Objective To investigate the effectiveness and surgical skills of microsurgical repair of radial nerve deep branch injury. Methods Between March 2001 and February 2011, 49 cases of radial nerve deep branch injury were treated by microsurgical technique. There were 40 males and 9 females with an average age of 32 years (range, 19-58 years), including 13 cases of knife-cut injury, 9 cases of electric-saw injury, 7 cases of dagger-stab injury, 6 cases of glass-cut injury, 5 cases of iatrogenic injury, 4 cases of Monteggia fracture, 3 cases of nailgun injury, and 2 cases of crush injury of the forearm complicated by fracture of the proximal radius. The disease duration ranged from 3 hours to 3 years and 8 months (mean, 4.9 months). The sites of injury were at front of supinator tube in 15 cases, in the supinator tube in 23 cases, and at back of supinator tube in 11 cases. One-stage repair was performed by end-to-end suture in 21 cases, including 9 cases of epineurial neurorrhaphy and 12 cases of perineurial neurorrhaphy; two-stage repair was performed in 28 cases, including 26 cases of sural nerve graft and 2 cases of neurolysis. Results Postoperative wounds primarily healed. All patients were followed up 21.5 months on average (range, 12-39 months). At last follow-up, in 21 cases of one-stage repair, the muscle strength of the extensor pollicis longus was level 5 in 13 cases, and level 4 in 8 cases; in 28 cases of two-stage repair, the muscle strength of the extensor pollicis longus was level 5 in 2 cases, level 4 in 21 cases, level 3 in 4 cases, and level 2 in 1 case; and significant difference was found (Z= — 5.340, P=0.000). In 9 cases undergoing epineurial neurorrhaphy at one-stage repair, the muscle strength of the extensor pollicis longus was level 5 in 3 cases, and level 4 in 6 cases; in 12 cases undergoing perineurial neurorrhaphy at one-stage repair, the muscle strength of the extensor pollicis longus was level 5 in 10 cases, and level 4 in 2 cases; and significant difference was found (Z= — 2.279, P=0.023). In 26 cases undergoing nerve graft at two-stage repair, the muscle strength of the extensor pollicis longus was level 5 in 2 cases, level 4 in 20 cases, level 3 in 3 cases, and level 2 in 1 case; in 2 cases undergoing neurolysis at two-stage repair, the muscle strength of the extensor pollicis longus was level 4 in 1 case and level 3 in 1 case; and no significant difference was found (Z= — 1.117, P=0.264). According to the upper arm function assessment criterion issued by Hand Surgery Association of Chinese Medicine Association, the results were excellent in 18 cases, good in 3 cases in one-stage repair patients; excellent in 2 cases, good in 21 cases, fair in 4 cases, and poor in 1 case in two-stage repair patients; and there was significant difference (Z= — 5.340, P=0.000). Conclusion Microsurgical one-stage repair of radial nerve deep branch injury can obtain better effectiveness than two-stage repair by nerve graft, and perineurial neurorrhaphy is significantly better than epineurial neurorrhaphy.
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.
