Intraoperative measurement of choline acetyltransferase activity to evaluate the functional status of donor nerve during reinnervated free muscle transfer: a preliminary report

Intraoperative choline acetyltransferase activity measurements were used to evaluate the functional status of donor nerves during reinnervated free muscle transfer. This technique was applied to 3 cases. One was a lower-type brachial plexus injury in combination with radial nerve injury; the other 2 were Volkmann's ischemic contractures. Gracilis muscle was transferred for reconstruction of wrist extension in all cases. The donor nerves included 1 anterior interosseous nerve and 2 posterior interosseous nerves. A fascicle with choline acetyltransferase activity above 2,000 cpm was considered to be reliable as a motor fascicle. Reinnervation of transferred muscle was confirmed by electromyographic examination within the first 3.3 months (range, 2.5 to 4 months) after surgery and all muscles obtained useful recovery. This technique can directly and quantitatively verify the functional quality of the donor motor fascicle when the quality of the donor nerve is in doubt.