Foley catheter after ureteroscopy and JJ stent placement: a randomised prospective European Association of Urology Section of Urolithiasis-Young Academic Urologists (EULIS-YAU) endourology study.

OBJECTIVES: To evaluate the effects of inserting a Foley catheter after ureteroscopy (URS) and JJ stent placement on pain scores, voiding patterns, biochemical parameters and postoperative complications. PATIENTS AND METHODS: A randomised clinical trial (1:1) with adult patients following unilateral URS + JJ stent placement was planned. In Group A, no Foley catheter was placed, in Group B, a Foley catheter was placed following URS + JJ stent placement. The primary objective was to evaluate effect of placing a Foley catheter on International Prostate Symptom Score (IPSS), Ureteric Stent Symptom Questionnaire (USSQ) score and postoperative biochemical parameters. The secondary objective was to evaluate postoperative complications. RESULTS: A total of 112 patients were included (56/group). A ureteric access sheath was used in each patient. Patients had similar demographic and surgical parameters. The pre- and postoperative biochemical analyses including white blood cell count, C-reactive protein, procalcitonin and creatinine levels were similar between the two groups. The IPSS were similar between the two groups. All the subdomains of the USSQ were similar between two groups except Total Body Pain score, which was lower in Group B. The visual analogue scale scores were similar. Complications were all Clavien-Dindo Grade I and II, and the complication rate was 5.4% and 8.9% in Group A and B, respectively. CONCLUSION: Placing a Foley catheter following URS + JJ stent placement did not show significant effects on postoperative biochemical parameters and voiding symptoms. However, a Foley catheter lowered the Total Body Pain score on the USSQ without having significant effects on VAS scores. The practice of placing a Foley catheter following URS and JJ stent placement should be based on surgeon's preference keeping in mind the potential positive effect on pain scores.

A machine learning approach using stone volume to predict stone-free status at ureteroscopy.

INTRODUCTION: To develop a predictive model incorporating stone volume along with other clinical and radiological factors to predict stone-free (SF) status at ureteroscopy (URS). MATERIAL AND METHODS: Retrospective analysis of patients undergoing URS for kidney stone disease at our institution from 2012 to 2021. SF status was defined as stone fragments < 2 mm at the end of the procedure confirmed endoscopically and no evidence of stone fragments > 2 mm at XR KUB or US KUB at 3 months follow up. We specifically included all non-SF patients to optimise our algorithm for identifying instances with residual stone burden. SF patients were also randomly sampled over the same time period to ensure a more balanced dataset for ML prediction. Stone volumes were measured using preprocedural CT and combined with 19 other clinical and radiological factors. A bagged trees machine learning model with cross-validation was used for this analysis. RESULTS: 330 patients were included (SF: n = 276, not SF: n = 54, mean age 59.5 ± 16.1 years). A fivefold cross validated RUSboosted trees model has an accuracy of 74.5% and AUC of 0.82. The model sensitivity and specificity were 75% and 72.2% respectively. Variable importance analysis identified total stone volume (17.7% of total importance), operation time (14.3%), age (12.9%) and stone composition (10.9%) as important factors in predicting non-SF patients. Single and cumulative stone size which are commonly used in current practice to guide management, only represented 9.4% and 4.7% of total importance, respectively. CONCLUSION: Machine learning can be used to predict patients that will be SF at the time of URS. Total stone volume appears to be more important than stone size in predicting SF status. Our findings could be used to optimise patient counselling and highlight an increasing role of stone volume to guide endourological practice and future guidelines.

Risk factors of early infectious complications after ureterorenoscopy for stone disease: a prospective study.

