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Background: In robot-assisted flexible ureteroscopy, planning a safety-enhanced path facilitates ureteroscope reaching the target safely and quickly. However, current methods rarely consider the safety impact caused by body motion of the anterior part, such as impingement on the lumen wall and sweeping motion risk, or the method can only be used in collision-free situations., Methods: The kinematic model of the anterior part under C-shaped and S-shaped collision bending is first analysed. Considering the newly defined impingement cost and sweeping area, the differential evolution algorithm is adopted to optimise the path in the configuration space. Experiments were performed to verify the effectiveness of the method., Results: Compared with the competing algorithm, the proposed algorithm reduced impingement cost and sweeping area by an average of 31.0% and 8.64%. Force measurement experiments verified the rationality of the impingement cost expression., Conclusion: The experimental results proved the feasibility of the proposed path planning algorithm., (© 2024 John Wiley & Sons Ltd.)

Climate change poses a significant global health challenge, with medical procedures contributing substantially to CO 2 emissions. Urology, as part of the broader healthcare sector, has begun integrating Planetary Health concepts to address this issue. While earlier studies have focused on Life Cycle Assessments (LCA) of urological procedures, these evaluations remain data-dependent, and insights into intra-hospital emissions are limited. This study introduces a methodical approach for analyzing intra-institutional processes of LCA for single-use and reusable flexible ureterorenoscopes (fURS). The LCA method was applied to assess the greenhouse gas emissions (CO 2 equivalents, CO 2 -eq) generated across the life cycle of fURS, including production, use-phase, reprocessing, maintenance, and disposal. The study approximated the Global Warming Potential (GWP) per one-hour use and evaluated associated health impacts using the ReCiPe2016(H) method, which measures Disability-Adjusted Life Years (DALYs). Results showed that for reusable fURS, assuming 133 usages per device and maintenance after every 11th use, each application generated 1.24 kg CO 2 -eq, equivalent to 1.15E-06 DALYs. In contrast, single-use fURS generated 4.93 kg CO 2 -eq and 4.57E-06 DALYs per application. The production and reprocessing stages were identified as having the greatest environmental and health impacts. For reusable fURS, electricity required during refurbishment and use phases was a key contributor, whereas the production phase accounted for most of the impact in single-use devices. Overall, singleuse fURS had a substantially higher potential environmental and health impact than their reusable counterparts. This study underscores the environmental and health impacts of ureterorenoscopy and highlights the importance of incorporating Planetary Health principles into healthcare practices. It provides a foundation for further analyses and research, aiming to drive transformative action in the healthcare sector toward sustainability., Competing Interests: Declarations. Conflicts of interest: MT, JL, JH, IT, AS, MS, SR have no conflict of interest to declare., (© 2024. The Author(s).)

Flexible and navigable suction ureteral access sheath (FANS) is a potential game changer in flexible ureteroscopy (FURS). The influence of sheath size on outcomes needs research. The primary aim was to analyze 30-day single stage stone free status (SFS), zero fragment rate (ZFR) and complications when using 10/12Fr sheaths vis a vis other sheath sizes. The global FANS research group published the 30-day outcomes in patients who underwent FANS and reasoned this can be a potential game changer. We included 295 patients from this anonymized dataset with division into two groups: Group 1 (Smaller sheath) - 10/12Fr FANS, and Group 2 (Larger sheath) - 11/13Fr or 12/14Fr sheaths. Stone volume was similar between both groups (median 1320 mm 3 , p = 0.88). Ureteroscopy and total operative time was longer in the smaller sheath group (35 vs. 32 min, p = 0.02 and 50 vs. 45 min, p = 0.001, respectively). While 30-day computed tomography SFS (100% stone free or single residual fragment ≤ 2 mm) were not significantly different (96% vs. 95%, p > 0.99), ZFR (100% stone-free) was better with smaller sheaths (68% vs. 53%, p = 0.02). There was no difference in postoperative complication rates, and no sepsis in both groups. Urologists should consider individualizing appropriate sheath size in normal adult kidneys. Sheath size did not affect complication rates, risk of perioperative injury to the pelvicalyceal system or ureteric injury, but smaller FANS sheaths had similar high SFS. The ZFR with smaller sheaths was better, but this needs to be validated. These smaller sheath outcomes need to be balanced with longer ureteroscopy time, operative time, reach to the lower pole, ease of suction and visibility during lithotripsy. Large volume studies in different types of pelvicalyceal anatomy can determine if indeed smaller FANS is the best choice in FURS., Competing Interests: Declarations Ethics approval All procedures performed involving human participants were in accordance with the ethical standards of the institutional and/or national research committees and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The study was approved by the Ethics Committee of the Asian Institute of Nephrology and Urology, Hyderabad (#AINU 12/2022). Consent to participate Informed consent was obtained from all individual participants included in the study. Financial disclosures The authors have no relevant financial or non-financial interests to disclose. Competing interests The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To assess the time taken by the single use 7.5Fr suction flexible ureteroscope to reduce pressure under 40 mm Hg and to characterize the behavior of stones, fragments and dust during suction activation., Methods: An in vitro setting was developed for this experiment. A saline-filled globe, with the 7.5Fr single-use suction flexible ureteroscope, PU3033AH (ZhuHai Pusen Medical Technology Co, Ltd, Guangdon, China), an automatic irrigation pump and a pressure monitoring set were used at four modalities; i) continuous suction, no irrigation inflow; ii) continuous suction, irrigation inflow on; iii) one-second rate intermittent suction, irrigation inflow on, and iv) half-second rate intermittent suction, irrigation inflow on. The behavior of calcium oxalate stones from 0.5 to 5 mm when being aspirated via the ureteroscope into a plastic container filled with saline was recorded., Results: Suction with the PU3033AH worked properly with the inflow irritation on. The fastest strategy to lower the pressure was by continuously pressing the suction button with the irrigation inflow on. Overall, the median time to reach 40 mg was roughly 3.5 s. The PU3033AH could aspirate 0.5 mm stones. The suction mode on a continuous pattern allowed the relocation of stones ranging from 1 to 5 mm on an experimental setup with no obstacles., Conclusion: The PU3033AH was efficient in lowering pressure in a closed cavity mimicking the renal pelvis. Likewise, stone fragments under one millimeter were aspirated by the device whereas stones from one to five mm could be displaced when activating suction in continuous mode on an experimental setup with no obstacles., Competing Interests: Declarations Conflict of interest Dr. Laurian Dragos is lecturer for EMS and Boston Scientific and consultant for Ambu. Dr. Bhaskar Somani is consultant for Pusen, Boston Scientific, Cook Medical, Coloplast and Olympus. Dr. Oriol Angerri is lecturer for Boston Scientific and Cook Medical. Dr. Evangelos Liatsikos is consultant for Cook Medical and Karl Storz and lecturer for Karl Storz, Boston Scientific, EMS and Redpine. Dr. Panagiotis Kallidonis is lecturer for EMS and Cook Medical. None of the rest of authors have any conflict of interest to disclose., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: To compare intrarenal pressure (IRP) and irrigation flow by varying suspended water heights and hand-held pressure pumping during flexible ureteroscopy using an in vitro 3D printed kidney model., Methods: A 3D-printed silicone model was used to simulate the kidney. The ureteral access sheath(UAS) was connected to the kidney model and positioned at the ureteropelvic junction. Central venous pressure tubing was used to monitor the pressure in the renal pelvis under different conditions. Sheath sizes of 12Fr and 14Fr were tested with flexible ureteroscope (fURS) sizes of 7.5, 8.5, and 9.5Fr, respectively. The irrigation was gravity-based, with suspended water heights set at 60, 90, 120, 150, and 180 cm. The manual pumping as another set of measurement is used to measure the maximum intrarenal pressure., Results: Using a 12Fr sheath with a 9.5Fr fURS loading without additional accessories resulted in IRP ranging from 8.4 to 17.5 cmH2O, while manual pumping perfusion pressure exceeded 60 cmH2O. Loading a 200-um laser fiber reduced the pressure to 6.4-10.5 cmH2O, and using a stone basket decreased it to 4.0-5.0 cmH2O. Using a 14Fr sheath with a 9.5Fr fURS resulted in an IRP of 2.5-6.0 cmH2O, compared to 17 cmH2O with manual pumping. With a 12Fr sheath and a 7.5Fr fURS, the IRP ranged from 5.4 to 8.2 cmH2O, while manual pumping resulted in 25.5 cmH2O. With a 14Fr sheath and a 7.5Fr fURS, the IRP ranged from 1.5 to 4.3 cmH2O, and manual pumping resulted in 9.0 cmH2O., Conclusion: When using a UAS in a flexible ureteroscopy, the IRP can be maintained within a safe range with different fURS/UAS combos with a suspended water height of less than 180 cm. However, with specific fURS/UAS(9.5Fr/12Fr) combos, the IRP exceeded the safe limit when using manual pumping. Gravity irrigation with a suspended water height of less than 180 cm is safe in this simulated clinical environment., (© 2024. The Author(s).)

