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Objective: To evaluate the ablation speed (AS), laser efficiency and direct thermal lesions during urinary stone lithotripsy with the current available laser technologies: Holmium:YAG (Ho:YAG), pulsed-Thulium:YAG (p-Tm:YAG) and thulium fiber laser (TFL) in vitro using different laser settings. Materials and Methods: Ho:YAG, p-Tm:YAG, and TFL laser system were used in an in vitro ureteral model with a volume of 125 mm 3 Begostone. The following parameters were tested across all laser devices: 0.6J/10 Hz (6 W), 0.6 J/20 Hz (12 W), 1.5 J/10 Hz (15 W), and 1.5 J/20 Hz (30 W), employing short pulse width for all lasers and long pulse width for Ho:YAG and p-Tm:YAG. Ten participants conducted the experimental setup during 3-minutes laser on time, combining the laser technology, settings, and pulse widths, with a total of 20 different combinations. The efficiency, AS and ureteral damage resulting from each intervention were analyzed. Results: p-Tm:YAG and TFL demonstrated significantly higher efficiency compared with Ho:YAG (0.049 ± 0.02 Δgr/KJ and 0.042 ± 0.01 Δgr/KJ vs 0.029 ± 0.01 Δgr/KJ; p < 0.05). In all laser sources, as the power increases, the AS also increases ( p < 0.05). Furthermore, only at high-energy settings (1.5 J) higher frequency led to increase AS ( p < 0.05). Both, p-Tm:YAG and TFL exhibited higher AS compared to Ho:YAG (0.64 ± 0.33 Δgr/s and 0.62 ± 0.31 Δgr/s vs 0.44 ± 0.22 Δgr/s; p < 0.05). Regarding ureteral injuries, as the power increases, there is a higher chance of ureteral damage ( p = 0.031). No differences were observed between laser technologies ( p = 0.828). Conclusions: Both, p-Tm:YAG and TFL exhibited superior performances during laser lithotripsy compared with Ho:YAG, as they demonstrated higher efficiency and ablation speed. Thermal damage did not appear to be associated with specific laser equipment, but higher grades of lesions are described by increasing power.

Objective: To characterize the pulse characteristics and risk of fiber fracture (ROF) of the pulsed-Thulium:YAG (p-Tm:YAG) laser and to compare its ablation volumes (AVs) against Holmium:Yttrium-Aluminium-Garnet (Ho:YAG) laser and Thulium fiber laser (TFL). Materials and Methods: p-Tm:YAG (100 W-Thulio, Dornier-Medtech © , Germany) was characterized using single-use 272 μm core-diameter-fibers. p-Tm:YAG characterization included pulse shape, duration, and peak power (PP) studies. ROF was assessed after 5 minutes of continuous laser activation (CLA) at five decreasing fiber bend radii (1, 0.9, 0.75, 0.6, and 0.45 cm). p-Tm:YAG, Ho:YAG (120 W-Cyber-Ho, Quanta ® , USA), and TFL (60 W-TFLDrive, Coloplast ® , Denmark) AVs were compared using a 20-mm linear CLA at 2 mm/second velocity in contact with 20 mm 3 hard stone phantoms (HSP) and soft stone phantoms (SSP) (15:3 and 15:5 water to powder ratio, respectively) fully submerged in saline at 0.5 J-20 Hz or 1 J-10 Hz. After CLA, phantoms underwent three-dimensional (3D) micro-scanning (CT) and subsequent 3D segmentation to estimate the AVs, using 3DSlicer © . Each experiment was performed in triplicate. Results: p-Tm:YAG presents a uniform pulse profile in all of the available preset modes. PP ranged from 564 to 2199 W depending on pulse mode. No laser fiber fracture occurred at any bend radius. p-Tm:YAG achieved similar mean AVs to TFL and Ho:YAG for HSP (8.96 ± 3.1 vs 9.78 ± 1.1 vs 8.8 ± 2.8 mm 3 , p = 0.67) but TFL was associated with higher AVs compared with p-Tm:YAG and Ho:YAG (12.86 ± 1.85 vs 10.12 ± 1.89 vs 7.56 ± 2.21 mm 3 , p = 0.002) against SSP. AVs for HSP increased with pulse energy for p-Tm:YAG and Ho:YAG and (11.56 ± 1.8 vs 6.36 ± 0.84 mm 3 and 11.27 ± 1.98 vs 6.34 ± 0.55 mm 3 , p = 0.03 and p = 0.02), whereas AVs for SSP were similar across laser settings for all laser sources. AVs with TFL were similar across laser settings for both phantom types. Conclusion: p-Tm:YAG combines intermediate PP between Ho:YAG and TFL, a uniform pulse profile, no ROF with increasing deflection and effective ablation rates. Further clinical studies are needed to confirm these in vitro results.

Objectives: The super-pulsed thulium fiber laser (SP TFL) is a new alternative to high-power holmium laser for intracorporeal lithotripsy. The SP TFL has shown advantages in dusting regimes, but benefits in fragmentation regimes are less understood. The second-generation SP TFL introduces an advanced fragmentation pulse (AFP) sequence to maximize SP TFL's efficiency in fragmentation. This study evaluates safety and efficacy of the SP TFL fragmentation mode in ureteroscopy (URS) and mini percutaneous nephrolithotomy (mini-PCNL). Materials and Methods: The study was conducted in two phases. Safety of a new AFP was compared ex vivo to standard SP TFL fragmentation settings by measuring the dimensions of wounds created in porcine kidney after laser exposure for 0.5, 1.0, and 2.0 s. The resulting wounds were evaluated histologically using nitro blue tetrazolium chloride (NBTC) stain. In the clinical phase, the second-generation SP TFL was used to fragment and extract ureteral and renal stones in 40 patients using ureteroscopic and percutaneous approaches. The stone size, volume, density, laser-on-time, and total energy were recorded for each patient. In addition, the chemical composition, ablation rate, and ablation efficiency were assessed for each stone treatment. Results: The ex vivo mucosa damage profiles caused by AFP were similar to those caused by regular pulses. In clinical phase, the median volume and density for ureteral stones were 0.4 cm 3 and 1029 Hounsfield units (HU), for renal stones 1.3 cm 3 and 1113 HU, respectively. Different stone types were crushed into fragments suitable for extraction. The mean AFP energy was 3 J and the average power for ureteral stones was 10.5 W, whereas for renal stones it was 28.5 J and 31 W, respectively. The overall complication rate was low in both groups. Conclusion: ST PFL with AFP capability facilitates effective fragmentation of ureteral and renal stones of any composition during URS and mini-PCNL with minimal complication rates.

Background: Among emerging AI technologies, Chat-Generative Pre-Trained Transformer (ChatGPT) emerges as a notable language model, uniquely developed through artificial intelligence research. Its proven versatility across various domains, from language translation to healthcare data processing, underscores its promise within medical documentation, diagnostics, research, and education. The current comprehensive review aimed to investigate the utility of ChatGPT in urology education and practice and to highlight its potential limitations. Methods: The authors conducted a comprehensive literature review of the use of ChatGPT and its applications in urology education, research, and practice. Through a systematic review of the literature, with a search strategy using databases, such as PubMed and Embase, we analyzed the advantages and limitations of using ChatGPT in urology and evaluated its potential impact. Results: A total of 78 records were eligible for inclusion. The benefits of ChatGPT were frequently cited across various contexts. In educational/academic benefits mentioned in 21 records (87.5%), ChatGPT showed the ability to assist urologists by offering precise information and responding to inquiries derived from patient data analysis, thereby supporting decision making; in 18 records (75%), advantages comprised personalized medicine, predictive capabilities for disease risks and outcomes, streamlining clinical workflows and improved diagnostics. Nevertheless, apprehensions were expressed regarding potential misinformation, underscoring the necessity for human supervision to guarantee patient safety and address ethical concerns. Conclusion: The potential applications of ChatGPT hold the capacity to bring about transformative changes in urology education, research, and practice. AI technology can serve as a useful tool to augment human intelligence; however, it is essential to use it in a responsible and ethical manner.

