Dural Repair Using Chitosan Dural Graft And Hydroxybutyl Chitosan:an Experimental Study In Rabbits

Dural is an important barrier, and it is essencial to maintain the integrity of the structure and function to protect the the brain and spinal cord of great significance. The dual could be injured by trauma,tumor,or surgery,which can cause CSF leakage,infaction,and adhesion ect. Therefore surgical repair of the dual is very important and necessary. In this case,a new composite chitosan dural patch and temperature sensitive materials hydroxybutyl chitosan are used to repair in rabbits to study safety and efficacy of the new materals.Objective To evaluate the the efficacy and safety of chitosan dural graft and hydroxybutyl chitosan in duraplasty.Methods Thirty-six New Zealand rabbits were randomly divided into 2 groups with each 18. Group A were then divided into the experimental group 1 (chitosan dural graft) and the control group 1 (dural substitute derived from bovine pericardium) Group B were then divided into the experimental group 2(hydroxybutyl chitosan) and the control group 2.(the dural defect was left untreated). Six animals in group A and B were sacrificed 30d, 60d and 90d post-operation, respectively. The peripheral vein blood was collected and counted for WBC and lymphocytes pre-operation and 3d,30d and 60d post-operation. The specimens were evaluated by HE staining, Massion's staining, as well as CD34 detections by immunohistochemical staining.Results The counts of WBC and lymphocytes in A, B groups before operation did not differ from the findings 3d,30d and 60d post-operation (P>0.05). Histological evaluation showed that a new layer of collagen fibers appeared in experimental group 1 and 2, without adhension and local inflammatory infiltration. Dural substitute degradated in control group 1 with capillary ingrowth,but without new layer of collagen fibers. Severe adhesion appeared and showed excessive fibrosis in Control group 2. Massion's staining showed that in the experimental group 1, experimental group 2 and control group 2, collagen fibers increased over time, with the loose arrangement becoming dense. Collagen fibers in Control group 2 structure was greater than those in the experimental group 1,2. The changes of CD34 expression increased in experimental group 1,experimental group and Control group 2, and showed parable degree of the results.Conclusion Chitosan dural graft and hydroxybutyl chitosan are safe and applicable for dural defect repair.