The combination of proximal end-to-end neurorrhaphy and distal end-to-side or side-to-slde neurorrhaphy to improve functional recovery after nerve repair:an experimental study

Objective To investigate the effectiveness of nerve regeneration and target muscles recovery in high level nerve injury treated with combined proximal end-to-end neurorrhaphy and distal end-to-side or side- to-side neurorrhaphy,Methods The left fibial nerve of 80 female SD rats was transected proximally,The animals were randomly divided into five groups,In group A, the transected tibial nerve were sutured at the transected site in an end-to-end fashion,At the knee joint level, the windowed tibial nerve was sutured with the windowed neighboring peroneal nerve in a side-to-side fashion,In group B, the proximal coaptation was same as group A,At the knee joint level, a segment of 3 mm median nerve was harvested and bridged between the peroneal nerve and the distal part of the tibial nerve in an end-to-side fashion,In group C, only end-to-end neurorrhaphy of the tibial nerve was done at the transection site,In group D, the proximal end of the tibial nerve was ligated, reversed and sutured into neighboring muscles while the distal part was windowed at the knee joint level and sutured side-to-side with the windowed peroneal nerve,In group E, the proximal end of the tibial nerve was dealt with same as group D while a certain length of the distal tibial nerve was resected to the knee joint level and then sutured end-to-side with the windowed peroneal nerve,Assessment of nerve regeneration was carried out using electrophysiological and histological examination, electron microscopic evaluation and image analysis. Results Regenerating nerve fibers were observed in groups D and E at 4 weeks after the operation,The quantity and quality of the regenerated nerve fibers, conducting capacity, and the recovery of muscle and motor endplates in groups A and B were much better than those in groups C, D and E at 12 weeks after the operation. Conclusion Combined proximal end-to-end neurorrhaphy and distal end-to-side or side-to-side neurorrhaphy can provide early neurotropic support to the target muscles,This buys time for nerve regeneration in high level injuries, protects the target organs and results in more effective functional recovery.