The Experiment Research Of Nd:YAG Laser In Liposuction In Mini-pig Model

Objective More and more people suffer from obesity, for the demand of aesthetics and health, liposculpture become more and more popular in aesthetic surgery. Quite a lot of new techniques and lipolysis facilities emerge these years so as to decrease operator fatigue, reduce downtime and bleeding, promote skin contraction. As a new technique, laser lipolysis has been quite effective in fat removal and skin contraction in clinical use. However, it isn’t possible for us to know how is histologic changes of fat and skin like in human’s living body. In this study, we will investigate the changes and differences in Bama mini-pig model and found whether laser lipolysis had more advantages over traditional liposuction.Methods3female mini-pigs weight of15-17kg were included in this study. We design5squares of7×7cm2in each lateral symmetrically, and mark the squares with tattoos. In every two symmetrical squares, we chose one as laser group while the other traditional group randomly. In laser group,1064nm Nd:YAG laser were used after tumescent anesthesia done and the laser parameter is160mJ,40HZ. The energy we radiated in every square was40.0J/cm2. In traditional group, after tumescent anesthesia, we insert suction cannula connected with negative-pressure-syringe in the fat layer and move. Make sure when process of each square finished, the left fat layer is as thick as the symmetrical one. Pathological section was performed on post-operation instantly,7th and30th day. Surface temperature were monitored and we would found out the relationship between laser energy and surface temperature. Histologic changes of adipose tissue when operation finished,7th and30th day postoperatively, were examined. The number of fibroblasts in dermis (done on7th day post-operation),the thickness of dermis and fat layer, the change of the area of the tattoos(done on30th day postoperatively) were examined, too.Result With the increase of the energy radiated, the Surface temperature rised and didn’t exceed42℃; we found mechanical damage in fat layer of traditional group while sheets of dissolved adipocyte, coagulated vessel and collagen, carbonizing tissue in laser group postoperatively instantly. Fibroblast were found among adipocytes and there were more in laser group on the7th day and likewise when fibroblast changed into collagenous fiber on the30th day. Fibroblasts numbers in dermis of laser group increased significantly compared to traditional group (P<0.05) on the7th day postoperatively, The thickness of dermis of laser group were significantly increased compared to traditional group (P<0.05)on the30th day. The area of the tattoos, the thickness of remaining fat layer of laser group were less than traditional group on the30th day.(P<0.05)Conclusion Liposuction with Nd:YAG laser is quite effective and safe. The laser can melt adipose tissues and coagulate blood vessels and collagen. More importantly, the laser stimulates the formation of collagen in the region, enhancing skin elasticity and promoting skin contraction in the treated areas.