Division of Urotechnology, Department of Urology, Faculty of Medicine, Medical Centre - University of Freiburg, University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany.
World J Urol. 2018 Sep;36(9):1469-1475. doi: 10.1007/s00345-018-2303-x. Epub 2018 Apr 24.
To evaluate the thermal effect of Ho:YAG laser lithotripsy in a standardized in vitro model via real-time temperature measurement.
Our model comprised a 20 ml test tube simulating the renal pelvis that was immersed in a 37 °C water bath. Two different laser fibers [FlexiFib (15-45 W), RigiFib 1000 (45-100 W), LISA laser products OHG, Katlenburg-Lindau, Germany] were placed in the test tube. An Ho:YAG 100 W laser was used in all experiments (LISA). Each experiment involved 120 s of continuous laser application, and was repeated five times. Different laser settings (high vs. low frequency, high vs. low energy, and long vs. short pulse duration), irrigation rates (0 up to 100 ml/min, realized by several pumps), and human calcium oxalate stone samples were analyzed. Temperature data were acquired by a real-time data logger with thermocouples (PICO Technology, Cambridgeshire, UK). Real-time measurements were assessed using MatLab.
Laser application with no irrigation results in a rapid increase in temperature up to ∆28 K, rising to 68 °C at 100 W. Low irrigation rates yield significantly higher temperature outcomes. Higher irrigation rates result immediately in a lower temperature rise. High irrigation rates of 100 ml/min result in a temperature rise of 5 K at the highest laser power setting (100 W).
Ho:YAG laser lithotripsy might be safe provided that there is sufficient irrigation. However, high power and low irrigation resulted in potentially tissue-damaging temperatures. Laser devices should, therefore, always be applied in conjunction with continuous, closely monitored irrigation whenever performing Ho:YAG laser lithotripsy.
通过实时温度测量，在标准化的体外模型中评估 Ho:YAG 激光碎石术的热效应。
我们的模型由一个模拟肾盂的 20ml 试管组成，试管浸泡在 37°C 的水浴中。两种不同的激光光纤[FlexiFib（15-45W）、RigiFib 1000（45-100W），LISA 激光产品 OHG，德国卡德伯格-林道]被放置在试管中。所有实验均使用 Ho:YAG 100W 激光（LISA）。每个实验包括 120s 的连续激光应用，重复五次。分析了不同的激光设置（高频与低频、高能与低能、短脉冲与长脉冲持续时间）、冲洗率（0 至 100ml/min，由多个泵实现）和人草酸钙结石样本。使用带热电偶的实时数据记录仪（英国剑桥郡的 PICO Technology）采集温度数据。使用 MatLab 评估实时测量结果。
无冲洗的激光应用会导致温度迅速升高，达到∆28K，在 100W 时升高到 68°C。低冲洗率会产生显著更高的温度结果。较高的冲洗率会立即导致温度升高降低。最高激光功率设置（100W）时，100ml/min 的高冲洗率会导致温度升高 5K。
只要有足够的冲洗，Ho:YAG 激光碎石术可能是安全的。然而，高功率和低冲洗会导致潜在的组织损伤温度。因此，在进行 Ho:YAG 激光碎石术时，应始终将激光设备与连续、密切监测的冲洗结合使用。
