不同直径轴状脂肪移植的实验研究

EXPERIMENTAL RESEARCH OF CORE FAT TRANSFER WITH DIFFERENT DIAMETERS

目的通过改良取脂工具,研究不同直径轴状脂肪移植后的存活差异。方法在注射器轴状脂肪移植研究基础上,设计内径为4、6、8、10 mm的4种取脂工具。于2014年5月-2015年4月行自体脂肪移植的12例患者中,分别采用以上4种内径取脂工具抽取腹部脂肪标本（n=3）,测量脂肪葡萄糖转移量及脂肪细胞活性。取64只3~4周龄免疫缺陷裸鼠,随机分为A、B、C、D 4组,每组16只。以裸鼠背部皮下间隙为移植受区,分别移植用内径为4、6、8、10 mm取脂工具取出的0.5 m L脂肪组织。脂肪植入后,观察各组裸鼠存活情况及脂肪植入部位的外观。植入脂肪后1、2、4、8周,测量移植脂肪质量;每组随机处死4只裸鼠,取出受区剩余移植脂肪进行大体观察、组织学以及免疫组织化学染色观察,计数完整脂肪细胞及毛细血管。结果随着取脂工具内径增大,各组葡萄糖转移量逐渐增加,组间比较差异均有统计学意义（P〈0.05）;同一时间点脂肪细胞活性亦呈增高趋势,其中A、B组与D组比较,差异有统计学意义（P〈0.05）。脂肪植入后,随时间延长裸鼠背部隆起样外观均趋于平坦,但C、D组隆起程度优于A、B组;大体观察见C、D组脂肪保持正常形态,并有血管长入。脂肪植入后即刻及1周时,4组脂肪质量比较差异无统计学意义（P〉0.05）;2、4、8周时,A组明显小于其他3组（P〈0.05）,B组小于C、D组（P〈0.05）,C、D组间差异无统计学意义（P〈0.05）。组织学及免疫组织化学染色观察示,随时间延长,与其余3组比较,D组脂肪细胞形态完整性较好,坏死区域小,血管密度高。除植入后1周各组间差异无统计学意义（P〉0.05）外,其余各时间点A组完整脂肪细胞数明显少于其余3组（P〈0.05）,B组少于C、D组（P〈0.05）。各时间点随取脂内径增大,毛细血管数呈增加趋势,组间比较差异均有统计学意义（P〈0.05）。结论在10 mm范围内,取脂工具内径越大,可更好地保持组织完整性,脂肪植入裸鼠体内后血管密度更高、再血管化时间更短、形态维持的时间更持久。

Objective To investigate the survival rate of core fat tissue with different diameters by advanced fat harvesting instrument. Methods Based on core fat transfer by 1 m L syringe, the fat harvesting instrument was modified with different diameters, including 4, 6, 8, and 10 mm respectively. Between May 2014 and April 2015, the fat harvesting instrument with diameters of 4, 6, 8, and 10 mm was respectively used to harvest abdominal fat in 3 of 12 patients undergoing autologous fat transplantation. The glucose transportation quantities and the fat cell viability were measured. Then 64 nude mice at the age of 3-4 weeks were randomly divided into 4 groups（groups A, B, C, and D, n=16）. And 0.5 m L fat harvested with diameters of 4, 6, 8, and 10 mm was implanted into the dorsal subcutaneous space. After fat transplantation, the mice survival and the appearance at the recipient site were observed. At 1, 2, 4, and 8 weeks after fat transplantation, the grafted fat was harvested for gross, histological and immunohistochemical observations; the intact adipocytes and capillary were counted. Results The glucose transportation quantities gradually increased with increased diameter, showing significant difference among groups（P〈0.05）. And the fat cell viability had a rising tendency, showing significant differences when comparing groups A and B with group D（P〈0.05）. With the time passing by, the protuberant appearance became flat at the recipient site, but the appearance of groups C and D was better than groups A and B. Normal shape of the fat and capillary were found in groups C and D. At immediate and 1 week after fat transplantation, there was no significant difference in fat weight among 4 groups（P〈0.05）; the fat weight of group A was significantly less than that of groups B, C, and D（P〈0.05） at 2, 4, and 8 weeks after fat transplantation, and it was significantly less in group B than groups C and D（P〈0.05）, but no significant difference was found between groups C and D（P〈0.05）. Histological and immunohistochemical observations showed better integrity of the cells, less necrosis, and higher vascular density in group D than groups A, B, and C as time extension. The adipocyte integrity of group A was significantly worse than that of other 3 groups at other time points（P〈0.05） except at 1 week（P〈0.05）. At each time point, the capillary counting had an increasing trend with increased diameter in all groups, showing significant difference among groups（P〈0.05）. Conclusion With diameters within 10 mm, the thicker the core fat is transferred, the better integrlity, higher vessel density, and quicker revascularization time can be predicted. So the postoperative appearance could be maintained longer.