PURPOSE: To prospectively evaluate the rate and associated risk factors of early infectious complications after ureterorenoscopy for urolithiasis. METHODS: After ethical committee approval, 400 therapeutic retrograde ureterorenoscopy procedures between August 3, 2020 and November 24, 2021 were included for analysis in a single-center study. Postoperative infection was defined as an afebrile urinary tract infection, fever (≥ 38 °C) with pyuria (≥ 300 WBC/µL) or proven urinary pathogen, and urosepsis. The primary outcome was the rate of infectious complications after ureterorenoscopy. Secondary outcomes were the perioperative factors that increased the risk of infectious complications within 30 days of surgery using univariate and multivariate logistic regression analysis. RESULTS: Twenty-nine of four hundred (7.3%) patients developed an infectious complication within 30 days after ureterorenoscopy. Ten (2.5%) patients developed an afebrile urinary tract infection, eight (2.0%) developed fever with pyuria, five (1.3%) febrile urinary tract infection, and six (1.5%) urosepsis. On univariate analysis, preoperative stent-type JFil® pigtail suture stent was significantly associated with the dependent variable (p < 0.001). On multivariate logistic regression analysis, older age (OR 1.035; 95% CI 1.006-1.070; p = 0.02) was found to be significantly associated with developing a postoperative infectious complication. CONCLUSIONS: A 7.3% rate of postoperative infectious complications and 1.5% urosepsis rate were observed after therapeutic ureterorenoscopy, without the need of intensive care admission. The only significant risk factors were preoperative stent type (JFil® pigtail suture stent) on univariate analysis, and older age on multivariate logistic regression analysis. Further multicentric prospective observational data are needed in this field.

Radiation exposure of urologists during endourological procedures: a systematic review.

INTRODUCTION: Ionizing radiation is used daily during endourological procedures. Despite the dangers of both deterministic and stochastic effects of radiation, there is a lack of knowledge and awareness among urologists. This study reviewed the literature to identify the radiation exposure (RE) of urologists during endourological procedures. METHODS: A literature search of the Medline, Web of Science, and Google Scholar databases was conducted to collect articles related to the radiation dose to urologists during endourological procedures. A total of 1966 articles were screened. 21 publications met the inclusion criteria using the PRIMA standards. RESULTS: Twenty-one studies were included, of which 14 were prospective. There was a large variation in the mean RE to the urologist between studies. PCNL had the highest RE to the urologist, especially in the prone position. RE to the eyes and hands was highest in prone PCNL, compared to supine PCNL. Wearing a thyroid shield and lead apron resulted in a reduction of RE ranging between 94.1 and 100%. Educational courses about the possible dangers of radiation decreased RE and increased awareness among endourologists. CONCLUSIONS: This is the first systematic review in the literature analyzing RE to urologists over a time period of more than four decades. Wearing protective garments such as lead glasses, a thyroid shield, and a lead apron are essential to protect the urologist from radiation. Educational courses on radiation should be encouraged to further reduce RE and increase awareness on the harmful effects of radiation, as the awareness of endourologists is currently very low.

Trends in the use of radiation protection and radiation exposure of European endourologists: a prospective trial from the EULIS-YAU Endourology Group.

INTRODUCTION: Due to the radiation exposure for the urology staff during endourology, our aim was to evaluate the trends of radiation protection in the operation room by endourologists from European centers and to estimate their annual radiation. METHODS: We conducted a multicenter study involving experienced endourologists from different European centers to evaluate whether the protection and threshold doses recommended by the International Commission on Radiation Protection (ICRP) were being followed. A 36-question survey was completed on the use of fluoroscopy and radiation protection. Annual prospective data from chest, extremities, and eye dosimeters were collected during a 4-year period (2017-2020). RESULTS: Ten endourologists participated. Most surgeons use lead aprons and thyroid shield (9/10 and 10/10), while leaded gloves and caps are rarely used (2/10 both). Six out of ten surgeons wear leaded glasses. There is widespread use of personal chest dosimeters under the apron (9/10), and only 5/10 use a wrist or ring dosimeter and 4 use an eye dosimeter. Two endourologists use the ALARA protocol. The use of ultrasound and fluoroscopy during PCNL puncture was reported by 8 surgeons. The mean number of PCNL and URS per year was 30.9 (SD 19.9) and 147 (SD 151.9). The mean chest radiation was 1.35 mSv per year and 0.007 mSv per procedure. Mean radiation exposure per year in the eyes and extremities was 1.63 and 11.5 mSv. CONCLUSIONS: Endourologists did not exceed the threshold doses for radiation exposure to the chest, extremities and lens. Furthermore, the ALARA protocol manages to reduce radiation exposure.

