Cerebrospinal fluid composition after duraplasty with different substitutes in early and late postoperative periods (an experimental study)

Abstract

Objective. To study cerebrospinal fluid (CSF) changes after the duraplasty with autologous fascia, collagen-based material and chitin-chitosan membrane in early and late postoperative periods. Materials and methods. Chitosan-based films were made out of 3 % solution of chitosan for the research. We used 200 kDa chitosan (deacetylation rate 80–90 %) to produce chitin-chitosan membrane by using solvent evaporation method. For enhancing mechanical properties and reducing the degradation, chitin particles were added to the chitosan solution. Chitosan and chitin ratio was 80/20. The chitin/chitosan solution in Petri dishes was being dried out during 3 days at room temperature. Cerebrospinal fluid composition has been studied after the duraplasty with autofascia, collagen-based material and innovative chitosan-based graft in early and late postoperative periods. The duraplasty was performed by applying these materials to 90 Chinchilla rabbits breed. Animals were divided into three groups: I group — duraplasty using the fascia lata autograft, II group — duraplasty with the collagen-based material, III group — duraplasty using the chitin-chitosan membrane. The animals in the II and III groups were divided into 2 subgroups: A — plasty without fixing the material, B — plasty with fixing the material using atraumatic suture. CSF composition was studied before and after the operation had been performed in 2 weeks, 2 and 6 months. Results. The results of our study demonstrated the increase in density and protein level, the decrease in рН and glucose level and the extreme increase of cells, mostly neutrophils after the use of fascia lata for dural closure. At the same time, there were no substantial changes after dural closure with artificial collagen- and chitosan-based materials, the CSF composition normalized in 2 months after operation. Conclusion. The use of autologous fascia for duraplasty leads to an acute response of the cerebrospinal fluid in the early postoperative period and to residual pleocytosis. The chitosan-based graft application was followed by no complications at 6 months after surgery and only slight CSF response in the early postoperative period. There wasn’t any significant difference in CSF composition in chitosan- and the collagen-based material usage. Given the lack of changes in SCF tests between suture and no suture graft fixation except for a slight increase in erythrocyte number in the early postoperative period, the choice of material fixation method is entirely dependent on the clinical situation and does not affect the cerebrospinal fluid state.