Transplantation of adipose-derived stem cells promotes formation of prefabricated flap in a rat model.

Flap prefabrication is started with transposition of a vascular pedicle into a donor area that lacks an axial blood supply. Adipose-derived stem cells (ASCs) have been proven beneficial for promoting neovascularization and tissue regeneration in several animal models. Here we investigated the feasibility of applying ASCs as a novel strategy to promote flap prefabrication, which involves the processes of neovascularization and regeneration. Prefabricated flaps were performed by two-stage procedure in a rat model. At stage one, the right femoral vascular pedicle was dissected and embedded underneath the abdominal flap to form a man-made axial flap. At stage two, the prefabricated abdominal flap was elevated as an island flap based on the implanted femoral vessel. Ninety rats were randomly divided into 3 groups and received allogeneic ASCs, chondrocytes and phosphate-buffered saline (PBS), respectively during the first operation. Eighteen flaps of each group were harvested for vascular endothelial growth factor-A (VEGF-A) protein assay after the first surgery. The other flaps were processed for flap viability measurements by flap survival rate and capillary density after the second surgery. Results demonstrated that the ASCs treated group had higher survival percentage and capillary density of flap as compared with either PBS group or chondrocyte group. Furthermore, the ASC group had the highest level of in vivo VEGF-A among three groups, while the chondrocyte group had the lowest. These results indicate that ASCs are capable of promoting flap prefabrication, and its therapeutic potential is correlated with the angiogenic cytokines such as VEGF-A.