Nishimura T, Hashimoto H, Nakanishi I, Furukawa M
Department of Otolaryngology--Head and Neck Surgery, Kanazawa University School of Medicine, Japan.
Laryngoscope. 2000 Aug;110(8):1333-8. doi: 10.1097/00005537-200008000-00021.
OBJECTIVES/HYPOTHESIS: Autologous fat is an ideal material for augmentation in plastic surgery because of its minimal tissue reaction and easy availability, but its long-term graft survival is somewhat unpredictable. This study was conducted to determine how fat grafts get their vascular supply from the recipient bed and why they keep reducing in volume and weight.
Experimental study using animal models.
The expression of vascular endothelial growth factor (VEGF) in grafted fat tissue was examined by using immunohistochemical staining, and apoptotic cell death in the grafted fat was studied by using terminal deoxynucleotidyl transferase (TdT)-mediated deoxy-uridine triphosphate (dUTP)-biotin nick end-labeling method. Twenty-five Wistar rats were used as models of free fat grafts. Fat tissue taken from inguinal fat pads was grafted to the back skin with an 18-gauge needle injection.
The weight of the injected fat was significantly reduced on the 180th day compared with the original weight (32% +/- 10%). VEGF+ cells were observed in fibrous connective tissue of the grafts on days 7 and 30 but not after day 90. Apoptotic cells were also observed on days 7 and 30.
Angiogenic factors including VEGF started to revascularize the graft around day 7, and the extent of the vasculature was not reduced after the revascularization. In addition to necrosis in the graft's early stages, apoptosis induced by many factors in the graft's environment is also, at least in part, a cause of long-term volume reduction of the fat graft. Thus clinical application of angiogenic factors such as VEGF to fat grafts and control of apoptosis may contribute to improvements in fat-grafting techniques.
目的/假设：自体脂肪因其组织反应极小且易于获取，是整形手术中理想的填充材料，但其长期移植存活率存在一定的不可预测性。本研究旨在确定脂肪移植物如何从受区床获得血供，以及为何其体积和重量会持续减少。
使用动物模型的实验研究。
采用免疫组织化学染色检测移植脂肪组织中血管内皮生长因子（VEGF）的表达，并使用末端脱氧核苷酸转移酶（TdT）介导的脱氧尿苷三磷酸（dUTP）-生物素缺口末端标记法研究移植脂肪中的凋亡细胞死亡情况。25只Wistar大鼠用作游离脂肪移植模型。从腹股沟脂肪垫获取的脂肪组织用18号针头注射移植到背部皮肤。
与初始重量相比，第180天时注射脂肪的重量显著减轻（32%±10%）。在第7天和第30天时，在移植物的纤维结缔组织中观察到VEGF+细胞，但在第90天后未观察到。在第7天和第30天时也观察到凋亡细胞。
包括VEGF在内的血管生成因子在第7天左右开始使移植物重新血管化，血管化程度在血管化后未降低。除了移植物早期的坏死外，移植物环境中多种因素诱导的凋亡至少部分也是脂肪移植物长期体积减少的原因。因此，将VEGF等血管生成因子应用于脂肪移植以及控制凋亡可能有助于改进脂肪移植技术。