Temperature profile during endourological laser activation: introducing the thermal safety distance concept.

PURPOSE: To examine temporal-spatial distribution of heat generated upon laser activation in a bench model of renal calyx. To establish reference values for a safety distance between the laser fiber and healthy tissue during laser lithotripsy. METHODS: We developed an in-vitro experimental setup employing a glass pipette and laser activation under various intra-operative parameters, such as power and presence of irrigation. A thermal camera was used to monitor both temporal and spatial temperature changes during uninterrupted 60-second laser activation. We computed the thermal dose according to Sapareto and Dewey's formula at different distances from the laser fiber tip, in order to determine a safety distance. RESULTS: A positive correlation was observed between average power and the highest recorded temperature (Spearman's coefficient 0.94, p < 0.001). Irrigation was found to reduce the highest recorded temperature, with a maximum average reduction of 9.4 °C at 40 W (p = 0.002). A positive correlation existed between average power and safety distance values (Spearman's coefficient 0.86, p = 0.001). A thermal dose indicative of tissue damage was observed at 20 W without irrigation (safety distance 0.93±0.11 mm). While at 40 W, irrigation led to slight reduction in mean safety distance (4.47±0.85 vs. 5.22±0.09 mm, p = 0.08). CONCLUSIONS: Laser settings with an average power greater than 10 W deliver a thermal dose indicative of tissue damage, which increases with higher average power values. According to safety distance values from this study, a maximum of 10 W should be used in the ureter, and a maximum of 20 W should be used in kidney in presence of irrigation.

Fluid dynamics within renal cavities during endoscopic stone surgery: does the position of the flexible ureteroscope and ureteral access sheath affect the outflow rate?

PURPOSE: To evaluate the impact of ureteroscope position within renal cavities as well as different locations of the tip of the ureteral access sheath (UAS) on fluid dynamics during retrograde intrarenal surgery (RIRS). MATERIALS AND METHODS: A prospective observational clinical study was performed. Measurements with a flexible ureteroscope placed in the upper, middle and lower calyces were obtained with the tip of the UAS placed either 2 cm below the pyelo-ureteric junction (PUJ), or at the level of the iliac crest. RESULTS: 74 patients were included. The outflow rates from the middle and upper calyxes were statistically significantly higher compared to the lower calyx, both with the UAS close to the pyelo-ureteric junction and at the iliac crest. When the UAS was withdrawn and positioned at the level of the iliac crest, a significant decrease in outflow rates from the upper (40.1 ± 4.3 ml/min vs 35.8 ± 4.1 ml/min) and middle calyces (40.6 ± 4.0 ml/min vs 36.8 ± 4.6 ml/min) and an increase in the outflow from the lower calyx (28.5 ± 3.3 ml/min vs 33.7 ± 5.7 ml/min) were noted. CONCLUSIONS: Our study showed that higher fluid outflow rates are observed from upper and middle calyces compared to lower calyx. This was true when the UAS was positioned 2 cm below the PUJ and at the iliac crest. Significant worsening of fluid dynamics from upper and middle calyces was observed when the UAS was placed distally at the level of the iliac crest. While the difference was statistically significant, the absolute change was not significant. In contrast, for lower calyces, a statistically significant improvement was documented.

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

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

Urologists' opinion on treating asymptomatic stones: Would we treat ourselves as we treat our patients? Survey from European Association of Urology, Young Academic Urologists, Endourology and Urolithiasis working party.

