Do Prostate Imaging-Reporting and Data System (PIRADS) lesions predict holmium laser enucleation of prostate outcomes?

INTRODUCTION AND OBJECTIVES: Prostate magnetic resonance imaging (MRI) is used for prostate cancer (PCa) screening and risk stratification and is helpful for surgical planning for patients undergoing holmium laser enucleation of the prostate (HoLEP). There are few studies investigating the correlation between MRI Prostate Imaging-Reporting and Data System (PIRADS) lesion characteristics and HoLEP pathology and outcomes. METHODS: We performed retrospective review of patients who underwent HoLEP between January 2021 and August 2023 by a single surgeon. Preoperative, intraoperative, and postoperative characteristics and outcomes were analyzed for all patients who had a documented preoperative prostate MRI. RESULTS: There were 334 patients without a pre-existing diagnosis of PCa and with a preoperative prostate MRI, of which 140 (42%) had at least one PIRADS lesion. There was a total of 203 PIRADS lesions: 91 (45%) in the peripheral zone (PZ), 106 (52%) in the transition zone (TZ), and 6 (2%) not specified. Incidental PCa was noted in 44 (13%) patients at time of HoLEP. Presence or location of lesion was not significantly associated with rate or grade of incidental PCa on pathology. Greater number of lesions and lesion size correlated with longer procedure times. Lesion number, size, or grade were not found to correlate with cancer grade or rate of cancer. CONCLUSIONS: Grade, presence, location, size, and number of PIRADS lesions on preoperative prostate MRI for patients with an appropriate prior PCa workup were not significantly associated with incidental PCa or higher PCa grade on HoLEP pathology.

Ejaculatory and erectile function outcomes following holmium laser enucleation of the prostate.

PURPOSE: Holmium laser enucleation of the prostate (HoLEP) is a surgical treatment option for benign prostatic hyperplasia (BPH). Many men develop retrograde ejaculation postprocedure, but there is conflicting evidence regarding sexual function outcomes post-HoLEP. We sought to examine significant variations in patient-reported erectile and ejaculatory function within 12 months post-HoLEP. MATERIALS AND METHODS: We conducted a retrospective study for patients who underwent HoLEP between Nov 2018 and Feb 2022. Of the reviewed patients, 277 patients met inclusion criteria and completed pre and postoperative questionnaires, which included the Male Sexual Health Questionnaire- Ejaculatory Dysfunction (MSHQ-EJD) and the International Index of Erectile Function/Sexual Health Inventory for Men (IIEF-5/SHIM). Surveys were provided to patients up to 12 months postprocedure. Demographics and comorbidities associated with sexual dysfunction were collected. Responses to each question were analyzed to detect sub-categorical variations in sexual function as the secondary objective. Data was analyzed by using a linear mixed model. RESULTS: There was a significant decline in total scores for the MSHQ-EJD (8.70 pre-HoLEP vs. 6.58 post HoLEP, p ≤ 0.001) including a significant decline (p < 0.005) in questions 1-3 which assess ejaculatory ability, strength, and volume. There was not a significant decline in question 4 which assesses bother (2.552 pre-HoLEP vs. 3.119 post-HoLEP, p = 0.526). There was not a significant decline in the IIEF-5/SHIM postoperatively (11.51 pre-HoLEP vs. 13.327 post-HoLEP, p = 0.498). CONCLUSIONS: Patients undergoing HoLEP do not experience a decline in erectile function. Patients do experience a decline in ejaculatory function but did not find this bothersome.

The Efficacy and Safety of Radiation-Free Retrograde Intrarenal Surgery: A Prospective Multicenter-Based, Randomized, Controlled Trial.

