Novel strategy for soft tissue augmentation based on transplantation of fragmented omentum and preadipocytes

Current therapeutic procedures for soft tissue augmentation still lack the ability to induce rapidly formation of adipose tissue and its long-term stability, which is determined by rapid revascularization. The omentum is highly vascularized with microvascular endothelial cells (ECs) and is composed mainly of adipocytes that produce an enormously high level of vascular endothelial growth factor (VEGF). The aim of this study was to determine the potential usefulness of fragmented omentum tissues, with or without cotransplantation with preadipocytes, in soft tissue augmentation. Fragmented omentum tissues (approximately 500 mg) with or without preadipocytes (approximately 2.3 × 10⁶) isolated from epididymal adipose tissues were transplanted under the dorsal skin of Wistar rats by percutaneous injection and the tissues were left under the skin for up to 12 weeks. Regardless of cotransplantation with preadipocytes, the general morphological features of the transplanted tissue were as follows. The transplanted tissues, the weight loss of which was limited to 30-40%, contained viable adipocytes and some pseudocysts surrounded by fibrotic septa with minor inflammatory cell infiltration. High levels of triacylglycerol content, capillary density, and VEGF production were observed in transplanted tissues 12 weeks postoperation. Cotransplantation with preadipocytes enhanced adipose tissue formation significantly. These observations strongly indicate that transplantation of fragmented omentum tissues or cotransplantation with preadipocytes may be a promising therapeutic procedure for soft tissue augmentation.