Primary Study Of Effect On Chitosan Nerve Conduits In Peripheral Nerve Regeneration

Objective:Chitosan are natural biodegradable materials, the application of chitosan nerve conduit repair of nerve defects has become a hot research nerve graft in recent years. The experimental application of chitosan the rabbit tibial nerve conduit repair of nerve defect, to observe its effect on nerve regeneration. Experimental Materials and Methods:1, Preparation of Chitosan nerve conduit: catheter length 15mm, diameter of about 2mm, wall thickness of 0.2mm, with a special process by the Chinese Academy of Sciences, Changchun Institute of Applied Chemistry, Polymer Engineering Laboratory made their own R & D, has a good histocompatibility and plasticity, can be completely degraded.2. Animals of division and surgical methods: six experimental rabbits, considerable weight, male and female informal, is divided into three groups of two experimental groups to chitosan nerve conduit bridging (A Group), to tibial nerve defect model for the negative control (B group), to end-to-end nerve stump with a direct line for the positive control (C group), intramuscular narcotic anesthetic compound (0.03ml/kg). Rabbit sciatic nerve under the piriformis hole that is divided into tibial nerve and common peroneal nerve, sterile conditions, the right side of exposing rabbit tibial nerve under the piriformis hole after about 10mm below the cut tibial nerve Department, after the formation of neural retraction of about 10mm gap, the experimental group of non-invasive with 9-0 nylon suture to 12mm nerve conduit wall and outer membrane tibial nerve, respectively, the two ends to 4-pin 90°suture the two nerve ends were inserted into the appropriate catheter about 1.0mm. 10mm negative control group of nerve defect exclusion will be used for treatment. Positive control group after the cut tibial nerve with 9-0 nylon suture noninvasive tibial nerve on the two ends directly to the outer membrane 90°end-to-end suture anastomosis needle 4. Each group after surgery suture the skin, sub-cage rearing. Observation period is 12 weeks.3. Outcome measures: The postoperative wound healing in rabbits, limb and foot ulcers, the observation period after the end of Act ibid Postanesthesia cut from the original incision and exposed the tibial nerve, tibial nerve and the catheter to observe the general shape, line Detect neuroelectrophysiological remote nerve injury repair any nerve action potential and muscle contraction and nerve stump line from HE stained specimen observation. Analysis of nerve regeneration.Results:1.General observation and electroneurophysiological examinationAfter one week: three groups of rabbits wereⅠincision healing, limb claudication, foot was outside the booth; four weeks: three groups of rabbits in varying degrees of ankle and foot swelling and ulcers, particularly defect group, is still limping; 8 week: three groups of rabbits foot ulcers have healed, but more defects happen ulcer group; 12 weeks: the experimental group and the positive control group, less limp rabbit, a serious defect group is still limping. After 12 weeks, animals were anaesthetized from the original incision after the incision and exposed the tibial nerve and can be seen the experimental group thinned nerve conduit to soften significantly degrade absorption, with good connections at both ends of nerves, nerve morphology as same as the pre-operative, to connect Department through the nerve fibers can be seen, with the surrounding tissue adhesive, can be seen around a small amount of granulation tissue hyperplasia. Defect group of connective tissue proliferation defect can be seen, the formation of pseudo-neuroma. See the direct suture group of nerve fibers connecting good shape slightly rough than normal nerve ends and no granulation tissue formation of neuroma. Nerve stimulation electrode electrophysiological testing experimental group and the direct suture group shows that renewable regenerative nerve innervation of the anterior tibial muscle contraction; defect group anterior tibial muscle contraction.2. Nerve stump HE stained specimen observation.Experimental group defect rich capillary regeneration of nerve fibers, axons neatly arranged, form a complete bundle of nerve fibers, but the small nerve fibers than normal, showing proliferation of granulation tissue. Direct suture group intensive axon regeneration of nerve fibers, neatly arranged, coarse fibers, blood vessels small, no granulation tissue. Defect group in addition to the proximal tibial nerve has a small amount of recycled fiber, the connective tissue defect imposed mainly distal nerve stump to shrink significantly, the scarcity of nerve fibers.Conclusion:1. Chitosan nerve conduit can tibial nerve axon regeneration along the lumen from the proximal to the distal long to achieve the guidance and the purpose of promoting nerve regeneration, regeneration of tibial nerve function;2. The local inflammatory response caused by Chitosan nerve conduit that may affect the nerve fiber regeneration, the need to further examine ways to improve.