Purpose: This study aims to evaluate the efficacy of tip-flexible suctioning ureteral access sheath (TFS-UAS) compared to traditional ureteral access sheath (T-UAS) in flexible ureteroscopic lithotripsy (FURL) for unilateral upper urinary tract calculi., Methods: The study retrospectively compared outcomes from 103 cases using TFS-UAS and 138 using T-UAS treated with FURL for unilateral upper urinary tract calculi from January to October 2023. Assessed parameters included patient demographics, stone characteristics, preoperative urine cultures, ureteral pre-stenting, comorbidities, procedure time, stone-free rate (SFR), utilization of stone retrieval baskets, and postoperative Systemic Inflammatory Response Syndrome (SIRS) rates. The maximum angle of deflection was also measured when the flexible ureteroscope was located in different parts of the TFS-UAS with different diameters in vitro., Results: The TFS-UAS group achieved a higher Immediate SFR (76.70% vs. 63.77%, p = 0.031) and final SFR (89.32% vs. 73.91%, p = 0.003) than the T-UAS group, especially in the lower calyx stones (80.00% vs. 41.18%, p = 0.018) and upper urinary tract calculi with a cumulative diameter of 2 cm or larger (68.97% vs. 42.11%, p = 0.029). Notably, TFS-UAS with a 10 French (F) inside diameter size achieved a higher SFR (88.57% vs. 70.59%, p = 0.041) and a greater deflection angle than the 12.5 F inside diameter size. No significant variations were observed in the operative duration, hospitalization duration and the occurrence of SIRS between the compared cohorts., Conclusion: TFS-UAS significantly improves SFR in FURL treatment of unilateral upper urinary tract calculi, particularly for stones located in the lower calyx or with a cumulative diameter of 2 cm or greater, compared to T-UAS., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To create a machine-learning model for estimating the likelihood of post-retrograde intrarenal surgery (RIRS) sepsis., Methods: All consecutive patients with kidney stone(s) only undergoing RIRS in 16 centers were prospectively included (January 2022-August 2023)., Inclusion Criteria: adult, renal stone(s) only, CT scan (within three months), mid-stream urine culture (within 10 days)., Exclusion Criteria: concomitant ureteral stone, bilateral procedures. In case of symptomatic infection/asymptomatic bacteriuria, patients were given six days of antibiotics according to susceptibility profiles. All patients had antibiotics prophylaxis. Variables selected for the model: age, gender, age-adjusted Charlson Comorbidity Index, stone volume, indwelling preoperative bladder catheter, urine culture, single/multiple stones, indwelling preoperative stent/nephrostomy, ureteric access sheath, surgical time. Analysis was conducted using Python programming language, with Pandas library and machine learning models implemented using the Scikit-learn library. Machine learning algorithms tested: Decision Tree, Random Forest, Gradient Boosting. Overall performance was accurately estimated by K-Fold cross-validation with three folds., Results: 1552 patients were included. There were 20 (1.3%) sepsis cases, 16 (1.0%) septic shock cases, and three more cases (0.2%) of sepsis-related deaths. Random Forest model showed the best performance (precision = 1.00; recall = 0.86; F1 score = 0.92; accuracy = 0.92). A web-based interface of the predictive model was built and is available at https://emabal.pythonanywhere.com/ CONCLUSIONS: Our model can predict post-RIRS sepsis with high accuracy and might facilitate patient selection for day-surgery procedures and identify patients at higher risk of sepsis who deserve extreme attention for prompt identification and treatment., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: Flexible and navigable suction ureteral access sheaths (FANS) have been introduced without current evidence on how to optimize deflection. Aim was to evaluate in vitro deflection angles with 2 different FANS techniques-sheath advancement and ureteroscope deflection; and effects of sheath size-ureteroscope combinations., Methods: We evaluated in vitro deflection angles of 10/12Fr, 11/13Fr and 12/14Fr FANS (Hunan Reborn Medical Co. Ltd) with six single-use flexible ureteroscopes (Pusen Uscope 7.5Fr, OTU WiScope 7.5Fr, OTU WiScope 8.6Fr, Innovex EU-scope 8.7Fr, Red Pine RP-U-C12 8.7Fr and Boston Scientific Lithovue 9.5Fr). Two deflection techniques were tested: (1) sheath advancement-advancing the sheath forward over a maximally deflected ureteroscope, and (2) ureteroscope deflection-maximally deflecting the ureteroscope from various starting positions relative to tip of the sheath., Results: Intra and inter-scope comparisons of maximum deflection angles were significantly different (all ANOVA p < 0.01). Largest maximum angles for all ureteroscopes were with the sheath advancement technique (range 218°-277°), and second largest for most scopes using the ureteroscope deflection technique at tip (range 111°-212°), mostly deviating from manufacturer specifications (range 270°-275°). 10/12Fr and 11/13Fr sheath sizes were more flexible than 12/14Fr. Largest angles were with 11/13Fr sheath-OTU8.6Fr/Innovex8.7Fr combinations., Conclusion: Optimal deflection with FANS is achieved using either a sheath advancement technique, or ureteroscope deflection technique at tip. Despite using these optimized techniques, deflection angles specified by manufacturers seem hardly achievable. The sheath advancement technique and 11/13Fr sheath-OTU8.6Fr/Innovex8.7Fr combinations may be better suited for lower pole situations. Urologists should be aware of these differences and apply the findings to their FANS technique., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: To explore the feasibility and safety of aflexible ureteroscopy with intelligent control of renal pelvic pressure(FUS-ICP) without a post-operative indwelling urinary catheter ., Methods: In this retrospective study, we assessed patients with upper urinary tract stones who were treated with FUS-ICP at the Ganzhou People's Hospital from February 2022 to December 2023. Patients were divided into the non-urinary catheter (non-UC) and urinary catheter (UC) groups according to whether an indwelling catheter was used after surgery., Results: In total, 142 patients were included in the study. There was no significant difference in the preoperative general data between the two groups. Patients in the non-UC group performed better than those in the UC group in terms of catheter-related bladder irritation (P = 0.001), the Sedation-Agitation Scale score (P = 0.012), and the numerical rating scale (P = 0.003). The incidences of urinary retention (P = 0.620), urinary tract infection (P = 0.529), and replacement of urethral catheter s (P = 0.438) in the UC group were inferior to those in the non-UC group, but there was no statistical significance., Conclusions: It is feasible and safe to perform FUS-ICP without a post-procedure indwelling urinary catheter., (© 2024. The Author(s).)

Purpose: To evaluate and compare the clinical results of different single-use flexible ureteroscopes (su-fURS) used in retrograde intrarenal surgery (RIRS)., Materials and Methods: RIRS cases performed identically by an experienced surgeon between 2022 and 2023 in a single center were retrospectively analyzed. These surgeries were performed with three su-fURS (Redpine RP-U-C12, Hugemed HU30, and Pusen Uscope 3022 A). In the study, the age, gender, body mass index, and Charlson comorbidity index of the patients were compared, along with their clinical details, such as the stone size, volume, density, location, and history of hydronephrosis or a double J stent or SWL. Operation time, stone-free rates (SFR), perioperative and postoperative complications, and hospitalization times were also compared., Results: The study included 208 patients. Pusen had 63 cases, Hugemed had 62, and Redpine had 83. The comparison of the patient's demographic and clinical properties with stone-related variables was similar between the groups. The SFR was similar between the groups (p = 0.056). Perioperative, postoperative, and total complication rates and the need for a second intervention showed no significant differences among the three groups (p = 0.324, 0.088, 0.061, and 0.052, respectively)., Conclusion: In the first study comparing the clinical results of cases in which different su-fURS were used, no difference was observed in surgical outcomes and complications, even though the technical features of these devices were different. Urologists should select su-fURS based on clinical requirements, financial constraints, and personal experiences., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The correlation between novel negative pressure ureteroscopic lithotripsy (NP-URL) combined with flexible ureteroscopy (FU) and percutaneous nephrolithotomy (PCNL) on stone-free rates (SFR) remains unclear. There is a lack of evidence from Chinese populations regarding the relationship between SFR and NP-URL combined with FU (NP-URL-FU) versus PCNL. We aimed to assess the association between NP-URL-FU and PCNL on SFR. We conducted a cohort study involving 166 participants with 2-4 cm kidney stones. Data on SFR (7 days and 2 months) were collected from all participants. Logistic regression analysis was used to substantiate the research objectives. NP-URL-FU versus PCNL showed an 86% decrease in the 7-day SFR (OR = 0.14, 95% CI 0.07-0.29). The results remained stable even after adjusting for potential confounders. However, no statistically significant association was found between the surgical method and the 2-month SFR. Further exploratory subgroup analyses showed no significant interactions, with all P values > 0.05. Among patients with 2-4 cm kidney stones, NP-URL-FU was associated with a lower risk of incident 7-day SFR than PCNL. However, no statistically significant difference was found in the long-term stone removal rate. Therefore, NP-URL-FU may be a viable alternative surgical option for patients seeking minimally invasive procedures., (© 2024. The Author(s).)

