Electrophysiological, histopathological and functional evaluation of repair with modified "sleeve neurorrhaphy" in the rat sciatic nerve

Objective: The most commonly used method in peripheral nerve injury repair is the epineural repair technique. Recently, as an alternative to this technique, the concept of "sleeve neurorrhaphy" has come to the fore and studies have been conducted that have been shown to be superior to epineural repair. The aim of this study is to compare sleeve neurorrhaphy with epineural repair and present technical methods that facilitate the application of sleeve neurorrhaphy.. Materials and Method: In this study, a total of 21 Sprague-Dawley type rats were used in 3 groups: the sham group (n:5), the control group (n:8) who underwent epineural repair, and the experimental group (n:8) who underwent "sleeve neurorrhaphy". The right sciatic nerves of the rats were exposed by dissection. Skin repair was performed in the sham group without any additional procedures. While epineural repair was performed in the control group, the "sleeve neurorrhaphy" procedure was applied to the experimental group. Daily dressing was done for 3 months. At the end of 3 months, SFI (sciatic function index) measurement with walking track analysis and motor nerve conduction velocity measurement with EMG were performed. After the rats were sacrificed, the sciatic nerves were excised and histopathological examination was performed. Results: A statistically significant difference was found between the three groups in the SFI values obtained as a result of the walking track analysis (p <0.05). When motor nerve conduction velocity was evaluated, the sham group was found to be superior to the experimental and control groups (p <0.05), but no significant difference was found between the experimental and control groups. When the fiber diameter/axon diameter ratio was evaluated by histopathological examination, there was no significant difference between the sham and experimental groups, but a significant difference was found between these two groups and the control group (p <0.05). Conclusion: There was a significant difference in functional and histopathological analysis values between sleeve neurorrhaphy and epineural repair. Along with the technical recommendations mentioned in the study, "sleeve neurorrhaphy" is an important method that can be used in nerve repair.