Objective To observe the histomorphology and the biocompatibil ity of acellular nerve prepared by different methods, to provide the experimental evidence for the selection of preparation of acellular nerve scaffold. Methods Forty-eight adult Sprague Dawley rats, male or female, weighing 180-220 g, were selected. The sciatic nerves were obtained from 30 rats and were divided into groups A, B, and C (each group had 20 nerves). The acellular sciatic nerves were prepared by the chemical methods of Dumont (group A), Sondell (group B), and Haase (group C). The effect to remove cells was estimated by the degree of decellularization, degree of demyel ination, and intergrity of nerve fiber tube. The histocompatibil ity was observed by subcutaneous implant test in another 18 rats. Three points were selected along both sides of centre l ine on the back of rats, and the points were randomly divided into groups A1, B1, and C1; the acellular nerve of groups A, B, and C were implanted in the corresponding groups A1, B1, and C1. At 1, 2, and 4 weeks after operation, the rats were sacrificed to perform the general observation and histological observation. Results The histomorphology: apart of cells and the dissolved scraps of axon could be seen in acellular never in the group A, and part of Schwann cell basilar membrane was broken. In group B, the cells in the acellular never were not removed completely, the Schwann cell basilar membrane formed bigger irregular hollows, part of the Schwann cell basilar membrane was broken obviously. But in the group C, the cells were completely removed, the Schwann cell basilar membrane remained intactly. Group C was better than group A and group B in the degree of decellularization, degree of demyel ination, integrity of nerve fiber tube and total score, showing significant differences (P lt; 0.05). The subcutaneous implant test: there were neutrophils and lymphocytes around the acellular nerve in 3 groups at 1 week after implant. A few of lymphocytes were observed around the acellular nerve in 3 groups at 2 weeks after implant. The inflammation was less in groups A1, B1, and C1 at 4 weeks after implant, part of the cells grew into the acellular nerve and arranged along the Schwann cell basilar membrane. The reaction indexes of the inflammational cells in group A1 and group B1 were higher than that in group C1 at 1, 2, and 4 weeks after implant, showing significant differences (P lt; 0.01), but there was no significant difference between group A1 and group B1 (P gt; 0.05). Conclusion The acellular sciatic nerves prepared by Haase method has better acellular effect and the histocompatibil ity than those by the methods of Dumont and Sondell.
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.
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 make a comparison between the effects of the small intestinal submucosa (SIS) graft and the insideout vein graft on repairing the peripheral nerve defects. Methods SIS was harvested from the fresh jejunum of the quarantined pig by curetting the musoca, the tunica serosa, and the myometrium; then, SIS was sterilized, dried and frozen before use. Thirty-six male SD rats were divided into 3 groups randomly, with 12 rats in each group. Firstly, the 10mm defects in the right sciatic nerves were madein the rats and were respectively repaired with the SIS graft (Group A), the insideout autologous vein graft (Group B), and the autonerve graft (Group C). At 6 weeks and 12 weeks after the operations, the right sciatic nerves were taken out, and the comparative evaluation was made on the repairing effects by the histological examination, the neural electrophysiological examination, the computerized imaging analysis, and the Trueblue retrograde fluorescence trace. Results The histological examination showed that the regenerated nerve fibers were seen across the defects in the three groups at 6 weeks after the operations. The nerve fibers were denser, the formed nerve myelin was more regular, and the fibrous tissue was less in Group A than in Group B; the nerve regeneration was more similar between Group A and Group C. At 12 weeks after the operations, the neural electrophysiological examination showed that the neural conductive rate was significantly lower in Group B than in Groups A and C (Plt;0.05),but no statistically significant difference was found between Group A and GroupC (Pgt;0.05); the component potential wave amplitude was not statistically different between Group A and Group B; however, the amplitude was significantly lower in Groups A and B than in Group C (Plt;0.05). At 6 weeks and 12 weeks after the operations, the computerized imaging analyses showed that the axiscylinder quantity per area and the nerve-tissue percentage were significantly greaterin Group A than in Group B (Plt;0.05); the average diameter of the regenerated axis cylinder, the axiscylinder quantity per area, and the nerve-tissue percentage were significantly lesser in Group B than in Group C (Plt;0.05). At 12 weeks after the operations, the Trueblue retrograde fluorescence trace revealed that the positivelylabeled neurons were found in the lumbar 3-6 dorsal root ganglion sections in the three groups. Conclusion The small intestinal submucosa graft is superior to the autologous inside-out vein graft in repairing the peripheral nerve defects and it is close to the autonerve graft in bridging the peripheral nerve defects. Therefore, the small intestinal submucosa is a promising biological material used to replace the autonerve graft.
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.
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 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.
The sciatic nerves of adult rats were sectioned bilaterally and the ends of the nerves were placed in silicone tubes. One side of the distal nerve segment was inverted and that of the contralateral side was non-inverted. After 2, 4, 6 weeks, the rats were killed and the specimens were removed for macroscopic, histologic and morphometric analysis. The results showed that either the inverted or non-inverted distal nerve segments had no influence on the number of the myelinated axons in the regenerated nerves, but the number and density of the myelinated axons was markedly diminished in the inverted distal nerve segments.