V01-01: Prospective Transurethral Lithotripsy Study with SuperPulse Tm Fiber Laser
Laser lithotripsy is widely accepted as a first-line modality for treatment of many diagnoses of urinary tract stones. The de facto gold standard laser source for lithotripsy is a Ho:YAG laser emitting at the wavelength of 2.10 µm. Recently, a novel SuperPulse Tm fiber laser emitting at 1.94 µm has been introduced for this purpose. In this work, we evaluated performance of the SuperPulse Tm Fiber Laser system in a prospective clinical study.
SuperPulse Tm fiber laser has been cleared for clinical use by the Ministry of Health of Russian Federation. The study protocol has been approved by the institutional Ethical Review Board. SuperPulse Tm fiber laser system capable of operation with up to 40 W average power, 0.025 – 6 J pulse energy and 1600 Hz rep rate was used in this study. The study is on-going. Up to October 2018, total of 214 subjects (age range 19-83) have been enrolled into the study and total of 238 stones have been surgically treated with the device. Routine preoperative exam included multispiral CT (MCT) scan with the evaluation of stone density and location. Total procedure time, laser on time, stone extraction (when applicable) time were assessed. Control exam with kidney MCT was provided 30 days after operation.
Stone free-rates (no residual fragments) were 94% for kidney stones, 96% for ureter stones and 100% for bladder stones 30 days post treatment. On the dataset obtained and analyzed so far, the operation time and the laser on time varied between 4 to 38 min and 12 s to 14.4 min, respectively. No accidental damage of soft tissues was observed. The post-operative hospital stay time was 2.4 days on average. Optimal parameters in this study were found to be 0.1 – 0.2 J and rep rate 100 – 300 Hz for fine dusting and pop corning, 0.2 – 0.5 J and 50 – 150 Hz for dusting and 1 – 5 J and 10 to 40 Hz for fragmentation.
Data available so far indicate that SuperPulse Thulium fiber laser is efficacious and safe for lithotripsy. Longer-term follow ups are necessary to validate this conclusion.