Electrical fascicle identification as an adjunct to nerve repair

Twenty-eight upper extremity nerves in 25 patients were repaired using an electrical nerve stimulator to identify major fascicles for their sensory and motor content. The proximal stump was searched for major sensory fascicles, as determined by the patient's verbal response, while using a general anesthesia "wake-up" technique. The distal stump was searched for major motor fascicles, judged by the observed twitch in the appropriate intrinsic muscles of the hand. Repair was usually by selective fascicle suture combined with epineurial suture. Identification of the separate digital nerve fascicles in the distal stump was not attempted. Ten median and five ulnar nerves were evaluated after 2 to 4 years. Median nerve repairs have shown satisfactory results, with thenar motor recovery ranging from 25% to 95% of normal in nine of 10 cases. Pure median nerve supply of the thenar muscles was confirmed by ulnar nerve block. The small ulnar nerve sample also shows encouraging results, but more end results are needed to substantiate the current impression.