Comparison of Nylon Suture Versus 2 Fibrin Glue Products for Delayed Nerve Coaptation in an Animal Model

Abstract

To compare 2 different, commercially available fibrin glue products with nylon suture with regard to repair strength, muscle function, and axon regeneration after delayed nerve repair in an animal model. A total of 120 Lewis rats underwent transection of the sciatic nerve. On day 3 after transection, the nerves were reexposed. A primary repair was performed on 40 rats from each group using nylon suture, Tisseel fibrin glue, or Evicel fibrin glue. On days 0, 3, and 7 after repair, 10 rats from each group underwent burst strength testing. Seventy days after repair, 10 rats from each group underwent functional muscle testing and histomorphic analysis of the nerve, with the contralateral limb serving as the control. There was no significant difference in burst strength among the groups on days 0 and 3. On day 7, the burst strength of the Evicel and nylon suture groups was significantly greater than that of the Tisseel group. There were 5 total coaptation failures in both fibrin glue groups and none in the suture group. Seventy days after repair, tetanic muscle strength, muscle mass, axon inner diameter, and g-ratio were equivalent among all groups. Axon counts were equivalent between the nylon suture and Evicel groups, although in the nylon group axon counts were higher than for the Tisseel group. In an animal model with a 3-day delay in nerve repair, although dehiscences occurred, when the initial repair held, fibrin glue was not inferior to nylon suture with regard to repair strength and muscle recovery. Historical concerns regarding spontaneous fibrin glue-based nerve repair dehiscences are well-founded. However, when coaptation is maintained, commercially available fibrin glues support nerve regeneration.