Comparative Analyses and Ablation Efficiency of Thulium Fiber Laser by Stone Composition.

PURPOSE: There are limited data on ablation effects of thulium fiber laser (TFL) settings with varying stone composition. Similarly, little is known surrounding the photothermal effects of TFL lithotripsy regarding the chemical and structural changes after visible char formation. We aim to understand the TFL's ablative efficiency across various stone types and laser settings, while simultaneously investigating the photothermal effects of TFL lithotripsy. MATERIALS AND METHODS: Human specimens of calcium oxalate monohydrate, calcium oxalate dihydrate, uric acid, struvite, cystine, carbonate apatite, and brushite stones were ablated using 13 prespecified settings with the Coloplast TFL Drive. Pre- and postablation mass, ablation time, and total energy were recorded. Qualitative ablative observations were recorded at 1-minute intervals with photographs and gross description. Samples were analyzed with Fourier-transform infrared spectroscopy pre- and postablation and electron microscopy postablation to assess the photothermal effects of TFL. RESULTS: Across all settings and stone types, 0.05 J × 1000 Hz was the best numerically efficient ablation setting. When selected for more clinically relevant laser settings (ie, 10-20 W), 0.2 J × 100 Hz, short pulse was the most numerically efficient setting for calcium oxalate dihydrate, cystine, and struvite stones. Calcium oxalate monohydrate ablated with the best numerical efficiency at 0.4 J × 40 Hz, short pulse. Uric acid and carbonate apatite stones ablated with the best numerical efficiency at 0.3 J × 60 Hz, short pulse. Brushite stones ablated with the best numerical efficiency at 0.5 J × 30 Hz, short pulse. Pulse duration impacted ablation effectiveness greatly with 6/8 (75%) of inadequate ablations occurring in medium or long pulse settings. The average percent of mass lost during ablation was 57%; cystine stones averaged the highest percent mass lost at 71%. Charring was observed in 36/91 (40%) specimens. Charring was most often seen in uric acid, cystine, and brushite stones across all laser settings. Electron microscopy of char demonstrated a porous melting effect different to that of brittle fracture. Fourier-transform infrared spectroscopy of brushite char demonstrated a chemical composition change to amorphous calcium phosphate. CONCLUSIONS: We describe the optimal ablation settings based on stone composition, which may guide urologists towards more stone-specific care when using thulium laser for treating renal stones (lower energy settings would be safer for ureteral stones). For patients with unknown stone composition, lasers can be preset to target common stone types or adjusted based on visual cues. We recommend using short pulse for all TFL lithotripsy of calculi and altering the settings based on visual cues and efficiency to minimize the charring, an effect which can make the stone refractory to further dusting and fragmentation.

Thulium laser en bloc resection reduces recurrence rates in NMIBC patients with tumor diameters ≥3cm compared to transurethral resection: a non-randomized controlled study.

PURPOSE: The advantages of en bloc resection of bladder tumors (ERBT) over transurethral resection of bladder tumors (TURBT) in terms of patient prognosis are not yet clear, and there are some technical limitations. We aimed to compare the tumor recurrence in non-muscle invasive bladder cancer (NMIBC) patients with tumor diameter ≥ 3 cm undergoing either TURBT or thulium laser ERBT. METHODS: The patients included were those diagnosed with NMIBC based on pathological confirmation and underwent TURBT or modified thulium laser ERBT in the Department of Urology at Tongji Hospital from 2019 to 2024. The patients' medical records were meticulously collected and postoperative follow-up was diligently conducted by trained personnel. Recurrence-free survival curves were generated utilizing the Kaplan-Meier method, and group comparisons were performed using the log-rank trend test. To minimize biases, we employed stratified survival analysis, alongside univariate and multivariate Cox regression analysis. RESULTS: This study included a total of 396 patients with NMIBC, with 214 undergoing TURBT and 182 undergoing ERBT. For all patients, there was no significant difference (P = 0.180) in RFS between the TURBT and ERBT groups. For patients with tumor diameter ≥ 3 cm, stratified analysis revealed that the RFS of the ERBT group was significantly better than that of the TURBT group (P = 0.033). However, in patients with tumor diameter < 3 cm, there was no significant difference (P = 0.150) between the two groups. Univariate (HR: 0.52, 95% CI 0.28-0.96, P = 0.036) and multivariate (HR: 0.49, 95% CI 0.25-0.93, P = 0.031) Cox analyses revealed that ERBT was an independent protective factor for recurrence in NMIBC patients with tumor diameter ≥3cm. CONCLUSION: This study found that thulium laser ERBT may offer advantages in managing NMIBC patients with tumor diameters ≥ 3 cm. This could potentially drive the clinical application of thulium laser ERBT. TRIAL REGISTRATION: Protocol was registered at Chinese Clinical Trial Register (ChiCTR) with number ChiCTR2000035407 on 12 August 2020.

