Fetal nerve grafts preserved at deep breezing were used to repair the peripheral nerve defects. The nerve directs included the sural nerves (removed as the donor nerve in repairing other nerve defects) in 5 cases, and digital nerve in 2 cases. All of them got good sensitive function. Patients were followed up for 1 yeas, all patients had gained comparatively good sensation. The surgical technique was introduced, and the validity of the transplantation of fetal nerve was discussed.
Objective To make a histological evaluation of poly(dextrogyr-levogyr)lactide acide-triiodothy-ronine (PDLLA-T3) in sciatic nerve defect of rat. Methods Ninety SD rats were evenly divided into 3 groups (autograft group A, PDLLA-T3 group B and PDLLA group C). Group D was control group. The left sciatic nerves were cut off by operation and 1 cm-nerve-defect was set up. The specimens were collected 2 weeks,1 month and 2 months after the operation respectively, simultaneously the right sciatic nerves were collected as normal control group D. HE stainning, electron microscope, S100 immunohistochemistry, and Bielschowsky staining were done in all the specimens, the quantity and quality of the regenerated nerves were observed, and all the results were processed by image analyzer.Results Two weeks after the operation,histological observation indicated that the materials in groups B and C were not completely degraded. Transmission electron microscopic observationshowed that the myelin sheath was not thick and it was about 0.5 μm in thickness. There was no significant difference among the 3 groups. One month after theoperation, histological observation indicated that in group A the regenerated nerves passed through the scaffold and in the new nerves there were regenerated blood vessels. The materials in groups B and C were not completely degraded. S-100 immunohistochemical observation and Bielschowsky staining showed that in groupB PDLLA-T3 repaired the defect successfully and the regenerated nerve myelinsheath was 1.81±0.19 μm in thickness. The effect in group B was better thanthat of groups A and C (P＞0.05). Two months after the operation, the materials in groups B and C were completely degraded. The quantity of the regeneratednerves in group B confirmed by S-100 immunohistochemical observation and Bielschowslcy staining was more than that in group C(P＜0.05) and close to that in group A. The regenerated nerve myelin sheath in group B was 2.15±0.27 μm in the thickness and was thicker than that in group C (P＜0.05)， but thinner than that in groups A and D (P＜0.05). Conclusion PDLLA-T3 can repair the defect of rat sciatic nerve with satisfactory quantity andquality of regenerated nerves.
To find new technique for repair of peripheral nerve defect, the nerve elongation repair technique was adopted. Two cases with nerve defect were treated by this method. One was a 12 year old male, the defect length of right radial nerve was 7.2 cm at the elbow. The other one was a 28 year old male, the defect length of left ulnar nerve the was 5 cm at elbow. In this method, the nerve was elongated by slow stretch from distal and proximal end of the ruptured nerve. After a few days, the nerve was repaired by direct suture. After operation, the function of nerves were recovered in 119 days and 114 days respectively. Follow-up for 5 years, the function of the effected limbs were recovered to the normal side. It was concluded that: (1) the peripheral never can be elongated by slow stretch; (2) to stretch the nerve end in a rubber tube can prevent adhesion and connective tissue blocking; (3) strength and supporting point of stretching should be designed carefully.
Basing on the experimental results, 48 nerve defects (with the length of 3-4 cm in 21 cases, 4.1-5cm in 25 cases and 6cm in 2 cases) were repaired clinically by using vaseularized nerve sheath canal with living Schwann s cells, 87.5 percent of them obtained good results. The advantages were: (1) The neural sheath had rich blood supply with resultant less scar from its healing; (2) The living Schwann s cells would secrete somatomedin to promote the reproduction of neural tissues; and (3) The useless neurofib...
Ten, fifteen and twenty millimeter nerve defects were produced on both trunks of sciatic nerve in 18 rabbits. The stumps of the nerve were enclosed by a silicon tube in the right hind limb (slilcon group) and the left limbs were free (free group). The proximal and distal nerve stumps in both groups were elongated by using a selfdesigned nerve stretching device, and the nerve were gradually stretched by 1mm, 2mm and 3mm per day respectively. when the expected lengths were achieved, the defects of the nerve were managed by endtoend coaptation. The samples were analysed by electrophysiological examination, and light and electron microscopes. Results were as follows: (1) The nerve defect could be repaired by gradual elongation in rabbits; (2) The results of silicon group were superior to the free group; (3) The structure and microcirculation of the nerve would be damaged if the stretching speed exceeded the limit of 2mm per day. But the eventual results following repair by elongation could not reached the normal level.
To observe the effect of allogenic transplantation of deep frozen nerve in repairing sensory nerve defect, 22 patients who had received this type of treatment were followed up for 0.5-5 years. There were 18 males and 4 females in this group, and the average age was 28 years old. Thirty-six nerve defects including the common volar digital nerve, proper volar digital nerve were repaired by allograft of nerves stored at deep frozen (-80 degrees C). The storation period was ranged from 9 days to 1 years. The length of the nerves were 2 cm-12 cm. After follow-up for 3 years (ranged from 7 months-5 years), 23 cases of nerve allograft obtained excellent and good results (63.9%), 10 cases were fair (27.7%) and 3 cases were poor (8.3%). It was concluded that (1) frozen nerve is one of nice materials for repairing the nerve defect (lt; 5 cm); (2) the immunity of allogenenic nerve is weak; (3) the deep frozen storation can reduce the immunity of nerve; (4) the dimethyl sulfoxide can prevent the nerve tissue from injury by deep frozen; (5) the best temperature and period for deep frozen storation should be studied further.