Urothelial carcinoma (UC) affecting the urinary tract is recognized as one of the prevalent types of cancer, ranking fifth in terms of incidence. However, it is important to note that upper tract urothelial carcinoma (UTUC), in comparison to bladder cancer, is relatively uncommon and represents a minority of UC cases, accounting for ∼5% to 10%. It is worth emphasizing that as much as 60% of UTUC cases are invasive at the time of diagnosis, in contrast to 25% of bladder cancer cases. These statistics highlight the urgent need for well-designed, multidisciplinary strategies to guide optimal management for this vulnerable patient population, aiming to control treatment variability and minimize the risks associated with undertreatment and overtreatment. Methods: In this study, we present a comparative analysis of the contemporary guidelines on UTUC management from the European Association of Urology (EAU) and the American Urological Association/Society of Urologic Oncology (AUA/SUO) released in 2023. Our objective is to contrast the different guidelines and examine the evidence on which their recommendations are based. Results: By thoroughly reviewing the guidelines from both organizations, we observed substantial agreement on the management of UTUC. However, we also identified noticeable differences among these guidelines, leading to a wide range of recommendations. These disparities might stem from variations in clinical practices, regional preferences, and the availability of resources. It is crucial to acknowledge that both the EAU and AUA/SUO base their guidelines on the latest scientific evidence and expert consensus within their respective regions. Conclusions: These findings underscore the importance of ongoing collaboration, knowledge exchange, and harmonization of guidelines to improve the standard of care for UTUC globally. Future research should focus on identifying areas of consensus and bridging the gaps between different international guidelines to enhance the management outcomes for this challenging disease.

Purpose: On February 6, 2018, the European Atomic Energy Community reduced the annual equivalent dose limit for the lens from 150 to 20 mSv/year, because of its association with cataracts at low radiation doses. Our aim was to estimate the radiation doses received by the lens during endourologic procedures that require fluoroscopy. Materials and Methods: Multicenter study including prospective data of annual eye dosimeters between 2017 and 2020. Four endourologists used an eye dosimeter in endourologic procedures that require fluoroscopy (ureteroscopy, retrograde intrarenal surgery, and percutaneous nephrolithotomy). Surgeons 1 and 2 wore leaded glasses; surgeon 1 also used the as low as reasonably achievable (ALARA) protocol. Descriptive statistical analysis using SPSS 25.0 was conducted. Results: Surgeons 1, 2, 3, and 4 performed a median of 159, 586, 102, and 129 endourologic procedures per year, respectively, for a total of 641, 2340, 413, and 350 procedures between 2017 and 2020. The median annual dose of lens radiation exposure was 0.16, 1.18, 3.79, and 1.42 mSv per year, respectively, which corresponds to 0.001, 0.009, 0.024, and 0.012 mSv per procedure. The two surgeons who used leaded glasses registered a lower radiation dose per procedure (0.001 vs 0.027). Similarly, the urologist who used the ALARA protocol registered the lowest lens radiation dose compared with the three surgeons who did not use it (0.001 vs 0.023). Conclusions: The endourologists who participated in this study effectively comply with current guidelines on radiation exposure to the lens. Registered eye lens radiation does not seem to be related to the number of procedures but rather to the use of leaded glasses and the ALARA protocol.

Objectives: To compare the outcomes of using low-power (up to 30 W) vs high-power (up to 120 W) holmium lasers in retrograde intrarenal surgery (RIRS) in children and to analyze if lasering techniques and the use of access sheath have any influence on the outcomes. Methods: We retrospectively reviewed data from 9 centers of children who underwent RIRS with holmium laser for the treatment of kidney stones between January 2015 and December 2020. Patients were divided into two groups: high-power and low-power holmium laser. Clinical, perioperative variables and complications were analyzed. Outcomes were compared between groups using Student's t -test for continuous variables, and Chi-square and Fisher's exact test for categorical variables. A multivariable logistic regression analysis model was also performed. Results: A total of 314 patients were included. A high-power and low-power holmium laser was used in 97 and 217 patients, respectively. Clinical and demographic variables were comparable between both groups, except for stone size where the low-power group treated larger stones (mean 11.11 vs 9.70 mm, p  = 0.018). In the high-power laser group, a reduction in surgical time was found (mean 64.29 vs 75.27 minutes, p  = 0.018) with a significantly higher stone-free rate (SFR) (mean 81.4% vs 59%, p  < 0.001). We found no statistical differences in complication rates. The multivariate logistic regression model showed lower SFR in the low-power holmium group, especially with larger ( p  = 0.011) and multiple stones ( p  < 0.001). Conclusion: Our real-world pediatric multicenter study favors high-power holmium laser and establishes its safety and efficacy in children.

Objective: To evaluate using an inanimate model the thermal injury and laser efficiency on high frequency, high energy, and its combination in hands of junior and experienced urologists during holmium YAG (Ho:YAG) and Thulium fiber laser (TFL) lithotripsy. Methods: A Cyber: Ho 150 WTM and Fiber Dust TFL (Quanta System) with 200 μm core-diameter laser fibers (LF) were used in a saline in vitro ureteral model. Each participant (five junior and five experienced urologists) performed 32 sessions of 5-minute lasering (125 mm 3 phantom BegoStones™), comparing four modes (3 J/5 Hz [1.5 W], 0.3 J/20 Hz [6 W], 1.2 J/5 Hz [6 W], and 1.2 J/20 Hz [24 W]). Transparent tip and cleaved LF, and digital and fiberoptic ureteroscopes were also compared. Ureteral damage was classified in a scale (0-5) according to the burns and holes seen in the ureteral model's surface. Results: High-power (HP) setting (24 W) was associated with higher delivered energy and higher ablation rates (ARs) in both lasers ( p  < 0.001). For the same power setting (6 W), there was no difference in delivered energy or stone ARs. Regardless the settings, a higher AR was observed with TFL than with Ho:YAG (0.5Δ mg/s ± 0.33 vs 0.39 Δmg/s ± 0.31, p  = 0.002) laser. Higher mean AR was found with cleaved tip vs transparent tip ( p  = 0.03) in TFL. For both lasers, higher ureteral damage was observed in the 24 W group ( p  = 0.006) and in the junior urologists ( p  = 0.03). Between 6 W groups, different types of lesions were found and junior urologist have more lesions when high frequency was used, for both Ho:YAG ( p  = 0.05) and TFL ( p  = 0.04). Conclusion: More stone ARs and reduced operative time are observed in HP settings; however, more ureteral thermic-related damage is produced. When comparing the same power, higher energy or frequency does not modify the AR. Nonetheless, more ureteral thermic-related thermal damage is observed in high-frequency settings in unexperienced hands.

