Autologous fat grafting is used increasingly in plastic surgery, but optimum graft preparation methods have not been identified. Although the liposuction harvested fat is easily aspirated into a syringe, viable tissue is diluted by the aqueous fraction collected in tumescent liposuction. The purpose of this study is to characterize graft material and compare graft retention of lipoaspirate processed by three common methods.
Methods/Technique:
Fat was harvested by suction assisted (SAL) and was prepared for grafting by centrifugation, filtration (both SAL and UAL harvest), or telfa rolling to remove the aqueous fraction. Each group was grafted subcutaneously into nude mice. Volume retention for each group was measured at 6 weeks. Additionally, for filtered fat, filtrands and filtrates were tested for composition, parcel size, and stromal vascular fraction (SVF).
Results/Complications:
In the murine model, centrifugation and filtration resulted in similar volume retention at 6 weeks; however, telfa rolling resulted in a significantly greater graft volume. For filtered fat, only the filtrand survived when grafted, while the filtered particles showed minimal retention. Ultrasound and suction assisted harvest resulted in similar graft survival when filtered. SVF cell counts across groups were consistently larger in the filtrands than filtrate fractions.
Conclusion:
Telfa rolling of fat increases graft volume retention, but is not amenable to larger volume procedures. Filtration is a reliable and simple method of separating aqueous solutes from viable fat and can be applied to large volume harvest. Fat and particulate matter that passes through 800 micron filters is not viable graft material.