Motor Neurotization by Segmental Epineurectomy and Implantation: Lateral Muscular Neurotization

Abstract

In this study, we aimed to develop a new muscular neurotization technique, in which transection of the donor nerve is avoided. We investigated the outcome of insertion of the donor nerve within the denervated muscle following segmentary epineurectomy (lateral muscular neurotization). Thirty-five male Wistar rats were evaluated in five groups, including sham control, denervation control, denervation combined with segmentary epineurectomy, direct muscular neurotization, and lateral muscular neurotization. Electromyography, muscle weight measurements, and histological evaluations were performed at postoperative months 2 and 3. The denervation group was statistically successful for denervation as compared with the sham control group for all parameters. The lateral neurotization group was successful in preventing muscle atrophy and gaining reinnervation in electromyographic, histological, and weight parameters. The direct neurotization group was also successful in histological and weight parameters. Lateral muscular neurotization is promising because it does not interrupt the fascicular integrity and is successful in reinnervation; therefore, it seems to be a good alternative for direct muscular neurotization.

Functional Recovery of Completely Denervated Muscle: Implications for Innervation of Tissue-Engineered Muscle

“…31 Therefore, CMAP is dependent on the electrode location, and its recovery does not necessarily indicate recovery of normal muscular function. However, CMAP has been considered a functional indicator in a number of studies, 20,22,24,27,33,34 and our study suggests that this is not the case.…”

“…Many previous studies 19,20,22,23,25,[28][29][30][31][32][33]36,37 did not exclude any effects from uninjured collateral nerves in denervated muscle. In the present study, the common peroneal nerve was implanted into the GM after excision of a 10-mm segment of the tibial nerve and a sensory nerve branch.…”

“…25,30,33 This study is minimally biased based on these factors, because the donor nerve was transplanted immediately after transection of all branches of the recipient's nerve, and the graft was placed close to the native motor endplate zone. However, this model does not address issues that may arise when implanting a 3D muscle construct into the environment of a severe traumatic injury.…”

“…21,22,26,28 Previous studies designed to determine whether functional recovery occurs after nerve transplantation did not investigate endpoints beyond the electrophysiological recovery. 20,22,24,27,33,34 In addition, many preclinical and clinical studies 19,22,23,25,[28][29][30][31][32][33]36,37 did not exclude the possible effects of the presence of uninjured collateral nerves on muscle function and regeneration.…”

“…In patients who lack a distal nerve segment for anastomosis, direct nerve transplantation into the denervated muscle (neurotization) [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] is indicated. This group would include those receiving a transplant of tissue-engineered muscle to repair volumetric muscle loss, because the engineered muscle does not contain host nerve tissue and thus cannot be anastomosed.…”