Experimental study on the efficacy of a hybrid artificial nerve: The hot dog method

Introduction: We hypothesized that hybrid artificial nerves might overcome the limitations of a nerve conduit by isolating nerve fascicles from autologous nerves. Nerve sacrifice during harvest, a drawback of conventional autologous nerve transplantation, may be reduced by the hot dog method. The hot dog method (based on the morphology of hybrid artificial nerves) adds nerve conduits to autologous nerve fascicles. Methods: Forty-eight rats with a 10-mm sciatic nerve defect were divided into six groups ( n = 8 per group) according to the neural reconstruction method: autologous nerve transplantation, the hot dog method, nerve conduit, nerve fascicle transplantation, sham control, and nerve fascicle isolation were classified as Groups I, II, III, IV, V, and VI, respectively. The sciatic nerve function was assessed in these groups, a histological evaluation was performed, and statistical analyses were conducted based on these data. Results: Group III (nerve conduit) and Group IV (nerve fascicle transplantation) showed the lowest functional and axonal regenerative effects, followed by Group II (hot dog method) and Group I (autologous nerve transplantation). Group VI (nerve fascicle isolation) tended to achieve better recovery in motor function and axonal regeneration than Group I (autologous nerve transplantation). Conclusions: The hot dog method is simple, safe, and easy to execute. This method can serve as a new neural reconstruction method that uses artificial nerves.

Long-Term Outcome of Sciatic Nerve Regeneration Using Bio3D Conduit Fabricated from Human Fibroblasts in a Rat Sciatic Nerve Model

Previously, we developed a Bio3D conduit fabricated from human fibroblasts and reported a significantly better outcome compared with artificial nerve conduit in the treatment of rat sciatic nerve defect. The purpose of this study is to investigate the long-term safety and nerve regeneration of Bio3D conduit compared with treatments using artificial nerve conduit and autologous nerve transplantation. We used 15 immunodeficient rats and randomly divided them into three groups treated with Bio3D ( n = 5) conduit, silicon tube ( n = 5), and autologous nerve transplantation ( n = 5). We developed Bio3D conduits composed of human fibroblasts and bridged the 5 mm nerve gap created in the rat sciatic nerve. The same procedures were performed to bridge the 5 mm gap with a silicon tube. In the autologous nerve group, we removed the 5 mm sciatic nerve segment and transplanted it. We evaluated the nerve regeneration 24 weeks after surgery. Toe dragging was significantly better in the Bio3D group (0.20 ± 0.28) than in the silicon group (0.6 ± 0.24). The wet muscle weight ratios of the tibial anterior muscle of the Bio3D group (79.85% ± 5.47%) and the autologous nerve group (81.74% ± 2.83%) were significantly higher than that of the silicon group (66.99% ± 3.51%). The number of myelinated axons and mean myelinated axon diameter was significantly higher in the Bio3D group (14708 ± 302 and 5.52 ± 0.44 μm) and the autologous nerve group (14927 ± 5089 and 6.04 ± 0.85 μm) than the silicon group (7429 ± 1465 and 4.36 ± 0.21 μm). No tumors were observed in any of the rats in the Bio3D group at 24 weeks after surgery. The Bio3D group showed significantly better nerve regeneration and there was no significant difference between the Bio3D group and the nerve autograft group in all endpoints.

Az autológ idegtranszplantátumok helyett alkalmazott módszerek a kéz idegsérüléseinek helyreállításában

For a long time in the clinical practice the autologous nerve transplants are used in reconstruction of the segmental defects of injured hand nerves. The published outcomes, especially in case of the motor and mixed (sensory and motor) nerves, however, were not satisfactory. Hence, it remained a problem and in the focus of research. The author aimed to study this topic and drawing conclusions in his literary review publication. According to the recent results, the replacement of the autologous nerve transplants with other materials (e.g. nerve conduits, various allografts, etc.) has shown good outcomes in mixed nerves too, if the distance of the resected nerve ends do not exceed 6 mm and the diameter of the nerves were not more than 3–7 mm. The applications of these methods have shown poor results, if the defect and/or the nerve diameter were larger. So, in these cases the autologous nerve transplantation remains the optimal management in the future. Orv Hetil. 2017; 158(30): 1163–1167.