Holmium:yttrium-aluminium-garnet laser with MOSES technology is more efficient than thulium fibre laser in supine mini-percutaneous nephrolithotomy.

OBJECTIVES: To address the paucity of literature comparing outcomes achieved with utilisation of the high-power holmium:yttrium-aluminium-garnet (Ho:YAG) laser with MOSES technology vs those achieved with the thulium fibre laser (TFL) in mini-percutaneous nephrolithotomy (PCNL). METHODS: A retrospective review was performed of patients undergoing supine mini-PCNL between August 2021 and May 2023. Exclusion criteria were urinary diversion, simultaneous utilisation of >1 laser platform, use of any other form of fragmentation, and ureteric stones. The Ho:YAG platform (Lumenis Pulse P120H™ with MOSES technology, 120W; Boston Scientific®) and the TFL (Soltive SuperPulsed Thulium Fibre [SPTF], 60W; Olympus®) were compared. Data on stone-free rate (SFR) were determined by computed tomography performed on the first postoperative day and presented as absence of stone fragments, no fragments larger than 2 mm, or no fragments larger than 4 mm. RESULTS: A total of 100 patients met the inclusion criteria, 51 mini-PCNLs with the Ho:YAG laser and 49 with the SPTF laser. No significant differences in demographics or stone characteristics were detected between the two groups. The Ho:YAG laser utilised less energy and time, resulting in higher ablation efficiency (P < 0.05) and less total operating time (P < 0.05). Overall, there was no difference in SFR in any category between the Ho:YAG group and the SPTF group (no fragments: relative risk [RR] 0.81, 95% confidence interval [CI] 0.59-1.12, P = 0.21; fragments <2 mm: RR 0.86, 95% CI 0.67-1.10, P = 0.23; fragments <4 mm: RR 0.96, 95% CI 0.80-1.15, P = 0.67). CONCLUSIONS: Although we observed an equivalent postoperative SFR, this study supports a shorter operating time and greater intra-operative laser efficiency with the Ho:YAG laser over the SPTF laser in mini-PCNL.

Exploring optimal settings for safe and effective thulium fibre laser lithotripsy in a kidney model.

OBJECTIVES: To explore the optimal laser settings and treatment strategies for thulium fibre laser (TFL) lithotripsy, namely, those with the highest treatment efficiency, lowest thermal injury risk, and shortest procedure time. MATERIALS AND METHODS: An in vitro kidney model was used to assess the efficacy of TFL lithotripsy in the upper calyx. Stone ablation experiments were performed on BegoStone phantoms at different combinations of pulse energy (EP ) and frequency (F) to determine the optimal settings. Temperature changes and thermal injury risks were monitored using embedded thermocouples. Experiments were also performed on calcium oxalate monohydrate (COM) stones to validate the optimal settings. RESULTS: High EP /low F settings demonstrated superior treatment efficiency compared to low EP /high F settings using the same power. Specifically, 0.8 J/12 Hz was the optimal setting, resulting in a twofold increase in treatment efficiency, a 39% reduction in energy expenditure per unit of ablated stone mass, a 35% reduction in residual fragments, and a 36% reduction in total procedure time compared to the 0.2 J/50 Hz setting for COM stones. Thermal injury risk assessment indicated that 10 W power settings with high EP /low F combinations remained below the threshold for tissue injury, while higher power settings (>10 W) consistently exceeded the safety threshold. CONCLUSIONS: Our findings suggest that high EP /low F settings, such as 0.8 J/12 Hz, are optimal for TFL lithotripsy in the treatment of COM stones. These settings demonstrated significantly improved treatment efficiency with reduced residual fragments compared to conventional settings while keeping the thermal dose below the injury threshold. This study highlights the importance of using the high EP /low F combination with low power settings, which maximizes treatment efficiency and minimizes potential thermal injury. Further studies are warranted to determine the optimal settings for TFL for treating kidney stones with different compositions.

