Fine tuning lipoaspirate viability for fat grafting

The efficient harvest of abundant viable adipocytes for grafting is of considerable interest. Hand aspiration, low-g-force, short-duration centrifugation, and harvest of the lower sublayer of fat centrifugate maximize viable adiopocytes, but this process is cumbersome with conventional equipment. The Lipose Corporation (Greenwich, Conn.) has produced special syringes, filters, and a low-g-force centrifuge (Viafill system) to facilitate this process. The adipocyte viability using this system is presented.

Six women underwent fat graft harvest using the Viafill system from the lower hips (n = 6) and/or upper hips (n = 3). After centrifugation for 2 minutes at 50 g, the lower, middle, and top sublayers of the adipose layer were analyzed for viable adipocyte counts using trypan blue vital staining. Additional samples from standard power-assisted liposuction were obtained and analyzed similarly.

The mean difference in square-root transformation of cell counts between the bottom sublayer of centrifuged fat and the middle sublayer was 0.95 (95 percent CI, 0.61 to 1.3), and the difference between the middle and top sublayers was 0.67 (CI, 0.50 to 0.84). Thus, the bottom sublayer had approximately 2.5 to 3 times more cells than the top sublayer. The difference between the hand aspirate samples and the power-assisted liposuction samples was significant (1.62; CI, 1.35 to 1.90).

This study reconfirms the authors' early findings that atraumatic harvest of lipoaspirate yields high cell counts and that adipocyte density is greatest at the lowest sublayer of centrifuged fat. The Viafill system provides a more efficient and user-friendly system for fat grafting while maintaining cell counts similar to the authors' technique using conventional equipment.