological examination was optimized and an intraoperative design was created.

Results: Since 2011 14 patients have been operated on a cC7 transfer. After the first 5 cases, in which one of the patients came out with a permanent deficit of the M. ext. dig. com. (M3), intraoperative electrophysiology was extended. By using a monopolar stimulation probe, every single root from C5 to C8 is examined from each side to gain an EMG of the associated muscles. Each amplitude is evaluated and compared. In addition C7 is separately stimulated. Its anterior division is compared to the posterior division. Only after having analyzed all EMG amplitudes, does the surgeon make the decision whether to transfer the whole root or just one part of C7. Since then no permanent deficit has occurred. In summary one surgery was interrupted without using C7 and 4 patients just received the front part of the C7 root to the affected N. medianus or to part of the radial nerve. Transient paraesthesias occurred in 9 cases, 4 patients suffered a transient paresis of the M. trizeps and 9 cases had no motor deficits at all. But one case sustained a permanent deficit of the M. ext. dig. com. (M3).

Conclusions: Although the extended intraoperative electrophysiology takes time, it is a reliable tool to minimize the risk of permanent motor deficits for the cC7 transfer.