Thulium fiber laser vs Ho:YAG in RIRS: a prospective randomized clinical trial assessing the efficacy of lasers and different fiber diameters (150 µm and 200 µm).

INTRODUCTION: The aims of the study: (1) to compare the Super Pulse Thulium Fiber Laser (SP TFL) and the holmium: yttrium-aluminium-garnet (Ho:YAG) lasers in retrograde intrarenal surgery (RIRS); (2) to compare the efficacy of SP TFL laser fibers of different diameters (150 µm and 200 µm). METHODS: A prospective randomized single-blinded trial was conducted. Patients with stones from 10 to 20 mm were randomly assigned RIRS in three groups: (1) SP TFL (NTO IRE-Polus, Russia) with fiber diameter of 150 µm; (2) SP TFL with 200-µm fiber; and (3) Ho:YAG (Lumenis, USA) with 200-µm fiber. RESULTS: Ninety-six patients with kidney stones were randomized to undergo RIRS with SP TFL using a 150-µm fiber (34 patients) and a 200-µm fiber (32 patients) and RIRS with Ho:YAG (30 patients). The median laser on time (LOT) in the 200-µm SP TFL group was 9.2 (6.2-14.6) min, in 150-µm SP TFL-11.4 (7.7-14.9) min (p = 0.390), in Ho:YAG-14.1 (10.8-18.1) min (p = 0.021). The total energy consumed in 200-µm SP TFL was 8.4 (5.8-15.2) kJ; 150-µm SP TFL - 10.8 (7.3-13.5) kJ (p = 0.626) and in Ho:YAG-15.2 (11.1-25.3) kJ (p = 0.005). CONCLUSIONS: Irrespective of the density, RIRS with SP TFL laser has proven to be both a safe and effective procedure. Whilst the introduction of smaller fibers may have the potential to reduce the duration of surgery, SP TFL results in a reduction in the LOT and total energy for stone ablation in RIRS compared with Ho:YAG.

Thulium fiber laser in endourology: current clinical evidence.

PURPOSE OF REVIEW: To review and summarize preclinical and clinical data on thulium fiber laser's (TFL) effectiveness (ablation rate, stone-free rate etc.) and safety in terms of laser injuries and thermal damage. This enables us to assess how the in-vitro evidence translates into the clinical real-life scenario. RECENT FINDINGS: In this analysis, a total of 21 preclinical trials have been included. Most of the trials use conventional Holmium:YAG laser as a comparator, with only a few assessing lasers with pulse modulation. Most of the trials focus on the superior ablation rate and superior dusting features of TFL, as well as comparison of retropulsion (both in conventional Ho:YAG and in a pulse modulation), with a few studies assessing safety aspects. A total of 13 trials assessed TFL, clinically, in percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS). The clinical data obtained suggest that lithotripsy by TFL is safe, facilitates effective stone fragmentation, and results in a reduction of retropulsion. Unfortunately, most of the clinical trials lack a direct comparator, and so no clear-cut comparisons are possible. SUMMARY: During in-vitro studies, TFL demonstrated to be a new energy source with a great potential for improved ablation, lower retropulsion and improved dusting. These claims are supported in contemporary clinical studies, reporting superior ablation and negligible retropulsion in both PCNL and RIRS. However, it should be noted that the data regarding clinical results compared with conventional Ho:YAG is still limited.

Thulium fiber laser in urology: physics made simple.

PURPOSE OF REVIEW: In this narrative review, we will focus on a novel thulium fiber laser's physical properties in terms of its clinical applicability. RECENT FINDINGS: TFL has successfully moved forward from the preclinical trials into clinical practice and now is being widely used in clinics around the world. The available data suggest that the device effectively operates in soft tissues - benign prostate hyperplasia (BPH) and bladder tumors, as well as in lithotripsy. Also, the first promising results were obtained from laparoscopic surgery showing its possible applicability in the management of renal cell carcinoma. The constructional changes in fiber laser's design, lead to alteration of laser-tissue interactions, which resulted in clinical advantages of the device. Yet, the exact mechanism often is considered complex for understanding. With this work, we are aiming to build a bridge between biophysics and clinical practice and give a simple explanation of how the devices is working and why the knowledge of it is important for a clinician. SUMMARY: The more effective wavelength (closer to the water absorption peak), favorable beam profile, different modes of action allowing to decrease carbonization on one hand and retropulsion on the other, all this makes TFL an evolution in urologic surgery. Further trials investigating on the possible pros and cons of the device are awaited.

