Yamamoto H, Uchibayashi T, Namiki M
Department of Urology, Toyama Prefectural Central Hospital.
Nihon Hinyokika Gakkai Zasshi. 1997 Oct;88(10):885-91. doi: 10.5980/jpnjurol1989.88.885.
We report basic animal experimental study which was evaluated the thermocoagulation effects of two different type of Nd:YAG laser (pulse and continuous wave (CW) laser).
The Rotalase internally reflecting fiber delivery system coupled to the pulse and CW Nd:YAG laser was used to create lesions in Seminoma tissue implanted Scid mice with the fiber tip 2 mm away from the target tissue under the water. Laser power output used was 20, 40 and 60-watt for varying times (30-180 sec) of irradiation. Stationary lesions, where a single spot of target was irradiated, were created. On the other hand, we measured tissue temperatures at 7, 10 and 14 mm from tissue surface. The seminoma tissues removed from Scid mice were photographed after bisection, the fixed in 10% formalin and examined histologically.
For the purpose of these experiments, ablated tissue is defined as the volume of tissue that has been destroyed by both coagulation and vaporization. Estimates of the volume of ablated tissue were made by macroscopic examination of the bisected lesion, measuring the depth and width of the lesion as seen from the edges of the coagulated area around vaporized zone. The mean depth and width penetration, volume ablation and rising of the tissue temperature at pulsed 60-watt, 60 seconds was greater than that observed at other groups. Irradiated spot lesions were characterized by an initial 10-20 second period of tissue blanching followed by an audible "popcorn phenomenon" which meant more than 100 degrees C in tissue temperature, then formation of small surface bubbles as tissue began to evaporate and char.
This study suggests the potential usefulness of the pulse Nd:YAG laser for Visual Laser Ablation of the Prostate (VLAP).
我们报告了一项基础动物实验研究，该研究评估了两种不同类型的Nd:YAG激光（脉冲激光和连续波（CW）激光）的热凝效果。
将与脉冲和连续波Nd:YAG激光耦合的Rotalase内部反射光纤传输系统用于在植入了精原细胞瘤组织的Scid小鼠中制造损伤，光纤尖端在水下距靶组织2毫米处。使用的激光功率输出为20、40和60瓦，照射时间不同（30 - 180秒）。制造了固定损伤，即对单个靶点进行照射。另一方面，我们在距组织表面7、10和14毫米处测量了组织温度。从Scid小鼠身上取出的精原细胞瘤组织在切成两半后拍照，然后固定在10%福尔马林中并进行组织学检查。
对于这些实验，消融组织被定义为通过凝固和汽化而被破坏的组织体积。通过对切开的损伤进行宏观检查，测量从汽化区周围凝固区域边缘观察到的损伤深度和宽度，来估计消融组织的体积。在60瓦脉冲、60秒时，平均深度和宽度穿透、体积消融以及组织温度升高均大于其他组观察到的情况。照射的点状损伤的特征是最初10 - 20秒的组织变白期，随后是可听到的“爆米花现象”，这意味着组织温度超过100摄氏度，然后随着组织开始蒸发和碳化形成小的表面气泡。
本研究表明脉冲Nd:YAG激光在前列腺可视激光消融术（VLAP）中具有潜在的应用价值。
