Cryopreservation And Replantation Of Autologous Skull Flap After Porous Washing

Objective: Establishment of surgical skull defect model with New Zealand white rabbits.we perforate(no transfixion and no traffic),wash bone flap and frozen for three months,then rewarm,culture 24 h in vitro medium and replant bone flaps.To evaluate whether cryopreservation and replantation of autologous bone flap after porous washing could reduce the inflammatory response and the occurrence rate of bone absorption,increase the number of vascular endothelial cells in the autologous bone flap.Methods: Sixteen healthy,adult and male New Zealand white rabbits,weight(2±0.2)kg.Establishing of left parietal bone defect model about 1.0 x 1.0cm2 and rabbits were randomly divided into experimental group and control group,eight rats in each group.For the bone flaps of the experimental group,we perforate(no transfixion and no traffic),wash,frozen for three months,rewarm,culture 24 h in vitro medium and replant.For the bone flaps of the control group,except washing,was the same as the experimental group.On the first,third,seventh and fourteenth days after bone flap replantation,2ml venous blood was extracted to detect the concentration of IL-1 and TNF-? by ELISA method.Four weeks after replanting,we take complete skull outside the border 2-3mm of replanted bone flaps to observe gross morphology and stain HE staining and immunohistochemical staining for CD31.Results:(1)On the first,third,seventh and fourteenth days after bone flap replantation,comparing with control group,the concentrations of serum IL-1 and TNF-? were lower in the experimental group,the difference was statistically significant,P<0.05;(2)Four weeks after replantation,the replanted bone flaps is white,the surrounding skull is bright red,callus can be seen around the inner plate and the outer plate of the replanted bone flaps,the edge of sutura healed well and formed compact callus with hard texture.No bone absorption(0/8)was found in experimental group;Three autologous skull flaps was found partial absorption(3/8)in control group;(3)HE staining showed that the replanted bone flaps of both experimental group as well as control group healed with the primary skull defect and there is a clear boundary.HE staining was observed under microscope,it can see that the replanted bone flaps healed well and new fibrous callus formation at healing site,there is many osteocytes of the replanted bone flaps;(4)Compared with the control group,the occurrence rate of bone absorption was decreased and the number of vascular endothelial cells was significantly increased in the experimental group.Conclusions: Cryopreservation and replantation of autologous skull flaps after porous washing could reduce the inflammatory response and the occurrence rate of bone absorption,increase the number of vascular endothelial cells in the autologous bone flap.