Prospective Single-Center Study of SuperPulsed Thulium Fiber Laser in Retrograde Intrarenal Surgery: Initial Clinical Data.

INTRODUCTION: The objective of this study was to present our clinical experience of using the thulium fiber laser in retrograde intrarenal surgery (RIRS). METHODS: A prospective clinical study performed after the IRB approval (Sechenov University, Russia). Patients with stones <30 mm were treated with SuperPulsed thulium fiber laser (SP TFL) (NTO IRE-Polus, Russia) through a 200-µm-diameter fiber. Stone size, density, the duration of the operation, and laser on time (LOT) were measured. Based on the surgeon's feedback, retropulsion and intraoperative visibility were also assessed (Likert scale). Stone-free rates (SFRs) were assessed with a low-dose CT scan 90 days after the operation. RESULTS: Between January 2018 and December 2019, 153 patients (mean age 54 ± 2.8 years) underwent RIRS with SP TFL (mean stone density 1,020 ± 382 HU). Median stone volume was 279.6 (139.4-615.8) mm3. Median LOT was 2.8 (IQR 1.6-6.6) min with median total energy for stone ablation 4.0 (IQR 2.1-7.17) kJ, median ablation speed was 1.7 (1.0-2.8) mm3/s, median ablation efficacy was 13.3 (7.3-20.9) J/mm3, and energy consumption was 170.3 (59.7-743.3) J/s. Overall, the SFR (at 3 months) was 89%. The overall complication rate was 8.4%. Retropulsion was present in 23 (15.1%) patients. Visibility was estimated as optimal in most patients, with poor visibility reported in only 13 (8.5%) patients. CONCLUSION: The SP TFL is a safe and efficient tool in lithotripsy, irrespective of the stone type and density. Retropulsion is minimal and visibility is maintained with SP TFL. Nonetheless, further clinical studies are needed to ensure optimal comparison with conventional holmium:YAG lithotripsy.

EAU, AUA and NICE Guidelines on Surgical and Minimally Invasive Treatment of Benign Prostate Hyperplasia: A Critical Appraisal of the Guidelines Using the AGREE-II Tool.

OBJECTIVE: To critically appraise the methodological rigour of the clinical practice guidelines (CPGs) vis-à-vis BPH surgery as used by specialist research associations in the US, Europe and UK, and to compare whether the guidelines cover all or only some of the available treatments. METHODS: The current guidelines issued by the EUA, AUA and NICE associations have been analyzed by 4 appraisers using the AGREE-II instrument. We also compared the recommendations given in the guidelines for surgical and minimally invasive treatment to find out which of these CPGs include most of the available treatment options. RESULTS: According to the AGREE II tool, the median scores of domains were: domain 1 scope and purpose 66.7%, domain 2 stakeholder involvement 50.0%, domain 3 rigor of development 65.1%, domain 4 clarity of presentation 80.6%, domain 5 applicability 33.3%, domain 6 editorial independence 72.9%. The overall assessment according to AGREE II is 83.3%. The NICE guideline scored highest on 5 out of 6 domains and the highest overall assessment score (91.6%). The EAU guideline scored lowest on 4 out of 6 domains and has the lowest overall assessment score (79.1%). CONCLUSIONS: The analyzed CPGs comprehensively highlight the minimally invasive and surgical treatment options for BPH. According to the AGREE II tool, the domains for clarity of presentation and editorial independence received the highest scores. The stakeholder involvement and applicability domains were ranked as the lowest. Improving the CPG in these domains may help to improve the clinical utility and applicability of CPGs.

Superpulse thulium fiber laser lithotripsy: an in vitro comparison of 200 µm and 150 µm laser fibers.

PURPOSE: To investigate the thermal effects, stone retropulsion and ablation rate of SuperPulse Thulium-fiber laser (SP TFL) with two different surgical fibers of 200 and 150 µm in diameter. METHODS: SP TFL (NTO IRE-Polus, Fryazino, Russia) performance with 200 and 150 µm fibers (NTO IRE-Polus, Fryazino, Russia) was evaluated. Before each test, the laser fiber was cleaved, and the power measurement was taken to verify the actual laser output power. To compare the laser fibers in well-controlled environments, a number of setups were used to assess retropulsion, ablation efficacy, fiber burnback, energy transmission, and safety. RESULTS: Power measurements performed before each test revealed a 4.7% power drop for a 200 µm fiber SP TFL (14.3 ± 0.5 W) and 7.3% power drop for a 150 µm fiber SP TFL (13.9 ± 0.5 W) versus the nominally indicated power (15.0 W). Retropulsion with the TFL was minimal and comparable between fibers. We found no clinically relevant temperature differences between SP TFL with either 200 or 150 µm fibers. The ablation efficacy tended to be comparable under most parameters. Yet, we did observe a decreased diameter of residual fragments after the ablation with a 150 µm fiber. CONCLUSION: The smaller fiber (150 µm) is not inferior to 200 µm fiber in terms of fiber burnback, retropulsion, safety, and ablation rate. Moreover, it has the potential to decrease the diameter of fragments during lithotripsy, which may facilitate dusting during RIRS.

