Experimental Study On Transfer And Repair Of Autologous Free Dermis Fat Flap In Bama Miniature Pigs

Objective: In this experiment,large volume autologous free dermis fat flap(free dermal fat graft,FDFG)transfer repair was successfully performed in Bama miniature pigs,and the microvessel density(Microvessel density,)in different time nodes of autologous FDFG was analyzed and compared.The expression of MVD and vascular endothelial growth factor(vascular endothelial growth factor,VEGF)was used to investigate the characteristics of graft volume maintenance.Methods: Six healthy Guangxi Bama mini-pigs,all of which were 5-6month-old sows,weighing 15-20 kg,were randomly divided into three groups,2in each group.In the same day,the same group of surgeons implanted autologous FDFG into the muscle surface of the abdominal wall of small pigs.The FDFG,was taken out at 2,4,8 weeks after operation and the adipose tissue in the operation area of the experimental animals was taken as the 0-week control group on the day of operation.All the specimens were stained with HE.The histological morphology was observed under light microscope.The expression of VEGF and the expression of MVD.in adipose tissue after CD31 staining of platelet-endothelial cell adhesion molecule were measured byimmunohistochemistry.Results:All the subjects were able to survive FDFG,the overall volume was in a trend of gradual reduction,the thickness reduction was the most obvious in2 weeks,the overall reduction was about 32%,and the trend of reduction gradually stabilized after the fourth week.About 52% thickness can be maintained after 8 weeks.The MVD were 11.42 ±0.75,11.75 ±1.45,9.42 ±1.36,respectively,which were significantly higher than that of 0-week adipose tissue(MVD = 3.92 ±0.45,p < 0.05,P < 0.05),and the MVD of adipose tissue was11.42 ±0.75,11.75 ±1.45,9.42 ±1.36 respectively at the 2nd,4th and 8th week.2,4,8 weeksundefined VEGF scores were 7.50 ±0.69,8.25 ±0.65,4.67 ±0.45,respectively,compared with the VEGF score of 1.33 ±0.28 in adipose tissue at 0weeks,p < 0.05,and the difference was statistically significant.Conclusion:1.It was feasible to carry out free dermis fat flap transfer repair in Bama mini pigs.2.FDFG will have more microvessels in 2 weeks than 4 weeks,and the number of microvessels will decrease relatively,but it will gradually thicken and increase after 8 weeks.