Application of CO2 laser in the Neurosurgical Microscopic Operation

利用日本红外工业公司的60z激光器，比较了脉冲波形CO2激光器与连续波形CO2激光器的效果。在两种激光器功率相同的情况下，脉冲CO2激光照射引起的组织变化是连续CO2激光照射引起的组织变化的3倍。血脑屏障在暴露后24小时内损伤最大，但一周后仍能修复。接下来研究的激光器是CO2和YAG激光器的脉冲波，分别使用或同时使用日本红外工业公司的130 YZ。单用Nd:YAG激光照射止血效果最好，其次为CO2和Nd:YAG联合照射，CO2单用照射止血效果最差。CO2与Nd:YAG激光联合使用时，Nd:YAG激光功率越大，出血发生越少。激光联合照射的病变面积大于CO2或Nd:YAG激光单独照射的病变面积。Nd:YAG激光有助于增加病变直径，CO2激光有助于增加病变深度。研究了Nd:YAG和CO2激光束对动物微血管的影响。Nd:YAG激光照射后的脑组织软x线微血管造影和组织学检查显示，被照射脑组织及周围水肿组织有广泛的无血管或少血管区，其中存活血管变窄、变细，无明显出血。这些发现似乎与Nd:YAG激光的高止血能力相对应。另一方面，CO2激光照射后周围水肿层的血管结构不像Nd:YAG激光照射时受影响明显，凝血层中心蒸发组织缺损附近血管充血，有时血管破裂，可能导致暴露后出血。

The effect of puls-wave form CO2 laser was compared with that of continuous wave form using the 60z of Nihon-Infrared Industry Company. The tissue change by the puls wave form CO2 laser exposure was three times more than that of continous wave form CO2 laser if the power is the same in both lasers. The breakdown of the BBB was the greatest 24 hours after the exposure, but was still repaired one week thereafter.The lasers in the next study were pulse wave form CO2 and YAG lasers, employed separately or simultaneously using 130 YZ of Nihon Infrared Industries Company. The efficiency of laser exposure for hemostasis was greatest in Nd:YAG laser alone followed by combined CO2 and Nd:YAG laser and least in CO2 laser alone. In the combination of CO2 and Nd:YAG lasers, the more the power of Nd:YAG laser used, the less the hemorhage occurred. The size of the lesion by the combined laser exposure was greater than that of CO2 or Nd:YAG laser alone. Nd:YAG laser contributed to increase the diameter, and the CO2 laser the depth of the lesion.Effect of Nd:YAG and CO2 laser beam on micro-vasculature was examined in experimental animal. Soft x-ray microangiography and histological examination of brain after Nd:YAG laser exposure revealed broad avascular or oligovascular zone din the irradiated and the surrounding edematous tissue, in which the survived vessels showed narrowing and tapering without significant leak of blood. These findings seemed to correspond to high hemostatic capability of Nd:YAG laser. Vascular structure in the surrounding edematous layer after CO2 laser exposure, on the other hand, was not so significantly affected by exposure as in Nd:YAG laser, and congested and sometimes reptured vessels were found close to the central vaporized tissue defect in the coagulation layer which might cause postexposure hemorrhage.