Comparison of holmium:yttrium-aluminium-garnet (YAG), thulium fiber laser, and pulsed thulium:YAG lasers on soft tissue: an ex vivo study.

OBJECTIVES: To assess laser-tissue interactions through ablation, coagulation, and carbonisation characteristics in a non-perfused porcine kidney model between three pulsed lasers: holmium (Ho): yttrium-aluminium-garnet (YAG), thulium fiber laser (TFL), and pulsed thulium (p-Tm):YAG. MATERIALS AND METHODS: A 150-W Ho:YAG, a 60-W TFL, and a 100-W p-Tm:YAG lasers were compared. The laser settings that can be set identically between the three lasers and be clinically relevant for prostate laser enucleation were identified and used on fresh, unfrozen porcine kidneys. Laser incisions were performed using stripped laser fibers of 365 and 550 µm, set at distances of 0 and 1 mm from the tissue surface at a constant speed of 2 mm/s. Histological analysis evaluated shape, depth, width of the incision, axial coagulation depth, and presence of carbonisation. RESULTS: Incision depths, widths, and coagulation zones were greater with Ho:YAG and p-Tm:YAG lasers than TFL. Although no carbonisation was found with the Ho:YAG and p-Tm:YAG lasers, it was common with TFL, especially at high frequencies. The shapes of the incisions and coagulation zones were more regular and homogeneous with the p-Tm:YAG laser and TFL than with Ho:YAG laser. Regardless of the laser used, short pulse durations resulted in deeper incisions than long pulse durations. Concerning the distance, we found that to be effective, TFL had to be used in contact with the tissue. Finally, 365-µm fibers resulted in deeper incisions, while 550-µm fibers led to wider incisions and larger coagulation zones. CONCLUSION: Histological analysis revealed greater tissue penetration with the p-Tm:YAG laser compared to the TFL, while remaining less than with Ho:YAG. Its coagulation properties seem interesting insofar as it provides homogeneous coagulation without carbonisation, while incisions remained uniform without tissue laceration. Thus, the p-Tm:YAG laser appears to be an effective alternative to Ho:YAG and TFL lasers in prostate surgery.

Experts' recommendations in laser use for the treatment of bladder cancer: a comprehensive guide by the European Section of Uro-Technology (ESUT) and Training and Research in Urological Surgery and Technology (TRUST)-Group.

PURPOSE: To identify laser settings and limits applied by experts during laser vaporization (vapBT) and laser en-bloc resection of bladder tumors (ERBT) and to identify preventive measures to reduce complications. METHODS: After a focused literature search to identify relevant questions, we conducted a survey (57 questions) which was sent to laser experts. The expert selection was based on clinical experience and scientific contribution. Participants were asked for used laser types, typical laser settings during specific scenarios, and preventive measures applied during surgery. Settings for a maximum of 2 different lasers for each scenario were possible. Responses and settings were compared among the reported laser types. RESULTS: Twenty-three of 29 (79.3%) invited experts completed the survey. Thulium fiber laser (TFL) is the most common laser (57%), followed by Holmium:Yttrium-Aluminium-Garnet (Ho:YAG) (48%), continuous wave (cw) Thulium:Yttrium-Aluminium-Garnet (Tm:YAG) (26%), and pulsed Tm:YAG (13%). Experts prefer ERBT (91.3%) to vapBT (8.7%); however, relevant limitations such as tumor size, number, and anatomical tumor location exist. Laser settings were generally comparable; however, we could find significant differences between the laser sources for lateral wall ERBT (p = 0.028) and standard ERBT (p = 0.033), with cwTm:YAG and pulsed Tm:YAG being operated in higher power modes when compared to TFL and Ho:YAG. Experts prefer long pulse modes for Ho:YAG and short pulse modes for TFL lasers. CONCLUSION: TFL seems to have replaced Ho:YAG and Tm:YAG. Most laser settings do not differ significantly among laser sources. For experts, continuous flow irrigation is the most commonly applied measure to reduce complications.

Is "Kidney Stone Calculator" efficient in predicting ureteroscopic lithotripsy duration? A holmium:YAG and thulium fiber lasers comparative analysis.

PURPOSE: 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. CONCLUSION: 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.

