Comparative Study On Purification Effects Of Different Purification Methods In Autologous Fat Transplantation

Background:Autologous fat transplantation(AFT)is a clinical technique which harvests fat tissue,purifies it in vitro and then transplants it back.It is now widely used in the field of plastic surgery.But its big inconsistency of survival situation is still one of the main problems on clinic,and purification process is one of the main factors that affects the fat survival largely.There is still no unified standard purification process for clinical AFT technology to get the best result of transplantation at present.Objective:To analyze the effective factors of gravity sedimentation,centrifugation and cotton pad concentration respectively.And to evaluate the effects of these factors on tumescent infiltration solution and oil removing and purification of fat granule.By comparing the effects of water and oil removing of the tree method and evaluating the survival rates of transplanted fat tissue purified in animal experiment,we want to provide some scientific basis and guides for clinical operation and processing.Methods:Part one,by using control variables method,we analyzed the effects of different factors of purification methods on efficiency of tumescent infiltration solution and oil removing,and try to find the best procedures of each method.Part two,by comparing the fat productive rates and the ingredients proportions of the purified fat,to explore the purifying efficiency and rate of waste of gravity sedimentation,centrifugation and cotton pad concentration and evaluate the advantages and disadvantages of them from different dimensions.Part three,using nude mice as experimental animals,to compare the difference of survival rate among these purification methods in vivo.Results:Gravity sedimentation had the lowest purification ability and 1h or more sediment could separate out more than 85%of its maximum.In centrifugation method,3min was needed to remove the water and 5-10min was needed for oil removing.Around 200g centrifuge force,the volume the water changed most,and 200g can separate out more than 90%of water.The oil produced along with centrifuge force,and beyond 200g,the damage increased with centrifuge force.In cotton pad concentration,5-6.7cm2/ml contact area can remove most water and oil and 5min contact time reached saturation condition of cotton pad.In comparison,cotton pad concentration had the best purification ability,followed by centrifugation method,with gravity sedimentation worst,and there were significant statistically difference among them,p<0.001.And the productive rate of concentrated fat from high to low in the order was gravity sedimentation,1000rpm centrifugation,1200g centrifugation and cotton pad concentration.In animal experiment,after 48h fat transplantation on nude mice,all groups had obvious decline in fat weight and gravity sedimentation declined most,followed by centrifugation method and cotton pad concentration.And in the early stage of transplantation,cotton pad concentration group had the highest survival rate of weight and volume,followed by centrifugation method and gravity sedimentation,with significant difference.Conclrusion:Gravity sedimentation needs more than 1h to stand.The best centrifuge time and force are 3-5min and 150-200g.And best procedures of cotton pad concentration are 5-6.7cm2/ml contact area and 5min contact time.Cotton pad concentration has the best efficiency of water and oil removing and gravity sedimentation was worst.Centrifugation method is in the middle but produces more oil when centrifuge force beyond 200g and the volume of oil increased with centrifuge force.The rate of waste is the lowest in gravity sedimentation group and highest in cotton pad concentration group.In animal experiment,cotton pad concentration group has the highest survival rate of weight and volume,followed by centrifugation method and gravity sedimentation.