Laser lithotripsy mechanisms can cause the chemical decomposition of stone components and the emergence of different end products. However, the potentially toxic end products formed during thulium fiber laser (TFL) lithotripsy of cystine stones have not been sufficiently investigated. The aim of our in vitro study is to analyze the chemical content of the gas products formed during the fragmentation of cystine stone with TFL. Human renal calculi consisting of 100% pure cystine, calcium oxalate monohydrate, or uric acid were fragmented separately with TFL in experimental setups and observed for gas release. After the lithotripsy, only the cystine stones showed gas formation. Gas chromatography-mass spectrometry was used to analyze the gas qualitatively, and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) and X-ray diffraction was used to examine the dried cystine stone fragments. Fragmentation of the cystine stones released free cystine, sulfur, hydrogen sulfide, and carbon disulfide gas. The SEM-EDX and X-ray diffraction analyses revealed that the free cystine in the dried fragments contained 43.1% oxygen, 28.7% sulfur, 16.1% nitrogen, and 12.1% carbon atoms according to atomic weight. The detection of potentially toxic gases after lithotripsy of cystine stones with TFL indicates a risk of in vivo production. Awareness needs to be increased among healthcare professionals to prevent potential inhalation and systemic toxicity for patients and operating room personnel during TFL lithotripsy of cystine stones.

Background and Objectives: In the surgical treatment of benign prostatic hyperplasia (BPH), laser enucleation of the prostate is recommended as an alternative to transurethral resection (TURP) and open prostatectomy (OP). The thulium fiber laser, with its superficial penetration depth, can offer a rapid learning process by causing less heat injury and capsule damage. This study compares the first 60 cases of an endourologist performing thulium fiber enucleation of the prostate (ThuFLEP) without a mentor to the results of OP and TURP performed by experienced surgeons. It also identifies the case number at which the operation time for ThuFLEP starts to plateau. Materials and Methods: Between 1 November 2021 and 1 November 2023, the initial 60 ThuFLEP cases of an endourologist with no prior enucleation experience were compared with TURP and OP operations performed by experienced surgeons. Since the first 60 ThuFLEP cases involved 80-120 cc prostates, TURP and OP operations within this size range performed during the same period were included in the study. The groups were assessed for age, preoperative and postoperative prostate volume, PSA levels, the IPSS, the IPSS Quality of Life (QoL), and maximum urinary flow (Qmax). The 60 consecutive ThuFLEP cases were divided into three groups of 20 (Groups 1, 2, and 3) and compared for operation time, IPSS, and Qmax. Results: The operation time for TURP was shorter than for ThuFLEP and OP (p < 0.001). There was no significant difference between ThuFLEP and OP in postoperative Qmax and IPSS, while TURP had lower values than the other two methods. For ThuFLEP, the operation time was longer in the first 20 cases but plateaued in groups 2 and 3 (p < 0.001). Postoperative Qmax and IPSS values showed no significant differences among the three ThuFLEP groups (p > 0.05). Conclusions: For large prostates, ThuFLEP provides better postoperative results than TURP and offers shorter catheterization and hospital stay times than OP. Its short learning curve makes it a preferable method for treating BPH compared to other laser techniques.

OBJECTIVE: To evaluate the stone ablation rate and direct thermal damage from thulium fiber laser (TFL) lithotripsy using continuous (C) and burst (B) lasing techniques on an in vitro ureteral model.
METHODS: The TFL Drive (Coloplast, Humlebaek, Denmark) was used in an in vitro saline-submerged ureteral model. Ten participants, including five junior and five experienced urologists, conducted the experimental setup with 7 different settings comparing two lasing techniques: steady-state lasing (0.5 J/10 Hz = 5W for 300 s and 0.5 J/20 Hz = 10W for 150 s) and burst, intermittent 5 s on/off lasing (0.5 J/20 Hz, 0.5 J/30 Hz, 0.5 J/60 Hz, 0.1 J/200 Hz, and 0.05 J/400 Hz) with a target cumulative energy of 1500 J using cubic 125 mm3 phantom BegoStonesTM. Ureteral damage was graded 1-3 based on the severity of burns and holes observed on the surface of the ureteral model.
RESULTS: The were no significant differences in stone ablation mass neither between C and B lasing techniques, nor between expertise levels. At C lasing technique had only mild ureteral lesions with no significant differences between expertise levels (p: 0.97) or laser settings (p: 0.71). At B lasing technique, different types of thermal lesions were found with no expertise (p: 0.11) or setting (p: 0.83) differences. However, B laser setting had higher grade direct thermal lesions than C (p: 0.048).
CONCLUSIONS: Regarding efficacy, C and B lasing techniques achieve comparable stone ablation rates. Safety-wise, B lasing mode showed higher grade of direct thermal lesions. These results should be further investigated to verify which of the lasing mode is the safest in vivo. Until then and unless proven otherwise, a C mode with low frequency should be recommended to avoid ureteral wall lesions.

