Different concentrations of mitomycin C to prevent peridural adhesion in rats after laminectomy: A qualitative and quantitative research

Xuekang ZHANG; Lixin WANG; Xiaojian CAO; Ning ZHANG; Guanzhong WANG; Huiying JIA

ABSTRACT

BACKGROUND:

At present,using membrane materials to separate spinal dura mater and scar tissue or using semiliquid materials to surround the dimension of operation are very common after laminectomy.However,therapeutic eflfects ale not satisfactory.Inhibition to the proliferation of fibroblasts,which are the main components of repairing cells,and regulating collagen metabolism have become a hot spot for preventing and treating pathological scar by a biological method.

OBJECTIVE:

To compare the therapeutic effects of topical application of different concentrations of mitomycin C (MMC)on preventing pefidural adhesion in rats after laminectomy by a qualitative and quantitative combined method.

DESIGN:

A completely randomized grouping.controlled animal experiment.

SETTING:

Department of Orthopaedics,Second People's Hospital of Lianyungang City.MATERIALSForty healthy adult male SD rats,weighing 200-220 g,were provided by the Animal Experimental Center,Nanjing Medical University.MMC was produced in Union Fermentation Co.,Ltd(Batch No.425ACI,Import drugs registration No.H20020163,Japan).

METHODS:

The study was performed at the Animal Laboratory Center,Nanjing Medical University,and the Basic Experimental Center,Medical College,Jiangsu University from June 2004 to October 2006.The 40 SD rats were ralndomly divided into 4 groups with 10 rats in each groupMMC high-,medium-,and low-concentration groups,and a control group.After anesthesia,each rat was removal of L1 vertebral plate.A defect(0.2 cm×0.5 cm)was created to expose duml mater.After hemostasia,cotton Pads soaked either with various concentrations ofMMC(0.1,0.05,0.01 g/L)or saline were covered on the laminectomy defects in the three MMC-treated groups and the control group for 5 minutes respeetively.The protocol was carried out in accordance with ethical guidelines for the use and care of animals.MAIN OUTCOME

MEASURES:

After the operation,4 rats were randomly selected from all anesthetized rats in each group,separately.The peridural scar tissue in the laminectomy segment was cut for calculating the contents of hydroxyproline.Spine columns in the laminectomy segment including Surrounding muscle tissue were resected for measuring irregular sear transverse area and counting the number 0ffibroblasts.The degree of peridural scar adhesion was evaluated by the light microscope.

RESULTS:

Forty rats were included in the final analysis.In the control group,peridural scar tissue was dense and closely adhered to dura mater.In the MMC high-concentration group.no noticeable peridural adhesion was found.and contents of hydroxyproline,collagen tissue area and the amount of fibroblasts in the scartissue were significantly reduced compared to control group(all P＜0.05).In the MMC medium-and low-concentration groups,contents of hydroxyproline,collagen tissue area and the amount of fibroblasts had reduced to different extents compared to control group.There was significant difference only in the amount of fibroblasts between the MMC mediumconcentration group and the control group(P＜0.05).Incontinuous adhesion between scar tissue and dura mater was found in the MMC medium-and low-concentration groups.

CONCLUSION:

Topical application of 0.1 g/L MMC can effectively reduce peridural scar tissue hyperplasia and avoid peridural scartissue adhesion afterlaminectomy.