The effect of lidocaine and adrenaline on the viability of injected adipose tissue--an experimental study in nude mice.

Adipose tissue injection as a free graft for the correction of soft tissue defects is a widespread procedure in plastic surgery. The main problem in achieving long-term soft tissue augmentation is partial absorption of the injected fat, and hence the need for over-correction and re-injections. Lidocaine, used for local anesthesia, has been suspected as an inhibitor of growth of adipocytes in culture and slowing down glucose transport and lipolysis in adipocytes. In addition, reduced blood supply by local application of epinephrine was accused of having a negative effect on the graft. The purpose of this study was to examine the effect of local anesthesia, administered to the fat donor site, on the take of the injected fat. Human adipose tissue, obtained by suction-assisted lipectomy, was injected subcutaneously into the scalp of nude mice. Local anesthesia of the fat donor site consisted of a solution with 600 mg of lidocaine (0.06%) and epinephrine 1:1000000. In a control group, normal saline with no local anesthesia or epinephrine was administered to the donor site. One cc of fat was injected after centrifugation into each animal scalp. There were 10 animals in each group. The animals were sacrificed 15 weeks after the procedure. Graft weight and volume were measured, and histologic evaluation was performed. No significant differences were demonstrated between the groups in regard with the grafts' weight and volume and the histologic parameters investigated. In conclusion, local anesthesia solution, consisting of lidocaine and epinephrine, does not alter the take of fat grafts, and has no influence on the adipocytes viability.