Introduction: Incidence of urolithiasis in children has increased in recent years and with technological advancements and miniaturization of surgical instruments, pediatric urologists have acquired an impressive arsenal for their treatment. Retrograde intrarenal surgery (RIRS) has gained widespread popularity as it is a natural extension of semirigid ureteroscopy and can be done through natural orifice minimizing the morbidity of percutaneous access. The aim of this narrative review is to describe how RIRS has evolved over the decades in children and if the age-related anatomical difference impacts reported outcomes especially stone-free rate (SFR) and complications. Materials and Methods: An electronic literature search from inception to October 15, 2021 was performed using Medical Subject Heading terms in several combinations on PubMed, EMBASE, and Web of Science without language restrictions. A total of 2022 articles were founded and 165 articles were full-text screening. Finally, 2 pediatric urologists included 51 articles that summarize the available literature regarding the development and use of RIRS in children. Results: RIRS as of today is well established as a superior modality for all stones in all locations compared with extracorporeal shockwave lithotripsy both in children and adults. The passive dilation has decreased the need of active ureteral dilation, but the need to perform prestenting is not defined yet. Regarding the use of the ureteral access sheath, the literature tends to lean toward its placement in most cases, but we do not know its long-term effects over the growth of children. Finally, the SFR has increased as the experience of pediatric urologists increases, as well as the number of complications has decreased. Conclusion: RIRS in pediatrics has crossed many milestones, yet many areas need further research and larger data are required to make RIRS the procedure of choice for renal stone management in children across all age groups.

Introduction : We aimed to evaluate if the biochemical composition of urinary stones can be determined by analyzing the stone dust only, and whether a photo taken during the surgery could be useful for completing the morpho-constitutional analysis. Materials and Methods : Twenty patients went through a retrograde intrarenal surgery for renal stone treatment with thulium fiber laser (Fiber Dust; Quanta, 2020) using 150 μm silica core laser fibers. After laser lithotripsy, residual fragments (RF) were removed with a basket (ZeroTip; Boston Scientific) and spontaneously floating stones particles were considered stone dust and were aspirated through the working channel. Pairs of RF and stone dust were labeled and sent to analysis by scanning electron microscopy and Fourier transform infrared spectroscopy. Photos of the stone (surface and section) were taken from videos recorded during the surgery. Results : A total of 20 patients were included in this study. Mean age was 49.8 years with metabolic and genetic disorders. Mean stone volume was 750 mm 3 for ureteral stones and 2334 mm 3 for renal stones. Mean stone density was 1187 HU. Positive urine culture was found in 25% patients. In 2/20 (10%), the biochemistry differed only in the relative proportions of each constituent, while in 5/20 (25%), only one component was missing. Laser crystalline conversion was found in 3/20 (15%). Whewellite and weddellite layers were found in photos, thus adding missing information from dust stone analysis. Conclusion : By analyzing aspirated dust through the ureteroscope's working channel with physical techniques, we can understand the lithogenic process of the urinary stone, without needing to analyze the stone fragment. Morphologic analysis, given by a proper stone picture, adds missing information in specific cases.

Introduction: The aim of this study is to perform a literature review of stiff guidewires used in urology and to investigate if there is an official definition for stiffness (shaft rigidity) of wires. Materials and Methods: A literature search was performed for all English language articles in MEDLINE and Scopus databases, Google Scholar, and the official websites of international companies. Guidewires from different companies were included. Results: We analyzed 14 different stiff guidewires from the companies, Boston Scientific, Coloplast, Cook Medical, Olympus, Terumo, Rocamed, and Bard Urological, according to their characteristics. We found no concrete data regarding their stiffness on the official websites. In addition, there were a few published studies about the Amplatz Super Stiff guidewire (Boston Scientific), ZIPwire™ Stiff Nitinol Hydrophilic guidewire (Boston Scientific), HiWire Stiff Nitinol Core Wire Guide (Cook Medical), Amplatz Fixed Core Wire Guide (Cook Medical), and NiCore™ Nitinol Guidewire-Stiff (Bard Urological), whereas there were no available data for the majority of stiff guidewires. Conclusions: Stiff guidewires are listed in catalogs of companies without any information regarding their classification. They are only divided into stiff and standard versions without knowing the differences between them. The companies and their manufacturers should adopt a common method to calculate and define the stiffness of each guidewire.

Objective: To assess the diagnostic accuracy and intra-observer agreement of endoscopic stone recognition (ESR) compared with formal stone analysis. Introduction: Stone analysis is a corner stone in the prevention of stone recurrence. Although X-ray diffraction (XRD) and infrared spectroscopy are the recommended techniques for reliable formal stone analysis, this is not always possible, and the process takes time and is costly. ESR could be an alternative, as it would give immediate information on stone composition. Materials and Methods: Fifteen endourologists predicted stone composition based on 100 videos from ureterorenoscopy. Diagnostic accuracy was evaluated by comparing the prediction from visual assessment with stone analysis by XRD. After 30 days, the videos were reviewed again in a random order to assess intra-observer agreement. Results: The median diagnostic accuracy for calcium oxalate monohydrate was 54% in questionnaire 1 (Q1) and 59% in questionnaire 2 (Q2), whereas calcium oxalate dihydrate had a median diagnostic accuracy of 75% in Q1 and 50% in Q2. The diagnostic accuracy for calcium hydroxyphosphate was 10% in Q1 and 13% in Q2. The median diagnostic accuracy for calcium hydrogen phosphate dihydrate and calcium magnesium phosphate was 0% in both questionnaires. The median diagnostic accuracy for magnesium ammonium phosphate was 20% in Q1 and 40% in Q2. The median diagnostic accuracy for uric acid was 22% in both questionnaires. Finally, there was a diagnostic accuracy of 60% in Q1 and 80% in Q2 for cystine. The intra-observer agreement ranged between 45% and 72%. Conclusion: Diagnostic accuracy of ESR is limited and intra-observer agreement is below the threshold of acceptable agreement.

Purpose: Retrograde intrarenal surgery (RIRS) requires urologists to adopt an awkward body posture for long durations. Few urologists receive training in ergonomics despite the availability of ergonomic best practices utilized by other surgical specialties. We characterize ergonomic practice patterns and rates of musculoskeletal (MSK) pain among urologists performing RIRS. Methods: A web-based survey was distributed through the Endourological Society, the European Association of Urology, and social media. Surgeon anthropometrics and ergonomic factors were compared with ergonomic best practices. Pain was assessed with the Nordic Musculoskeletal Questionnaire (NMQ). Results: Overall, 519 of 526 participants completed the survey (99% completion rate). Ninety-three percent of urologists consider ergonomic factors when performing RIRS to reduce fatigue (68%), increase performance (64%), improve efficiency (59%), and reduce pain (49%). Only 16% received training in ergonomics. Residents/fellows had significantly lower confidence in ergonomic techniques compared with attending surgeons with any career length. Adherence to proper ergonomic positioning for modifiable factors was highly variable. On the NMQ, 12-month rates of RIRS-associated pain in ≥1 body part, pain limiting activities of daily living (ADLs), and pain requiring medical evaluation were 81%, 51%, and 29%, respectively. Annual case volume >150 cases (odds ratio [OR] 0.55 [0.35-0.87]) and higher adherence to proper ergonomic techniques (OR 0.67 [0.46-0.97]) were independently associated with lower odds of pain. Limitations include a predominantly male cohort, which hindered the ability to assess gender disparities in pain and ergonomic preferences. Conclusions: Adherence to ergonomic best practices during RIRS is variable and may explain high rates of MSK pain among urologists. These results underscore the importance of utilizing proper ergonomic techniques and may serve as a framework for establishing ergonomic guidelines for RIRS.

