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.

Holmium laser with MOSES technology (MoLEP) vs Thulium fiber laser enucleation of the prostate (ThuFLEP) in a real-world setting. Mid-term outcomes from a multicenter propensity score analysis.

PURPOSE: To compare Holmium laser with MOSES technology (MoLEP) and Thulium fiber laser enucleation of the prostate (ThuFLEP) in terms of surgical and functional outcomes. METHODS: We performed a retrospective analysis of all patients who underwent either procedure in five centers (January 2020-January 2022). EXCLUSION CRITERIA: previous urethral/prostatic surgery, radiotherapy, concomitant surgery. Propensity score matching (PSM) analysis was performed to adjust for the bias inherent to the different characteristics at baseline. Differences between procedures were estimated using Firth Penalized Likelihood regression for International prostate symptom score (IPSS), quality of life (QL), maximum flow rate (Qmax). RESULTS: PSM retrieved 118 patients in each group. Baseline characteristics were similar except for PSA and number of men on indwelling catheter (higher in MoLEP group). Median surgical time was significantly longer in the MoLEP group despite the enucleation and morcellation times being similar. Median catheter dwelling time and postoperative length of stay were similar. Most of the early complications were Clavien ≤ 2 grade. There were only two Clavien grade 3 complications (one for each group), one grade 4 in MoLEP group. Rate and type of early and persistent incontinence (> 3 months) were similar. At 12-month, proportion of patients reaching a decrease (Δ) of IPSS ≥ 18 from baseline was significantly larger in MoLEP group, with no significant difference in ΔQmax > 12 ml/sec and ΔQL ≥ -3. CONCLUSION: MoLEP and ThuFLEP were safe and efficacious procedures with similar short-term operative and functional outcomes. At 1-year, MoLEP patients had a sustained reduction of IPPS score.

Comparison of EEP and TURP long-term outcomes: systematic review and meta-analysis.

OBJECTIVE: To compare long-term reoperation rate and functional outcomes between EEP (endoscopic enucleation of the prostate) and TURP (transurethral resection of the prostate). EVIDENCE ACQUISITION: A systematic literature review of Medline, Scopus, and Web of Science was conducted with primary outcome assessed being reoperation rate and secondary outcomes after a long term (> 3 years) being functional outcomes or related values (prostate volume, PSA level, etc.). EVIDENCE SYNTHESIS: Five studies were found with long-term follow-up 4-7 years. EEP reoperation rate ranged from 0 to 1.27%, while from 1.7 to 17.6% for TURP. Meta-analysis showed significantly lower OR for EEP, 0.27 (95% CI 0.24-0.31), with notable homogeneity of the results, I2 = 0%. Long-term Qmax and IPSS were significantly better for EEP. Qmax pooled mean difference was 1.79 (95% CI 1.72-1.86) ml/s with a high concordance among the studies, I2 = 0%. IPSS mean difference -1.24 (95% CI - 1.28 to - 1.2) points, I2 = 57% but QoL did not differ, with mean difference being 0.01 (95% CI - 0.02 to 0.04), I2 = 0%. IIEF-5 score was also significantly better for EEP, mean difference 1.08 (95% CI 1.03-1.13), but heterogeneity was high, I2 = 70%. PSA level and prostate volume were only reported in one study and favored EEP slightly yet statistically significant. CONCLUSION: EEP had a significantly lower reoperation rate and better functional outcomes (Qmax and IPSS) at long term compared with TURP. It may also be beneficial in terms of IIEF-5, PVR, and PSA level.

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.

A systematic review and meta-analysis of placebo effect in clinical trials on chronic prostatitis/chronic pelvic pain syndrome.

