Kautzky M, Susani M, Steurer M, Schenk P
Department of Otorhinolaryngology, University of Vienna Medical School, Austria.
Lasers Surg Med. 1997;20(3):265-71. doi: 10.1002/(sici)1096-9101(1997)20:3<265::aid-lsm5>3.0.co;2-o.
The specifics of the ablation mechanism of the holmium:YAG laser remain largely unexplored. Following laser exposure to the oral mucosa of rats, the ultrastructural damage profile obtaining to varying degrees in blood vessels, erythrocytes, nerves, and muscle cells was examined. An attempt was made to relate the cytoplasmatic alterations to the tissue ablation modes of midinfrared lasers described in the literature.
STUDY DESIGN/MATERIALS AND METHODS: The biological effects of a new pulsed holmium:YAG laser (lambda = 2,120 nm) on the oral mucosa of rats were examined by light and transmission electron microscopy. Laser incisions reaching into the muscle layer were made on different sites of the tongue of white rats. Laser energy (400 mJ, 2.5 microseconds pulse, 2 Hz) was delivered to the target via 400 microns nylon fibers.
The fine-structural morphology of the sublingual mucosa after laser surgery of the epithelial surface revealed no carbonization layer but a 150-micron-wide zone of lacunar structures extending to the lamina propria. In the muscle cells there is partial decomposition of the cell contents resulting in the development of electron optically empty spaces within the cortical cytoplasm underneath the intact plasma membrane of the muscle cell. The organelles within the cell remain ultrastructurally intact.
These features support the assumption of an additional nonthermal holmium:YAG laser-tissue interaction.
钬激光消融机制的具体细节在很大程度上仍未得到充分探索。在大鼠口腔黏膜接受激光照射后，对血管、红细胞、神经和肌肉细胞中不同程度出现的超微结构损伤情况进行了检查。尝试将细胞质改变与文献中描述的中红外激光组织消融模式联系起来。
研究设计/材料与方法：通过光学显微镜和透射电子显微镜检查了一种新型脉冲钬激光（波长 = 2120纳米）对大鼠口腔黏膜的生物学效应。在白色大鼠舌头的不同部位制作深入肌肉层的激光切口。激光能量（400毫焦，2.5微秒脉冲，2赫兹）通过400微米尼龙纤维传递至目标部位。
上皮表面激光手术后舌下黏膜的精细结构形态显示无碳化层，但有一个150微米宽的腔隙结构区域延伸至固有层。在肌肉细胞中，细胞内容物部分分解，导致在肌肉细胞完整质膜下方的皮质细胞质内出现电子光学上的空泡。细胞内的细胞器在超微结构上保持完整。
这些特征支持了钬激光与组织存在额外非热相互作用这一假设。