Laser endoscopic procedures on the prostate: it is the small details that count.

PURPOSE OF REVIEW: This review aims to highlight the pros and cons of each laser device and to consider additional possible milestones for the development of laser technologies in the surgical treatment of benign prostate hyperplasia. RECENT FINDINGS: Over the last three decades, lasers' role in endourology has gone from strength to strength. Specifically, the primary techniques where laser surgery for BPO relief is concerned are vaporization and enucleation. The idea behind vaporization is that lasers are able to vaporize substantial amounts of tissue due to deep ablation depth and increased power. The most efficient devices for vaporization are those affecting hemoglobin as primary chromophore and/or using a continuous firing mode (KTP/LBO:YAG, diode lasers, Tm:YAG). As for enucleation, multiple devices have been suggested for the adequate anatomical enucleation of the prostate (EEP). As it is a skill-dependent technique, the EEP is effective irrespective of which device the surgeon uses. However, some devices have shown significant advances where enucleation is concerned. SUMMARY: The choice of device should be based primarily on the technique the surgeon prefers. Although the most suitable lasers for vaporization are hemoglobin-targeting and/or continuous wave devices, the EEP may be done with any enough powered laser, yet some provides specific effects which you should be aware before the surgery.

Robot-Assisted Magnetic Resonance Imaging-Targeted versus Systematic Prostate Biopsy; Systematic Review and Meta-Analysis.

INTRODUCTION: Robot-assisted devices have been recently developed for use in prostate biopsy. However, it is possible advantages over standard biopsy remain unclear. We aimed to assess the diagnostic performance and safety of robot-assisted targeted (RA-TB) and systematic prostate biopsies (RA-SB). METHODS: A systematic literature search was performed in MEDLINE and Scopus databases. The detailed search strategy is available at Prospero (CRD42021269290). The primary outcome was the clinically significant prostate cancer (PCa) detection rate. The secondary outcomes included the overall detection rate of PCa, cancer detection rate per core, and complications. RESULTS: The clinically significant cancer detection rate, overall cancer detection rate, and "per patient" did not significantly differ between RA-TB and RA-SB [OR = 1.02 (95% CI 0.83; 1.26), p = 0.05, I2 = 62% and OR = 0.95 (95% CI 0.78; 1.17), p = 0.17, I2 = 40%, respectively]. There were no differences in the clinically insignificant cancer detection rate "per patient" between RA-TB and RA-SB [OR = 0.81 (95% CI 0.54; 1.21), p = 0.31, I2 = 0%]. RA-TB had a significantly higher cancer detection rate "per core" [OR = 3.01 (95% CI 2.77; 3.27), p < 0.0001, I2 = 96%]. CONCLUSION: RA-TB and RA-SB are both technically feasible and have comparable clinical significance and overall PCa detection rates.

Retrograde intrarenal surgery versus percutaneous nephrolithotomy in larger kidney stones. Could SuperPulsed Thulium-fiber laser change the game?

INTRODUCTION: The aim of this article was to compare retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) efficacy and safety with SuperPulsed Thulium-fiber laser (SP TFL) for stones 20 mm and larger. MATERIAL AND METHODS: Patients with large kidney stones (20 mm and larger) were recruited to undergo PCNL or RIRS with SP TFL lithotripsy. Both groups were comparable in terms of stone size and density, operation time, laser-on time (LOT), stone-free rate, residual fragments and complication rate. Stone retropulsion and visibility were assessed based on the surgeon's feedback using Likert scales. RESULTS: A total of 14 and 56 patients were included in the RIRS and PCNL groups, respectively. The mean stone density was 833.8 ±298.3 HU in the RIRS group and 882.3 ±408.5 HU in the PCNL group (p = 0.072). The median LOT was 11.7 (10.0-15.5) min for RIRS and 10.0 (6.0-12.1) min for PCNL (p = 0.207). The median total energy for stone ablation was 13.8 (11.8-25.0) kJ for RIRS and 12.0 (7.0-20.1) kJ for PCNL (p = 0.508). The median ablation speed was 3.9 (3.9-5.7) mm3/sec for RIRS and 5.0 (4.6-11.3) mm3/sec for PCNL (p = 0.085). We found a significant correlation between retropulsion and the type of surgery performed: with higher retropulsion in the PCNL (r = 0.298 with p = 0.012). The stone-free rate at 3-months was 85.7% in RIRS and 89.3% in PCNL (p = 0.505). CONCLUSIONS: SP TFL is a safe and effective modality for lithotripsy for both, RIRS and PCNL, achieving minimal retropulsion and good visibility. No discrepancies in procedure duration, complications, or LOT were identified between the different modalities.