OBJECTIVE: To study the effect of subcutaneous implant of peripheral nerve allograft on sciatic nerve regeneration in rats. METHODS: Out of 30 male Wistar rats, 6 were donors and 24 were divided randomly into 2 groups. In experimental group (group A, n = 12), a 15 mm segment of sciatic nerve harvested from donors was separately inserted into subcutaneous compartment on the right thigh; two weeks later, the segment of sciatic nerve in subcutaneous compartment was removed and transplanted into a 10 mm sciatic nerve defect of left, which was made immediately. In the control group (group B, n = 12), a 10 mm sciatic nerve defect was made and immediately repaired in situ on the left thigh. The regeneration of sciatic nerve was examined histologically (after 2, 4, 8, and 14 weeks) and electrophysiologically (after 14 weeks of operation). RESULTS: After 2 weeks of operation, the inflammatory reaction was a little ber in group A than in group B. After 4 weeks, the intensity of the inflammatory reaction was similar between two groups; some collagen fibers proliferated. After 8 weeks, the inflammatory reaction ended and the collagen fibers proliferated obviously. After 14 weeks of operation, the structure of epineurium was in integrity and there was no obvious difference in perineurium and endonurium between two groups. A large number of myelinated nerve fibers and a small number of unmyelinated nerve fibers regenerated. The structure of myelin sheath was in integrity. The number and size of regenerated axon had no significant difference between two groups(P gt; 0.05). The conduction velocity, the peak value and the latent period of motor nerve were no significant difference between two groups (P gt; 0.05). CONCLUSION: The allograft of sciatic nerve inserted into subcutaneous compartment can promote nerve regeneration.
ObjectiveTo summarize the applications of Schwann cells (SCs), stem cells, and genetically modified cells (GMCs) in repair of peripheral nerve defects. MethodsThe literature of original experimental study and clinical research related with SCs, stem cells, and GMCs was reviewed and analyzed. ResultsSCs play a key role in repair of peripheral nerve defects; the stem cells can be induced to differentiate into SCs, which can be implanted into nerve conduits to promote the repair of peripheral nerve defect; genetically modified technology can enhance the function of SCs and different stem cells, which has been regarded as a new option for tissue engineered nerve. ConclusionAlthough great progress has been made in tissue engineered nerve recently, mostly limited to the experimental stage. The research of seed cells in application of tissue engineered nerve need be studied deeply.
ObjectiveTo investigate the effect of electrospun chitosan/polylactic acid (ch/PLA) nerve conduit for repairing peripheral nerve defect in rats. MethodsNerve conducts loaded with ch/PLA was made by the way of electrospun. The mechanical property, hydrophility, biocompatibility were tested, and the scanning electron microscope was used to observe the ultrastructure. The same experiments were also performed on pure PLA nerve conducts as a comparison. Then, 54 Sprague Dawley rats were divided into 3 groups randomly, 18 rats in each group. Firstly, the 10 mm defects in the right sciatic nerves were made in the rats and were respectively repaired with ch/PLA (group A), autografts (group B), and no implant (group C). At 4, 8, and 12 weeks after operation, general observations, sciatic functional index (SFI), electrophysiological evaluation, wet weight of gastrocnemius and soleus muscles, histological examination, immunohistological analysis, and transmission electron microscopy were performed to evaluate the effects. ResultsCompared with pure PLA nerve conducts, the addition of chitosan could improve the mechanical property, hydrophility, biocompatibility, and ultrastructure of the nerve conducts. At 4 weeks postoperatively, the regenerated nerve bridged the nerve defect in group A. The SFI improved gradually in both group A and group B, showing no significant difference (P>0.05). Compound muscle action potentials and nerve conduction velocity could be detected in both group A and group B at 8 and 12 weeks after operation, and significant improvements were shown in both groups (P<0.05). The wet weight and myocyte cross section of gastrocnemius and soleus muscles showed no significant difference between group A and group B (P>0.05), but there was significant difference when compared with group C (P<0.05) at 12 weeks postoperatively. Immunohistological analysis revealed that S-100 positive Schwann cells migrated in both group A and group B, and axon also regenerated by immunohistological staining for growth associated protein 43 and neurofilaments 160. Transmission electron microscopy showed no significant difference in the diameter of nerve fiber between group A and group B (P>0.05), but the thickness of myelin sheath in group A was significantly larger than that in group B (P<0.05). ConclusionThe electrospun ch/PLA nerve conduits can effectively promote the peripheral nerve regeneration, and may promise an alternative to nerve autograft for repairing peripheral nerve defect.