Objective: This study aimed to evaluate the accuracy and effectiveness of renal pelvic pressure (RPP) control during flexible ureteroscopic perfusion at various sites., Methods: Flexible ureteroscopy for the intelligent control of RPP was based on a ureteral access sheath (UAS) that integrated pressure measurement and suction functions (with automatic adjustment). Eleven consecutive patients with indurating nephrostomy tubes were enrolled. The nephrostomy tube was connected to a disposable invasive blood pressure sensor. The RPP was zeroed after the pressure stabilized. The flow rate and control value were set at 100 ml/min and - 5 mmHg, respectively. An 8.5 Fr flexible ureteroscope was irrigated at the renal pelvis, as well as the upper, middle, and lower calyces of the kidney for 1 min., Results: All 11 patients with upper urinary tract calculi underwent successful UAS placement. Pressures measured by the sheath and fistula during perfusion were - 5.07 ± 1.41 and - 4.89 ± 1.07 mmHg at the renal pelvis, -5.16 ± 1.36 and - 5.12 ± 1.32 mmHg at the upper calyces, -4.98 ± 0.87 and - 5.39 ± 1.01 mmHg at the middle calyces, as well as -4.95 ± 1.56 and - 5.64 ± 1.24 mmHg at the lower calyces, respectively. There were no significant differences in pressure between the sheath and fistula groups or in sheath and fistula pressures among parts. The RPP fluctuated; however, all values were within the safe limit of 20 mmHg., Conclusion: The UAS-based pressure monitoring technology can accurately and reliably monitor and control RPP within a set range., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: A new digital single-use flexible ureteroscope, Pusen direct in scope suction (DISS) 7.5Fr (PU3033AH), was evaluated with respect to manoeuvrability, suction quality, visibility and clinical efficiency., Methods: A prospective cohort study was conducted in six tertiary reference centers in Europe and Asia between February-April 2024. Adult patients who underwent flexible ureteroscopy and laser lithotripsy (fURSL) for urolithiasis were included. Demographic, intraoperative and follow-up characteristics were recorded. Quality parameters were rated by each surgeon using a Likert scale., Results: a total of 57 fURSL were performed. Preoperative characteristics revealed a mean stone volume of 480.00mm 3 (mean Hounsfield Unit- 998). 57.9%(n = 33) of the patients were pre-stented, and a ureteric access sheath was used in 64.9%(n = 37). Integrated-suction was deemed helpful in 94.7%(n = 54) fURSL as reported by the operators. An initial stone free rate (SFR) confirmed by postoperative imaging was achieved in 84.21%(n = 48). Quality parameters of the scope reached a mean Likert score of 4.5, with a "very good" mean evaluation for "scope placement", "visual quality", "irrigation", "deflection", "manoeuvrability", and "weight". "Suction quality" and "overall performance satisfaction" were rated "good". Comparing the Pusen DISS scope with other previously used scopes, overall satisfaction was rated 4.1. When asked if the surgeons would be willing to use the Pusen DISS 7.5Fr scope in the future, all the six surgeons answered positively., Conclusion: The DISS 7.5 Pusen ureteroscope displayed good visibility, manoeuvrability and suction quality, with excellent operative results. Further evaluation with larger comparative cohorts will help understand the potential of in-vivo use of integrated suctioning systems for fURSL., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: While the efficacy of flexible ureterorenoscopy (URS) in managing solitary kidney stones (KSs) is widely acknowledged, its effectiveness in treating multiple stones has scarcely been investigated. This study aims to assess the effectiveness and safety of retrograde intrarenal surgery (RIRS) utilizing flexible URS and laser lithotripsy in the management of multiple KSs.  Methods: This study was a single-group cohort study conducted on patients with multiple KSs who underwent treatment with RIRS using flexible URS and laser lithotripsy. Stone-free status was considered as the lack of residual stone fragments or any residual stone of any size. The first follow-up appointment was arranged 3-4 weeks following the procedure. If significant residual stones were present, patients underwent reintervention within 2-4 weeks., Results: A total of 110 patients with multiple KSs were included. The mean stone burden was 27.5 ± 7.9 mm, and the mean duration of the operation was 54.9 ± 19.7 minutes. Seven cases (6.3%) experienced intraoperative complications, while postoperative complications were found in eight cases (7.3%). After four weeks, a stone-free rate (SFR) was documented in 80.9% of the cases, and this rate increased to 93.6% after three months. The SFR after three months was significant with Guy's stone score (p < 0.001); however, it did not reach a significant level with any other parameters.  Conclusions: The RIRS with flexible URS may be an effective and potentially safe procedure for treating multiple KSs. It may yield a favorable SFR with an acceptable complication rate.

Purpose: This study aims to evaluate the clinical efficacy of using a tip‑flexible suctioning ureteral access sheath (TFS-UAS) in combination with a traditional ureteral access sheath (T-UAS) and a disposable flexible ureteroscope (DFU) for treating large renal stones (2-4 cm in diameter)., Methods: We retrospectively collected clinical data from 238 patients who underwent retrograde intrarenal surgery (RIRS) at Ganzhou People's Hospital between January 2019 and October 2023. The study included 238 patients who met the inclusion criteria, with 125 in the observation group using TFS-UAS and 113 in the control group using T-UAS. We compared differences in the stone-free rate (SFR), complication rates, surgery duration, and average hospital stay between the two groups., Results: All 238 surgeries were successfully completed. The stone-free rates for the observation group at the first and thirtieth day post-surgery were 87.20% and 95.20%, respectively, whereas for the control group, the rates were 73.45% and 85.84%, showing statistically significant differences (P < 0.05). The overall complication rates were 1.6% for the observation group and 14.16% for the control group, also statistically significant (P < 0.001). The surgical times for stone removal were (101.17 ± 25.64) minutes for the observation group and (86.23 ± 20.35) minutes for the control group, with significant differences (P < 0.05)., Conclusion: Compared to T-UAS, combining TFS-UAS with DFU for treating renal stones of 2-4 cm diameter, although more time-consuming, resulted in higher SFRs and improved safety., (© 2024. The Author(s).)

To compare the outcomes of using Ultrathin semirigid retrograde ureteroscopy and antegrade flexible ureteroscopy to treat proximal ureteric stones of sizes 1-2 cm. A prospective randomized multicenter study included patients who had proximal ureteric stones 1-2 cm, amenable for ureteroscopy and laser lithotripsy between August 2023 and February 2024. Two hundred thirty patients were divided evenly into two treatment groups. Group I included patients treated with antegrade flexible ureteroscopy and holmium laser stone fragmentation, and Group II included patients treated with retrograde ultrathin semirigid ureteroscopy. The study groups were compared in terms of patient demographics, stone access success, operation time, reoperation rates, peri-operative complications, and stone-free status. Group I included 114 patients, while Group II included 111. The mean age of the patients was 33.92 ± 10.37 years, and the size of the stones was 15.88 ± 3 mm. The study groups had comparable demographics and stone characteristics. The mean operative time was significantly longer in group I than in group II (102.55 ± 72.46 min vs. 60.98 ± 14.84 min, respectively, P < 0.001). Most reported complications were MCCS grades I and II, with no significant difference between the study groups. The stone-free rate after four weeks was 92.1% and 81.1% for groups I and II, respectively, which increased to 94.7% and 85.6% after eight weeks (P > 0.05). Antegrade flexible ureteroscopy is equivalent to retrograde ultrathin semirigid ureteroscopy in treating proximal ureteric stones regarding stone-free status and procedure-related morbidity. However, the antegrade approach has a longer operative time, greater fluoroscopy exposure, and longer hospital stays., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: This study aims to assess stone-free rates after flexible ureterorenoscopy (fURS) using the T.O.HO. (Tallness, Occupied lesion, Hounsfield unit evaluation) scoring system and Ito's nomogram., Materials and Methods: In the study conducted with 484 patients, the following parameters were analyzed: age, sex, comorbidities, hospitalization, affected side, extracorporeal shock wave lithotripsy (ESWL) history, stone length, stone density, number of stones, location, and presence of hydronephrosis., Results: Multivariate logistic regression analysis revealed that stone length, stone number, and lower pole stone location were associated with the prediction of stone-free status. The cut-off value for Ito's score was determined to be 13.5 points, with an AUC of 0.792 (sensitivity, 0.609; specificity, 0.821) and a 95% confidence interval of (0.752-0.832) (Fig. 1). The cutoff for the T.O.HO. score was 6.5 points, with an AUC of 0.744 (sensitivity 0.738, specificity 0.602) and a 95% confidence interval of (0.699-0.789)., Conclusion: In conclusion, T.O.HO. scoring system and the Ito's nomogram are promising tools to predict stone-free status (SFS) after fURS in preoperative evaluation. In addition, the success of scoring systems in predicting SFS preoperatively appears promising and offers a potentially valuable approach., (© 2024. The Author(s).)