Knowing the inside of a laser. / Conocer la parte interna del láser.

"Theatre acting is the operation with ascalpel, movie acting is an operation with a laser". Michael Caine. Being the instrument in hands of urologist laser is much more than a single-application device. Its applicability is deeply dependent on physical properties, settings, and environment. With knowledge of how the device work, why it affects the tissue, and how this laser-tissue interaction goes surgeon can shape further clinical work to choose the best devices or techniques of surgery. Tailoring the laser effects on the needs of the patient. In this paper, we tried to briefly describe what a laser device consists of, the most important laser-tissue interactions that are necessary for understanding the operation of the laser, and the main laser systems that are used in urology.

Michael Caine dijo que las actuaciones de quirófano son con bisturí y las actuaciones en películas son con láser. En manos de urólogos, el láser es mucho más que una técnica. Su aplicabilidad depende de las habilidades físicas, la disposición de los elementos y el ambiente. El conocimiento del láser permite al cirujano escoger la técnica correcta para cada caso. En este manuscrito, describimos en qué consiste el láser, las interacciones con el tejido y los principales tipos de láser en urología.

Superpulsed Thulium Fiber Laser for Stone Dusting: In Search of a Perfect Ablation Regimen-A Prospective Single-Center Study.

Objective: To compare the efficacy of the standard and higher frequency regimens for superpulsed thulium fiber laser (SP TFL) retrograde intrarenal surgery (RIRS). Materials and Methods: A prospective study of patients with renal calculi of 10-30 mm was performed. For RIRS, we used the SP TFL (NTO IRE-Polus, Russia) and a 9.5F flexible ureteroscope with 270° deflection and 3.6F working channel. Retropulsion and visibility were assessed based on the surgeon's feedback using three-point Likert scales. The stone-free rate was assessed at 3 months with CT. Results: A total of 40 patients were included in the study with a mean age of 56 years, mean stone density of 880 ± 381 HU, mean stone size of 16.5 ± 6.8 mm, and median stone volume of 883 (interquartile range 606-1664) mm3. Both ablation efficacy and speed were higher in the 200-Hz mode (2.7 J/mm3vs 3.8 J/mm3 and 5.5 mm3/second vs 8.0 mm3/second, respectively); moreover, the higher frequency correlated with increased ablation speed (r = -0.21, p = 0.019). However, both increased energy and frequency did not lead to increase of laser-on time or intraoperative complication rates. Conclusions: SP TFL is able to effectively disintegrate stones during RIRS with minimal complication rates. The use of higher frequency regimens showed higher efficacy and ablation speed and was not associated with increased complication rates.

Knowing the inside of a laser / Conocer la parte interna del láser

"Theatre acting is the operation with a scalpel, movie acting is an operation with a laser". Michael Caine. Being the instrument in hands of urologist laser is much more than a single-application device. Its applicability is deeply dependent on physical properties, settings, and environment. With knowledge of how the device work, why it affects the tissue, and how this laser-tissue interaction goes surgeon can shape further clinical work to choose the best devices or techniques of surgery. Tailoring the laser effects on the needs of the patient. In this paper, we tried to briefly describe what a laser device consists of, the most important laser-tissue interactions that are necessary for understanding the operation of the laser, and the main laser systems that are used in urology

Michael Caine dijo que las actuaciones de quirófano son con bisturí y las actuaciones en películas son con láser. En manos de urólogos, el láser es mucho más que una técnica. Su aplicabilidad depende de las habilidades físicas, la disposición de los elementos y el ambiente. El conocimiento del láser permite al cirujano escoger la técnica correcta para cada caso. En este manuscrito, describimos en qué consiste el láser, las interacciones con el tejido y los principales tipos de láser en urología