BACKGROUND: It is a common practice to control efficacy of pharmacological treatment with a placebo group. However, placebo itself may affect subjective and even objective results. The purpose of this study was to evaluate the placebo effect on symptoms of CP/CPPS to improve future clinical trials. METHODS: A search at three databases (Scopus, MEDLINE, and Web of Science) was conducted to identify double-blind placebo-controlled clinical trials on the treatment of CP/CPPS published until April 2021. The primary outcome - National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) score. SECONDARY OUTCOMES: Qmax, PVR, IPSS, and prostate volume. RESULTS: A total of 3502 studies were identified. Placebo arms of 42 articles (5512 patients, median 31 patients) were included in the systematic review. Systematic review identified positive changes in the primary endpoint, meta-analysis of 10 articles found that NIH-CPSI total score results were significantly influenced by placebo, mean difference -4.2 (95% confidence interval [CI]: -6.31, -2.09). Mean difference of NIH-CPSI pain domain was -2.31 (95% CI: -3.4, -1.21), urinary domain -1.12 (95% CI: -1.62, -0.62), quality of life domain -1.67 (95% CI: -2.38, -0.96); p < 0.001 for all. In case of the objective indicator - Qmax, there were three articles included in the meta-analysis. Qmax mean change from baseline was 0.68 (95% CI: -0.85, 2.22, p = 0.38). Systematic review showed no significant changes in pain, measured by VAS or other scores, IPSS and PVR. CONCLUSIONS: Placebo significantly affected the subjective parameters (NIH-CPSI) and limitedly affected various other measurements of pain (visual analog scale, McGill pain questionnaire). There was no long-term effect on IPSS and objective measurements (Qmax, PVR). This study can be used in further clinical trials to develop general rules of CPPS treatment assessment.

Randomized prospective trial of the severity of irritative symptoms after HoLEP vs ThuFLEP.

PURPOSE: To compare the short-term postoperative functional outcomes and severity of irritative symptoms following holmium and thulium fiber laser enucleation (HoLEP and ThuFLEP). METHODS: This prospective randomized single-blinded study was performed in accordance with CONSORT. The inclusion criteria were IPSS > 20 or Qmax < 10 ml/s. Patients were randomized between HoLEP and ThuFLEP. Demographics, objective data (PSA, prostate volume, etc.), data on urinary and sexual function (IPSS, IIEF, QoL, QUID, Qmax, ICIQ-MLUTS) were collected. Detailed perioperative information and postoperative data on functional outcomes at 1, 2, 3, 4, 6, 8, 10, 12 weeks and 6 months were collected. RESULTS: Data on 163 participants were included (77-HoLEP, 86-ThuFLEP). No differences were found in surgery duration; number of postoperative complications (Clavien-Dindo I-III), catheterization time and hospital stay. Functional outcomes up to 6 months didn't differ between the groups (IPPS, IIEF, QoL, QUID, ICIQ-MLUTS, Qmax, p > 0.05). Total ICIQ-MLUTS, bother and voiding scores at 1 and 3 months significantly increased compared with the baseline in both groups (p < 0.05). No difference between the groups were observed. In HoLEP the SUI series rate was 1.3% and 1.3% after 3 and 6 months following the procedure; in ThuFLEP: it was 3.5% and 2.3% respectively (p = 0.35 and p = 0.54). CONCLUSION: The preliminary results of the study showed no apparent differences in functional outcomes (IPSS, Qmax), rate of SUI or irritative symptoms. Both ThuFLEP and HoLEP are efficient ways of treating benign prostatic obstruction. Both surgeries are comparable in terms of duration and postoperative complication rates.

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.

Ex vivo study of Ho:YAG and thulium fiber lasers for soft tissue surgery: which laser for which case?

The goal of this study was to assess the ablation, coagulation, and carbonization characteristics of the holmium:YAG (Ho:YAG) laser and thulium fiber lasers (TFL). The Ho:YAG laser (100 W av.power), the quasi-continuous (QCW) TFL (120 W av.power), and the SuperPulsed (SP) TFL (50 W av.power) were compared on a non-frozen porcine kidney. To control the cutting speed (2 or 5 mm/s), an XY translation stage was used. The Ho:YAG was tested using E = 1.5 J and Pav = 40 W or Pav = 70 W settings. The TFL was tested using E = 1.5 J and Pav = 30 W or Pav = 60 W settings. After ex vivo incision, histological analysis was performed in order to estimate thermal damage. At 40 W, the Ho:YAG displayed a shallower cutting at 2 and 5 mm/s (1.1 ± 0.2 mm and 0.5 ± 0.2 mm, respectively) with virtually zero coagulation. While at 70 W, the minimal coagulation depth measured 0.1 ± 0.1 mm. The incisions demonstrated zero carbonization. Both the QCW and SP TFL did show effective cutting at all speeds (2.1 ± 0.2 mm and 1.3 ± 0.2 mm, respectively, at 30 W) with prominent coagulation (0.6 ± 0.1 mm and 0.4 ± 0.1 mm, respectively, at 70 W) and carbonization. Our study introduced the TFL as a novel efficient alternative for soft tissue surgery to the Ho:YAG laser. The SP TFL offers a Ho:YAG-like incision, while QCW TFL allows for fast, deep, and precise cutting with increased carbonization.