Background: To compare the operative effect and clinical efficacy of the Moses laser mode and the Raykeen holmium laser energy platform powder mode under flexible ureteroscopic lithotripsy in patients with impacted upper ureteral stones., Methods: From March 2022 to September 2022, 72 patients were divided into a Moses laser group and a Raykeen laser group according to surgical method, with 36 patients in each group. CT and ureteroscopy confirmed that all patients had isolated impacted upper ureteral stones. The stone volume (mm 3 ), stone density (Hu) and severity of hydronephrosis were measured by CT. Postoperative complications were evaluated using the Clavien-Dindo score., Results: There were no complications of ureteral stenosis related to the laser treatment. The operative time and lithotripsy time were lower in the Moses laser group than in the Raykeen laser group (P < 0.05). The stone-free survival rate did not differ significantly between the two groups (P = 0.722). Stone volume was found to be positively correlated with laser energy and lithotripsy time in both groups (P < 0.01). There was no significant correlation between laser energy and lithotripsy time or ureteral stone density (Hu) in the Moses laser group (P > 0.05) or the Raykeen laser group (P > 0.05)., Conclusions: The contact mode of Moses technology and the powder mode of Raykeen laser lithotripsy can be used for the ablation of a single impacted upper ureteral stone. The ablation speed was related to the stone volume and the severity of polyp hyperplasia, not the stone density. We recommend the use of the powdered mode as a therapeutic measure for the treatment of impacted upper ureteral stones in flexible ureteroscopic lithotripsy., (© 2024. The Author(s).)

Purpose: To evaluate the stone clearance rate and limitations of a novel integrated suction capability within a single-use flexible ureteroscope according to stone particle size., Methods: Varying sized stone particles were created using a stone phantom (Begostone Plus, Bego ©, Lincoln, RI, USA). Particle size ranged as follows: 63-125 µm, 125-250 µm, 250-500 µm, 500 µm- 1 mm and 1-2 mm. These were mixed with Normal saline (0.9%) to mimic in vivo conditions. The suction enabled single-use flexible ureteroscope (Pusen, Zhuhai, China) was used to aspirate stone fragments in three trials. Firstly, aspiration of 5 g of each dust range was attempted. Secondly, a direct comparison of the integrated suction to a manual syringe technique was applied to 1 g of each size range. Finally, aspiration was applied to 5 g of a heterogenous 1:1:1:1:1 mixture. Endoscopic clearance rate (g/min) and number of blockages were recorded. Each challenge was repeated three times., Results: The integrated suction cleared 100% of dust < 250 µm. Endoscopic clearance rates were significantly faster than manual aspiration (3.01 g/min versus 0.41 g/min) for dust between 125 and 250 µm (p = 0.008). Complete endoscopic clearance by 180 s (without encountering test limiting blockages) was unsuccessful for particles > 250 µm. Clearance rates were greatly limited by stone particle size heterogeneity above 250 µm, to 0.09 g/min., Conclusion: This technology works better in vitro than previously DISS evaluated methods when challenged by stone dust < 250 µm. However, this adaptation is significantly challenged in the presence of stone dust particles > 250 µm., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: To evaluate the efficacy of a novel temperature control flexible ureteroscope system in the precise monitoring and control of intrarenal temperature (IRT) during ureteroscopy., Methods: We developed a novel temperature control flexible ureteroscope system (PT-Scope), including a temperature-monitoring ureteroscope and a irrigation-suction platform for temperature regulation. A porcine thermometry model was established to observe temperature changes under varying holmium laser powers (10, 20, 30 W) and irrigation rates (0, 20, 50 mL/min), utilizing percutaneous nephrostomy thermometry and PT-Scope measurements, with subsequent evaluation of temperature variations at different distances from the laser fiber tip. A porcine kidney stone model was established while porcine was randomly assigned to two groups: In the temperature control group, PT-Scope was connected to the irrigation-suction platform with temperature regulation, while in the nontemperature control group without temperature regulation. Comparative analysis was performed to evaluate differences in IRT between the two groups., Results: Across various laser powers and irrigation rates, the temperature measurement capability of the PT-Scope was precise, demonstrating consistency with percutaneous nephrostomy temperature measurements. The temperature obtained from the PT-Scope reflect the temperature approximately 0.05 cm away from the fiber tip, whereas temperatures close to fiber tip were significantly higher. The peak temperature of the temperature control group vs nontemperature control group were 31.70 ± 2.609°C and 44.37 ± 3.318 °C, respectively (P < 0.01). The mean temperature of the temperature control group vs nontemperature control group was 27.40 ± 2.107 °C vs 35.9 ± 1.921 °C (P < 0.01)., Conclusion: PT-Scope has demonstrated the capability to precisely monitor and control IRT within a safe threshold., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest to declare., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: We sought to evaluate the technical feasibility of performing a combined robotically assisted mini-percutaneous nephrolithotomy (PCNL) and flexible ureteroscopy (URS) procedure by a single urologist using the MONARCH Platform, Urology (Johnson & Johnson MedTech, Redwood City, California)., Material and Methods: In this prospective, first-in-human clinical trial, 13 patients underwent robotically-assisted PCNL for renal calculi at the University of California-Irvine, Department of Urology. Successful completion of the procedure was assessed as the primary endpoint. Postoperative adverse events were monitored for 30 days following the completion of the procedure. Stone ablation efficiency was evaluated on postoperative day 30 with low-dose 2-3 mm slice CT scans. Patients were classified according to the maximum length of their residual stone fragments as either absolute stone-free (Grade A), < 2 mm remnants (Grade B), or 2.1-4.0 mm remnants (Grade C)., Results: The combined robotic mini-PCNL and URS procedure was successfully completed in 12 of 13 procedures. No robotic device-related adverse events occurred. Preoperative stone burden was quantified by both maximum linear measurement (median 32.8 mm) as well as by CT-based volume (median 1645.9 mm 3 ). Using the unique robotically assisted targeting system, percutaneous access was gained directly through the center of the renal papilla in a single pass in all cases. Median operative time was 187 minutes (range: 83-383 minutes). On postoperative day 30, a 98.7% (range: 72.9%-100.0%) volume reduction was achieved, with 5 Grade A (38.5%), 1 Grade B (7.7%), and 2 Grade C (15.4%). Three patients experienced complications (2 grade 1 and one grade 2 Clavien-Dindo)., Conclusions: Our preliminary investigation demonstrates the safety, efficacy, and feasibility of a unique robotic-assisted combined mini-PCNL and URS platform.

Objectives: To investigate the safety of short-term stenting following flexible ureteroscopic lithotripsy (fURL) for patients without preoperative stents. Retaining double-J stent for 1-2 weeks after fURL is a common practice. At present, data on short-term stenting after non-pre-stented fURL is still lacking., Methods: 182 patients who met inclusion criteria were retrospectively divided into the 2-days group (2-day removal, 76 cases) and the 1-week group (1-week removal, 106 cases). The study endpoint was stent-associated adverse symptoms assessed by follow-up and completed validated questionnaires on postoperative days (POD) 7 and 12. A postoperative imaging review was performed 1 month after the surgery., Results: No statistical differences were found in the patients' demographic and stone-related characteristics. The 2-days group showed fewer urinary tract symptoms and lower scores on the ureteral stent symptom questionnaire on POD 7: less backache during urination (p = 0.004), less hematuria (p = 0.031), less frequent urination (p = 0.004), lower urinary symptoms index (p < 0.001), lower general health index (p < 0.001), and lower performance index (p < 0.001). There were no significant differences in fever (p = 0.372), visual analogue scale score (p = 0.760), and painkiller requirements (p = 0.160) on POD 7. The average general health score and work performance score remained significantly higher in the 1-week group patients at 5 days after removal compared to the 2-days group patients at 5 days after removal. (p < 0.001, p = 0.005). Five patients in the 2-days group and 15 patients in the 1-week group returned to the emergency department for additional treatments. No patient required rehospitalization. Stone-free rates were 85.5% in the 2-days group and 80.2% in the 1-week group (p = 0.499), respectively, and none of the patients got aggravating hydronephrosis., Conclusions: Compared to the common 1-week stent removal option, short-term stenting after non-pre-stented fURL is safe, which can enhance the patient's quality of life., (© 2024. The Author(s).)