暂无摘要。

Through an ex vivo experimental study, we aimed to compare the effects of the Ho: YAG laser Virtual Basket (VB™) modulation and a Thulium fiber laser (TFL) on kidney tissue in different environments and using laser configurations. The 100 W Ho: YAG (Cyber Ho, Quanta System, Italy) and 60 W TFL (Fiber Dust, Quanta System, Italy) laser devices were used. The following laser settings were selected: power in the range of 10-60 W, frequency of 20-40 Hz, and energy of 0.5-1-1.5 J. A medium pulse duration of 600 µsec was used for VB™, while short (spdTFL; 50 µsec) and long (lpdTFL; 15,000 µsec) were used for TFL. The tissue\'s incision depth (ID), vaporization area (VA), coagulation area (CA), total laser area (TLA = VA + CA), surface section (SS), and lateral effect (LE) were measured. In total, 108 experiments were conducted. No statistically significant difference in mean VA, TLA, ID, LE, or SS was observed between VB™, spdTFL, and lpdTFL in the low-power output group in saline (p > 0.05). However, the mean CA was statistically significantly higher for VB™ (p = 0.005). In saline and high-power output group, the mean VA, CA, TLA, LE, and ID were higher when using lpdTFL than other pulse durations (p = 0.001, p = 0.001, p = 0.001, p = 0.006, and p = 0.001, respectively). Similar to lpdTFL, VB™ may provide controlled dissection and incision as well as haemostasis. At different laser settings, the individual effects of laser properties (such as pulse length, energy and frequency) on tissue may be more significant.

Introduction: The thulium fiber laser (TFL) generates a focused beam, which can be transmitted to laser fibers with small core diameters and may facilitate in situ lower-pole lithotripsy. This study compares lithotripsy performance of the 150 and 200 µm TFL in a lower pole benchtop kidney model. Materials and Methods: Using a 3D model printed from an actual kidney, in situ laser lithotripsy was performed on 1 cm lower-pole BegoStones (calcium oxalate monohydrate consistency) using four different settings (all 20W) and two fiber sizes (150 and 200 µm). Procedure time, laser time, total pulse energy, and fiber stripping were compared between the two fibers using an ANOVA or independent t-test. Results: The 150 µm fiber at 0.2 J × 100 Hz had the shortest lasing and procedure time (17.3 and 18.5 minutes) and lowest total pulse energy (20.75 kJ) compared with other study arms (p < 0.001). Overall procedure time, lasing time, and total pulse energy were significantly different between the 8 settings (p < 0.001 for all). At higher frequency (100 and 200 Hz), lasing time was significantly faster compared with 20 and 50 Hz (19.9 vs 27.3 minutes; p < 0.001). Furthermore, the average total procedure time was shorter with 150 µm compared with 200 µm regardless of settings (23.2 vs 29.8 minutes; p < 0.001). Conclusion: The 150 µm fiber results in shorter procedure and lasing time at lower total energy levels during lower-pole in situ lithotripsy. Overall, the fastest setting was 0.2 J and 100 Hz with the 150 µm fiber. Smaller laser fibers can potentially allow more efficient in situ laser lithotripsy with better irrigation and visibility at higher deflection angles.

暂无摘要。

OBJECTIVE: Thulium fiber laser (TFL) emerged as a competitor of holmium:yttrium-aluminum-garnet (Ho:YAG) laser for anatomic enucleation of the prostate (AEEP) in men with lower urinary tract symptoms (LUTS) related to benign prostatic obstruction (BPO). The aim was to compare the surgical outcomes of Ho:YAG and TFL for AEEP.
METHODS: A literature search was conducted to identify reports published from inception until January 2024. The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed to identify eligible studies. The coprimary outcomes were the postoperative International Prostate Symptom Score (IPSS), IPSS-Quality of Life (IPSS-QoL), and peak urinary flow (Qmax).
UNASSIGNED: Five studies met our inclusion criteria, and data from 1287 and 1555 patients who underwent AEEP with Ho:YAG (holmium laser enucleation of the prostate [HoLEP]) and TFL (thulium fiber laser enucleation of the prostate [ThuFLEP]), respectively, were reviewed. ThuFLEP was associated with a better IPSS at 3 mo even if the difference was not clinically significant (mean difference [MD] 0.59, 95% confidence interval [CI]: 0.29-0.88; p < 0.001). No difference was found for IPSS at 6-12 mo (p = 0.9), and IPSS-QoL at 3 mo (p = 0.9) and 6-12 mo (p = 0.2). HoLEP was associated with a better Qmax at 3 mo (MD 1.41 ml/s, 95% CI: 0.51-2.30; p = 0.002) and ThuFLEP at 6-12 mo (MD -2.61 ml/s, 95% CI: -4.68 to 0.59; p = 0.01), but the differences were not clinically significant. No difference was found in the major (p = 0.3) and overall (p = 0.3) complication rates. HoLEP was associated with shorter enucleation (MD -11.86, 95% CI: -22.36 to 1.36; p = 0.03) but not total operative time (p = 0.5).
CONCLUSIONS: The present review provides the most updated evidence on the impact of Ho:YAG and TFL in AEEP, demonstrating that these two energy sources are effective in relieving bothersome LUTS in men with BPO.
RESULTS: Thulium fiber laser is a new energy source that can be used safely for performing endoscopic enucleation of the prostate in men with bothersome symptoms associated with benign prostatic enlargement.

