An Experimental Study On The Application Of MMC And TAA To Prevent Postoperative Epineural Scar Formation After Peripherial Nerve Entrapment In Rats

Objective: Peripherial nerve entrapment have long been a common clinical problem. With the development of microsurgical technique,the reparation and regeneration of peripherial nerve after peripherial nerve entrapment are perfect increasingly.However,Perineural scarring is one of the factors affecting the clinical results in peripheral nerve surgery. This phenomenon causes tethering of peripheral nerves, which restricts nerve mobility during limb movement. Tethering of nerves, which if severe and prolonged, can give rise toischemia and further nerve injury. Reduction of perineural scar formation not only might improvethe outcome after peripheral nerve surgery but also would facilitate secondary operation and thereby decrease the risk of complications.Mitomycin C (MMC), a well known chemotherapeutic agent, is also a widely used topical agent in the field of ophthalmology for preventing postoperative fibrosis, especially in strabismus surgery, glaucoma filtering surgery, photorefractive keratectomy, and radical keratotomy. In addition, aprevious experimental study showed that MMC was effective in preventing postlaminectomy fibrosis. Previous studies have demonstrated that MMC inhibits fibroblastic proliferation and reduces fibroblast collagensynthesis.So the mechanism of MMC effects in promoting peripheral never reparation and regeneration, and then to provide theoretical basis for clinical applications, it was performed by anatomical, light and electron microscopic observations, morphometric analysis, electrophysiological assessment and immunochemical staining in Mackinnon's model of Wistar rats.Methods: Seventy-two adult female Wistar rats weighing 230–250 g (n=18)were performerd experimentally on rats sciatic nerve models designed by Mackinnon, after the sciatic nerve in 72 Wistar rats were compressed for 12 weeks, the rats were divided randomly into 4 grous during externalneurolysis ,and the following drugs were injected around the epineurium topically after external neurolysis:in group A (control group)only sodium chloride 0.2mL was placed, in group B Triamcinoloni Acetonidi Acetatis(TAA) 0.4 mg /0.2 ml was injected topically, in group C MMC 0.04 mg /0.2ml was placed; The group D is associated drug group : MMC0.02mg/0.1 ml plugs TAA0.2mg/0.1 ml.At the 2^nd, 4^th and 8^th week postoperation, the samples were observed by anatomical, light microscope observation .and at different times postoperation, electrophysiological assessment was conducted to measure the latency, nerve conduction velocity and amplitude of compound muscle action potentials, at the same time the SFI index were analyzed. All dates were analyzed statistically.At the 8^th week postoperation, the samples were observed by electron microscope observation, and the content and distribution of collagen in sciatic nerves were observed with both conventional light and polarization microscopy combined with morphometric analysis and picrosirius-red staining.Results:1 The anatomical and light microscope observation: At the 2nd week postoperation, more...