Peripheral Nerve Repair Using An H-shaped Nerve Regeneration Chamber In Rats

Objective : This research refer to the mechanism of chemotaxis chemotropism,chooses the saphenous nerve as the sensory branch,similar diameter of femoral nerve muscular branches as motor branch.The design of H-shaped tube as the nerve regeneration chamber,Which were used to make the rat model of sensory and motor nerve sheath,To explore the tendency of the chemotaxis chemotropism by observing the nerve regeneration.Methods: In this study,Using H-shaped nerve regeneration chamber,creating a relatively independent micro-environment.First,make "H" shaped nerve conduits,Choose a silicone tube about 5 mm long,4 mm in diameter,respectively on both ends set into two thin silicone tube about 2mm in diameter,between the two groups of thin silicone tube keep about2 mm gap.Then established the animal model of peripheral nerve injury.The effect of H-type nerve regeneration chamber / catheter on motor and sensory nerve regeneration after peripheral nerve injury was further studied.The use of H-shaped nerve regeneration room,we can effectively create a different type of nerve tissue are not affected by the inter-catheter micro-environment.The choice of 60 female Wistar rats(weight 200g-250g),each of a group of 15,were randomly divided into 4groups,Near the inguinal levels we find saphenous nerve,and Select similar diameter of motor branch of femoral nerves,each rat saphenous nerve and femoral nerve cut from the middle,using H-shaped tube design,nerve growth chamber,according to the different connectionmode and the gap(small gap distance was 2mm),A-sensory-motor small gap bridging para-position group;B-,sensory-motor small gap bridging cross group;C-sensory-motor relative anastomosis group;Dsensory-motor cross anastomosis group.6 weeks after operation,Nerve electrophysiological parameters(mainly Amp and CV)were performed firstly,and compare the electrophysiological indexes(Amp and CV),researched the degree of functional recovery of sensory nerve and motor nerve in every groups.Put all the rats to death,Probed experiment site,exposure,H-shaped nerve regeneration chamber,And cut open the silicone tube,General observation were performed on every groups of anastomotic site.Taking specimens from the H-shaped chamber,HE staining,acetylcholinesterase histochemical staining,toluidine blue staining,Marsland-Luxolfastblue(LFB)double staining were performed in every specimens.By the HE staining,We can obserb The continuity of nerve fibers,arrangement and The number and density of nerve fibers.By the acetylcholinesterase histochemical staining,We can learn the degree of nerve repair in each groups by The expression of acetylcholinesterase.By the toluidine blue staining,observed Distribution and myelin sheath of medullated nerve fiber ? By the Marsland-Luxolfastblue(LFB)double staining : We learned the Arrangement,direction,and distribution of regenerating fibers.The electron microscope were used at observing number of regenerated nerve fiber,diameter and myelin thickness on each groups.All the indexes were analyzed statistically.Results:After the operation,suture of wound of rats,feeding for 6 weeks.Firstly,we used electrophysiological methods to compare the nerveconduction velocity and amplitude.In particular,nerve regeneration in group A and group C was significantly better than that in group B and D after nerve regeneration.the recovery of group B was better than that of group D.There were no statistical differences between group A and C.This finding is consistent with the studies using histological methods.Put all the rats to death,Probed experiment site,exposure,H-shaped nerve regeneration chamber,And cut open the silicone tube,General observation were performed on every groups of anastomotic site.The results showed that,The diameter of regenerating fibers in A group Similar to normal,healthy nerve.Renewable parts without neurological tumor growth and inflation caused by hyperplasia,Mild adhesion were observed in anastomosis.In B group,there are areadhesios between sensory nerve and motor nerve.The diameter of regenerating fibers are inferior to normal,healthy nerve.,sensory nerve and motor nerve were separable.In C group,There are swelling growth in anastomosis.there areadhesios between sensory nerve and motor nerve.In D group,There are serious swelling growth in anastomosis,And serious areadhesios between sensory nerve and motor nerve.sensory nerve and motor nerve were difficult to separate.After operation,respectively were observed and recorded the following indicator.The nerve fibers and the myelin sheath of the H-shaped tube were observed by various staining.The nerve fiber regeneration was observed in group A,B and C.Although the nerve fiber diameter and myelin sheath thickness of group B were slightly inferior to group A and C Group,but the difference was not statistically significant,B group is still visible continuous regeneration of nerve fibers,intact myelin and axon.The results showed that the proximal motor nerveregeneration in group B tends to distal motor nerve,showing cross-growth.This study further confirmed the existence of tissue-specific neurotropic growth,and proved the existence of neurotropic growth anatomical specificity and end organ specificity.At the same time,we preliminarily proved that the H-shaped nerve conduit plays an important role in motor nerve regeneration.Conclusion : In H-shaped nerve regeneration chamber,Sensory fiber beam tends to sensory nerve fibers distal growth,motor nerve fiber bundles tends to motor nerve fiber growth direction.Combined with the longitudinal section of fiber cross to prove that the nerve bundle has specific function.In the aspect of nerve regeneration,para-position small gap bridging is better than cross small gap bridging.And we also find that there were no statistical differences between small gap bridging and directly sutured.This test proved topographic specificity and end organ specificity in nerve regeneration.