Evaluation of the learning curve for Thulium fiber laser enucleation of prostate (ThuFLEP): retrospective study of a single-surgeon experience in real-world settings.

PURPOSE: To assess the learning curve of Thulium Fiber Laser Enucleation of prostate (ThuFLEP) of a single surgeon inexperienced in laser endoscopic enucleation of prostate (EEP). METHODS: We retrospectively analyzed all patients with benign prostate hyperplasia undergoing ThuFLEP at our center between January 2022 and August 2023 by one surgeon. Inclusion criteria were International Prostate Symptom Score > 7, prostate volume < 200 g, and maximal urinary flow rate < 15 mL/s. The surgeon was inexperienced in laser EEP and trained by watching educational videos of ThuFLEP before starting to perform the procedure under mentoring during the first 4 cases. Procedural data (enucleation and morcellation efficiency, complications) and functional results up to 3 months were evaluated. Patients were divided into 4 cohorts of 20 consecutive cases to evaluate outcomes evolution throughout time. RESULTS: The mean age of the patients was 69.9 years (SD 7.8) and mean prostate volume was 89.9 g (SD 25.8). Preoperative functional parameters were comparable between the groups. Mean enucleation efficiency (EE) ratio and morcellation efficiency (ME) ratio reached respectively 0.78 g/min (SD 0.55) and 2.49 g/min (SD 1.03) and both variables significantly increased from group 1 to group 3 (p < 0,001). Perioperative complications remained low throughout the caseload with similar significant 3-month functional improvements between all groups. CONCLUSION: This is the first study to evaluate ThuFLEP learning curve for a single surgeon inexperienced in laser EEP with limited mentoring. Under these real-world conditions, nearly 60 cases were needed to complete the learning curve with a complications rate remaining low throughout the training process.

Comparison of HoLEP, ThuLEP and ThuFLEP in the treatment of benign prostatic obstruction: a propensity score-matched analysis.

PURPOSE: To compare the efficacy and safety of Holmium laser enucleation of the prostate (HoLEP), Thulium laser enucleation of prostate (ThuLEP) and Thulium fibre laser enucleation of prostate (ThuFLEP) by performing propensity score matched analysis (PSM). METHODS: We retrospectively analysed the patients who underwent HoLEP (Group 1, n = 696), ThuLEP (Group 2, n = 146) and ThuFLEP (Group 3, n = 193) surgery because of benign prostatic obstruction (BPO). A 1:1:1 HoLEP: ThuLEP: ThuFLEP group matching was performed using PSM analysis. Perioperative, postoperative functional outcomes and complications were analysed and compared. RESULTS: We observed significant improvement in functional parameters regarding IPSS, Qmax, PVR and quality of life in all groups compared to baseline values at the 1st, 6th and 12th postoperative months. There was no significant difference between different laser types in terms of urge (UUI) and stress urinary incontinence (SUI) at 1st postoperative month. In all three groups, no patient had postoperative SUI or UUI at 6th and 12th postoperative months. In addition, no significant difference was observed between laser types in terms of postoperative complications. CONCLUSION: HoLEP, ThuLEP and ThuFLEP are safe and effective LEP methods with improvement in functional parameters and low complication rates. Similar results in terms of functional outcomes and complications clearly show that these surgeries are alternatives to each other for the patients with BPO. Experts' opinions, practices and enucleation techniques should also be taken into consideration when choosing a laser for BPO surgery.

A prospective analysis of thulium laser enucleation in benign prostatic hyperplasia comparing low- and high-power approaches for prostates exceeding 80 g.