Background/aim: Management of asymptomatic kidney stones is an ongoing debate with follow-up and treatment guidelines based on low-level evidence. Our aim was to evaluate current management of asymptomatic urinary stones. Materials and methods: A 70-question survey was designed in collaboration with European Association of Urology, Young Academic Urologists, Section of Uro-Technology and Section of Urolithiasis groups and distributed. Responders filled out hypothetical scenarios from 2 perspectives, either as treating physicians, or as patients themselves. Results: A total of 212 (40.01%) responses were obtained. Median responder age was 39 years. 75% of responders were interested in "urolithiasis". 82.5% had never experienced a renal colic, 89.6% had never undergone urolithiasis treatment.Overall, as the kidney stone scenarios got more complicated, the invasiveness of the treatment preference increased. As "the physician", responders preferred the conservative option in all situations more than they would choose as "the patient". For ureteral stones, conservative approach was most preferred for small stones and ureteroscopy became more preferred as the stone size increased.For smaller kidney stones, the most preferred follow-up schedule was 4-6 monthly, whereas for larger and complicated stones it was 0-3 monthly from both perspectives respectively. For all ureteral stone scenarios, 0-4 weekly follow-up was mostly preferred.Interestingly, having had a renal colic was an independent predictor of an interventional approach, whereas having had an intervention was an independent predictor of a conservative approach. Conclusion: Current treatment and follow-up patterns of asymptomatic urinary stones are in agreement with international guidelines on symptomatic stones.In most of the urolithiasis situations urologists chose a conservative approach for their patients compared to what they would prefer for themselves. Conversely, urologists, in the scenarios as "the patient", would like to have a more frequent follow-up schedule for their stones compared to how they would follow-up their patients.

International Alliance of Urolithiasis guideline on retrograde intrarenal surgery.

OBJECTIVES: To set out the second in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis that concerns retrograde intrarenal surgery (RIRS), with the aim of providing a clinical framework for urologists performing RIRS. MATERIALS AND METHODS: After a comprehensive search of RIRS-related literature published between 1 January 1964 and 1 October 2021 from the PubMed database, systematic review and assessment were performed to inform a series of recommendations, which were graded using modified GRADE methodology. Additionally, quality of evidence was classified using a modification of the Oxford Centre for Evidence-Based Medicine Levels of Evidence system. Finally, related comments were provided. RESULTS: A total of 36 recommendations were developed and graded that covered the following topics: indications and contraindications; preoperative imaging; preoperative ureteric stenting; preoperative medications; peri-operative antibiotics; management of antithrombotic therapy; anaesthesia; patient positioning; equipment; lithotripsy; exit strategy; and complications. CONCLUSION: The series of recommendations regarding RIRS, along with the related commentary and supporting documentation, offered here should help provide safe and effective performance of RIRS.

Ureteroscopy and lasertripsy with pop dusting using high power holmium laser for large urinary stones > 15 mm: 6.5-year prospective outcomes from a high-volume stone center.

INTRODUCTION: Ureteroscopy and stone lasertripsy (URSL) is a recognized technique for treatment of urinary tract stones. Holmium:Yag laser has been successfully used for this purpose for the last two decades. More lately, pulse modulation with Moses technology and high power lasers have been introduced with the result of faster and more efficient stone lasertripsy. Pop dusting is a two-stage combined treatment using a long pulse Ho:YAG laser, initially in contact mode with the stone 'dusting' (0.2-0.5 J/40-50 Hz) followed by non-contact mode 'pop-dusting' (0.5-0.7 J/20-50 Hz). We wanted to look at the outcomes of lasertripsy for renal and ureteric stones using a high-power laser machine. METHODS: Over a period of 6.5 years (January 2016-May 2022), we prospectively collected data for patients undergoing URSL for stones larger than 15 mm treated using high power Ho:YAG laser (60W Moses or 100W laser). Patient parameters, stone demographics and outcomes of URSL were analyzed. RESULTS: A total of 201 patients, underwent URSL for large urinary stones. In 136 patients (61.6%) stones were multiple and the mean single and cumulative stone size was 18 mm and 22.4 mm respectively. A pre- and post-operative stent was placed in 92 (41.4%) and 169 (76%) respectively. The initial and final stone free rate (SFR) were 84.5% and 94% respectively and 10% patients underwent additional procedure to achieve stone free status. 7 (3.9%) complications were recorded, all related to UTI/sepsis, with 6 Clavien II and 1 Clavien IVa complication. CONCLUSION: Dusting and pop-dusting has shown to be successful and safe with the ability to treat large, bilateral or multiple stones with low retreatment and complication rates.