Systematic review of the endoscopic enucleation of the prostate learning curve.

INTRODUCTION: It has been shown that endoscopic enucleation of the prostate (EEP) allows for similar efficacy and safety, no matter what energy and type of instruments we use, but the length of learning may differ greatly. The aim of this systematic review is to verify if there is any significant difference between EEP methods in learning. EVIDENCE ACQUISITION: We performed a systematic literature search in three databases and included only the articles containing their own data on the EEP learning curve assessment during the last 10 years. The primary endpoint was to determine the necessary experience needed to achieve a plateau. The secondary endpoints were to review methods used to evaluate a learning curve. EVIDENCE SYNTHESIS: The final sample included 17 articles, containing a total of 4615 EEPs performed by 76 surgeons, the most common method was HoLEP (9/17). The majority of articles studying HoLEP report a learning curve of experience level achievement in roughly 30-40 (min 20; max 60) cases. The studies of GreenLight laser showed high heterogeneity in the results with minimum of 20 cases and maximum of 150-200 cases. TUEB required roughly 40-50 cases to reach the plateau. CONCLUSION: Although EEP is considered challenging, it shows a steep learning curve with a plateau after 30-50 cases. Proper criteria are critical for accurate assessment of the learning curve. The Trifecta and Pentafecta criteria are currently the most appropriate method to evaluate EEP learning.

The impact of the laser fiber-tissue distance on histological parameters in a porcine kidney model.

PURPOSE: To evaluate the impact of the fiber-tissue distance on histological parameters in a porcine kidney model. METHODS: Four lasers were tested at 60 W using a 600-µm bare-ended fiber: a continuous wave (cw) thulium fiber laser (TFL), a super pulsed (SP) TFL, a Ho:YAG laser, and a blue diode laser (BDL). All tissue samples were mounted on a motorized XY-translation stage. The fiber-tissue distance was changed within a range from 0to 6 mm. Ten incisions were made with each laser at each distance. Afterwards, the tissue samples were sliced with a microtome for lactate dehydrogenase staining to determine zones of thermal damage. RESULTS: In contact mode, the largest incision depth was found for the cw TFL (1.7 ± 0.1 mm) compared to the SP TFL (1.0 ± 0.1 mm), BDL (0.9 ± 0.1 mm) and HoYAG laser (1.1 ± 0.1 mm), respectively. With regard to the coagulative properties, the SP TFL and the Ho:YAG laser showed comparable coagulation depths with 0.7 ± 0.1 and 0.6 ± 0.1 mm, respectively. At 2 mm fiber-tissue distance, the Ho:YAG laser was the only laser that vaporized tissue (incision depth: 0.2 ± 0.1 mm). The BDL was the only laser that caused coagulation at a distance of 3-5 mm. CONCLUSION: Our results support the clinical observation that cw TFL must be defocused for best coagulation, while the coagulation depth of the SP TFL remains nearly constant within the range of 0-3 mm. Increasing the distance of the laser fiber to the tissue up to 5 mm did not cause significant differences with regard to coagulation depth using the BDL.

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.

A systematic review and meta-analysis of Histoscanning™ in prostate cancer diagnostics.

CONTEXT: The value of Histoscanning™ (HS) in prostate cancer (PCa) imaging is much debated, although it has been used in clinical practice for more than 10 years now. OBJECTIVE: To summarize the data on HS from various PCa diagnostic perspectives to determine its potential. MATERIALS AND METHODS: We performed a systematic search using 2 databases (Medline and Scopus) on the query "Histoscan*". The primary endpoint was HS accuracy. The secondary endpoints were: correlation of lesion volume by HS and histology, ability of HS to predict extracapsular extension or seminal vesicle invasion. RESULTS: HS improved cancer detection rate "per core", OR = 16.37 (95% CI 13.2; 20.3), p < 0.0001, I2 = 98% and "per patient", OR = 1.83 (95% CI 1.51; 2.21), p < 0.0001, I2 = 95%. The pooled accuracy was markedly low: sensitivity - 0.2 (95% CI 0.19-0.21), specificity - 0.12 (0.11-0.13), AUC 0.12. 8 of 10 studiers showed no additional value for HS. The pooled accuracy with histology after RP was relatively better, yet still very low: sensitivity - 0.56 (95% CI 0.5-0.63), specificity - 0.23 (0.18-0.28), AUC 0.4. 9 of 12 studies did not show any benefit of HS. CONCLUSION: This meta-analysis does not see the incremental value in comparing prostate Histoscanning with conventional TRUS in prostate cancer screening and targeted biopsy. HS proved to be slightly more accurate in predicting extracapsular extension on RP, but the available data does not allow us to draw any conclusions on its effectiveness in practice. Histoscanning is a modification of ultrasound for prostate cancer visualization. The available data suggest its low accuracy in screening and detecting of prostate cancer.

