Objective o study the feasibility of homologous vascularized nerve transplantation after ultra deep cryopreservation. Methods Vascularized sciatic nerve from 12 female dogs was transplanted after ultra deep cryopreservation. Fortyeight male dogs were divided into 4 groups: ultra deep cryopreservation homologous vascularized nerve (group A), ultra deep cryopreservation homologous nerve (group B), fresh homologous vascularized nerve (group C), and fresh autologous vascularized nerve (group D). The gross appearance, patency rate of arteryand morphological transplanted nerve were observed 1, 4 and 12 weeks after transplantation respectively. Immunological analysis was performed using IL 2 assay and T lymphocyte subpopulations assay after 4 weeks. Image pattern analysis andelectromyogram were observed after 12 weeks. Results In groups A and D, no toe ulcer occurred, the atrophy of later limb and the sense of pain from skin of calf were restore significantly in the postoperative 12th week. In groups B and C, toe ulcer occurred, the atrophy of later limb and the sense of pain from skin of calf were not restored significantly in the postoperative 12thweek. The vessel patency rate of groups A and D was 83.3%, which was significantly higher than that of group C (50%,Plt;0.05). The changes of IL2 and Th, Ts in group C were significantly higher than that in groups A,B,D(Plt;0.01). There were increased vessel and regenerated nerve in transplanted nerve under optical microscope and image pattern analysis in groups A and D. There were shorter latent period of motor evoked potential, greater amplitude of action potenlial and faster motor nerve conducting velocity in groups A and D after 12 weeks. Conclusion The antigenicity of the homologous never and vessel may be reduced significantly by being frozen, and cryopreserved vascularized nerve can transferred successfully without the use of immunosuppressive agents. Vascularized nerve may restore good significantly for the thick nerve.
Objective To investigate the appropriate concentration of tripterygium wilfordii and immunological rejection of rats’ sciatic nerve allograft with the tripterygium wilfordii’s pretreatment so as to explore tripterygium wilfordii’ s suppression. Methods Sixty SD rats (male, weighing 270-290 g), as sciatic nerve allograft acceptor were randomized into5 groups (groups A, B, C, D and E, n=12). To repair the sciatic nerve defect of SD rats, the Wistar rats’ sciatic nerve allografts about 15 mm long were used with 24 hours’ soak of different concentrations of tripterygium wilfordii (group A: 200 mg/L, group B: 400 mg/L, group C: 800 mg/L). The control groups (group D: the fresh sciatic nerve allograft from donors; group E: the fresh sciatic nerve allograft from themselves) were establ ished. At different time points after operation, the morphological examinations (the observation of histology, l ight microscope, electron microscope), the detection of myelin basic protein’s (MBP) content and the analyses of CD4+ and CD8+ T cells on the allografts in the acute phase were performed Results There was no significant difference in morphology among groups A, B and C, the adhesions between allografts and connective tissue were milder than that of group D, and the allografts’ morphous and the inflammatory cell infiltration were better than that of group D. The degeneration of myel in sheath was observed at different levels and there was no significant difference between group B and group E (P gt; 0.05). There was a significant difference in immunological rejection between groups A, B, C and group D (P lt; 0.05). Conclusion Tripterygium wilfordii can effectively suppress the acute immunological rejection in the early stage after operation, and protect the myel in sheath to a certain extent.