Complication rate after pediatric shock wave lithotripsy according to Clavien-Dindo grading system: results from a systematic review and meta-analysis of the existing literature.

PURPOSE: Shockwave lithotripsy (SWL) is a minimally invasive technique utilized for renal and ureteric stones in children. Despite being considered safe, certain complications have been recorded. We performed this systematic review and meta-analysis to provide a pooled analysis of Clavien-Dindo graded complications after SWL in children. METHODS: MEDLINE/PubMed, Scopus and Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, were screened from inception to 12/02/2022 by two authors independently. Only randomized controlled trials providing Clavien-Dindo classification or relevant clinical information were considered eligible. Overall complications were calculated using the aggregate number of each complication divided by the total number of patients in studies with data. RESULTS: Pooled analysis revealed that from children treated with SWL, 27.7% [95% CI 13.1-49.4] suffered Clavien I complications, 4.9% [95% CI 3.1-7.6] Clavien II complications, 2.7% [95% CI 1.6-4.7] Clavien III complications, 2.3% [95% CI 1.3-4] Clavien IV complications, while no Clavien V complications were recorded. In total, 28.1% [95% CI 15.6-45.3] of children suffered minor complications (Clavien-Dindo I-II), while 3% [95% CI 1.8-5] major complications (Clavien-Dindo III-V). Pooled analysis revealed that 10.7% [95% CI 3.2-30.1] of patients suffered macroscopic hematuria, 7.3% [95% CI 2.1-22.7] pain, 5.5% [95% CI 3.3-9] steinstrasse, 5.3% [95% CI 3-9.3] fever, 2.2% [95% CI 0.8-5.6] sepsis, 1.1% [95% CI 0.3-3.7] urinoma, 1% [95% CI 0.4-2.7] symptomatic hematoma and 1% [95% CI 0.3-2.7] asymptomatic hematoma. Need for re-treatment was 42.6% [95% CI 31.4-54.7] and need for auxiliary procedures was 11.8% [95% CI 8.5-16.1]. CONCLUSION: SWL is an irreplaceable tool for treating urolithiasis in children. Although a minimally invasive technique, parents and children should be adequately informed about the risk of minor/major complications.

Assessment of single-probe dual-energy lithotripters in percutaneous nephrolithotomy: a systematic review and meta-analysis of preclinical and clinical studies.

PURPOSE: To evaluate the safety and efficacy of single-probe dual-energy (SPDE) lithotripters in patients undergoing percutaneous nephrolithotripsy (PCNL) through a systematic review and meta-analysis. METHODS: We searched PubMed, Cochrane Library, Scopus and Embase databases until July 2022 for any preclinical or clinical studies, exploring the safety and efficacy of different SPDE lithotripters in patients undergoing PCNL. We performed a meta-analysis to compare stone-free rate, bleeding, or other complications and mean operative time between SPDE lithotripters and other lithotripters (PROSPERO: CRD42021285631). RESULTS: We included 16 studies (six preclinical, seven observational and three randomized with 625 participants) in the systematic review and four in the meta-analysis. Preclinical studies suggest that SPDE lithotripters are safe and effective for the management of renal stones. Among clinical studies, four studies assessed Trilogy with no comparative arm, two compared Trilogy or ShockPulse with a dual-probe dual-energy lithotripter, two compared Trilogy with a laser, one compared ShockPulse with a pneumatic lithotripter, and one directly compared Trilogy with ShockPulse. Comparing SPDE lithotripters to other lithotripters, no significant differences were demonstrated in stone free rate (OR 1.13, 95% CI 0.53-2.38, I2 = 0%), postoperative blood transfusion (OR 1.33, 95% CI 0.34-5.19, I2 = 0%), embolization (OR 0.45, 95% CI 0.02-12.06), operative time (WMD: 2.82 min, 95% CI -7.31-12.95, I2 = 78%) and postoperative complications based on the Clavien-Dindo classification. CONCLUSIONS: SPDE lithotripters represent a promising treatment modality for patients requiring PCNL. Despite the initial encouraging findings of preclinical and isolated clinical studies, it seems that Trilogy or ShockPulse provide similar efficiency compared to older generation devices.