INTRODUCTION AND OBJECTIVES: To compare the perioperative and functional outcomes of low-power and high-power thulium:YAG VapoEnucleation (ThuVEP) of the prostate for the treatment of large-volume benign prostatic hyperplasia (BPH) (> 80 ml). PATIENTS AND METHODS: A prospective analysis of 80 patients with symptomatic BPO and prostatic enlargement (more than 80 ml) was conducted. They were divided randomly into two groups (40 patients in each group). One group was treated with low-power ThuVEP, and the other group was treated with high-power ThuVEP. All patients were assessed preoperatively and early postoperatively, and 12-month follow-up data were analyzed. The complications were noted and classified according to the modified Clavien classification system. RESULTS: The mean age at surgery was 68 (± 6.1) years, and the mean prostate volume was 112 (± 20.1) cc, and there were no differences between the groups (p = 0.457). The mean operative time was 88.4 ± 11.79 min for group A and 93.4 ± 16.34 min for group B, while the mean enucleation time was 59.68 ± 7.24 min for group A and 63.13 ± 10.75 min for group B. There were no significant differences between the groups regarding catheterization time and postoperative stay. The quality of life (QoL), International Prostate Symptom Score (IPSS), maximum urinary flow rate (Qmax), postvoiding residual urine (PVR), and prostate volume improved significantly after treatment and were not significantly different between those treated with the different energies. The incidence of complications was low and did not differ between both the groups. CONCLUSION: Low-power ThuVEP is feasible, safe, and effective with comparable results with high-power ThuVEP in the treatment of BPO.

Real-world experience with the new pulsed solid-state Thulium: YAG laser (Thulio) for endoscopic enucleation of the prostate.

PURPOSE: The solid-state Thulium laser (Tm: YAG) is a novel alternative to the widely used Holmium laser for endoscopic enucleation of the prostate (EEP) due to its relatively high peak power. The aim of this study was to examine the efficacy and safety of a new pulsed Tm: YAG laser in its first application in humans. METHODS: Data were retrospectively collected for the first 103 patients who underwent EEP with a new pulsed solid-state Tm: YAG laser (Thulio®, Dornier MedTech Systems GmbH, Weßling, Germany). Peri- and postoperative data were assessed. Procedure-specific complications were graded using Clavien-Dindo Classifications (CDC). Patients were interviewed 15 months after the surgery to evaluate functional and long-term outcomes. Statistical analysis was performed with Statistical Package for the Social Sciences (SPSS®). RESULTS: The mean preoperative prostate volume was 105.6 ± 55.0 ml. Median enucleation speed was 4.1 g per minute (range 1.1-9.7). Short-term postoperative complications occurred in 21 patients (20.4%), but no high-grade complications (CDC ≥ IV) were observed. Five patients suffered gross haematuria and required reintervention (CDC IIIb; 4.9%). After 15 months, 76 patients (73.8%) participated in the follow-up interview, where seven patients (9.2%) reported complications, including two reinterventions for urethral strictures (CDC IIIb; 2.6%). Most patients reported an improvement in continence (54.0%) and urine stream (93.4%), but no difference in erectile function (81.6%). No persistent dysuria was reported. Patient satisfaction with the surgery results was very high (96.1%). CONCLUSION: Endoscopic enucleation of the prostate with the new pulsed solid-state Tm: YAG laser is a safe and effective option for surgical BPH treatment. TRIAL REGISTRATION: German Clinical Trials Register number: DRKS00031676. Registration date: 10 May 2023, retrospectively registered.

Anatomic endoscopic enucleation of the prostate using a novel hybrid thulium:yttrium-aluminium-garnet laser generator: surgical technique and clinical outcomes.

PURPOSE: We aim to report here the first clinical series of patients treated with AEEP using a novel hybrid thulium:yttrium-aluminium-garnet (Tm:YAG) laser generator (RevoLix HTL, LISA Laser Products, Germany), i.e. capable of emitting both in pulsated and continuous-wave. METHODS: We included 39 consecutive patients who underwent hybrid Tm:YAG AEEP (hybrid ThuLEP) at a single center starting from July 2022 and were followed-up until 3 months after surgery. Complete baseline, intraoperative, and follow-up demographic and clinical data were collected. The International Prostatic Symptoms Score (IPSS) questionnaire was used to quantify urinary symptoms at baseline and during follow-up. Post-operative follow-up further included a PSA test, uroflowmetry with post-void residual volume (PVR) measurement. Clavien-Dindo classification was used to classify complications. RESULTS: Median (IQR) age at surgery and prostate volume were 68 (IQR 63-74) years and 85 (60-105) cc. Both en-bloc or two-lobes technique enucleation were performed according to the intraoperative and endoscopic anatomy, with a median operative time of 85 (63-108) minutes. Bladder catheter was removed in all cases on postoperative day two. Intraoperative bleeding requiring conversion to bipolar enucleation was observed in two patients. After discharge, one patient developed arm phlebitis which was treated with anticoagulants leading to new onset haematuria requiring short term catheterisation (Clavien-Dindo grade II) and two more patients had a single episode of acute urinary retention (Clavien-Dindo grade I). Median pre- vs postoperative Qmax and IPSS were 8.0 (7.0-9.4) vs. 25.0 (22.5-32.5) ml/s and 22 (20-28) vs. 1 (0-2), whereas PVR decreased from 70 (50-115) to 0 (0-26) ml. CONCLUSIONS: Hybrid ThuLEP is a feasible and effective surgical procedure for the management of benign prostatic obstruction.

