During nerve reconstruction, nerves of different thicknesses are often sutured together. When we suture thick nerves to thin nerves, differences in the number of contacting axon fibers are sometimes seen between end-to-side neurorrhaphy and end-to-end neurorrhaphy. We examined whether the type of neurorrhaphy affects the number or thickness of regenerated axon fibers.
End-to-end neurorrhaphy resulted in a significantly greater number of regenerated axonal fibers after 6 weeks than end-to-side neurorrhaphy ; however, no such differences were seen at 12 postoperative weeks. While the regenerated axonal fibers were thicker at 6 weeks than at 12 weeks, no significant differences in axon fiber thickness were detected between end-to-end and end-to-side neurorrhaphy.
We suggest that end-to-end neurorrhaphy results in greater numbers of regenerated axons and increased axon thickness during the early postoperative period. As rapid reinnervation is one of the most important factors influencing the restoration of target muscle function, we consider that end-to-end neurorrhaphy is desirable when suturing thick nerves to thin nerves.