Pattern of key opinion leaders talks at major international urological meetings reflects the main differences in flexible ureteroscopy and PCNL diffusion.

OBJECTIVE: To analyze the pattern of speaker activity related to both flexible ureteroscopy (fURS) and percutaneous nephrolithotomy (PCNL) during plenary sessions at the main (endo)urological international meetings over the last 10 years. METHODS: We reviewed the meeting programs of the main endourological international meetings (EAU, AUA, WCE, and SIU) during 2011-2019. We detected all invited speakers at plenary sessions regarding fURS or PCNL. The proportion of fURS and PCNL talks was evaluated yearly during the study period. In order to analyze plenary session speaker composition, we estimated and compared the mean number of talks per speaker according to surgical technique. We also analyzed possible differences in age distribution according to the topic of the talk as well as the presence of young (i.e., < 45 years) speakers. Data were analyzed using descriptive statistics. RESULTS: During the last 10 years, a total of 498 plenary talks were found. Of those, 260 (52.2%), 211 (42.4%), and 27 (5.4%) discussed PCNL, fURS, or both, respectively. PCNL was more frequently discussed at the beginning and the end of the study period. Mean [SD] number of talks per speaker was higher for PCNL (2.9 [3.4] vs 1.6 [1.4], p < 0.001), meaning that a wider variety of speakers was invited to give fURS talks. Speakers discussing fURS were younger (median [interquartile range, IQR] age 48 [44-56] vs 52 [47-60] years, p < 0.001), and a higher proportion of young speakers was observed in the fURS group (26% vs 15% p < 0.001). PCNL speakers were more commonly discussing fURS than fURS speakers discussing PCNL (23% vs 17%, p = 0.43). CONCLUSIONS: We found a wider variety of speakers at fURS plenary sessions as compared to PCNL ones. It is easier and quicker to become an internationally recognized expert in the field of fURS rather than PCNL. PCNL speakers were able to master fURS more frequently than the other way around.

What to expect from the novel pulsed thulium:YAG laser? A systematic review of endourological applications.

INTRODUCTION: Several preclinical studies about a novel pulsed-thulium:yttrium-aluminum-garnet (p-Tm:YAG) device have been published, demonstrating its possible clinical relevance. METHODS: We systematically reviewed the reality and expectations for this new p-Tm:YAG technology. A PubMed, Scopus and Embase search were performed. All relevant studies and data identified in the bibliographic search were selected, categorized, and summarized. RESULTS: Tm:YAG is a solid state diode-pumped laser that emits at a wavelength of 2013 nm, in the infrared spectrum. Despite being close to the Ho:YAG emission wavelength (2120 nm), Tm:YAG is much closer to the water absorption peak and has higher absorption coefficient in liquid water. At present, there very few evaluations of the commercially available p-Tm:YAG devices. There is a lack of information on how the technical aspects, functionality and pulse mechanism can be maximized for clinical utility. Available preclinical studies suggest that p-Tm:YAG laser may potentially increase the ablated stone weight as compared to Ho:YAG under specific condition and similar laser parameters, showing lower retropulsion as well. Regarding laser safety, a preclinical study observed similar absolute temperature and cumulative equivalent minutes at 43° C as compared to Ho:YAG. Finally, laser-associated soft-tissue damage was assessed at histological level, showing similar extent of alterations due to coagulation and necrosis when compared with the other clinically relevant lasers. CONCLUSIONS: The p-Tm:YAG appears to be a potential alternative to the Ho:YAG and TFL according to these preliminary laboratory data. Due to its novelty, further studies are needed to broaden our understanding of its functioning and clinical applicability.