Introduction and Objectives: The thulium fiber (Tm-F) laser is currently studied as an alternative to the holmium: yttrium-aluminum-garnet (Ho:YAG) laser, the gold standard for endocorporeal laser lithotripsy. We aimed to evaluate the ex vivo effects of an accidental Tm-F laser exposure on bovine eyes and to test the protective action of different eyeglasses in preventing eye lesions in case of an accident. Methods: A 50-W TFL generator (IPG Photonics ® , Russia) with a wavelength of 1940 nm and 200-μm core diameter fibers (CDFs) were used. The laser fiber tip was pointed perpendicularly at different distances (0, 1, 3, 5, 8, and 10 cm, respectively) to the pupil center of the bovine eye. The Tm-F laser was activated for 1 or 3 seconds at three different settings (0.5 J-20 Hz, 1 J-10 Hz, and 2 J-10 Hz, respectively). The experiment was repeated using laser safety glasses and eyeglasses. After lasering, eye samples were immersed in a 0.5% fluorescein serum (Faure-Ciba-Geigy ® , Switzerland), then rinsed with saline. White and blue light examination looked for localized epithelial burns (LEBs), extended epithelial burns (EEBs), superficial corneal ulcerations (SCUs), and deep corneal ulcerations (DCUs). Results: A total of 68 bovine eyes were used. Despite the laser settings, both DCU (contact) and SCU (1 cm) developed without eye protection for 1 and 3 seconds of lasering. At the 3-cm fiber-eye distance, only burning lesions were observed. Over 5 cm, no lesion was found. At contact or 1-cm fiber-eye distance, pulse energy did not change the lesion grade, but at 3 cm, high pulse energy led to higher grade corneal lesions (0.5 J-10 Hz:LEB; 1 J-10 Hz:EEB). Despite the fiber-eye distance, no corneal lesions were reported in the laser safety glass or eyeglass group for 1 second of laser exposure. Conclusions: Our study highlights the risk of eye damage caused by Tm-F. Without proper eye protection, the Tm-F laser can cause corneal lesions up to 5 cm in distance with 1 second of exposure despite laser settings. Only dedicated protective eyeglasses are effective for long exposures.

Objectives: To assess the effect of various factors on laser fiber tip degradation with the thulium fiber laser (Tm-fiber): fiber stripping, adjustable laser settings (energy, frequency, peak power), and stone density. Methods: Two hundred seventy-three micrometer fibers were used with a 50W Tm-fiber. First, we assessed the evolution of power transmission with stripped and unstripped fibers submerged in saline. The laser was continuously activated for 5 minutes. The influence of each laser parameter (energy, frequency, and peak power) on fiber degradation was assessed by loss of power transmission and reduction of tip length. Second, we assessed the evolution of power transmission after 150 seconds of lithotripsy in a quasicontact mode against soft and hard BegoStones. The influence of lithotripsy with different laser settings on fiber degradation was assessed by loss of power transmission. Results: Power transmission was close to 100% with stripped fibers, while a power gain appeared for unstripped fibers after 5 minutes of laser emission. Thus, only stripped laser fibers were used during the second series of experiments. Regardless of laser settings, there was a constant loss of measured power transmission after lithotripsy with a significant difference between soft and hard stones, p  < 0.0001. Power transmission was 67% and 78% against hard and soft stones, respectively. While there was no influence of peak power on power output against hard stones, there was a significant one against soft stones. Conclusions: The main determinant of loss of power transmission during lithotripsy in contact mode with Tm-fiber is the stone density. Higher loss of power transmission occurs against hard stones than soft stones. All peak powers may be used against hard stones without a difference, while high peak power appears as an additional factor of power loss against soft stones, but this decrease will not the reach the one obtained with hard stones.

Background: Percutaneous nephrolithotomy (PCNL) is the first-choice treatment of renal stones larger than 2 cm. We aimed to evaluate if lasers perform as equal as non-laser devices in patients with kidney stones candidate to PCNL. Materials and Methods: A comprehensive literature search was performed in MEDLINE through PubMed, Scopus, and Cochrane Central Register of Controlled Trials (CENTRAL) to assess differences in the perioperative course, incidence of postoperative complications, and stone-free rate (SFR) in patients with kidney stones undergoing laser vs non-laser PCNL in randomized studies. The incidences of complications were pooled using the Cochran-Mantel-Haenszel Method with the random effect model and expressed as risk ratios (RRs), 95% confidence intervals (CIs), and p -values. Surgical time and length of stay were pooled using the inverse variance of the mean difference (MD) with a random effect, 95% CI, and p -values. Analyses were two tailed, with a significance set at p  ≤ 0.05. Results: Six articles, including 732 patients (311 patients undergoing holmium laser and 421 non-laser PCNL), were included in meta-analysis. Surgical time and postoperative stay were shorter in the non-laser group (MD: 11.14, 95% CI: 2.32 to 19.96, p  = 0.002; MD: -0.81, 95% CI: -2.18 to 0.57, p  = 0.25, respectively). SFR was significantly higher in the non-laser group (RR: 1.08, 95% CI: 1.01 to 1.15, p  = 0.03). Patients undergoing laser PCNL had a nonsignificant higher risk of postoperative fever >38°C (RR: 0.64, 95% CI: 0.31 to 1.30, p  = 0.22). Transfusion rate did not differ between the two groups (RR: 1.02, 95% CI: 0.50 to 2.11, p  = 0.95). The need for stent positioning because of urine extravasation was higher risk in the laser group, but the difference did not reach significance (RR: 0.49, 95% CI: 0.17 to 1.41, p  = 0.19). Conclusions: Non-laser PCNL showed better perioperative outcomes and SFR compared to holmium laser PCNL.

Objective: To assess the fiber-tissue interaction through ablation, coagulation, and carbonization characteristics of the Ho:YAG laser and super pulsed thulium fiber laser (TFL) in a nonperfused porcine kidney model. To assess the degradation of laser fibers during soft tissue treatment. Methods: A 50 W TFL generator was compared with a 120 W Ho:YAG laser. The laser settings that can be set identically between the two lasers (pulse energy and frequency), and clinically relevant for prostate laser enucleation, were identified and used for tissue incisions on fresh nonfrozen porcine kidneys. For each parameter, the short, medium, and long pulse durations for the Ho:YAG generator and the different peak powers 150, 250, and 500 W for the TFL generator were also tested. Laser incisions were performed with 550 μm stripped laser fiber fixed on a robotic arm at a distance of 0.1 mm with the tissue surface and at a constant speed of 10 mm/s. Histologic analysis was then performed, evaluating incision shape, incision depth and width, axial coagulation depth, and presence of carbonization. Degradation of the laser fiber was defined as reduction of laser fiber tip length after laser activation. Results: Incision depths and areas of coagulation were greater with the Ho:YAG laser than those with the TFL. Although no carbonization zone was found with the Ho:YAG laser, this was constant with the TFL. Although a fiber tip degradation was constantly observed with Ho:YAG laser, except in the case of a long pulse duration and low pulse energy (0.2 J), this was not the case with TFL. Conclusion: TFL appears to be an efficient alternative to Ho:YAG laser for soft tissue surgery. The histologic analysis found greater tissue penetration with the Ho:YAG laser and different coagulation properties between the two lasers. These results need to be investigated in vivo to assess the clinical impact of these differences and find the optimal settings for laser prostate enucleation.