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.

Autonomous robots: a new reality in healthcare? A project by European Association of Urology-Young Academic Urologist group.

PURPOSE OF REVIEW: Artificial intelligence appears as a potential revolution in the general process of medical training, disease diagnosis and treatment. A novel disruptive technology of the 21st century will be 'learner' robots from artificial intelligence systems able to use all the combination of the available knowledge in medical repositories to give the best standard of care. RECENT FINDINGS: The autonomy level of robots depends on three factors: the complexity of the task; the environment in which the robot operates, and the required level of human-robot interaction. Autonomous robots in healthcare may be classified in delivery, nurse, and surgical robots. The increasing capability of robots to perform independent actions and complex tasks raises responsibility and accountability issues in a wide variety of application domains. Ethical analyses of these issues are underway and are mostly oriented toward the development of ethical policies requiring a law frame on robotic autonomous behaviors. SUMMARY: Autonomous robots have the potential to improve current medical practice offering a more secure, reliable, and reproducible medicine. Many advancements are required for these new technologies to be fully integrated. Furthermore, the ethical implications of these technologies are yet to be evaluated.

Acute kidney injury in COVID-19: are kidneys the target or just collateral damage? A comprehensive assessment of viral RNA and AKI rate in patients with COVID-19.

PURPOSE OF REVIEW: To investigate the possible effects of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) on kidney function and assess the rate of viral ribonucleic acid (RNA) shedding/detection in urine. RECENT FINDINGS: Most of the research on the topic suggests that for the moment our ability to estimate whether SARS-CoV-2 is a direct causative agent in acute kidney injury (AKI) or whether it has a cytokine storm effect is limited. During our prospective assessment of 333 patients with COronaVIrus Disease 2019 (COVID-19) it was found that frequency of AKI of 9.6% (32 cases). Despite previous data suggestive of the ability to detect SARS-CoV-2 in urine, we were unable to identify any traces of messenger ribonucleic acid (mRNA) in our group. Both COVID-19 severity (odds ratio, OR = 23.09, confidence interval, CI 7.89-67.57, P < 0.001) and chronic kidney disease (CKD) history (OR = 7.17, CI 2.09-24.47, P = 0.002) were associated with the AKI rate. SUMMARY: AKI is a relatively frequent condition for patients with COVID-19 and is normally correlated with the severity of the disease and the patient's history of CKD. The available data fail to address whether SARS-CoV-2 mRNA is present in urine, whereas our prospective trial data suggest that mRNA is undetectable in urine irrespective of the severity of the disease.

Endoscopic lithotripsy with a SuperPulsed thulium-fiber laser for ureteral stones: A single-center experience.

OBJECTIVES: To estimate the efficacy and safety of SuperPulsed thulium-fiber laser ureteral lithotripsy and to identify optimal laser settings. METHODS: Patients with solitary stones were prospectively included. Lithotripsy was performed with a SuperPulsed thulium-fiber laser (NTO IRE-Polus, Fryazino, Russia) using a rigid ureteroscope 7.5 Ch (Richard Wolf, Knittlingen, Germany). We analyzed the efficacy of lithotripsy by measuring total energy required for stone disintegration, "laser-on" time, ablation speed, ablation efficacy, and energy consumption. Stone retropulsion and visibility were assessed using a three-point Likert scale. Complications were assessed using the Clavien-Dindo classification system. RESULTS: A total of 149 patients were included. The mean stone density was 985 ± 360 Hounsfield units, the median (interquartile range) stone volume was 179 (94-357) mm3 . The median (interquartile range) total energy was 1 (0.4-2) kJ, and laser-on time 1.2 (0.5-2.7) min. The median (interquartile range) stone ablation speed was 140 (80-279) mm3 /min, energy for ablation of 1 mm3 was 5.6 (3-9.9) J/mm3 and energy consumption was 0.9 (0.6-1) J/min. A correlation was found between retropulsion and the energy used (r = 0.5, P < 0.001). Multivariable analysis showed energy to be a predictor of increased retropulsion (odds ratio 65.7, 95% confidence interval 1.6-2774.1; P = 0.028). No predictors for worse visibility were identified. CONCLUSION: The SuperPulsed thulium-fiber laser provides effective and safe lithotripsy during ureteroscopy regardless of stone density. Fiber diameter and laser frequency do not influence visibility or safety. Optimal laser settings are 0.5 J × 30 Hz for fragmentation and 0.15 J × 100 Hz for dusting.

