Wollin Daniel A, Ackerman Anika, Yang Chen, Chen Tony, Simmons Walter Neal, Preminger Glenn M, Lipkin Michael E
Division of Urologic Surgery, Duke University Medical Center, Durham, NC.
Division of Urologic Surgery, Duke University Medical Center, Durham, NC.
Urology. 2017 May;103:47-51. doi: 10.1016/j.urology.2017.01.007. Epub 2017 Jan 16.
To more clearly define the efficiency and potential benefits of variable pulse-width laser technology for ureteroscopic lithotripsy, we performed comparative in vitro evaluations assessing stone comminution, laser fiber tip degradation, and stone retropulsion.
All experiments were conducted using a Swiss LaserClast Holmium:YAG laser (Electro Medical Systems, Nyon, Switzerland) with adjustable pulse duration (300 µs-1500 µs). To assess comminution efficiency and fiber tip degradation, a "dusting" model was employed; the laser fiber tip was moved by a 3-dimensional positioning system in a spiral motion across a flat BegoStone surface submerged in water. Comminution efficiency was measured as the loss of stone mass while fiber tip degradation was measured simultaneously. The same laser and fiber were used in a pendulum model to measure stone retropulsion with a high-speed resolution camera.
In our dusting model, comminution was significantly greater at high energy (2 J/5 Hz). At the high energy setting, comminution was significantly greater with long pulse duration than short pulse, although this difference was not seen at the high frequency setting (1 J/10 Hz). Tip degradation was increased at high energy settings and was even more pronounced with short pulse duration than long pulse. Short pulse duration caused far more retropulsion than the long pulse setting.
In an in vitro dusting model, a longer laser pulse duration provides effective stone comminution with the advantage of reducing laser fiber tip degradation and stone retropulsion.
为了更清晰地界定可变脉宽激光技术在输尿管镜碎石术中的效率和潜在益处，我们进行了比较性体外评估，以评估结石粉碎、激光光纤尖端降解和结石后推情况。
所有实验均使用瑞士LaserClast钬:钇铝石榴石激光（瑞士尼翁的电子医疗系统公司），其脉冲持续时间可调（300微秒 - 1500微秒）。为评估粉碎效率和光纤尖端降解情况，采用了“喷粉”模型；激光光纤尖端通过三维定位系统在浸没于水中的扁平BegoStone表面做螺旋运动。粉碎效率通过结石质量损失来衡量，同时测量光纤尖端降解情况。使用同一激光和光纤在摆锤模型中，用高速分辨率相机测量结石后推情况。
在我们的“喷粉”模型中，高能量（2焦耳/5赫兹）时粉碎效果显著更佳。在高能量设置下，长脉冲持续时间的粉碎效果明显优于短脉冲，尽管在高频率设置（1焦耳/10赫兹）下未观察到这种差异。高能量设置下尖端降解增加，短脉冲持续时间时比长脉冲更明显。短脉冲持续时间比长脉冲设置导致更多的结石后推。
在体外“喷粉”模型中，较长的激光脉冲持续时间能有效粉碎结石，具有减少激光光纤尖端降解和结石后推的优势。
