| Background and Objective Autologous fat transplantation,which is widely used in plastic reconstruction,is easy to operate and the tissue for transplantation is safe and rich in source.Improving the survival rate of transplantation and reducing the long-term absorption rate are the key points to improve the diagnosis and treatment technology.Basic research of tissue engineering has found that many cells and growth factors assisted fat transplantation can significantly improve the survival rate of fat,which provides a theoretical basis for clinical application.However,in the preparation process,the need to add exogenous substances increases related risks,which limits the clinical application of related products.In the first part of the study,considering biological safety,the third generation platelet concentrate growth factor was selected as the research object and compared with platelet-rich fibrin using wet cell-assisted lipotransfer technique to explore the effect of combined adipose tissue transplantation on the survival of transplanted adipose tissue and provide experimental support for its clinical application.The second part is to evaluate the clinical efficacy and safety of the CGF combined CAL fat filling treatment for facial depressed deformity,and compare it with fat transplantation alone group.Methods1.CGF and PRF were prepared from autologous vein blood of new Zealand white rabbits.Compound cell-assisted fat transplantation(CAL)technique was performed on the established animal model,and its effect on the survival of transplanted fat was tested in vitro.Thirty healthy New Zealand male rabbits,two rabbits in each pair,60 ears in total,were randomly divided into four groups: CGF target group,PRF controlgroup,CAG control group and blank control group.After anesthesia and disinfection,adipose tissue was cut from scapular region of rabbit back to prepare the adipose tissue for transplantation,and venous blood was drawn to prepare CGF and PRF.After mixing the prepared graft with adipose tissue,it was implanted into a circular subcutaneous space with a diameter of 3 cm in the recipient area of the back of rabbit ear.The survival situation of transplanted fat was generally observed after operation,and the survival rate/absorption rate of transplanted fat was calculated by measuring the volume of fat.Five pairs of rabbit,altogether 10,were sacrificed at 2,4 and 12 weeks respectively after operation.Histological observation was performed after HE staining.Four weeks after operation,oil red O staining and histological observation were performed on the specimens.The expression of VEGF was detected by immunohistochemical staining 4 weeks after operation,and the vascular density was calculated by CD31 immunohistochemical staining,statistical analysis results.2.In the second part,the data of 43 outpatients who received facial fat filling were analyzed.Among them,22 patients received simple fat transplantation and 21 patients received complex wet CAL with autologous CGF.After operation,color Doppler ultrasonography was performed to observe the effect of the operation.The restoration,fat absorption rate,intraoperative and postoperative complications of the two groups were counted,and satisfaction survey was collected.Results1.The establishment of experimental animal model was completed,and all experimental animals survived.Samples were taken at 2,4 and 12 weeks after fat transplantation.At the 2nd week after operation,the adipocytes in the blank control group were surrounded by fibrous connective tissue,accompanied by infiltration of a small amount of inflammatory cells and scattered microvessels.There were few fibrous connective tissue around adipose tissue in CGF target group and PRF control group.CAG control group was in the middle,and neovascularization was observed.The vascularization structure of CGF target group and PRF control group was clearer.At the4 th week after operation,a small amount of fibrous connective tissue was observed around adipocytes in each group compared with last week,and a large number of mature blood vessel-like structures were observed between adipocytes.Local remodeling was further improved.There were fewer fat vacuoles and fibrous connective tissue in the adipose tissue of PRF control group than that of the blank control group.CAG control group was in the middle.In CGF target group,more normal adipocytes and fewer fat vacuoles were found in the adipose tissue,and the adipose tissue is more homogeneous..At the 12 th week after operation,the adipose tissue of each group was homogeneous,and there were more neovascularization in adipose tissue.Capillaries were located beside adipocytes in normal adipose tissue,and there was no significant difference in connective tissue.2.In the fourth week after operation,the oil red O staining showed that the adipose tissue of each group had red staining.The thickness of the adipose tissue of the blank control group and the CAG control group was thinner,the uneven staining of fat cells and the size of lipid droplets were different.The PRF control group was in the middle,and the lipid droplet distribution was more uniform than the former two groups;the adipose tissue layer thickness of the CGF target group was more obvious,the fat cells were more uniform,the size was uniform,the cell distribution was more uniform,and