Experimental Study On Mitomycin Fibrin Gel Sustained-release On Epidural Scar

Research objectiveThrough the animal experiment of mitomycin C (MMC) formed fibrin gel(FG) sustained release drug for the prevention and treatment of epidural scaradhesion after laminectomy.Method1. The96SD rat were subjected to L1-segment laminectomy and spinal duramater was exposed. After operation, FG-MMC was administered to preventepidural scar adhesion. With methods of random grouping, the64rat weredivided into4groups according to administration concentration of MMC, groupA0.1mg/ml； group B0.3mg/ml； group C0.5mg/ml; group D0.7mg/ml.Experimental Sampling of scar tissue in the laminoplasty segment was carriedout respectively at1、2、3、4、5、6、7and8weeks with3rat tested in eachtime-point. The dura adhesion degree in the laminoplasty segment was assessedby visual examination, and MMC concentration in rabbit vivo wasdetermined.Then we found out the most effective drug dose by making thedose-effect curve.2. The48SD rat were subjected to L1-segment laminectomy and wererandomly divided into the following4treatment groups：group E(MMC), groupF(FG), group G (FG-MMC,0.5mg/ml), group H(saline group). ExperimentalSampling of scar tissue in the laminoplasty segment was carried out at4weeksafter operation. The dura adhesion degree in the laminoplasty segment wasassessed by visual examination, The proliferation of fibroblast cells anddistribution of collagen was evaluated by HE staining and Masson staining.Collagen content was determined indirectly by detecting the concentration ofhydroxyproline in scar tissue. The preventive effect of epidural scar adhesion after laminectomy were compared in different groups.Result1. The dura adhesion degree was the most severe in A group, and the least inC group. the peak of drug release rate was found after4weeks in group A、 B、C、 D. Drug release rate stayed at a low level in other time points and decreasedgradually, and C、 D two group was significantly higher than that of fibroblast50%inhibition concentration (ID50). Statistics analysis showed that as for theinhibiting effect on epidural scar adhesion, the optimum concentration ofFG-MMC was0.5mg/ml.2. In the group E and F,the loose extradural scar tissue but not obviousadhesion to dura matter can be observed in the laminoplasty segment withproliferation of fibroblast and collagen tissue and irregular collagen distribution.In group g, there was a potential lacuna between dura and surrounding tissues.No obvious peridural adhesion was formed and motion degree of the dura isnormal. It could also be found that hydroxyproline in scar tissue decreaseddramatically. Severe peridural adhesion with massive proliferation of scar tissuewas formed in grouph accompanied by proliferation of fibroblast and collagentissue and irregular collagen distribution.ConclusionThe mixture of MMC and FG had a prevention and treatment effect ofepidural scar adhesion after laminectomy and the best effect was obtained in theconcentration of0.5mg/l.