Objectives: To report our initial experience of one-stage flexible ureteroscopic lithotripsy(FURL) with 11/13Fr suctioning ureteral access sheath(UAS) and 8.55Fr single-use digital flexible ureteroscope(SDFU) in upper ureteral or renal calculi., Materials and Methods: We retrospectively collected the clinical data of 900 adult patients with upper ureteral or renal calculi treated by FURL with 11/13Fr suctioning UAS and 8.55Fr SDFU from January 2022 to April 2024. Demographics, peri- and postoperative outcomes were assessed., Results: In all, 40 of 940 cases(4.26%) failed to introduce UAS and required second-stage FURL because of ureterostenosis and were excluded. Mean stones size of the remaining 900 eligible cases was 1.68 ± 0.58 cm in greatest diameter. There were 228 cases of upper ureteral stone, 456 cases of renal stone and 216 cases of concomitant ureteral and renal calculi. The mean operation time was 52.20 ± 20.21 min and the postoperative hospital stay was 2.87 ± 1.37 days. The stone-free rate of 1 month postoperatively was 89.56% and only 2.44% of patients with residue underwent additional reoperation. The rate of postoperative fever, postoperative pain needing analgesic and slight ureteral mucosal injury were 5.11%, 8.22% and 7.78%, respectively. None of patient suffered from severe complications, such as sepsis or ureteral perforation., Conclusion: It's practical and suitable for the vast majority of adult patients to undergo FURL in single session with 11/13Fr suctioning UAS without preoperative stenting. FURL with 11/13Fr suctioning UAS and 8.55Fr SDFU is feasible, reliable, safe, and efficient in the management of renal stone and upper ureteral stone., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: To systematically synthesize existing reported literature calculating the carbon footprint (CFP) of urological surgical practice and identify opportunities for improving the environmental impact of urology surgical practice., Methods: A systematic review was performed following PRISMA guidelines. The Cochrane, Embase, Ovid MEDLINE, and PubMed were searched between 1971 and 2023, with inclusion and exclusion criteria. The outcome measures were mapped across the included studies including assessment of risk of bias., Results: A total of 345 studies with titles were identified from an initial search, however only 5 were included. Three studies compared singleuse with reusable cystoscopes concluded that single-use cystoscopes are non-inferior to reusable cystoscopes environmentally due to the carbon footprint associated with decontamination and repackaging. Similarly, in a single study, the CFP of single-use and reusable ureteroscopes is comparable. Lastly, a single study concluded that robotics-assisted surgery in prostate cancer may be a better option than other approaches in terms of environmental sustainability., Conclusions: In conclusion, although minimally invasive (including robotic approaches) and endoscopic surgeries offer significant opportunities to improve healthcare we do need to consider the environmental impact. However, there is a paucity of good-quality literature to guide urological surgical practice to reduce the CFP and improve sustainability., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The purpose of this study is to compare the outcomes of transperitoneal laparoscopic ureterolithotomy (TPLU), retrograde flexible ureteroscopy (R-fURS), and mini-percutaneous antegrade flexible ureteroscopy (A-fURS) for treating large (≥ 15 mm) impacted proximal ureteral stones. A total of 105 adult patients were randomized into 3 equal groups: group A (35) patients underwent TPLU, group B (35) patients underwent R-fURS, and group C (35) patients underwent A-fURS. The initial stone-free rate was 100%, 68.6%, and 80% in groups A, B, and C, respectively. The mean operative time (OT) was (85.0 ± 7.57 min) in group A, (61.0 ± 8.21 min) in group B, and (89.57 ± 15.12 min) in group C. The three groups were comparable concerning the overall complications. R-fURS is a less invasive modality for treating such stones; however, it is associated with a lower SFR and a higher rate of auxiliary procedures. Both TPLU and miniperc A-fURS are effective and valuable alternatives for treating large impacted proximal ureteric stones., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To report real-time IRP and FR while performing flexible ureteroscopy in porcine kidney model utilizing LithoVue™ Elite (Boston Scientific®) with different irrigation systems, including automated pumps., Methods: Using an ex-vivo model of porcine kidney, IRPs were measured with LithoVue Elite. Ureteroscopic settings (US) were tested with all permutations of irrigation methods (IM), working channel occupant (WCO), and ureteral access sheaths (UAS). IMs included: Single Action Pumping System (SAPS™, Boston Scientific), Thermedx FluidSmart™ (Stryker®), and ENDOMAT™ (Karl Storz®). Pumps were tested at 50, 100, and 150 mmHg. WCOs included a 1.9Fr zero-tip basket, 200 µm, and 365 µm laser fibers. UASs utilized 11/13Fr and 12/14Fr 36 cm., Results: 84 different US were tested (252 experiments). ENDOMAT had higher IRP but the same FR as Thermedx at the same US for 50 and 100 mmHg (p < 0.01). SAPS had higher IRP and FR than pumps in all US studies (p < 0.01). There was positive correlation between pressure set by the pump and both IRP and FR (rho > 0.9). As the diameter of the WCO increased, lower IRP and FR were observed with the pumps (p < 0.01). With SAPS, IRP was similar regardless of WCO, but FR was decreased with the increased diameter of WCO (p = 0.81 and p < 0.01, respectively). There was significantly higher IRP when using 11/13Fr UAS than 12/14Fr (p < 0.01)., Conclusion: IRP was higher with SAPS than automated pumps. ENDOMAT showed higher IRP than Thermedx when under 150 mmHg. IRP and FR increase with higher pump pressure and decrease with larger diameter WCO. Likewise, a larger UAS significantly reduced IRP., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: To compare the clinical efficacy and safety of single-use and reusable digital flexible ureteroscopy for the treatment of lower pole stones., Methods: We enrolled 135 patients underwent reusable flexible ureteroscopy (FURS) and 78 patients underwent single-use digital FURS. Demographic, clinical variables, anatomical parameters of the lower calyx and perioperative indicators were compared in the two groups., Results: Thirty-six patients in the infundibuloureter angle (IPA) < 45° subgroup had a mini-percutaneous nephrolithotomy (mini-PCNL), including 25 patients in the reusable FURS group and 11 patients in the single-use FURS group. The demographic and clinical variables in the two FURS groups were comparable. There was no statistical difference in the success rate of stone searching (P > 0.05). In terms of the success rate of lithotripsy, there was also no statistical difference in the IPA ≥ 45° subgroup (P > 0.05), whereas single-use FURS was superior in the IPA < 45° subgroup (χ2 = 6.513, P = 0.011). The length of the working fiber in the reusable FURS and single-use FURS groups was 3.20 ± 0.68 mm and 1.75 ± 0.47 mm, respectively (t = 18.297, P < 0.05). The use of a stone basket in the reusable FURS (31/135, 23.0%) was significantly higher than that in the single-use FURS (8/78, 10.3%) (χ2 = 5.336, P = 0.021). Compared with the reusable FURS group, the single-use FURS group had shorter operation times (P < 0.05) and higher stone-free rate (SFR) (χ2 = 4.230, P = 0.040). There was no statistical difference in the intraoperative transfer of mini-PCNL and postoperative complications between the two groups (P > 0.05)., Conclusions: Single-use and reusable FURS are alternative methods for removal of lower pole stones (i.e., 2 cm or less). Single-use FURS has a high success rate of lithotripsy, shorter operation time, and high stone-free rate., (© 2024. The Author(s).)