A historical comparison of thulium fiber laser systems for stone lithotripsy: navigating toward safe and effective parameters.

INTRODUCTION AND OBJECTIVES: Medical device companies have introduced new TFL machines, including Soltive (Olympus, Japan), Fiber Dust (Quanta System, Italy), and TFLDrive (Coloplast, France). The primary objective of this study is to compare our initial clinical experiences with TFL using those devices. Through this historical comparison of Thulium Fiber Laser systems for stone lithotripsy, we aim to advance our understanding and approach toward achieving safe and effective TFL parameters. MATERIALS AND METHODS: The data for this comparative analysis were extracted from three distinct prospective series that were previously published, outlining our initial clinical experience with the Soltive (Olympus, Japan), FiberDust laser (Quanta System, Italy), and TFLDrive laser (Coloplast, France). Parameters such as stone size, stone density, laser-on time (LOT), and laser settings were meticulously recorded. Additionally, we assessed critical variables such as ablation speed (expressed in mm3/s) and Joules/mm3 for each lithotripsy procedure. RESULTS: A total of 149 patients were enrolled in this study. Among them, 120 patients were subjected to analysis concerning renal stones. Statistically significant differences were observed in the median (IQR) stone volume: 650 (127-6027) mm3 for TFLDrive, 1800 (682.8-2760) mm3 for Soltive, and 1125 (294-4000) mm3 for FiberDust (p: 0.007); while there were no differences regarding stone density among the groups. Significant variations were identified in median (IQR) pulse energy, frequency, and total power. The Soltive group exhibited lower energy levels (0.3 J vs. 0.6 J, p: 0.002) but significantly higher pulse frequency (100 Hz vs. 17.5 Hz, p: 0.003) and total power (24 W vs. 11W, p: 0.001) compared to the other groups. Laser-on time showed no substantial differences across all three groups. Additionally, a statistically significant difference was observed in median J/mm3, with the TFLDrive group using higher values (24 J/mm3, p: 0.001), while the Soltive group demonstrated a higher median ablation speed of 1.16 mm3/s (p: 0.001). The overall complication rate remained low for all groups, with comparable stone-free rates. CONCLUSION: By reducing pulsed frequency, we improved laser efficiency, but smaller volumes lead to decreased efficiency due to increased retropulsion and fragment movement. Further studies are needed to identify and establish the appropriate laser settings for this new technology.

An in vitro study of irrigation rate, operator duty cycle and intrarenal temperature in superpulse fiber thulium laser lithotripsy.

OBJECTIVE: The present study aimed to examine the relationship between irrigation velocity, operator duty cycle (ODC), and intrarenal temperature during retrograde intrarenal surgery with a superpulse fiber thulium laser. METHODS: Place the stones into the fresh isolated porcine kidneys, use puncture needle to place the temperature probe 2 mm around the stones, and place the pressure probes in the upper calyx, lower calyx, and renal pelvis. Place the entire setup in a 37 °C constant temperature water bath to simulate the human body environment. The laser power varies between 10 and 30 W, and the irrigation speed is 10-30 ml/min. Additionally, at a laser power of 20 W and an irrigation speed of 10 ml/min, different On-Duty Cycles (ODC) are set. Monitor the changes in temperature and pressure. RESULTS: A direct proportionality of temperature in the kidney to the rate of irrigation has been reported between 10 W and 30 W laser powers. The percentage ratio of the rate of irrigation and power in the laser is 1:1, which can keep the temperature in the kidney at a safe level. At a laser power of 20 W and irrigation of 10 ml/min, the temperature inside the kidney increases sharply with the increase in ODC. By decreasing the ratio of ODC, the increase of temperature inside the kidney can be brought to a great reduction. CONCLUSION: Maintaining a 1:1 ratio between laser power and irrigation speed can effectively prevent thermal damage or injury to kidney tissue.Additionally, by adjusting the On-Duty Cycle (ODC) ratio, the intrarenal temperature can also be reduced.