This study aims to identify optimal parameters for using Thulium fiber lasers (TFL) in ureteral stone lithotripsy to ensure laser safety and maximize efficacy. Our goal is to improve the outcomes of single-use semi-rigid ureteroscopy for treating stones located in the proximal ureter. A clinically relevant thermal testing device was designed to investigate heating effects during TFL stone fragmentation. The device was utilized to identify safe power thresholds for TFL at various irrigation rates. Three other devices were used to assess varying pulse energy effects on stone fragmentation efficiency, dusting, retropulsion, and depth of tissue vaporization. Comparative experiments in fresh porcine renal units were performed to validate the efficacy and safety of optimal TFL parameters for semi-rigid ureteroscopy in proximal ureteral stone procedures. Our study found that the improved device generated a higher thermal effect. Furthermore, the safe power threshold for laser lithotripsy increased as the irrigation rate was raised. At an irrigation rate of 40 ml/min, it is safe to use an average power of less than 30 watts. Although increasing pulse energy has a progressively lower effect on fragmentation and dust removal efficiency, it did lead to a linear increase in stone displacement and tissue vaporization depth. Thermal testing showed 20 W (53.87 ± 2.67 °C) indicating potential urothelial damage. In our study of laser lithotripsy for proximal ureteral stones, the group treated with 0.3 J pulses had several advantages compared to the 0.8 J group: Fewer large fragments (> 4 mm): 0 vs. 1.67 fragments (1-2.25), p = 0.002, a lower number of collateral tissue injuries: 0.50 (0-1.25) vs. 2.67 (2-4), p = 0.011, and lower stone retropulsion grading: 0.83 (0.75-1) vs. 1.67 (1-2), p = 0.046. There was no significant difference in operating time between the groups (443.33 ± 78.30 s vs. 463.17 ± 75.15 s, p = 0.664). These findings suggest that TFL irradiation generates a greater thermal effect compared to non-irradiated stones. Furthermore, the thermal effect during laser lithotripsy is influenced by both power and irrigation flow rate. Our study suggests that using a power below 15 W with an irrigation flow rate of 20 ml/min is safe. Moreover, a pulse energy of 0.3 J appears to be optimal for achieving the best overall stone fragmentation effect.

OBJECTIVE: This study aimed to evaluate the ability of Kidney Stone Calculator (KSC), a flexible ureteroscopy surgical planning software, to predict the lithotripsy duration with both holmium:YAG (Ho:YAG) and thulium fiber laser (TFL).
METHODS: A multicenter prospective study was conducted from January 2020 to April 2023. Patients with kidney or ureteral stones confirmed at non-contrast computed tomography and treated by flexible ureteroscopy with laser lithotripsy were enrolled. \"Kidney Stone Calculator\" provided stone volume and subsequent lithotripsy duration estimation using three-dimensional segmentation of the stone on computed tomography and the graphical user interface for laser settings. The primary endpoint was the quantitative and qualitative comparison between estimated and effective lithotripsy durations. Secondary endpoints included subgroup analysis (Ho:YAG-TFL) of differences between estimated and effective lithotripsy durations and intraoperative outcomes. Multivariate analysis assessed the association between pre- and intraoperative variables and these differences according to laser source.
RESULTS: 89 patients were included in this study, 43 and 46 in Ho:YAG and TFL groups, respectively. No significant difference was found between estimated and effective lithotripsy durations (27.37 vs 28.36 min, p = 0.43) with a significant correlation (r =  + 0.89, p < 0.001). Among groups, this difference did not differ (p = 0.68 and 0.07, respectively), with a higher correlation between estimated and effective lithotripsy durations for TFL compared to Ho:YAG (r =  + 0.95, p < 0.001 vs r =  + 0.81, p < 0.001, respectively). At multivariate analysis, the difference was correlated with preoperative (volume > 2000 mm3 (Ho:YAG), 500-750 mm3 SV and calyceal diverticulum (TFL)), operative (fragmentation setting (p > 0.001), and basket utilization (p = 0.05) (Ho:YAG)) variables.
CONCLUSIONS: KSC is a reliable tool for predicting the lithotripsy duration estimation during flexible ureteroscopy for both Ho:YAG and TFL. However, some variables not including laser source may lead to underestimating this estimation.