Liao Yunzhou, Zha Rongwei, Mei Xuehan, Wang Chenyang, Li Zhilong, Wang Huaixiong, Lei Cheng, Li Sheng, Wang Du, Wang Xinghuan
The Institute of Technological Sciences, Wuhan University, Wuhan, China.
Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China.
Int Urol Nephrol. 2025 Jun 5. doi: 10.1007/s11255-025-04584-1.
This study aims to explore the influence of different laser parameters on stone retropulsion and ablation rate during thulium fiber laser (TFL) lithotripsy, and to evaluate its dusting effect.
An experimental setup was designed to simultaneously measure the displacement and mass loss of stones. Ex vivo lithotripsy experiments were performed using a self-designed TFL system with average power ranging from 10 to 30 W, frequency from 10 to 1000 Hz and pulse energy from 25 to 3000 mJ. Stone retropulsion and ablation rates were systematically evaluated across various parameter configurations. Additionally, the size distribution of particles generated during lithotripsy was comprehensively assessed.
A higher average power resulted in a more intense stone retropulsion and a higher ablation rate. With a constant average power, both decreased as the frequency increased and the pulse energy decreased. The trend of mass loss was similar to that of the ablation rate. When the frequency was fixed, an increase in pulse energy significantly enhanced the retropulsion, whereas an increase in frequency at fixed pulse energy had a smaller impact on retropulsion. When the frequency reached 250 Hz and the pulse energy was reduced to 120 mJ, the stone retropulsion essentially disappeared. The maximum ablation rate (112.247 mg/min) was achieved at 10 Hz × 3000 mJ. For average powers fixed at 20 W and 10 W, the optimal parameters for the highest ablation rates were identified as 20 Hz × 1000 mJ and 20 Hz × 500 mJ, resulting in ablation rates of 65.451 mg/min and 40.742 mg/min, respectively. Under several representative configurations, all generated particles had diameters less than 600 μm.
Compared with frequency, pulse energy has a greater impact on both retropulsion and ablation rate. For non-fixed stones, increasing the pulse energy enhances the ablation rate but also intensifies the retropulsion effect, which can partially offset the increase in ablation rate. The TFL exhibits an excellent dusting effect. A conservative setting of 10 W, frequency below 50 Hz and pulse energy above 200 mJ can be referenced for clinical application.
本研究旨在探讨不同激光参数对铥光纤激光（TFL）碎石术中结石回退和消融率的影响，并评估其粉末化效果。
设计了一个实验装置来同时测量结石的位移和质量损失。使用自行设计的TFL系统进行体外碎石实验，平均功率范围为10至30 W，频率为10至1000 Hz，脉冲能量为25至3000 mJ。系统评估了各种参数配置下的结石回退和消融率。此外，还全面评估了碎石过程中产生的颗粒的尺寸分布。
较高的平均功率导致更强的结石回退和更高的消融率。在平均功率恒定的情况下，随着频率增加和脉冲能量降低，两者均下降。质量损失趋势与消融率相似。当频率固定时，脉冲能量增加会显著增强回退，而在固定脉冲能量下频率增加对回退的影响较小。当频率达到250 Hz且脉冲能量降至120 mJ时，结石回退基本消失。在10 Hz×3000 mJ时达到最大消融率（112.247 mg/min）。对于固定在20 W和10 W的平均功率，最高消融率的最佳参数分别确定为20 Hz×1000 mJ和20 Hz×500 mJ，消融率分别为65.451 mg/min和40.742 mg/min。在几种代表性配置下，所有产生的颗粒直径均小于600μm。
与频率相比，脉冲能量对回退和消融率的影响更大。对于非固定结石，增加脉冲能量可提高消融率，但也会增强回退效应，这可能会部分抵消消融率的增加。TFL表现出出色的粉末化效果。临床应用可参考保守设置10 W、频率低于50 Hz和脉冲能量高于200 mJ。
