End-to-side neurorrhaphy: an experimental study in rabbits.

The concept of end-to-side nerve repair was recently introduced; however, most authors have reported conflicting results with this technique. This study was conducted to assess the effectiveness of end-to-side nerve repair in both fresh and predegenerated specimens by histological evaluation in an animal study in rabbits. Thirty male rabbits were divided into three groups. In group 1 (n = 14), the peroneal nerve was divided and sutured end-to-side to the tibial nerve via an epineurial window. In group 2 (n = 13), the peroneal nerve was divided and sutured end-to-side to the tibial nerve after a 1-week "predegeneration period." In group 3 (n = 3), which was considered the control group, the peroneal nerve was divided and sutured to the adjacent soft tissues. After 3 months, specimens were harvested for histological evaluation. Nerve fiber count, in normal peroneal nerves, averaged 532/cross section. In groups 1 and 2, average nerve fiber count in implanted peroneal nerves was 6.24 and 7.00/cross section, respectively. No significant statistical difference was observed between fresh and "predegenerated" groups (P = 0.90). These data suggest that collateral sprouting of donor nerves is possible after end-to-side neurorrhaphy through an epineurial window, but the number of nerve fibers in recipient nerves is too low to result in any functional recovery in the target organ.