Objective To explore the effect of tri pterygium glycoside (TG) on the skeletal muscle atrophy and apoptosis after nerve allograft. Methods Twenty Wistar male rats were adopted as donors, weighing 200-250 g, and the sciatic nerves were harvested. Fifty SD male rats were adopted as recipients, weighing 200-250 g. Fifty SD rats were made the models of10 mm right sciatic nerve defect randomly divided into five groups (n=10): group A, group B, group C, group D and group E.groups A and B received fresh nerve allograft, groups C and D received sciatic nerve allograft pretreated with TG, and group E received autograft. The SD rats were given medicine for 5 weeks from the second day after the transplantation: groups A and E were given physiological sal ine, groups B and D TG 5 mg/ (kg·d), and group C TG 2.5 mg/ (kg·d). At 3 and 6 weeks, respectively, after nerve transplantation, general observation was performed; the structure of skeletal muscles was observed by HE staining; the diameter of skeletal muscles was analyzed with Image-Pro Plus v5.2; the ultrastructure of skeletal muscles was observed by TEM; the expressions of Bax and Bcl-2 were detected by immunohistochemical staining; and the apoptosis of skeletal muscles was detected by TUNEL. Results All rats survived to the end of the experiment. In general observation, the skeletal muscles of SD rates atrophied to different degrees 3 weeks after operation. The muscular atrophy in group A was more serious at 6 weeks, and that in the other groups improved. The wet weight, fiber diameter and expression of Bcl-2 in group A were significantly lower than those in groups B, C, D and E (P lt; 0.01)；those in groups B, C and D were lower than those in group E (P lt; 0.05); and there were no significant differences among groups B, C and D (P gt; 0.05). The apoptosis index and expression of Bax in group A were significantly higher than those in groups B, C, D and E (P lt; 0.01)；those in groups B, C and D were higher than in groupE (Plt; 0.05); and there were no significant differences among groups B, C and D (P gt; 0.05). Three weeks after nerve allograft, under the l ight microscope, the muscle fibers became thin; under the TEM, the sarcoplasmic reticulum was expanded. Six weeks after nerve allograft, under the l ight microscope, the gap of the muscle fibers in group A was found to broaden and connective tissue hyperplasia occurred obviously; under the TEM, sarcomere damage, serious silk dissolution and fragmentary Z l ines were seen in group A, but the myofibrils were arranged tidily in the other groups, and the l ight band, dark band and sarcomere were clear. Conclusion TG can decrease the skeletal muscle atrophy and apoptosis after nerve allograft. The donor’s nerve that is pretreated with TG can reduce the dosage of immunosuppressant for the recipient after allograft.
Since Ⅰ982, Twenty-five cases of birth injuries of brachial plexus have been treated by microsurgical technipue. The satisfactory result has been obtained. The excellent and good rate are 76 per cent. The operative method included endoneurolysis, anastomosis of nerve, supraclavicular nerve grafting and transposition of phrenic nerve, accessory nerve and cervix motor nerve. In this article, the early diagnosis and differentiel diagnosis, practical physical examination method, and operative technipue were descused.
Objective To investigate the research advance in repair of the peripheral nerve defect with an acellular nerve allograft. Methods The recent related literature was extensively and comprehensively reviewed. The methods and the effects of the allografts with acellular nerves were analyzed. Results The immunogenicity of the allograft was more significantly relieved by the chemical treatment than by the physicaltreatment. The effect of the chemical treatment on the axon regeneration was better than that of the physical treatment. Conclusion Because of the limitation of the host Schwann cell translation in the longsegment acellular nerve allografts, the effect of Schwann cells is not satisfactory and regeneration of the nerve is limited. So, the recellularized treatment with some related measures can enhance the host Schwann cell translation so that this problem can be solved.
A 0.6cm segment of right common peroneal nerve was resected in 60 SpragueDawley rats. The nerve defects were bridged by adhering the epineurium with autogenous nerve, vein, skeletal muscle, tendon and silastic tube. According to the kinds of the grafts used, the rats were divided into 5 groups. In 6 and 12 weeks after operation, the effect was assessed by motor nerve conduction velocity, weight of the anterior tibial muscle, number of distal axons and histological examination. It was demonstrated that the result from autogenous nerve graft was superior to other grafts in all aspects and that of the vein graft was better thanthe other three. The characteristics of the nerve regeneration and the process of maturation in different types of the grafts were discussed. The related microenvironment which caused the difference was also discussed.