Temperature changes during laser lithotripsy with Ho:YAG laser and novel Tm-fiber laser: a comparative in-vitro study.

AIM: The aim of this study was to compare the thermal effects of Ho:YAG and Tm-fiber lasers during lithotripsy in an in-vitro model via real-time temperature measurement. METHODS: We compared a Ho:YAG laser (pav up to 100 W, Lumenis, Yokneam, Israel) and a superpulse Tm-fiber laser (SP TFL, pav up to 40 W, NTO IRE-Polus, Fryazino, Russia), both equipped with 200 µm bare-ended fibers. The following settings were used: 0.2 J, 40 Hz (nominal pav 8 W). Power meter FieldMaxII-TO (Coherent, Santa Clara, CA, USA) was used to verify output laser power (pav). Each laser was fired for 60 s in two setups: (1) thermos-insulated (quasi-adiabatic) cuvette; (2) actively irrigated setup with precise flow control (irrigation rates 0, 10, 35 mL/min). RESULTS: Power measurements performed before the test revealed a 10% power drop in Ho:YAG (up to 7.2 ± 0.1 W) and 6.25% power drop in SP TFL (up to 7.5 ± 0.1). At the second step of our experiment, irrigation reduced the respective temperatures in the same manner for both lasers (e.g., at 35 mL/s SP TFL - 1.9 °C; for Ho:YAG laser - 2.8 °C at 60 s). CONCLUSION: SP TFL and Ho:YAG lasers are not different in terms of volume-averaged temperature increase when the same settings are used in both lasers. Local temperature rises may fluctuate to some degree and differ for the two lasers due to varying jet streaming caused by non-uniform heating of the aqueous medium by laser light.

Effect of optical fiber diameter and laser emission mode (cw vs pulse) on tissue damage profile using 1.94 µm Tm:fiber lasers in a porcine kidney model.

PURPOSE: To evaluate the ablation capacity using two Thulium fiber lasers (TFL) in a porcine kidney model. METHODS: All tissue samples were mounted on a motorized stage for a precise speed of cutting. A continuous wave (cw) TFL and a super pulsed (SP) TFL were used at power settings of 60 and 120 W with 200 and 600 µm laser fibers. After lactate dehydrogenase staining, histological evaluation was performed to measure the vaporization volume (VV), ablation depth (AD), thermo-mechanical damage zones (TMZ), coagulation zones (CZ) and the carbonization grade (CG). RESULTS: At 120 W, no significant differences were seen between 200 and 600 µm fibers utilizing the cw TFL regarding VV (24.6 vs. 28.2 mm3/s), AD (5.6 vs. 5.7 mm), TMZ (0 vs. 0 mm2) and CZ (18.1 vs. 12.3 mm2). Using the SP TFL, no significant differences between both fiber diameters with regard to VV (4 vs. 6.2 mm3/s), AD (2.7 vs. 3.4 mm), TMZ (1 vs. 2.6 mm2) and CZ (3.1 vs. 2.2 mm2) at 120 W were found, respectively. However, the VV of the cw TFL at 60 W was significantly less compared to 120 W using 200 and 600 µm fibers, respectively, whereas the SP TFL did not show significant differences between 60 and 120 W with regard to VV. SP TFL showed a consistently lower CG compared to cw TFL. CONCLUSIONS: This experiment suggests that there is no significant difference using 200 or 600 µm laser fibers in cw or SP TFLs. However, the cw TFL produces a coagulation zone three to five times larger than the SP TFL regardless of the fiber diameter.