the transplanted fat volume was the highest in the CGF target group.Immunohistochemical staining of VEGF showed that brown and yellow granules were found in all groups at 4th week after operation,and fewer positive granules were found in CAG control group and blank control group;that of CGF target group and PRF control group is of deep color and large quantity.3.There was a significant difference in fat survival rate between the target group and the control group at 4,8 and 12 weeks after operation.The CGF target group was(85.40±2.58)%,(63.75±5.76)%,and(63.62±5.75)%;The PRF control group was(83.27±2.85)%,(60.53±2.69)%,and(54.91±3.01)%.Respectively the CAG control group was(66.45±3.98)%,(51.45±3.26)%,(40.94±5.02)%,and the blank control group was(54.23±2.63)%,(41.60±2.42)%,(27.07±2.32)%.The results showed that the fat survival of CGF target group and PRF control group was better than that of the other two groups in the same period,and the long-term stability of the CGF target group is better than the PRF control group.The blank control group had the lowest fat survival rate.Compared with the control group,the CGF target group had faster agglutination,faster neovascularization,higher regenerated fat survival,less self-absorption,and longer-term stability.4.The densities of blood vessel sections were ranked from high to low as follows:the CGF target group had(65.61±1.88)per high power field of vision,the PRF control group had(55.78±6.21)per high power field of vision,the CAG control group had(42.89±2.51)per high power field of vision,and the blank control group had(25.81±2.87)per high power field of vision.There was significant difference between the CGF target group and the PRF control group,CAG control group and blank control group.CGF could promote the transplantation of fatty capillaries,and its pro-vascularization effect was better than the control group.5.The facial appearance of the two groups was improved significantly after fat transplantation and filling,and no serious complications were found.During the follow-up visit,some patients were accompanied by swelling and discomfort in the operative area in the early stage,which was mostly relieved 2-3 days after the operation.The swelling had basically subsided one week after the operation.Generally speaking,there was no obvious hardening in the transplantation area,and the outline was round and full.B-ultrasound echo imaging showed that CGF group had less liquefaction in the early stage,more uniformly spreaded fat and better survival than simple fat granule transplantation group.There was a statistically significant difference in the survival rate of transplanted fat between the two groups at the first,third and sixth months after operation.The survival rate of composite CGF group was(85.07±3.47)%,(79.84±3.34)%,(78.84±5.06)%.There was no significant difference between postoperative 3mon and 6mon(p=0.308).In the autologous fat granule transplantation group,the survival rate was(67.53±5.33)%,(56.77±4.03)%,(51.04±4.75)%.Comparing the situation of implant survival between 3mon and 6mon postoperative,t=5.82(p<0.001).The probability of finding liquefaction foci in the autologous fat granule group was 40.91% one month after operation,and the fat filling ratio was54.55% in 6 months.The probability of finding liquefaction foci in the autologous fat granule complex CGF group was 9.52%.The secondary and multiple fat filling operation ratio is 19.05%?The results showed that the survival rate of CGF composite fat granules after injection was high,the long-term stability of grafts was good,the probability of secondary surgery was reduced,and the patient's satisfaction with treatment was high.Conclusion1.The results of rabbit fat transplantation experiments show that adipose tissue undergoes a process of continuous fat remodeling and angiogenesis after transplantation.Due to multiple factors and the effects of CGF and PRF,the alteration of transplanted adipose tissue,the rate of reconstruction,and the rate of neovascularization were different in different groups.Through analysis of the experiment results,the CGF target group had a faster rate of adipose tissue reconstruction,earlier neovascularization,and less infiltration of inflammatory cells around the fat cells.CGF mixed fat transplantation has the effect of improving the survival of transplanted fat and reducing fat absorption.The long-term effect observation of graft stability is better than PRF mixed fat transplantation,and it is expected to be an effective means for tissue transplantation filling.3.Apply CGF-combined wet CAL technology for the treatment of facial depression in practice,and the therapeutic effect is compared with the simple centrifugally concentrated fat granule transplantation.The results suggest that,after using this technology in fat filling transplantation,the survival rate of transplanted fat tissue after operation is higher,the chance of liquefaction is reduced,the postoperative graft stability is better.The absorption rate is reduced due to good tissue survival,which can effectively avoid or reduce refilling.After filling,the local skin was full and round,and the surrounding area was excessively natural.No obvious adverse reactions were observed,and the patient's satisfaction with the treatment was high. |
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