PURPOSE: Fluoroscopy is usually required during retrograde intrarenal surgery (RIRS). Although fluoroscopy is considered necessary for effective and safe RIRS, there is growing awareness regarding radiation exposure risk to patients and surgeons. We conducted a multicenter-based, randomized, controlled trial to compare the safety and effectiveness of radiation-free (RF) RIRS with radiation-usage (RU) RIRS for kidney stone management. MATERIALS AND METHODS: From August 2020 to April 2022, patients with a unilateral kidney stone (≤20 mm) eligible for RIRS were prospectively enrolled in 5 tertiary medical centers after randomization and divided into the RF and RU groups. RIRS was performed using a flexible ureteroscope with a holmium:YAG laser. The primary end point of this study was the success rate, defined as complete stone-free or residual fragments with asymptomatic kidney stones ≤ 3 mm. The secondary end point of this study was ascertaining the safety of RF RIRS. The success rates were analyzed using a noninferiority test. RESULTS: Of the 140 consecutive randomized participants, 128 patients completed this study (RF: 63; RU: 65). The success rates (78% vs 80%, P = .8) were not significantly different between the groups. The rate of high-grade (grade 2-4) ureter injury was not significantly higher in the RF group compared to the RU group (RF = 3 [4.8%] vs RU = 2 [3.1%], P = .6). In RF RIRS, the success rate was noninferior compared to RU RIRS (the difference was 2.2% [95% CI, 0.16-0.12]). CONCLUSIONS: This study demonstrated that the surgical outcomes of RF RIRS were noninferior to RU RIRS.

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.

Q-switched 1064 nm Nd: YAG laser restores skin photoageing by activating autophagy by TGFß1 and ITGB1.

Excessive ultraviolet B ray (UVB) exposure to sunlight results in skin photoageing. Our previous research showed that a Q-switched 1064 nm Nd: YAG laser can alleviate skin barrier damage through miR-24-3p. However, the role of autophagy in the laser treatment of skin photoageing is still unclear. This study aims to investigate whether autophagy is involved in the mechanism of Q-switched 1064 nm Nd: YAG in the treatment of skin ageing. In vitro, primary human dermal fibroblast (HDF) cells were irradiated with different doses of UVB to establish a cell model of skin photoageing. In vivo, SKH-1 hairless mice were irradiated with UVB to establish a skin photoageing mouse model and irradiated with laser. The oxidative stress and autophagy levels were detected by western blot, immunofluorescence and flow cytometer. String was used to predict the interaction protein of TGF-ß1, and CO-IP and GST-pull down were used to detect the binding relationship between TGFß1 and ITGB1. In vitro, UVB irradiation reduced HDF cell viability, arrested cell cycle, induced cell senescence and oxidative stress compared with the control group. Laser treatment reversed cell viability, senescence and oxidative stress induced by UVB irradiation and activated autophagy. Autophagy agonists or inhibitors can enhance or attenuate the changes induced by laser treatment, respectively. In vivo, UVB irradiation caused hyperkeratosis, dermis destruction, collagen fibres reduction, increased cellular senescence and activation of oxidative stress in hairless mice. Laser treatment thinned the stratum corneum of skin tissue, increased collagen synthesis and autophagy in the dermis, and decreased the level of oxidative stress. Autophagy agonist rapamycin and autophagy inhibitor 3-methyladenine (3-MA) can enhance or attenuate the effects of laser treatment on the skin, respectively. Also, we identified a direct interaction between TGFB1 and ITGB1 and participated in laser irradiation-activated autophagy, thereby inhibiting UVB-mediated oxidative stress further reducing skin ageing. Q-switched 1064 nm Nd: YAG laser treatment inhibited UVB-induced oxidative stress and restored skin photoageing by activating autophagy, and TGFß1 and ITGB1 directly incorporated and participated in this process.

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.

Solid state, pulsed-wave 355 nm UV laser atherectomy debulking in the treatment of infrainguinal peripheral arterial disease: The Pathfinder Registry.