Background: With recent technological advancement, new and improved endoscopic instruments and laser devices have catapulted flexible ureteroscopy to the forefront, hence making retrograde intrarenal surgery (RIRS) a popular choice for the management of renal stones. However, RIRS has also resulted in an increasing number of work-related musculoskeletal disorders, which can have a detrimental impact on surgeons' physical health and operative lifespan. The aim of our review is to examine the impact and feasibility of ergonomic adjustments and outline future directions and recommendations to improve the awareness of and reduce the prevalence of musculoskeletal injuries among urologists. Methods: This study was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A thorough literature review was conducted of several databases using the following keywords and Medical Subject Headings (MeSH) terms to generate a search strategy: nephrolithiasis, kidney calculus, renal calculus, staghorn calculus, ergonomics, position, fatigue, comfort, tire, physical strain, visual strain, muscle, ureteroscopy, RIRS, laser, and lithotripsy. Studies were chosen for inclusion by reviewers independently, and the data were consolidated for analysis. Results: A total of 1446 articles were identified on initial literature search; 23 were included in the final analysis. The impact of various ergonomic modifications on operative outcomes, surgeons, surgical equipment, and patients, was analyzed. In addition, we summarized all the improvements that resulted in better ergonomics in RIRS. Conclusion: Ergonomics in RIRS is poorly understood and there are currently no formal guidelines for this aspect. While modern endourology armamentarium seems to help with procedural ergonomics, more needs to be done to enhance surgeon comfort, protect surgeon longevity, and prioritize the health and safety of endourologists.

Objectives: The Thulium Fiber Laser (TFL) is studied as an alternative to the holmium:yttrium-aluminium-garnet (Ho:YAG) laser for lithotripsy, with the advantage of an induced bubble stream (IBS). This in vitro study compared the TFL's IBS with 150- and 272 μm-core-diameter laser fiber (CDF) and in four irrigant fluids. Methods: A TFL of 50 W (IPG Photonics © ) and 150 and 272 μm-CDF (Boston Scientific © ) were used, comparing nine energies (in the range from 0.025 to 4 J). An experimental setup consisted of a vertically disposed fiber in a cuvette filled with saline, iodinated contrast agent (IOA), human urine, or deionized water (DW) at ambient temperature. High-speed imaging of three consecutive IBS was performed to determine the influence of energy on their maximum length (ML; μm), width (MW; μm), and duration (MD; μs). Fibers were cleaved with ceramic scissors between each experience. Results: The IBS had higher ML and MW and MD with 150CDF than 272CDF. Maximum pulse rate for 150CDF and 272CDF was 2182 and 2000 Hz, respectively. Every maximum power was higher than the technological limit of TFL (>50 W). At equal energy density, 150CDF was associated with lower dimensions and durations. The IBS had higher maximum dimensions in IOA compared with saline solution (SS). Compared with DW and urine, IBS in IOA were longer beyond 500 mJ. Over 25 mJ, IBS were thinner in DW, urine, and SS. The IBS in DW, urine, and SS had similar maximum dimensions. The IBS's duration was higher in IOA compared with DW, urine, and SS, meaning a lower theoretical maximum pulse rate and power in IOA. Conclusion: Lasering with 150CDF fits with lower pulse energies-higher pulse rates settings than 272CDF, such as fine dusting mode. In IOA, Induced Bubbles Streams present higher dimensions and durations than in other studied fluids, related to its higher viscosity. Safety distance and pulse rate should be increased and decreased, respectively.

Purpose: There is no clear evidence that high-power (HP) laser generators perform better than low-power (LP) ones in terms of lithotripsy outcomes. We aimed to perform a systematic review of literature to compare the efficacy outcomes of both HP and LP during ureteroscopic lithotripsy. Materials and Methods: A computerized bibliographic search of the Medline, Embase, and Cochrane databases was performed for all studies reporting perioperative outcomes of HP and LP lithotripsy. Using the methodology recommended by the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, we identified 22 nonrandomized noncomparative retrospective studies published between 2015 and 2019 that were eligible for inclusion in this systematic review. Because of the lack of comparative studies, we decided to perform two separate meta-analytic syntheses for LP and HP studies, then we compared them using a Wald-type test. Results: Overall, the selected studies included 6403 patients. Study design, exposure assessment, selection criteria, and outcome of interest were heterogeneous. LP studies were more common ( n  = 17, 77%), whereas HP studies were more common in the latest inclusion period. Faster lithotripsy (32.9 minutes vs 63.9 minutes, p  < 0.01) was observed in HP studies. However, stone volume resulted twofold higher (2604 mm 3 vs 1217 mm 3 , p  = 0.048) in LP studies. Pooled stone-free rate was similar in both LP and HP studies, 81% and 82%, respectively, p  > 0.05. No difference in complication rate was observed between the two groups, p  = 0.12. Conclusions: HP laser lithotripsy appears to require shorter operative time, with similar stone-free and complication rates as compared with LP traditional lithotripsy. However, when taking into account stone burden, this advantage seems to be lost, or at least not to be comparable with what observed in laboratory studies. Because of the lack of high-level comparative evidence, further clinical studies are needed to elucidate the benefits of using HP laser generators during ureteroscopic stone treatment.

Background: Despite technology incorporation to percutaneous nephrolithotomy (PCNL), residual stone fragments (RSFs) may still persist after PCNL and need to be addressed to avoid regrowth or ureteral obstruction. The objective of this study was to compare the outcomes of retrograde intrarenal surgery (RIRS) to extracorporeal shockwave lithotripsy (SWL) for treating patients with RSFs after a previous standard PCNL. Materials and Methods: Adult patients with RSF after a standard PCNL submitted to RIRS or SWL in our Institution from January 2017 to January 2020 were retrospectively studied. Stone-free rate (SFR) was evaluated on postoperative day (POD) 90 by noncontrast CT (NCCT) or ultrasound and kidney, ureter, and bladder radiograph (KUB) for each renal unit. Surgical complications based on Clavien-Dindo classification during the 90 days of follow-up were recorded. Sample size was calculated for a power of 80% and a significance level of 0.05, assuming SFR of 20% for SWL and 50% for RIRS. Results: Thirty-three patients treated by SWL were compared with 36 patients treated by RIRS. Hospitalization time was longer in the RIRS group (4.18 vs 12.33 hours, p  = 0.001). SFR and success rate were lower in SWL than RIRS group (24.2% vs 58.3%, p  = 0.007 and 30.3% vs 72.2%, p  = 0.004, respectively), using POD 90 NCCT in 81.8% and ultrasound and KUB in 18.2% of the SWL group and using POD 90 NCCT in 100% of the RIRS group. Minor complications (Clavien-Dindo < III) occurred in 11 of 36 (30.6%) patients submitted to RIRS and in 2 of 33 (6.1%) patients submitted to SWL group ( p  = 0.025). Two patients (6.1%) of the SWL group had Clavien-Dindo IIIb complication owing to Steinstrasse and were submitted to ureteroscopy. Emergency room visits were similar between groups (6.1% vs 8.3%, p  = 1.0). Conclusions: RIRS has better SFR, higher minor complications, and lower major complications than SWL for the treatment of RSFs after standard PCNL.

Objective: To compare whether the outcomes of ultrasound-guided access percutaneous nephrolithotomy (USGA-PCNL) are similar to standard fluoroscopy-guided access percutaneous nephrolithotomy (FGA-PCNL). Methods: A review was developed by using the MEDLINE and Scopus databases and following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. Studies comparing the USGA-PCNL and the FGA-PCNL were included. Case reports, editorials and letters, unpublished studies, posters, and comments abstracts were excluded. Results: We found 12 published articles that compared USGA-PCNL and FGA-PCNL. These included six randomized controlled trials, three case-control trials, and three meta-analyses. The overall results showed no difference in the success of percutaneous access, bleeding, blood transfusion, operative time, postoperative complications, or hospital stay. Conclusion: The reported data demonstrate that there are no significant differences between the fluoroscopic-guided access PCNL and the ultrasonographic access PCNL. The choice of puncture depends on the surgeon's expertise in a particular technique and the patient and stone characteristics. Both approaches are equally safe and effective in experienced hands. It is important to recall that the use of one technique does not exclude the use of the other, and they can sometimes be complementary to each other.

