评估脉冲CO2激光和Er:YAG激光用于颅骨组织消融的可行性与有效性。以健康新西兰兔为实验动物,常规手术暴露颅盖骨组织,并置于由计算机自动控制的一维电动平移台上,调节工作距离和扫描速率,分别用两种激光进行非接触式垂直扫描照射,获得长约3 cm的消融凹槽。以电钻为对照组,肉眼和显微镜观察切削凹槽形貌和形态学改变;常规病理切片并摄取图像,测量切削凹槽截面几何尺寸和不同部位热损伤厚度,分析比较两种波长激光的消融率和消融效率。结果表明,两种激光都可以用于骨头的切削,并产生类似电钻的切削效果。脉冲CO2激光的消融率高于Er:YAG激光,但热损伤严重;Er:YAG激光可以获得更高的消融效率和更小的热损伤,其切削效果优于脉冲CO2激光。此外,血液对光的吸收会影响消融效率和热损伤,临床应用中必须尽量减少出血量。

The feasibility and validity of skull tissue ablation with pulse CO2 and Er:YAG lasers were evaluated. Healthy male New Zealand rabbits in vivo were used in the experiment. Skull tissue of animal model was completely exposed by surgeon with conventional methods,and then put on a PC-controlled motorized linear drive stage and moved repeatedly through the focused beam of both lasers with certain work distance and moving rate until an about 3 cm length ablation groove was obtained. Diamond drill was used as control group. The appearance and morphological changes of ablation groove were observed by naked eye and microscope. Following traditional histological process,the micrographs of ablation groove′s cross-section slices were obtained,and its geometry and thermal injury thickness were measured. The ablation rate and ablation efficiency for both lasers were also compared. It shows that both lasers can be used for bone hard tissue ablation and similar outcomes as diamond drill were obtained. Pulse CO2 laser presents high ablation rate with strong thermal damage,while Er:YAG laser shows better outcomes compared with CO2 laser with higher ablation efficiency and smaller thermal injury. Furthermore,light absorption by blood during operation will reduce ablation efficiency and increase thermal injury which should be controlled efficiently in clinical application.