Effect of the Number of Sutures on Nerve Repair: A Mechanical, Functional and Morphometric Study of Tibial Nerve Regeneration in Wistar Rats

Background: Nerve repair with microsurgical techniques is the gold standard and the most widely used surgical treatment for nerve reconstruction. However, the optimum number of microsutures for approximation of nerve ends has not been investigated thoroughly, as the focus of previous studies has been on in vitro examination of biomechanical strength of the repaired nerve. Objectives: In this study, we investigated the effect of the number of suture on nerve repair, concerning mechanical, functional, and morphometric aspects. Methods: Twenty-four male Wistar rats were subjected to tibial nerve transection and randomly divided into three groups: control with no repair; repair with 1 suture; and repair with 3 sutures. Tibial functional index (TFI) was determined weekly for two months to assess the functional recovery. At the end of the study, macroscopic and microscopic evaluations as well as adhesive strength quantification at the site of the injury were performed. Results: There was no significant difference in the TFI measures between 1-suture and 3-suture groups during 8 weeks (P > 0.05). Adhesive strength was not significantly different between three groups (P > 0.05); however, it was higher in both suture groups compared with the control group. Scar index was 0.50 (SD = 0.06, n = 2) in control, 0.54 (SD = 0.08, n = 4) in 1-suture, and 0.58 (SD = 0.13, n = 4) in 3-suture groups. The comparison of the mean of differences in scar index and vascular index did not imply significant differences (P > 0.05). Conclusions: Repair of rat’s tibial nerve with one or three microsutures gave comparable outcomes. This may suggest that for functional recovery of the fine nerves, simple approximation with minimum number of sutures is sufficient.