Steady-state versus burst lasing techniques for thulium fiber laser.

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). CONCLUSION: 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.

Experts' recommendations in laser use for the treatment of urolithiasis: a comprehensive guide by the European Section of Uro-Technology (ESUT) and Training-Research in Urological Surgery and Technology (T.R.U.S.T.)-Group.

PURPOSE: To identify laser lithotripsy settings used by experts for specific clinical scenarios and to identify preventive measures to reduce complications. METHODS: After literature research to identify relevant questions, a survey was conducted and sent to laser experts. Participants were asked for preferred laser settings during specific clinical lithotripsy scenarios. Different settings were compared for the reported laser types, and common settings and preventive measures were identified. RESULTS: Twenty-six laser experts fully returned the survey. Holmium-yttrium-aluminum-garnet (Ho:YAG) was the primary laser used (88%), followed by thulium fiber laser (TFL) (42%) and pulsed thulium-yttrium-aluminum-garnet (Tm:YAG) (23%). For most scenarios, we could not identify relevant differences among laser settings. However, the laser power was significantly different for middle-ureteral (p = 0.027), pelvic (p = 0.047), and lower pole stone (p = 0.018) lithotripsy. Fragmentation or a combined fragmentation with dusting was more common for Ho:YAG and pulsed Tm:YAG lasers, whereas dusting or a combination of dusting and fragmentation was more common for TFL lasers. Experts prefer long pulse modes for Ho:YAG lasers to short pulse modes for TFL lasers. Thermal injury due to temperature development during lithotripsy is seriously considered by experts, with preventive measures applied routinely. CONCLUSIONS: Laser settings do not vary significantly between commonly used lasers for lithotripsy. Lithotripsy techniques and settings mainly depend on the generated laser pulse's and generator settings' physical characteristics. Preventive measures such as maximum power limits, intermittent laser activation, and ureteral access sheaths are commonly used by experts to decrease thermal injury-caused complications.

Ablation efficiency and laser safety of a novel superpulsed thulium fiber laser: a in vitro study.

PURPOSE: To assess the ablation efficiency of the Superpulsed Thulium Fiber Laser (SP-TFL) and investigate the thermal effects of SP-TFL. METHODS: A SP-TFLwas employed to evaluate ablation efficiency. Fresh ex-vivo pig kidneys and ureters were utilized to evaluate the renal pelvis and ureter temperature changes, different irrigation rates(0, 15, 38mL/min) and a long pulse width were used. RESULTS: The research indicated that as laser output power increased, ablation rates significantly increased. Ablation rates(mg/min) were higher and the energy per ablated mass(J/mg) was lower at lower frequencies(10-50 Hz). Under the same frequency and single pulse energy, super short and short pulse widths demonstrated higher ablation rates at higher frequencies (exceeding 100 Hz). The temperature of the renal pelvis and ureter decreased with increasing irrigation rates. In the renal pelvis, without irrigation, the temperature quickly reached the critical threshold of 43℃. The irrigation rate was 15 ml/min and power was no more than 18 W, the renal pelvis temperature did not reach 43℃. When the irrigation rate were 38 ml/min, the temperature did not risen to 43℃. In the ureter, without irrigation, the temperature also quickly reached 43℃. The temperature reached 43℃ when the power exceeded to12W with an irrigation rate of 15 ml/min. With an irrigation rate of 38 ml/min, the temperature reached 43℃ at a laser power of 30 W. CONCLUSIONS: The SP-TFL demonstrated promising ablation effectiveness especially for lower frequencies and super short and short pulse widths model. Proper irrigation rates, single pulse energy, frequency and pulse width are crucial during lithotripsy.

Evaluation of the learning curve for Thulium laser enucleation of the prostate in a contemporary cohort.

