[Morphometric evaluation of the effectiveness of post-traumatic peripheral nerve regeneration after a single and...

Sciatic nerve (SN) transection and microsurgical suture were performed in 41 dogs to assess the effect of electrostimulation (ES) on peripheral nerve regeneration. 23 dogs served as a control group, ES of the spinal cord and SN was made with alternating current of 50-Hz frequency in 18 dogs: in 13 dogs one course of 18 sessions was performed within the period of 1-2.5 months after surgery (ESL1), in 5 dogs two courses were performed: the first one--in a similar time interval, the second one--within 6-7.5 months after surgery (ES2). The mean diameter of myelinated fibers (MF) after 2.5, 4, 6, and 12 postoperational months for ES1 was significantly greater than the control values, mainly due to the increase of axonal diameter. After 12 months, the tendency towards the restoration of MF diameter bimodal distribution was marked in ES2, and, to a lesser degree, in ES1. Thus, it was found that ES effectively activates the regeneration and differentiation of MF, but leads to their relative hypomyelination.