Do Hounsfield Units have any significance in predicting intra- and postoperative outcomes in retrograde intrarenal surgery using Holmium and Thulium fiber laser? Results from the FLEXible ureteroscopy Outcomes Registry (FLEXOR).

PURPOSE: To evaluate outcomes of flexible ureteroscopy for renal stones by comparing hard versus soft stones based on their attenuation on computed tomography (Hounsfield Units-HU). METHODS: Patients were divided into two groups according to the type of laser employed [Holmium:YAG (HL) or Thulium fiber laser (TFL)]. Residual fragments (RF) were defined as > 2 mm. Multivariable logistic regression analysis was performed to evaluate factors associated with RF and RF needing further intervention. RESULTS: 4208 patients from 20 centers were included. In whole series, age, recurrent stones, stone size, lower pole stones (LPS), and multiple stones were predictors of RF at multivariable analysis and LPS and stone size with RF requiring further treatment. HU and TFL were associated with lesser RF and RF requiring an additional treatment. In HU < 1000 stones, recurrent stones, stone size, and LPS were predictors of RF at multivariable analysis, whereas TFL was less likely associated with RF. Recurrent stones, stone size, and multiple stones were predictors of RF requiring further treatment, while LPS and TFL were associated with lesser RF requiring further treatment. In HU ≥ 1000 stones, age, stone size, multiple stones, and LPS were predictors of RF at multivariable analysis, while TFL was less likely associated with RF. Stone size and LPS were predictors of RF requiring further treatment, whereas TFL was associated with RF requiring further treatment. CONCLUSION: Stone size, LPS, and use of HL are predictors of RF after RIRS for intrarenal stones regardless of stone density. HU should be considered an important parameter in predicting SFR.

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

PURPOSE: To highlight and compare experts' laser settings during endoscopic laser treatment of upper tract urothelial carcinoma (UTUC), to identify measures to reduce complications, and to propose guidance for endourologists. METHODS: Following a focused literature search to identify relevant questions, a survey was sent to laser experts. We asked participants for typical settings during specific scenarios (ureteroscopy (URS), retrograde intrarenal surgery (RIRS), and percutaneous treatment). These settings were compared among the reported laser types to find common settings and limits. Additionally, we identified preventive measures commonly applied during surgery. RESULTS: Twenty experts completed the survey, needing a mean time of 12.7 min. Overall, most common laser type was Holmium-Yttrium-Aluminum-Garnet (Ho:YAG) (70%, 14/20) followed by Thulium fiber laser (TFL) (45%, 9/20), pulsed Thulium-Yttrium-Aluminum-Garnet (Tm:YAG) (3/20, 15%), and continuous wave (cw)Tm:YAG (1/20, 5%). Pulse energy for the treatment of distal ureteral tumors was significantly different with median settings of 0.9 J, 1 J and 0.45 J for Ho:YAG, TFL and pulsed Tm:YAG, respectively (p = 0.048). During URS and RIRS, pulse shapes were significantly different, with Ho:YAG being used in long pulse and TFL in short pulse mode (all p < 0.05). We did not find further disparities. CONCLUSION: Ho:YAG is used by most experts, while TFL is the most promising alternative. Laser settings largely do not vary significantly. However, further research with novel lasers is necessary to define the optimal approach. With the recent introduction of small caliber and more flexible scopes, minimal-invasive UTUC treatment is further undergoing an extension of applicability in appropriately selected patients.

