Epineurial and perineurial fascicular nerve repairs: a critical comparison

To compare the results of epineurial and intrafascicular perineurial nerve repair techniques, ulnar nerves of 20 domestic cats were severed proximal to the medical humeral epicondyle. One nerve was repaired with No.8-O nylon by standard epineurial technique with the aid of three to five magnifications; the other nerve was repaired with No. 10-O nylon by intrafascicular perineurial technique under higher magnification. Four to five months following neurorrhaphies, the ambulation pattern, fanning of claws, and sensation were evaluated subjectively. Objective measurements included efficiency, absolute strength, and exact weight of the flexor carpi ulnaris muscle. Proximally and distally to each neurorrhaphy, complete axon counts were taken. Histochemically and histologic analyses were made on reinnervated muscles and neuromas. No statistically significant differences were detected between the results of epineurial and intrafascicular perineurial neurorrhaphies. These findings indicate that, following acute nerve laceration in the cat, epineurial neurorrhaphy is as satisfactory as is intrafascicular perineurial neurorrhaphy.