BACKGROUND: Atherectomy is an important option for debulking atherosclerotic plaque from diseased arteries in patients with infrainguinal arterial disease. Laser atherectomy uses a high-powered laser to remove the plaque from the arteries to restore blood flow. AIMS: The Pathfinder multicenter registry was initiated to evaluate the safety and efficacy of the 355 nm laser atherectomy system in a real-world setting for the treatment of de novo, re-stenotic and in-stent restenosis (ISR) lesions in infrainguinal arteries of patients with peripheral artery disease (PAD). METHODS: The study was a prospective, single-arm, multicenter, open-label registry study for patients treated with the 355 nm laser system. Clinical and lesion characteristics, procedural safety and efficacy data, and baseline, 6-, and 12-month outcomes data, including Ankle Brachial Index (ABI), Rutherford class, and Walking Impairment Questionnaires (WIQ), were collected. The primary efficacy endpoint was the achievement of ≤30% final residual stenosis at the index lesion postatherectomy and adjunctive therapy evaluated by an angiographic Core Lab. The primary safety endpoint was the percentage of subjects who did not experience periprocedural major adverse events (PPMAEs) before discharge. RESULTS: One hundred and two subjects with 121 lesions treated with the 355 nm laser device at 10 centers were included in the analysis. Mean age was 68.4 ± 10.21 years, 61.8% of subjects were male, 44.6% had critical limb ischemia (CLI), and 47.3% had tibial lesions. The mean residual stenosis at the end of the procedure was 24.4 ± 15.5 with 69 lesions (69.0%) achieving technical procedural success (<30% stenosis); similar rates were observed for subjects with ISR (25.5 ± 14.9), chronic total occlusion (CTO) (28.1 ± 17.0), and severe calcification (36.5 ± 21.6) lesions. Mean ABI, Rutherford, and WIQ scores were improved at both 6 and 12 months. Ninety-seven of 102 subjects (95.1%) met the primary safety endpoint of not experiencing a PPMAE before discharge. CONCLUSIONS: The initial data from the Pathfinder Registry demonstrates the 355 nm laser system is safe and effective in a real-world setting for performing atherectomy in patients with infrainguinal PAD.

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.

Salvage holmium laser enucleation of the prostate after previous interventions: a systematic review.

OBJECTIVE: To investigate the feasibility, safety and efficacy of holmium laser enucleation of the prostate (HoLEP) in the re-treatment setting (salvage HoLEP) and compare it to the primary HoLEP procedure that is commonly used for the treatment of benign prostate hyperplasia (BPH). MATERIALS AND METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, PubMed, Scopus, and Cochrane databases were systematically screened, from inception to 8 August 2022. Other potentially eligible studies were retrieved using the reference lists of the included studies. Retrospective and prospective studies, both comparative and non-comparative, were included. RESULTS: A total of 12 studies met the inclusion criteria and were included in the final qualitative synthesis. One study was prospective comparative (non-randomised), seven studies were retrospective comparative, and four studies were retrospective non-comparative or case series. In total, 831 patients were treated with salvage HoLEP in the above studies. Previous intervention before salvage HoLEP ranged among studies. The most commonly performed was transurethral resection of the prostate. Intraoperative parameters of salvage HoLEP were comparable with those reported during primary HoLEP, while all postoperative outcomes were significantly improved after salvage HoLEP and were similar with those observed after primary HoLEP. No major complications were noted after salvage HoLEP according to Clavien-Dindo classification. CONCLUSIONS: Salvage HoLEP after previous interventions for treating recurrent or residual BPH is a feasible, safe, and efficient procedure. Data presented in selected studies, along with the holmium laser's physical properties to resect more tissue and to dissect along the true anatomical plane of BPH, render HoLEP an ideal salvage treatment modality for recurrent or residual BPH symptoms.

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.

Effect of detrusor underactivity on surgical outcomes of holmium laser enucleation of the prostate.

OBJECTIVE: To evaluate the effect of detrusor underactivity (DUA) on the postoperative outcomes of holmium laser enucleation of the prostate (HoLEP) in patients with benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: Patients with BPH who underwent HoLEP between January 2018 and December 2022 were enrolled in this prospective database study. Patients were divided into DUA (bladder contractility index [BCI] <100) and non-DUA (BCI ≥100) groups. Objective (maximum urinary flow rate [Qmax], post-void residual urine volume [PVR]) and subjective outcomes (International Prostate Symptom Score [IPSS], Overactive Bladder Symptom Score [OABSS], satisfaction with treatment question [STQ], overall response assessment [ORA], and willingness to undergo surgery question [WUSQ]) were compared between the two groups before surgery, and at 3 and 6 months after HoLEP. RESULTS: A total of 689 patients, with a mean (standard deviation [SD]) age of 69.8 (7.1) years, were enrolled. The mean (SD) BCI in the non-DUA (325 [47.2%]) and DUA (364 [52.8%]) groups was 123.4 (21.4) and 78.6 (14.2), respectively. Both objective (Qmax and PVR) and subjective (IPSS, IPSS-quality of life, and OABSS) outcomes after surgery significantly improved in both groups. The Qmax was lower in the DUA than in the non-DUA group postoperatively. At 6 months postoperatively, the total IPSS was higher in the DUA than in the non-DUA group. There were no significant differences in surgical complications between the two groups. Responses to the STQ, ORA, and WUSQ at 6 months postoperatively demonstrated that the patients were satisfied with the surgery (90.5% in the DUA group; 95.2% in the non-DUA group), their symptoms improved with surgery (95.9% in the DUA group; 100.0% in the non-DUA group), and they were willing to undergo surgery again (95.9% in the DUA group; 97.9% in the non-DUA group). There were no significant differences in the responses to the STQ and WUSQ between the two groups. CONCLUSION: Our midterm results demonstrated that patients with BPH and DUA showed minimal differences in clinical outcomes after HoLEP compared to those without DUA. The overall satisfaction was high in the DUA group.