Indications, preferences, global practice patterns and outcomes in retrograde intrarenal surgery (RIRS) for renal stones in adults: results from a multicenter database of 6669 patients of the global FLEXible ureteroscopy Outcomes Registry (FLEXOR).

PURPOSE: To collect a multicentric database on behalf of TOWER research group to assess practice patterns and outcomes of retrograde intrarenal surgery (RIRS) for kidney stones. METHODS: Inclusion criteria: age ≥ 18 years, normal renal/calyceal system anatomy, calculi of any size, number, and position. STUDY PERIOD: January 2018 and August 2021. Stone-free status: absence of fragments > 2 mm, assessed post procedure according to the local protocol (KUB X-Ray and/or ultrasound or non-contrast CT scan). RESULTS: Twenty centers from fifteen countries enrolled 6669 patients. There were 4407 (66.2%) men. Mean age was 49.3 ± 15.59 years. Pain was the most frequent symptom indication for intervention (62.6%). 679 (10.2%) patients underwent RIRS for an incidental finding of stones. 2732 (41.0%) patients had multiple stones. Mean stone size was 10.04 ± 6.84 mm. A reusable flexible ureteroscope was used in 4803 (72.0%) procedures. A sheath-less RIRS was performed in 454 (6.8%) cases. Holmium:YAG laser was used in 4878 (73.1%) cases. A combination of dusting and fragmentation was the most common lithotripsy mode performed (64.3%). Mean operation time was 62.40 ± 17.76 min. 119 (1.8%) patients had an intraoperative injury of the ureter due to UAS insertion. Mean postoperative stay was 3.62 ± 3.47 days. At least one postoperative complication occurred in 535 (8.0%) patients. Sepsis requiring intensive care admission occurred in 84 (1.3%) patients. Residual fragments were detected in 1445 (21.7%) patients. Among the latter, 744 (51.5%) patients required a further intervention. CONCLUSION: Our database contributes real-world data to support to a better understanding of modern RIRS practice and outcomes.

The technological future of percutaneous nephrolithotomy: a Young Academic Urologists Endourology and Urolithiasis Working Group update.

PURPOSE OF REVIEW: With advancements in surgical technology along with procedural techniques, this article throws light on the latest developments and applications of artificial intelligence (AI), extended reality, 3D (three-dimensional) printing and robotics in percutaneous nephrolithotomy (PCNL). RECENT FINDINGS: This review highlights the applications of AI in PCNL over the past 2 years. Mostly studies have been reported on development of machine learning (ML) based predicting models and identification of stone composition using deep learning convolutional neural network (DL-CNN). But owing to the complexity of the models and lack of generalizability, it is still not incorporated in the routine clinical practice. Extended reality based simulation and training models have enabled trainees to enhance their skills and shorten the learning curve. Similar advantages have been reported with the use of 3D printed models when used to train young and novice endourologists to improve their skills in percutaneous access (PCA). Applications of robotics in PCNL look promising but are still in nascent stages. SUMMARY: Future research on PCNL should focus more on generalizability and adaptability of technological advancements in terms of training and improvement of patient outcomes.

Outcomes Associated with the Endourological Management of Stent Encrustation: Findings from a Literature Review on Behalf of the EAU YAU Urolithiasis Group.

PURPOSE OF REVIEW: Double J ureteric stents (DJs) are useful aids for urinary drainage in case of stones or tumour causing ureteric obstruction. Prolonged dwelling time such as when forgotten can lead to encrustation. Our aim was to perform a literature review to evaluate outcomes associated with endourological management of encrusted stents (ES). RECENT FINDINGS: There now exist validated tools which can aid in grading the severity of encrustation and aid operative planning such as the total number of surgeries that may be required. Evaluation of different treatment strategies remains under reported. Removal of encrusted stent is a challenging problem, and it typically requires a multimodal endourological approach.