PURPOSE: To assess the learning curve of Thulium laser enucleation of the prostate (ThuLEP) of a single surgeon. METHODS: Hundred patients suffering from benign prostatic hyperplasia were treated by the same surgeon. In all cases, a well-trained urologist was present in the operating room. Patients urinary function was assessed preoperatively using the International Prostate Symptoms Score (IPSS), maximum flow rate and Post-Void Residual volume. Preoperative prostate volume was recorded. Enucleation and morcellation efficiency and complication rate were evaluated. Patients were divided into 5 cohorts of 20 consecutive cases to assess changes in outcomes through time. RESULTS: Mean age of patients was 73.1 years (SD 17.5) and mean prostate volume was 89.7 ml (SD 55.1). Overall, mean enucleation and morcellation efficiency were 1.7 (SD 2.9) and 5.1 (SD 2.7) g/min. A statistically significant increase in enucleation efficiency was observed when comparing cohort 1 vs 2 (0.9 vs 1.3 g/min, p = 0.03) and cohort 2 vs 3 (1.3 vs 1.7 g/min, p = 0.02). A statistically significant increase in morcellation efficiency was observed when comparing cohort 1 vs 2 (2.8 vs 3.7 g/min, p = 0.02) and cohort 2 vs 3 (3.7 vs 4.9 g/min, p = 0.03). In both cases, no significant differences were observed when comparing the following cohorts. Complication rate showed no significant differences throughout the caseload. CONCLUSIONS: In our single-surgeon experience, we observed a learning curve of nearly 60 cases for the ThuLEP procedure in presence of a well-trained surgeon. Complication rate was low from the beginning of surgical experience.

Short-term postoperative recovery for patients after Thulium Laser Vapoenucleation of Prostate: evaluation of the impact of lower urinary tract symptoms on quality of life.

PURPOSE: We evaluated short-term postoperative recovery in patients with benign prostatic hyperplasia (BPH), especially focusing on symptoms reduction and life quality enhancement. METHODS: We prospectively enrolled 160 BPH patients who underwent surgery and were followed up regularly for 12 weeks, collecting the International Prostate Symptom Score (IPSS), Quality of Life (QoL), and Qmax. Regression analysis and mixed effect models were used to evaluate the tendency of symptoms on recovery from the perspective of quality of life. RESULTS: At 12 weeks, all patients recovered well with conspicuous change in IPSS, QoL and Qmax, that were 4.80 ± 4.59, 1.34 ± 1.14,20.02 ± 8.61 mL/s respectively. Voiding symptoms were significantly reduced by 79.4% at 2 weeks, whereas storage symptoms recovered slowly until 12 weeks with residual lower urinary tract symptoms (LUTS), predominantly urinary frequency and nocturia. Improvements in incomplete emptying urination and urinary frequency were significantly associated with QoL. CONCLUSIONS: With regards to the comprehensive full-cycle treatment of LUTS patients, in addition to the objective results, more attention should also be focused on the change in following symptoms, that is, incomplete emptying urination, urine frequency and urination difficulty, which play key roles in the enhancement of patients' quality of life.

Refining surgical strategies in ThuLEP for BPH: a propensity score matched comparison of En-bloc, three lobes, and two lobes techniques.

PURPOSE: This study compares the peri-operative and functional outcomes of three distinct surgical techniques in Thulium Laser Enucleation of the Prostate (ThuLEP) for benign prostatic hyperplasia (BPH). The main aim is to assess whether the En-bloc, Three-lobe, and Two-lobe techniques have differential effects on surgical efficacy and patient outcomes. METHODS: A retrospective analysis was conducted on patients undergoing ThuLEP for BPH between January 2019 and January 2024 at two tertiary centers. Propensity score matching was utilized to balance baseline characteristics among patients undergoing the different techniques. Surgical parameters, including operative time, enucleation time, morcellation time, energy consumption, and postoperative outcomes, were compared among the groups. RESULTS: Following propensity score matching, 213 patients were included in the analysis. Intraoperative analysis revealed significantly shorter enucleation, laser enucleation, morcellation and operative times and total energy delivered in the En-bloc and Two-lobe groups compared to the Three-lobe group. No significant differences were observed among the groups in terms of intraoperative and postoperative complications. There were no significant differences in functional outcomes at the 3-month follow-up among the groups. CONCLUSION: The findings of this study suggest that while the En-bloc and Two-lobe techniques may offer efficiency benefits and could be considered safe alternatives in ThuLEP procedures, the reduction in laser enucleation time and energy delivered did not necessarily translate into improvements in post operative storage symptoms or other functional outcomes for the patients. Surgeon preference and proficiency may play a crucial role in selecting the most suitable technique for individual patients. Future research should focus on larger-scale prospective studies to further validate these findings and explore potential factors influencing surgical outcomes.