Introduction: Kidney stone disease (KSD) is a highly prevalent disease worldwide. As water intake and its mineral content influence stone formation and recurrence, patients and physicians must be aware of the mineral content of drinkable water. We analyzed commercial bottled still water within Europe to assess the variation in its mineral composition across different manufacturers and countries. Materials and Methods: Data on the mineral composition of bottled still water regarding bicarbonate, calcium, magnesium, potassium, sodium, and sulfate concentration (mg/L) were collected from ten European countries. To collect the data, the two main supermarket chains in each participating country were either visited to check for the ingredient label on bottles or the online shop was consulted through the website of the supermarket in question. Descriptive statistics such as simple boxplots were used to illustrate the variation in mineral content. Results: One hundred eighty-two different commercial water brands were analyzed. Up to a fivefold variation in average concentrations per mineral between countries was observed. For calcium, a wide distribution was found in France and Switzerland compared with other countries with calcium levels ranging from 10.5 to 565 mg/L and 8.4 to 579 mg/L, respectively. By consuming 2 L of water with such high calcium levels, the daily reference intake for calcium is already achieved. Conclusions: The mineral content of bottled still water across Europe varies greatly. For patients with KSD it is important to be aware of the mineral content of the water they drink, as it might influence stone recurrence rates and necessitate alterations of their diet.

Introduction: The aim of this study was to prospectively compare the outcomes of bilateral same-session retrograde intrarenal surgery (BSS RIRS) with unilateral RIRS and to compare the outcomes of first with second operated kidneys in BSS RIRS. Subjects and Methods: Consecutive symptomatic adult patients with kidney stones up to 20 mm who accepted to be treated by RIRS were prospectively studied. Stone-free rate (SFR) was evaluated by non-contrast CT for each renal unit, and surgical complications were evaluated based on Clavien-Dindo classification. Results: SFR (73.9% vs 76.1%, p  = 0.830) and hospitalization time (14.43 ± 18.81 hours vs 13.00 ± 4.89 hours, p  = 0.564) were similar between unilateral and BSS RIRS groups, with less consumption of disposable devices in BSS RIRS ( p  = 0.017). Operative time was longer in BSS RIRS (61.24 ± 26.62 minutes vs 88.65 ± 33.19 minutes, p  < 0.001). Bilateral group had significant more overall complications by Clavien-Dindo classification than unilateral (15.9% vs 39.9%, p  = 0.030) and more emergency room (ER) visits (11.6% vs 34.8%, p  = 0.026). Moreover, although both groups temporarily increased creatinine levels, it was significantly higher in bilateral RIRS ( p  = 0.019). First operated kidney outcomes were similar to second operated kidney outcomes of BSS RIRS. Conclusion: Although BSS RIRS had similar SFR and consumed less disposable devices, it had a higher overall complication rate, a higher frequency of ER visits, and higher creatinine levels during follow-up than unilateral RIRS. There is no significant outcome difference between first and second operated kidneys in BSS RIRS.

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) mm 3 . Both ablation efficacy and speed were higher in the 200-Hz mode (2.7 J/mm 3 vs 3.8 J/mm 3 and 5.5 mm 3 /second vs 8.0 mm 3 /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.

Objective: To compare two commercially available ureteral access sheaths in their ability to access the renal collecting system and assess ureteral wall trauma using a prospective, randomized trial. Patients and Methods: Ninety-five patients undergoing ureteroscopy for renal stones were randomized to Cook Flexor™ or Boston Scientific Navigator HD™ 12/14F sheaths. If the initial sheath failed to advance, an alternate sheath was attempted. The primary outcome was the difference in these access sheaths to obtain access to the upper collecting system and the postoperative ureteral injury using standardized five-point classification system. Results: The overall success rate for sheath placement was 87.4% and did not differ for sheath groups. The Navigator HD was successful in 43% of the Flexor failures and was subjectively rated as easier to place ( p  = 0.018). Male gender, large stone burden, longer time of sheath insertion, and a more difficult subjective rating for sheath placement were associated with high-grade (grade 2 or 3) ureteral injury. Limitations include a small sample size and absence of long-term follow-up. Conclusion: Sheaths had equal success of placement and there was no significant difference in ureteral wall injury between the two sheaths. Subjectively difficult sheath placement and longer time of placement were associated with high-grade injury, suggesting that surgeons should carry a low threshold for switching to a smaller sheath when resistance is felt or if placement time is long. Clinical Trial number: Nct03349099.

Introduction: Urolithiasis in solitary kidney (SK) presents significant management dilemma as any insult to the kidney or its drainage can lead to significant morbidity. The treatment options include shock wave lithotripsy (SWL), percutaneous nephrolithotomy (PCNL), and ureteroscopy (URS). Our aim was to conduct a systematic review of literature on all available endourologic techniques reporting on the management of stones in an SK. Materials and Methods: We conducted a systematic review according to the Cochrane and PRISMA checklist for all English-language articles from inception to December 2018. All studies with a minimum of 10 patients that reported on endourologic management (SWL, PCNL, or URS) were included. Data were extracted for patient and stone demographics, outcomes including stone-free rate (SFR), adverse events, and renal function. Results: After an initial search of 553 articles, 27 were included for the final review (10 PCNL, 1 mini-PCNL, 9 URS, 1 SWL, and 6 comparative studies). The choice of treatment seemed to be based on stone size, with PCNL, URS, and SWL offered for mean stone sizes between 25-50, 10-28, and 12-15 mm, respectively. PCNL, URS, and SWL were reported in 1445, 792, and 186 patients, respectively, with a final SFR of 67%-97.7%, 43%-100%, and 73%-80% and a complication rate of 26.4%, 15%, and 16.7% across the three groups. The renal function deterioration was reported in 4/16 PCNL studies and in 1/15 URS studies, while it remained unaffected in the SWL study. Conclusions: Our review shows a rise of endourologic techniques in the management of stones in SK. Although PCNL was used for larger stones, it had a higher risk of major complications, including blood transfusion. While a good SFR was obtained for patients irrespective of the treatment modality, the selected intervention needs to be balanced with its safety profile and the need for ancillary procedures.

Introduction and Objectives: The Moses effect (ME) was described >30 years ago during normal laser functioning in a fluid medium. Recently, a laser device equipped with a pulse-modulating system called Moses™ technology (MT; Lumenis ® ) was marketed for both stone lithotripsy and prostate endoscopic surgery. We aimed to perform a literature revision of ME from a historical perspective up until its present-day applications. Evidence Acquisition: A search of Medline, PubMed, and Scopus was performed to identify articles published in English within the past 30 years addressing both ME and MT in relation to their urologic applications. Relevant studies were then screened, and the data were extracted, analyzed, and summarized. The preferred reporting items for systematic reviews and meta-analysis criteria were applied. Results: ME was first described in 1986 during endovascular laser tissue ablation. During the late 1980s and the early 1990s, the interest raised around ME led to its characterization and better definition. Despite this initial interest, ME gradually disappeared from the focus of researchers and clinicians. In 2017, MT was launched on the market, although postmarketing comparative efficacy and safety data are lacking. Conclusions: Although ME had been described and characterized during normal laser functioning >30 years ago, only very recently it began to regain some consideration after the marketing of MT, whose clinical outcomes are still awaited.