Purpose: To experimentally measure renal pelvis pressure (P RP ) in an ureteroscopic model when applying a simple hydrodynamic principle, the siphoning effect., Methods: A 9.5Fr disposable ureteroscope was inserted into a silicone kidney-ureter model with its tip positioned at the renal pelvis. Irrigation was delivered through the ureteroscope at 100 cm above the renal pelvis. A Y-shaped adapter was fitted onto the model's renal pelvis port, accommodating a pressure sensor and a 4 Fr ureteral access catheter (UAC) through each limb. The drainage flowrate through the UAC tip was measured for 60 s each run. The distal tip of the UAC was placed at various heights below or above the center of the renal pelvis to create a siphoning effect. All trials were performed in triplicate for two lengths of 4Fr UACs: 100 cm and 70 cm (modified from 100 cm)., Results: P RP was linearly dependent on the height difference from the center of the renal pelvis to the UAC tip for both tested UAC lengths. In our experimental setting, P RP can be reduced by 10 cmH 2 0 simply by lowering the distal tip of a 4 Fr 70 cm UAC positioned alongside the ureteroscope by 19.7 cm. When using a 4 Fr 100 cm UAC, P RP can drop 10 cmH 2 0 by lowering the distal tip of the UAC 23.3 cm below the level of the renal pelvis., Conclusion: Implementing the siphoning effect for managing P RP during ureteroscopy could potentially enhance safety and effectiveness., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Lithiasis is a common and recurrent disease. Flexible ureteroscopy (fURS) is the cornerstone of laser treatment of kidney stones. Kidney stones destruction requires its laser pulverization into small fragments in order to remove them through the ureter or improve their spontaneous expulsion along the urinary tract. However, most of the time, all the micro-fragments and dust created cannot be extracted using our surgical tools and may stay intra-renally at the end of the procedure. Adjuvant treatments (such as forced diuresis, inversion or mechanical pressure) were previously described to improve the expulsion of stone fragments after extra-corporeal shock wave lithotripsy. Nevertheless, the impact of adjuvant treatment after fURS remains unclear and mainly theoretical., Objective: The primary objective is to show that the injection of 40 mg of furosemide in slow intravenous during 10 min, after the procedure, increases the stone-free rate 3 months after a fURS for destruction of kidney stones with laser., Methods/design: The study will be a two-parallel group randomized, controlled, multicentric trial with a blinding evaluation. Nine French departments of urology will participate. Patients will be randomized in 2 groups: the experimental group (injection of 40 mg of furosemide at the end of the surgery) and a control one (usual care). Patients will be followed up for 3 months (± 2 weeks) after the surgery. Then, we will perform a low dose abdomino-pelvic CT scan. The primary outcome is the stone-free rate at 3 months. A centralized review of the images will be performed by two specialized radiologists, in a blind and crossed way to allow a homogenization of the results. The secondary outcomes will include the rate of early post-operative urinary tract infection (UTI), the evaluation of post-operative pain, and the safety of the use of furosemide in patients treated by fURS for renal stone laser destruction. As secondary objectives, it is also planned to look at the effect of the prescription of an alpha-blocker as usual treatment on stone-free rate and to assess the agreement between the imaging analysis of the urologist and the specialized radiologist., Discussion: Lithiasis is a public health problem. It affects about 10% of the general population. This prevalence is increasing (multiplied by 3 in 40 years), partly due to changes in the population's eating habits over the years. The lithiasis patient is a patient with a chronic disease requiring annual follow-up and who may suffer from multiple recurrences, with a recurrence rate at 5 years of 50%. Recurrences are partly due to residual fragments left in the kidneys at the end of the operation. Other risk factors for recurrence include dietary hygiene and the presence of an associated metabolic disease. The metabolic blood and urine tests recommended by the Association Française d'Urologie (AFU) can be used to manage these last two problems. As far as residual fragments are concerned, their presence leads to an early recurrence of stones because they form the bed for a new aggregation of crystals in the kidneys. Being able to reduce the rate of residual fragments in patients with the use of furosemide at the end of the intervention therefore seems essential in the management of recurrences in our patients. This will also improve our patients' quality of life. Indeed, lithiasis disease leads to chronic pain associated with acute pain that motivates consultations to the emergency for specialized management. This study is the first to evaluate the impact of forced diuresis with the use of furosemide on the stone-free rate after a fURS for destruction of kidney stone with laser., Trial Registration: ClinicalTrials.gov Identifier: NCT05916963 , first received: 22 June 2023. EU Clinical Trials Register EudraCT Number: 2022-502890-40-00., (© 2024. The Author(s).)

Upper urinary tract stones are a common urological disease that can be treated by flexible ureteroscopy (FURS) through the natural urinary tract, in addition to extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy. The advantages of FURS are less trauma, faster recovery, and fewer complications, while its disadvantages include poor results of lithotripsy and stone extraction when dealing with larger stones, and prolonged operation time. Over the last two decades, the emergence of new technologies such as FURS combined with negative pressure suction, robot-assisted FURS, and artificially intelligent FURS, coupled with improvements in laser technology (the use of thulium fiber lasers and the invention of single-use flexible ureteroscopes (su-fURS) suitable for primary level application, have significantly increased the global adoption of FURS. This surge in usage holds a promising future in clinical application, benefiting a growing number of patients with renal calculi. Accompanied by changes in technical concepts and therapeutic modalities, the scope of indications for FURS is broadening, positioning it as a potential primary choice for urolithiasis treatment in the future. This review outlines the progress in employing FURS for the treatment of renal calculi in order to generate insights for further research., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Purpose: Reusable flexible ureteroscopes may lose their mechanical functionality through overuse, which is known as "aging of the flexible ureteroscope." Although mechanical deterioration has been shown in several studies, the data about the effect of this situation on the efficacy and safety of retrograde intrarenal surgery (RIRS) are missing. The aim of our study was to evaluate the effect of the aging of flexible ureteroscopes on the efficacy and safety of RIRS. Methods: Patients who had undergone RIRS between 2017 and 2021 at a single center were retrospectively included in the study. Serial surgeries were performed using the same reusable flexible ureteroscope (Storz X 2 ) until it was broken or malfunctioned because of the aging process. Group 1 was formed by the first 10 cases on whom the flexible ureteroscopes were used, representing the youngest period of the instruments, whereas group 2 was composed of the last 10 cases on whom the flexible ureteroscopes were used, representing the oldest phase of the instruments. The operative and postoperative data-including the operation time, hospitalization time, intraoperative complications, postoperative complications, and stone-free rates-were compared between the two groups. Results: A total of five flexible ureteroscopes were included in the study. The number of cases for each flexible ureteroscope ranged between 87 and 133, with a median number of 107 cases. The demographic and clinical properties of patients in both groups were similar. The operation time, lasering time, and total laser pulse were similar between the groups. The stone-free rates in group 1 and group 2 were 82.0% and 78.0%, respectively ( p = 0.304). The complication rates were also similar between the groups ( p = 0.591). Conclusion: The aging of reusable flexible ureteroscopes did not negatively affect the efficacy and safety of RIRS. Therefore, surgeons may use the reusable types of flexible ureteroscopes until they are totally broken.

Background: The management of kidney stones, particularly those in the renal pelvis, is a critical aspect of urology. The European Association of Urology guidelines recommend Extracorporeal Shock Wave Lithotripsy or Endourology methods, encompassing Percutaneous Nephrolithotomy and Ureterorenoscopy (URS), for stones ranging from 10-20 mm. Robotic-assisted urological procedures have gained prominence in recent years, promising enhanced precision and safety., Objective: To provide a detailed account of the technical aspects and outcomes of a robotic URS (robo-URS) procedure in a 63-year-old male patient with a 15-mm renal pelvis stone, serving as a reference for urologists considering this approach., Materials: The patient presented with right flank pain, and an unenhanced computed tomography scan confirmed the presence of a 15 × 12 × 13 mm stone in the right renal pelvis. After assessment and preparation, robo-URS was performed using the Roboflex Avicenna robotic platform (ELMED, Ankara, Turkey) in conjunction with conventional urological instruments and laser technology., Results: The procedure was completed successfully in 50 minutes without any detectable blood loss or intraoperative complications., Conclusion: Robo-URS is a promising approach for managing renal pelvis stones. The procedure, demonstrated in this video article, underscores its technical feasibility, safety, and efficacy, making it a valuable resource for urologists seeking to expand their knowledge in stone management techniques., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: Stone extraction is an important treatment option when performing flexible ureteroscopic lithotripsy (f-URSL) for upper urinary stones. We used a f-URSL simulator model to investigate surgical factors affecting the efficacy of stone extraction with the one-surgeon basketing technique., Materials and Methods: This simulator-based study involved eight urologists and eight residents. These participants each performed two tasks, with Flexor (Cook Medical) and Navigator (Boston Scientific) ureteral access sheaths, with and without the M-arm (MC Medical) single-use basket holder, and with models representing both left and right kidneys. The two tasks were to touch each renal calix with the ureteroscope, and to extract stones. As outcomes, we recorded the number of times that the ureteroscope became stuck during insertion, the number of times a stone was dropped during removal, the number of times the basket forceps were opened and closed, and the time required to accomplish each task., Results: The ureteroscope became stuck significantly more often when Navigator was used compared with Flexor overall, and for both urologists and residents (all p<0.01). Stones were dropped significantly more often on the ipsilateral side (kidney on the same side as the operator's hand) than on the contralateral side overall (p=0.01), and the basket forceps were opened and closed significantly more often on the ipsilateral side than on the contralateral side both overall and by residents (all p<0.01)., Conclusions: The efficiency of stone extraction during f-URSL with the one-surgeon basketing technique was affected by differences in ureteral access sheath and the kidney side., Competing Interests: The authors have nothing to disclose., (© The Korean Urological Association.)

