Mitomycin C For The Prevention Of Adhesion Formation After Endoscopic Nasal Surgery In Rabbits

Endoscopic nasal surgery has developed from the original description by Messerklinger in the 1970s to become a full accepted technique for treating all kinds of sinus and nasal cavity desease. It is a great development in nasal surgery field and now it taking place of the tradition nasal surgery step by step. However, the recurrence of symptoms after ESS is often due to synethiae and scar formation in the nasal cavity. Mitomycin C (MMC) is a topical agent that has demonstrated clinical efficacy in the reduction of clinical scar formation. MMC was used as a chemotherapeutic agent because of its ability to cross-link DNA and inhibit cellular mitosis. MMC has been shown to have an antiproliferative action on fibroblasts. MMC has been used extensively to reduce scar formation associated with ophthalmologic surgery and it has beenshown to be effective in preventing stenosis of the drainage fistula.The purpose of this research project is to study if topically applied MMC at injured nasal mucosal will reduce the risk of adhesion formation and to observe the pathomorphology of the nasal mucosa. At the same time, to evaluate the effect of MMC in different concentrations on nasal mucosa healing to supply theory foundation for the clinical using and to observe the toxicity of using long time. It was hoped that by delaying the formation of fibrous scar tissue long enough to allow the establishment of an epithetlialzed tract and to find a perfect condition for the MMC use.METHODSSame treatments carried out on nasal mucosa of 70 rabbits. Injured rabbits were randomly divided into seven groups, including normal saline control group(A) and MMC group. MMC group was divided into three parts, one is low concentration and 5 minutes using time part(L5), one is high concentration and 5 minutes using time part(H5) and another is the medicine kept stay in the injured mucosa part(MS). Each part has two concentrations. The L5 part have 0.04 mg/ml(B). 0.4 mg/mL(C), and the H5 part include 1.0mg/mL(D) and 2.0mg/ml(E), the MS group including two concentration of 0.4mg/ml (F) and 1.0mg/ml (G) . For each rabbit, an absorbable gelatin sponge soaked with medicine applied to the site of injured nasal mucosa for corresponding time. Pathomorphology of different groups were observed and detected with light and election microscope and endoscopy after 1 month of the operation.RESULTS1. The results of endoscopic examination.The swollen degree of wound surface in control group was more serious and the adherence number was more as compared with those in MMC groups. In B group, 7 cases adherence appeared, so there was no significant different between group A and B. There are 2 cases of adherence in C group and the rate of the adherence in C group was significant different from that those in A group(P <0. 05). The mucosa healing is well in group C. There was no adherence formation in group H5 and MS. But there were 2 cases of perforation of nasal septum in group D, 5 cases in group E, 6 cases in group F and 9 cases in group G2. The results of light microscope and electron microscope examination.Under light microscope and electron microscope, there is an obviously antiproliferative effect on fibroblasts in C, D group and in group C nasal mucosal healing is well. In H5 and MS groups we observed the injured mucosa is discontinuation and parts of cilias lost and abnormal structure appeared in some cilias. Comparing the two groups, the MS group is more serious.CONCLUSIONSMMC was found to be efficient to inliibit adhesion during this research project. It may reduce the incidence of postoperative adhesions and to help the mucosa healing at the dosage 0.4mg/ml and 1 .Omg/ml used in this study. But high concentration and long time applied with MMC at the injured nasal...