Objective To study an effect of the peripheral nerve allograft with subcutaneous preservation at different times on the sciatic nerve regenerationin rats. Methods Fifty-five Wistar rats were used in this experiment, which were randomly divided into the following 5 groups: the experimental groups (Groups A, B, C, 10 rats), the control group (Group D, 10 rats), and the donorgroup (Group E, 15 rats). In the experimental groups, a 15-mm segment of the sciatic nerve harvested from the donors was separately inserted into the subcutaneous compartment on the left thigh after the 1week (Group A), 2-week (Group B), and 3week (Group C) preservation; the segment of the sciatic nerve in the subcutaneous compartment was removed and transplanted into a 10-mm defect of theright sciatic nerve, which was made immediately. In Group D, a 10-mm sciatic nerve defect was made and immediately repaired in situ on the right thigh. The function of the sciatic nerve was evaluated by the sciatic functional index (SFI) at 2, 4, 6, 8, 10 and 12 weeks after operation. The histological and electrophysiological examinations were performed at 12 weeks after operation. Results After operation, SFI decreased gradually at 12 weeks afteroperation, SFI inGroups A and D was at the minimal level and had a significant difference compared with that in Groups B and C (Plt;0.05).There was no significant difference between Group A and Group D. A large number of the myelinated nerve fibers and a small number of the unmyelinated nerve fibers were regenerated in Groups A and D. The number and the structure of the regenerated nerve were similar to the normal ones. The number and the size of the regenerated axon had a significant difference compared with those in Groups B and C (Plt;0.05). There was no significant difference between Group A and Group D. The conduction velocity and the latent period of the motor nerve had significant differences between Groups A and D and Groups B and C (Plt;0.05), and there was no significant difference betweenGroupA and Group D. Conclusion The nerve allograft with a 1-weeksubcutaneous preservation can promote nerve regeneration better.
Objective To observe the revascularization process of transplanted nerve after transplantation of long nerve and accompanying peri pheral vessels, to investigate its relationship with nerve regeneration. Methods The mediannerve defect models of the left forelimb (3 cm in length) were made in 60 New Zealand rabbits (aged 6-8 months, weighing 2.0-2.5 kg, and male or female), which were randomly divided into 2 groups (n=30). In situ anastomosis of the median nerves was performed in the control group; in situ anastomosis of the median nerves was made in parallel to the surrounding elbow veins, the transplanted epineurium and the adventitia were sutured with nerve anastomosis l ine in the experimental group. After operation, the gross observation, electrophysiological testing, and histopathology observation was performed at 1, 2, 4, 8, and 12 weeks, and transmission electron microscope at 12 weeks to observe the revascularization of nerve grafts, nerve fiber regeneration, and functional recovery. Results In the experimental group, revascularization was observed at 1 week after operation, and the degree of revascularization was significantly higher than that in the control group at 2, 4, 8, and 12 weeks. At 8 and 12 weeks, the nerve fiber regeneration speed, quality, and quantity in the experimental group were better than those in the control group. At 2, 4, 8, and 12 weeks, the nerve conduction velocities were (10.32 ± 0.94), (13.14 ± 1.22), (22.68 ± 1.16), and (24.09 ± 1.27) m/ s respectively in the experimental group, and were (9.18 ± 1.07), (11.12 ± 1.03), (19.81 ± 1.37), and (20.67 ± 1.19) m/s in the control group, showing significant difference at 12 weeks after operation (t=3.167, P=0.001). At 12 weeks in the experimental group, the myel in sheath had similar size, less sheath plate delamination, normal Schwann cells and rich organelles, in which normal microfilaments, microtubules and axonal mitochondria were observed; axonal mitochondria had clear crestfilm and no swelling and vacuolization, and the neurofibrils basically became normal. The myelinated nerve fibers area, myelin thickness, and axon diameter were (5.93 ± 0.94) mm2, (0.72 ± 0.12) μm, and (3.12 ± 0.12) μm respectively in the experimental group, and were (5.28 ± 0.72) mm2, (0.65 ± 0.09) μm, and (2.98 ± 0.16) μm respectively in the control group, all showing significant differences (t=3.736, P=0.002; t=3.271, P=0.002; t=4.533, P=0.001). Conclusion The transplanted nerves in parallel to large blood vessels can promote angiogenesis of the transplanted nerve, and accelerate the regeneration and functional recovery of the nerves.