Introduction: Ureteral stricture is often a consequence of urolithiasis or previous endourological procedures (1-3). Precisely delineating the stricture zone intraoperatively is crucial to minimize ureter shortening and target only the affected tissue (4, 5). Flexible ureteroscopy offers a significant advantage in this regard., Objective: This video aims to demonstrate the step-by-step technique of flexible ureteroscopic guided laparoscopic ureteroplasty for treating ureteral stricture caused by urolithiasis and prior endourological interventions., Patient and Methods: We present a case of a 36-year-old male with a history of urolithiasis and unsuccessful endourological treatments, including endoureterotomy and balloon dilation, diagnosed with re-stenosis of the proximal ureter of 1 cm through ureteroscopy and pyelography. He underwent a successful laparoscopic ureteroplasty. While the lead surgeon performed the laparoscopy, an assistant conducted the flexible ureteroscopy. Intraoperatively, using transillumination facilitated by the flexible ureteroscope, we can precisely identify the narrowed area, allowing for resection of only the damaged segment. Subsequently, we perform the end-to-end ureteroplasty, confirming its patency through the seamless passage of the ureteroscope. Upon completion, we employ a fat patch to safeguard the anastomosis., Results: The patient was discharged on the third postoperative day. Double J stent was removed six weeks after surgery. Symptoms resolved. Renal function improved: eGFR 49 to 67 ml/min. Furthermore, improvement was observed in the DTPA scan, and a decrease in hydronephrosis was noted on the follow-up tomography., Conclusion: Flexible ureteroscopy effectively identifies the stricture zone in laparoscopic ureteroplasty, enhancing surgical precision and outcomes. This approach is safe, effective, and reproducible, offering a valuable technique in the surgical treatment of ureteral strictures., Competing Interests: None declared., (Copyright® by the International Brazilian Journal of Urology.)

The purpose of this review is to analyze the trend in optical features and flexibility changes of flexible ureteroscopes over the past decades, and determine the correlation of individual parameters with release period as well as with dimensional parameters. Flexible ureteroscopes mentioned in the literature or those commercially available were searched. To minimize the search bias, the instruments were grouped by release date time-periods of < 2000 year, 2000-2009, 2010-2019, and 2020 onwards. The final review included only those instrument models for which data on minimum and maximum depth of field, field of view, direction of view, and deflection degree had been determined. The correlation among features investigated as well as with release period was also determined. 61 models of flexible ureteroscopes (27 fibreoptic and 34 digital scopes) were included. Among the different features investigated among fiberoptic endoscopes, minimum depth of field positively and negatively correlated with channel size and field of view, respectively, whereas maximum depth of view and field of view positively correlated with overall shaft and deflection degree, respectively. Up and down deflection strongly correlated with each other and both were negatively proportional to the distal tip size. For the digital endoscopes, minimum depth of field negatively and positively correlated with distal tip size and working length, respectively. Maximum depth of field positively correlated with field of view, whereas the latter was negatively proportional to the overall shaft. As for the fiberoptic counterparts, up and down deflection strongly correlated with each other. Field of view, up and down deflection of fiberoptic flexible ureteroscopes, were significantly increased among fiberoptic and digital endoscopes over decades. As flexible ureteroscopy technology has evolved, there has been a trend towards increasing field of view with up and down deflection. Given the importance of scope ergonomics, one aspect of this popularity is the improvement of optical characteristics and deflection degree, which significantly correlates with the release period., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: Upper urinary tract stones (UUTSs) are among the most common types of urinary stones, and their incidence rate has been increasing annually in recent years, seriously affecting the daily lives of patients. This study aimed to compare the treatment efficacy of one-stage and staged flexible ureteroscopic lithotripsy (FURL) for UUTSs., Methods: A total of 142 patients with UUTSs admitted to our hospital between December 2019 and March 2023 were selected for retrospective analysis, including 76 patients who received staged FURL (control group) and 66 patients who received one-stage FURL (observation group). The duration of surgery, length of stay, stone clearance rate, incidence of postoperative complications (from postsurgery to discharge), and total hospitalization cost were analyzed in both groups. The visual analog scale (VAS) score and activities of daily living (ADL) score were assessed before surgery (T0), 3 days after surgery (T1), and 7 days after surgery (T2). Patients were followed up for 1 month after surgery, and their quality of life was assessed using the MOS Item Short Form Health Survey (SF-36)., Results: There was no difference in the stone clearance rate or incidence of postoperative complications between the two groups ( p > 0.05). The operation time, hospitalization time and hospitalization cost in the observation group were 75.58 ± 15.91 min, 4.20 ± 1.24 days and 14312.62 ± 1078.89 yuan, respectively, which were lower than those in the control group ( p < 0.05). In addition, the VAS score at T3 was decreased to 1.49 ± 0.70, while the ADL and SF-36 scores were higher in the observation group ( p < 0.05)., Conclusions: One-stage FURL shortens the duration of surgery and length of stay, reduces hospitalization costs, and improves the quality of life of patients with UUTSs., Competing Interests: The authors declare no conflict of interest., (© 2024 The Author(s).)

Background: Propofol is effective and used as a kind of routine anesthetics in procedure sedative anesthesia (PSA) for ureteroscopy. However, respiratory depression and unconscious physical activity always occur during propofol-based PSA, especially in elderly patients. Esketamine has sedative and analgesic effects but without risk of cardiorespiratory depression. The purpose of this study is to investigate whether esketamine can reduce the propofol median effective dose (ED 50 ) for successful ureteroscope insertion in elderly male patients., Materials and Methods: 49 elderly male patients undergoing elective rigid ureteroscopy were randomly divided into two groups: SK Group (0.25 mg/kg esketamine+propofol) and SF Group (0.1 µg/kg sufentanil+propofol). Patients in both two groups received propofol with initial bolus dose of 1.5 mg/kg after sufentanil or esketamine was administered intravenously. The effective dose of propofol was assessed by a modified Dixon's up-and-down method and then was adjusted with 0.1 mg/kg according to the previous patient response. Patients' response to ureteroscope insertion was classified as "movement" or "no movement". The primary outcome was the ED 50 of propofol for successful ureteroscope insertion with esketamine or sufentanil. The secondary outcomes were the induction time, adverse events such as hemodynamic changes, hypoxemia and body movement were also measured., Result: 49 patients were enrolled and completed this study. The ED 50 of propofol for successful ureteroscope insertion in SK Group was 1.356 ± 0.11 mg/kg, which was decreased compared with that in SF Group, 1.442 ± 0.08 mg/kg (P = 0.003). The induction time in SK Group was significantly shorter than in SF Group (P = 0.001). In SK Group, more stable hemodynamic variables were observed than in SF Group. The incidence of AEs between the two groups was not significantly different., Conclusion: The ED 50 of propofol with esketamine administration for ureteroscope insertion in elderly male patients is 1.356 ± 0.11 mg/kg, significantly decreased in comparsion with sufentanil., Trial Registration: Chinese Clinical Trial Registry, No: ChiCTR2300077170. Registered on 1 November 2023. Prospective registration. http://www.chictr.org.cn ., (© 2024. The Author(s).)

Objective: To evaluate the safety and efficacy of rigid ureteroscopic lithotripsy with a pressure-controlling ureteral access sheath (PC-UAS) for complex steinstrasse., Methods: Thirty-one consecutive patients (male: 18; female: 13) with steinstrasse were enrolled, six of whom had concurrent kidney stones. The mean cumulative stone size was 2.7 ± 1.3 cm. The patients were treated with rigid ureteroscopic lithotripsy using a PC-UAS. The cavity pressure parameters were set as follows: control value at -15 mmHg to -2 mmHg, warning value at 20 mmHg, and limit value at 30 mmHg. The infusion flow rate was set at 150-200 ml/min. A holmium laser (550 μm) was used to powderize the stone at 2.0-2.5 J/pulse with a frequency of 20-30 pulses/s. Analyses included cavity pressure, operative time, stone-free rates, and complications., Results: Among the 31 patients, 29 were successfully treated with PC-UAS, with nine requiring adjunctive flexible ureteroscopy for stone migration to the kidney. Two procedures were converted to percutaneous nephrolithotomies due to failure of sheath placement. The cavity pressure of all 29 patients was well-maintained below 20 mmHg, with clear vision. The mean operative time was 48.2 ± 17.7 min. No complications, such as ureteral perforation, mucosal avulsion, or hemorrhage, occurred. Two cases of Clavien-Dindo grade I complications occurred. No major complications (Clavien-Dindo grade II-V) occurred. The mean postoperative hospitalization time was 1.7 days. The stone-free rates 1 day and 1 month after surgery were 93.1% and 96.6%, respectively. One patient with residual stones underwent extracorporeal shockwaves., Conclusions: Rigid ureteroscopic lithotripsy with PC-UAS can effectively control the cavity pressure, shorten the operation time, and improve the efficiency of broken stones, thus reducing the complication rate., (© 2024. The Author(s).)