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.

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.

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.

WATTS happening? Evaluation of thermal dose during holmium laser lithotripsy in a high-fidelity anatomic model.

PURPOSE: To evaluate the thermal profiles of the holmium laser at different laser parameters at different locations in an in vitro anatomic pelvicalyceal collecting system (PCS) model. Laser lithotripsy is the cornerstone of treatment for urolithiasis. With the prevalence of high-powered lasers, stone ablation efficiency has become more pronounced. Patient safety remains paramount during surgery. It is well recognized that the heat generated from laser lithotripsy has the potential to cause thermal tissue damage. METHODS: Utilizing high-fidelity, 3D printed hydrogel models of a PCS with a synthetic BegoStone implanted in the renal pelvis, laser lithotripsy was performed with the Moses 2.0 holmium laser. At a standard power (40 W) and irrigation pressure (100 cm H2O), we evaluated operator duty cycle (ODC) variations with different time-on intervals at four different laser settings. Temperature was measured at two separate locations-at the stone and away from the stone. RESULTS: Temperatures were highest closest to the laser tip with a decrease away from the laser. Fluid temperatures increased with longer laser-on times and higher ODCs. Thermal doses were greater with increased ODCs and the threshold for thermal injury was reached for ODCs of 75% and 100%. CONCLUSION: Temperature generation and thermal dose delivered are greatest closer to the tip of the laser fiber and are not dependent on power alone. Significant temperature differences were noted between four laser settings at a standardized power (40 W). Temperatures can be influenced by a variety of factors, such as laser-on time, operator duty cycle, and location in the PCS.

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.

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.

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.

Extracorporeal shock wave lithotripsy versus laser lithotripsy in the treatment of post-SWL steinstrasse: a randomized comparative study.

OBJECTIVE: To compare the efficacy of Holmium laser lithotripsy with that of extracorporeal shock lithotripsy (SWL) for post-SWL ureteral steinstrasse. MATERIALS AND METHODS: From January 2022 to July 2023, 36 patients with post-SWL ureteral steinstrasse were randomly divided into laser lithotripsy and SWL groups. Patients with pain, moderate to marked hydronephrosis, large leading stone fragments, and showing no spontaneous resolution within 3-4 weeks after medical expulsive therapy were included. Patients with sepsis were excluded. The success rate was the primary outcome. We compared the perioperative data between the groups. RESULTS: The success rate was higher in the ureteroscopy group than in the SWL group (p = 0.034). SWL was a significantly longer operation, and the fluoroscopy time was significantly longer in the SWL group than in the URS group (p = 0.027). Auxiliary procedures were more frequently performed in the SWL group than in the URS group (p = 0.02). JJ stents were inserted in 100% of patients in the URS group. Three patients (16.7%) underwent conversion to laser ureteroscopy after the second SWL session failed. No significant difference in the incidence of postoperative complications was observed between the groups, but the incidence of postoperative LUT was high in the ureteroscopy group. The mean hospital stay was 30 h in the ureteroscopy group. SWL was performed without the need for hospital admission. CONCLUSION: Ureteroscopic laser lithotripsy for steinstrasse was safe and effective, with a higher success rate, shorter fluoroscopy time, and shorter recovery period than SWL.