Objectives: To define the most suitable approach to assess residual stone fragments after retrograde intrarenal surgery (RIRS)., Methods: Ninety-two patients (115 renal units) submitted to RIRS for symptomatic kidney stones >5 mm and <20 mm or <15 mm in the lower Calyx diagnosed by noncontrast CT (NCCT) were prospectively studied. Residual fragments were assessed by endoscopic evaluation (END) at the end of the procedure and by NCCT, ultrasonography (US), and kidney, ureter, and bladder radiograph (KUB) on the 90th postoperative day (POD). NCCT was considered the gold standard for the evaluation of residual fragments after RIRS., Results: The 90th POD NCCT resulted in stone-free status in 74.8% (86/115), 0-2 mm in 8.7% (10/115), and >2 mm residual fragments in 16.5% (19/115) renal units. Stone-free status by END at the end of RIRS was coincident with NCCT in 93.0% of the cases (40/43). There were no cases of residual fragments >2 mm on NCCT if END resulted in stone-free status. In all cases where END resulted in residual fragments >2 mm, US proved to be correct according to NCCT. Neither US nor KUB was able to identify residual fragments between 0 and 2 mm. KUB had only 31.6% (6/19) sensitivity to detect residual fragments >2 mm and did not add sensitivity or specificity to US., Conclusions: In the follow-up imaging after RIRS, we suggest that if END resulted in residual fragments <2 mm, a 90th POD NCCT should be performed. US may be used if END showed fragments >2 mm.

Objective: To evaluate a portable electronic pH meter and to put its accuracy in perspective with reagent strips read by a layperson, a healthcare professional, and an electronic reading device., Materials and Methods: Based on a preanalysis on 20 patients, a sample size of 77 urine aliquots from healthy volunteers was necessary to obtain sufficient study power. Measurements of urinary pH were obtained by use of reagent strips, a portable pH meter and a laboratory pH meter (gold standard). Reagents strips were read by a professional experienced in interpreting strips, a layperson, and an electronic strip reader. The mean matched pair difference between measurement methods was analyzed by the paired t-test. The degree of correlation and agreement were evaluated by the Pearson's correlation coefficient and Bland-Altman plots, respectively., Results: The mean matched pair difference between the gold standard and all other pH measurement methods was the smallest with the portable electronic pH meter (bias 0.01, 95% confidence interval [CI] -0.07 to 0.08; p = 0.89), followed by strips read by a professional (bias -0.09, 95% CI -0.21 to 0.02; p = 0.10), layperson (bias -0.17, 95% CI -0.31 to -0.04; p = 0.015), and electronic strip reader (bias -0.29, 95% CI -0.41 to -0.16; p < 0.001). The portable electronic pH meter achieved the highest Pearson's correlation coefficient and narrowest 95% limits of agreement, followed by strip interpretation by a professional, electronic strip reader, and layperson. To quantify the ability of pH measurement methods to correctly classify values within a predefined urinary pH target range, we performed classification tests for several stones. The portable electronic pH meter outperformed all other measurement methods for negative predictive values., Conclusions: Findings of this study support that the portable electronic pH meter is a reliable pH measuring device. It appears to be more accurate compared to reagent strips readings.

Introduction: Flexible ureterorenoscopy (fURS) is one of the best solutions for treatment of renal calculi <2 cm and for upper urinary tract urothelial carcinoma conservative treatment. An adequate quality of vision is mandatory to help surgeon get better outcomes. No studies have been done, to our knowledge, about what fURS in the market has the best quality of vision., Materials and Methods: Seven different fURS were used to compare the image quality (Lithovue, Olympus V, Olympus V2, Storz Flex XC-in White Light and in Clara+Chroma mode-Wolf Cobra Vision, Olympus P6, and Storx Flex X2). Two standardized grids to evaluate contrast and image definition and three stones of different composition were filmed in four standardized different scenarios. These videos were shown to 103 subjects (51 urologists and 52 nonurologists) who had to evaluate them with a rating scale from 1 (very bad) to 5 (very good)., Results: No difference in terms of scores was observed for sex of the participants. Digital (D) ureterorenoscopes were rated better than fiber optics (FOs) ureterorenoscopes. Overall, Flex XC White Light and XC Clara+Chroma image quality resulted steadily better than other fURS (p < 0.0001). Olympus V generally provided a vision better than Lithovue. Cobra Vision and Olympus V2 had superimposable values that were significantly lower than Lithovue's ones. Olympus P6 and Storz X2 offered a low quality of vision compared to the others. In the medium simulating bleeding, Olympus V and V2 significantly improved their scores of 12% and 8.1%, contrary to rest of the ureterorenoscopes., Conclusion: D ureterorenoscopes have a better image quality than FO ones. The only disposable ureterorenoscope tested was comparable to the majority of other D ureterorenoscopes. The best image quality was provided by Storz D ureterorenoscopes, being Clara Chroma the favorite Spies Mode, according to literature.

Purpose: The holmium YAG (Ho:YAG) laser penetration depth (PD) of 0.4 mm has been widely described. Nonetheless, in physics, this concept refers to the tissue thickness at which 90% of the energy has been absorbed and not to the incision depth (ID) that the laser can achieve in tissue. The aim of this study is to evaluate the ablation efficiency of Ho:YAG laser on soft tissue., Materials and Methods: With an automated robotic arm, systematic fissures were performed on flat veal kidney specimens. Broad setting spectrums from 2.5 to 80 W, short and long pulse, were tested with 272 and 365 μm laser fibers. Experiments were repeated three times. Two pathologists in a blinded manner measured the width, depth, and coagulation area with electronic microscopy., Results: The overall mean ID was 2 mm (0.25-4.39) and the mean width was 1 mm (0.3-3.1). The mean coagulation thickness was 0.48 mm (0.25-1.73). The higher the frequency and energy, the deeper and wider was the incision p < 0.001. No differences were observed regarding the fiber diameter. The pulse length did not affect the ID, although the mean width was greater with short pulse p = 0.04. The outer mean coagulation was increased by increasing energy but not by increasing frequency p > 0.119., Conclusions: The overall mean ID was significantly higher than the theoretical 0.4 mm PD described for Ho:YAG laser. The energy, frequency, and pulse length had individual effects regarding ID, incision width, and coagulation. The ID should be specified in accordance with the laser's power output and should not be confused with the physics of PD concept.

Objective: To assess the "body mass index" (BMI) (weight and length) of 12 flexible ureteroscopes (digital and fiber optic) along with the light cables and camera heads, to make the best use of our instruments., Materials and Methods: Twelve different brand-new flexible ureteroscopes from four different manufacturers, along with eight camera heads and three light cables were evaluated. Each ureteroscope, camera head, and light cable was weighted; the total length of each ureteroscope, shaft, handle, flexible end-tip, and cable were all measured., Results: According to our measurements (in grams [g]), the lightest ureteroscope was the LithoVue (277.5 g), while the heaviest was the URF-V2 (942.5 g). The lightest fiber optic endoscope was the Viper (309 g), while the heaviest was the Cobra (351.5 g). Taking into account the entirety of the endoscopes, the lightest ureteroscope was the Lithovue and the heaviest was the Wolf Cobra with the Wolf camera "3 CHIP HD KAMERA KOPF ENDOCAM LOGIC HD" (1474 g). The longest ureteroscope was the URF-P6 (101.6 cm) and the shortest was the LithoVue (95.5 cm); whereas the Viper and Cobra had the longest shaft (69 cm) and URF-V had the shortest shaft (67.2 cm). The URF-V2 had the longest flexible end-tip (7.6 cm), while the LithoVue had the shortest end-tip (5.7 cm) in both directions (up/down), while the URF-V had the shortest upward deflection (3.7 cm)., Conclusions: Newer more versatile digital endoscopes were lighter than their traditional fiber optic counterparts in their entirety, with disposable endoscope having a clear advantage over other reusable ureteroscopes. Knowing the "BMI" of our flexible ureteroscopes is an important information that every endourologist should always take into consideration.

