Levi Jessica R, Veerappan Anna, Chen Bo, Mirkov Mirko, Sierra Ray, Spiegel Jeffrey H
Division of Facial Plastic and Reconstructive Surgery, Department of Otolaryngology-Head and Neck Surgery, Boston University School of Medicine, Boston, MA 02188, USA.
Arch Facial Plast Surg. 2011 Jan-Feb;13(1):41-50. doi: 10.1001/archfacial.2010.103.
To evaluate acute and delayed laser effects of subdermal lipolysis and collagen deposition using an in vivo pig model and to compare histologic findings in fatty tissue after continuous wave diode (CW) vs pulsed laser treatment.
Three CW lasers (980, 1370, and 1470 nm) and 3 pulsed lasers (1064, 1320, and 1440 nm) were used to treat 4 Göttingen minipigs. Following administration of Klein tumescent solution, a laser cannula was inserted at the top of a 10 × 2.5-cm rectangle and was passed subdermally to create separate laser "tunnels." Temperatures at the surface and at intervals of 4-mm to 20-mm depths were recorded immediately after exposure and were correlated with skin injury. Full-thickness cutaneous biopsy specimens were obtained at 1 day, 1 week, and 1 month after exposure and were stained with hematoxylin-eosin and trichrome stain. Qualitative and semiquantitative histopathologic evaluations were performed with attention to vascular damage, lipolysis, and collagen deposition.
Skin surface damage occurred at temperatures exceeding 46°C. Histologic examination at 1 day after exposure showed hemorrhage, fibrous collagen fiber coagulation, and adipocyte damage. Adipocytes surrounded by histiocytes, a marker of lipolysis, were present at 1 week and 1 month after exposure. Collagen deposition in subdermal fatty tissue and in reticular dermis of some specimens was noted at 1 week and had increased at 1 month. Tissue treated with CW laser at 1470 nm demonstrated greater hemorrhage and more histiocytes at damage sites than tissue treated with pulsed laser at 1440 nm. There was a trend toward more collagen deposition with pulsed lasers than with CW lasers, but this was not statistically significant. Histopathologic comparison between results of CW laser at 980 nm vs pulsed laser at 1064 nm showed the same trend. Hemorrhage differences may result from pulse duration variations. A theoretical calculation estimating temperature rise in vessels supported this hypothesis.
Pulsed lasers with higher peak powers provided better hemostatic effects than CW lasers. The degree of lipolysis depended on wavelength, laser power, and energy density. Subdermal laser irradiation can stimulate collagen deposition in subdermal tissue and reticular dermis.
使用活体猪模型评估皮下脂肪分解和胶原蛋白沉积的急性和延迟激光效应，并比较连续波二极管（CW）与脉冲激光治疗后脂肪组织的组织学结果。
使用三台连续波激光（980、1370和1470nm）和三台脉冲激光（1064、1320和1440nm）治疗4只哥廷根小型猪。在注射克莱因肿胀液后，将激光套管插入一个10×2.5厘米矩形的顶部，并在皮下穿过以形成单独的激光“通道”。暴露后立即记录表面温度以及4毫米至20毫米深度处的温度，并将其与皮肤损伤相关联。在暴露后1天、1周和1个月获取全层皮肤活检标本，并用苏木精-伊红和三色染色法染色。进行定性和半定量组织病理学评估，重点关注血管损伤、脂肪分解和胶原蛋白沉积。
皮肤表面损伤发生在温度超过46°C时。暴露后1天的组织学检查显示出血、纤维胶原纤维凝固和脂肪细胞损伤。暴露后1周和1个月出现被组织细胞包围的脂肪细胞，这是脂肪分解的标志。在1周时注意到皮下脂肪组织和一些标本的网状真皮中有胶原蛋白沉积，在1个月时有所增加。与用1440nm脉冲激光治疗的组织相比，用1470nm连续波激光治疗的组织在损伤部位表现出更大的出血和更多的组织细胞。与连续波激光相比，脉冲激光有更多胶原蛋白沉积的趋势，但这在统计学上不显著。980nm连续波激光与1064nm脉冲激光结果的组织病理学比较显示相同趋势。出血差异可能源于脉冲持续时间的变化。估计血管中温度升高的理论计算支持了这一假设。
具有较高峰值功率的脉冲激光比连续波激光具有更好的止血效果。脂肪分解程度取决于波长、激光功率和能量密度。皮下激光照射可刺激皮下组织和网状真皮中的胶原蛋白沉积。