Objective: To analyze the risk factors for laser fiber fractures when deflected to form a curve, including laser settings, size of the laser fiber, and the fiber bending diameter., Materials and Methods: Single-use 272 and 365 μm fibers (Rocamed ® , Monaco) were employed along with a holmium laser (Rocamed). Five different fiber curve diameters were tested: 9, 12, 15, 18, and 20 mm. Fragmentation and dusting settings were used at a theoretical power of 7.5 W. The laser was activated for 5 minutes and the principal judgment criterion was fiber fracture. Every test for each parameter, bending diameter, and fiber size combinations was repeated 10 times., Results: With dusting settings, fibers broke more frequently at a curved diameter of 9 mm for both 272 and 365 μm fibers (p = 0.037 and 0.006, respectively). Using fragmentation settings, fibers broke more frequently at 12 mm for 272 μm and 15 mm for 365 μm (p = 0.007 and 0.033, respectively). Short pulse and high energy were significant risk factors for fiber fracture using the 365 μm fibers (p = 0.02), but not for the 272 μm fibers (p = 0.35). Frequency was not a risk factor for fiber rupture. Fiber diameters also seemed to be involved in the failure with a higher number of broken fibers for the 365 μm fibers, but this was not statistically significant when compared with the 272 μm fibers (p > 0.05)., Conclusion: Small-core fibers are more resistant than large-core fibers as lower bending diameters (<9 mm) are required to break smaller fibers. In acute angles, the use of small-core fibers, at a low energy and long-pulse (dusting) setting, will reduce the risk of fiber rupture.

Introduction: Several studies have examined the link between temperature or monthly seasonal variations and urolithiasis. The majority of these studies have demonstrated a link between higher ambient monthly temperatures and the incidence of renal colic and kidney stone disease (KSD). However, a worldwide trend on this association has not been explored and we perform a systematic review to examine the effect of seasonal variations on renal colic and KSD., Materials and Methods: A systematic review of the literature for a 26-year period (1990-2017) was conducted on all studies reporting on the effect of seasonal variations and its link to KSD. Two reviewers independently extracted the data from each study, which were analyzed using SPSS version 24., Results: A total of 59 studies were identified, and after screening, 13 were included in this review. The studies ranged in duration from 1 to 9 years (mean: 5.5 years) and included seasonal/monthly variations for proven stones or lithotripsy treatments or emergency department presentations with renal colic. Except for one study, there was a statistically significant association between higher monthly mean temperatures and the incidence of KSD-related events reported from the United Kingdom, South Korea, the United States, Saudi Arabia, Italy, Spain, Taiwan, Japan, and New Zealand., Conclusions: Worldwide trends on the incidence of renal colic and KSD seem be affected by seasonal variation favoring warmer months, with data suggesting that higher ambient temperature has an association with KSD.

Background and Purpose: Modern flexible ureteroscopes (fURSs) have good deflection, but despite this, approaching an acute angled calix can still be difficult. The goals of our in vitro study were to assess the ability of the available modern fURSs to effectively access the sharp angled calices and to compare the end-tip deflection of the various fiber-optic and digital fURSs., Materials and Methods: Using a bench-training model for FURS (K-Box, Porgès-Coloplast), we tried to access an acute angled calix with nine different fURSs (BOA vision, COBRA vision, R.Wolf; FLEX X 2 , FLEX Xc, K.Storz; LithoVue, Boston Scientific; URF-P5, URF-P6, URF-V, URF-V2, Olympus). Passing the fURSs through a ureteral access sheath (ReTrace, Porgès-Coloplast), the maximum end-tip deflection for every fURS was measured with the tip extended out from the sheath at 1, 2, 3, and 4 cm. Two ranking methods were designed for scoring the fURSs, one based on total ranking points and the other on total degrees of deflection., Results: While all fiber-optic fURSs (except URF-P6) were able to access the sharp angled calix, none of the digital fURSs (except FLEX Xc) reached the difficult angled calix. Similarly, all fiber-optic fURSs had better end-tip deflection compared with the digital fURSs, except FLEX Xc, which was as deflectable as the fiber-optic fURSs. The fURSs showed an end-tip deflection (median difference of almost 21°) in favor of fiber-optic fURSs. Based on the scoring, the highest ranked fURS (best deflection) was FLEX X2 and the lowest ranked fURS (worst deflection) was URF-V2., Conclusions: Digital fURSs were less effective in accessing the sharp angled calix and they had lesser end-tip deflection compared with the fiber-optic counterparts. When approaching a difficult lower pole calix, it might be better to use a fiber-optic fURS.

Purpose: To propose and evaluate a new endoscopic technique using only a retrograde ureteroscopic approach for the removal of heavily encrusted ureteral stents. Methods: Data from 51 consecutive patients with encrusted and retained ureteral stents were prospectively collected. Description of the successive steps of surgery is detailed. The holmium yttrium aluminum garnet (Ho:YAG) laser properties offer the opportunity for fragmentation of stent-attached encrustation and the ability to cut the stent itself. Reducing the length of the stent is critical to creating space in the ureter and to allow free access for ureteroscopes or ureteral access sheath placement. The primary outcome of this study was the feasibility and the safety of this retrograde intrarenal approach. Some factors of encrustation and outcomes are also discussed in comparison with lithotripsy, percutaneous, laparoscopic, open surgery, or a combination of these techniques. Results: The removal of the encrusted stent was possible with only this retrograde technique in 98% of patients. The transection of the encrusted stent with the Ho:YAG laser was useful in 71% of the patients. Mean operative time was 110 minutes and mean hospital stay was 2.33 days. Postoperative complications were mainly nonobstructive pyelonephritis (10%). The most significant predictor of this life-threatening complication was the presence of struvite stones with the encrusted stent ( p  = 0.018). Contrariwise, operative time, body mass index, gender, and encrustation rate were not associated with postoperative pyelonephritis. Both cystine stone disease and pregnancy led to faster stent encrustation. Conclusions: Retrograde ureteroscopic surgery is efficient and safe for removing retained stents and associated stone burdens. The Ho:YAG laser is essential to perform the encrustation removal and sectioning of the stent.

Purpose: To evaluate in vitro the maximum pressure generated in an artificial kidney model when people of different levels of strengths used various irrigation systems. Materials and Methods: Fifteen people were enrolled and divided into three groups based on their strengths. Individual strength was evaluated according to the maximum pressure each participant was able to achieve using an Encore™ Inflator. The irrigation systems evaluated were as follows: T-Flow™ Dual Port, Hiline™, continuous flow single action pumping system (SAPS™) with the system close and open, Irri-flo II™, a simple 60-mL syringe, and Peditrol™. Each irrigation system was connected to URF-V2 ureteroscope, which was inserted into an artificial kidney model. Each participant was asked to produce the maximum pressure possible with every irrigation device. Pressure was measured with the working channel (WC) empty, with a laser fiber, and a basket inside. Results: The highest pressure was achieved with the 60 mL-syringe system and the lowest with SAPS continuous version system (with continuous irrigation open), compared to the other irrigation devices ( p  < 0.0001). Irrespective of the irrigation system, there was a significant difference in the pressure between the WC empty and when occupied with the laser fiber or the basket inside it ( p  < 0.0001). The stratification between the groups showed that the most powerful group could produce the highest pressure in the kidney model with all the irrigation devices in almost any situation. The exception to this was the T-Flow system, which was the only device where no statistical differences were detected among these groups. Conclusion: The use of irrigation systems can often generate excessive pressure in an artificial kidney model, especially with an unoccupied WC of the ureteroscope. Depending on the strength of force applied, very high pressure can be generated by most irrigation devices irrespective of whether the scope is occupied or not.