Purpose: Illumination characteristics of flexible ureteroscopes have been evaluated in air, but not in saline, the native operative medium for endourology. The aim was to evaluate light properties of contemporary ureteroscopes in air versus saline, light distribution analysis, and color temperature., Methods: We evaluated the Storz Flex-Xc and Flex-X2s, Olympus V3 and P7, Pusen 7.5F and 9.2F, and OTU WiScope using a 3D printed black target board in-vitro model submerged in saline. A spectrometer was used for lux and color temperature measurements at different opening locations., Results: Illuminance was higher in saline compared to air (5679 vs. 5205 lx with Flex-Xc, p = 0.02). Illuminance in saline differed between ureteroscopes (ANOVA p < 0.001), with highest for the Flex-Xc at 100% brightness setting (5679 lx), followed by Pusen 9.2F (5280 lx), Flex-X2s (4613 lx), P7 (4371 lx), V3 (2374 lx), WiScope (582 lx) and finally Pusen 7.5F (255 lx). The same ranking was found at 50% brightness setting, with the highest ureteroscope illuminance value 34 times that of the scope with lowest illuminance. Most scopes had maximum illuminance off center, with skewness. Three scopes had two light sources, with one light source for all other scopes. Inter-scope comparisons revealed significant differences of color temperature (ANOVA p < 0.001)., Conclusion: The study demonstrates the presence of inhomogeneous light spread as well as large differences in illumination properties of ureteroscopes, possibly impacting on the performance of individual scopes in vivo. Additionally, the study suggests that future studies on illumination characteristics of flexible ureteroscopes should ideally be done in saline, and no longer in air., (© 2024. The Author(s).)

Purpose: To investigate fluid absorption and its influencing factors during flexible ureteroscopy with intelligent control of renal pelvic pressure (RPP)., Methods: A total of 80 patients with upper urinary tract calculi underwent flexible ureteroscopy with intelligent control of RPP by pressure-measuring ureteral access sheath and were randomly divided into four groups. The RPP of Groups A, B, and C were set at - 5, 0 and 5 mmHg, respectively. Conventional flexible ureteroscopy with uncontrolled pressure served as control Group D. The perfusion flow rate was set at 100 ml/min in the four groups, with 20 patients in each group. The fluid absorption was measured by 1% ethanol every 10 min. Operation time, stone-free rate, and complications were recorded., Result: Seventy-three patients were finally included in the RCT. The general and preoperative data of the patients were comparable between the groups. The fluid absorption of Groups A, B, and C was significantly less than that of Group D (P < 0.01). Fluid absorption and operation time were positively correlated, and the correlation coefficients R were 0.864, 0.896, 0.918, and 0.947, respectively (P < 0.01). The fluid absorption of patients with vomiting, fever and ureteral injury was greater than that of patients without complications in the four groups (P < 0.01). In different groups, fluid absorption was greater in patients with ureteral injury Post-Ureteroscopic Lesion Scale (PULS) 1-3 than in noninjured patients (P < 0.01)., Conclusion: Flexible ureteroscopy with intelligent control of RPP effectively reduces the absorption of perfusion fluid. Operation time and ureteral injury are also key factors affecting perfusion fluid absorption., Registration Number and Date: NCT05201599; August 11, 2021., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: To determine whether dynamic renal scans - DTPA or MAG3 - routinely performed after flexible ureteroscopies (f-URS) could detect the development of an obstruction and thus promote prompt early intervention for kidney preservation., Patients and Methods: In this retrospective study, with all the data recorded prospectively between April 2010 and October 2023, 250 renal units in 242 patients with upper urinary tract stones (UUTS) who underwent ureterorenoscopy by one surgeon in the same medical center were evaluated. Stone-free rate (SFR) was defined as no residual fragments at all using an intraoperative "triple test". The following characteristics were examined: gender, BMI, age, Hounsfield unit, stone diameter, laterality, renal/ureteral stones, stone-free rate, and auxiliary procedures per renal unit. The Clavien-Dindo classification was used to report complications. Renal units with residual stones were scheduled for a 2nd f-URS. Post- flexible ureteroscopy ureteral obstruction and renal function were detected using renal scan DTPA or MAG-3. The primary outcome was renal/ ureteral obstruction., Results: The mean patient age was 53 years. The mean stone size was 12.3 mm. Stones in renal pelvis, upper, middle and lower calyces were treated in 9.2% (23), 27.6% (69), and 30.8% (77) of cases, respectively; 44% (110) ureteral stones were also treated. The single- and second-session SFRs were 94.8% and 99.7%, respectively. A third auxiliary procedure was needed in one renal unit (0.4%). The mean number of procedures per renal unit was 1.06 (264/250). Ureteral double-J stents were inserted in 53.6% (134) of the cases. In 37 (14.8%) cases, a stent was placed before surgery. Post-operative complications were minor, with readmission and pain control needed in only two patients (0.8%). No avulsion or perforation of the ureters was observed. In six patients with t1/2 between 10-20 minutes, a second renal scan revealed spontaneous improvement and no obstruction in five patients. One patient with large stones and a history of prior ureteroscopy developed a ureteral stricture (0.4%) and needed treatment with laser endoureterotomy., Conclusions: Post-flexible ureteroscopy obstruction due to ureteral stricture is very rare. A routine renal scan post-operatively may be used in potentially high-risk patients.

Purpose: The aim of the study was to evaluate illumination properties in an in-vitro kidney calyx model in saline., Design and Methods: We evaluated a series of contemporary flexible ureteroscopes including the Storz Flex-Xc and Flex-X2s, Olympus V3 and P7, Pusen 7.5F and 9.2F, as well as OTU WiScope using a 3D-printed closed pink kidney calyx model, submerged in saline. A spectrometer was used for illuminance and color temperature measurements at different openings located at center (direct light), 45° (direct and indirect light) and 90°(indirect light) to the axis of the scope., Results: Maximum illuminance was at the center opening for all scopes (range: 284 to 12,058 lx at 50% brightness and 454 to 11,871 lx at 100% brightness settings). The scope with the highest center illuminance (Flex-Xc) was 26 times superior to the scope with the lowest illuminance (Pusen 7.5Fr) at 100% brightness setting. For each scope, there was a peripheral illuminance drop ranging from - 43 to - 92% at 50% brightness and - 43% to - 88% at 100% brightness settings, respectively (all p < 0.01). Highest drop was for the P7 and the Pusen 9.2F. All scopes had illuminance skew, except the V3. All scopes had a warm color temperature., Conclusion: Illumination properties vary between ureteroscopes in an enclosed cavity in saline, and differs at center vs 45° and 90° positions within scopes. Peripheral illuminance drop can be as high as - 92%, which is undesirable. This may affect the choice of ureteroscope and light brightness settings used in surgery by urologists., (© 2024. The Author(s).)

Purpose: To date, no study has evaluated effects of varying brightness settings on image quality from flexible ureteroscopes submerged in saline. The aim was to evaluate blackout and whiteout occurrences in an in-vitro kidney calyx model., Material and Methods: We evaluated a series of contemporary flexible ureteroscopes including the Storz Flex-Xc and Flex-X2s, Olympus V3 and P7, Pusen 7.5F and 9.2F, as well as OTU WiScope using a 3D-printed enclosed pink in-vitro kidney calyx model submerged in saline. Endoscopic images were captured with ureteroscope tip placed at 5 mm,10 mm and 20 mm distances. The complete range of brightness settings and video capture modes were evaluated for each scope. Distribution of brightness on a grayscale histogram of images was analyzed (scale range 0 to 255). Blackout and whiteout were defined as median histogram ranges from 0 to 35 and 220 to 255, respectively (monitor image too dark or too bright for the human eye, respectively)., Results: Blackout occurred with the P7, Pusen 7.5F, 9.2F and WiScope at all distances, and V3 at 20 mm - with lowest brightness settings. Whiteout occurred with Flex-X2s, V3 and P7 at 5 mm and 10 mm, as well as with V3 and P7 at 20 mm - mostly with highest brightness settings. The Flex-Xc had neither blackout nor whiteout at all settings and distances., Conclusion: Blackout or whiteout of images is an undesirable property that was found for several scopes, possibly impacting diagnostic and therapeutic purposes during ureteroscopy. These observations form a guide to impact a urologist's choice of instruments and settings., (© 2024. The Author(s).)

Backgrounds: In the renal intrarenal stone surgery (RIRS) procedure, ureteral access sheath (UAS) is still used in the majority of surgeries to both protect the flexible ureteroscope (FURS) and reduce intrarenal pressure. ClearPETRA is a new UAS that has an integrated aspiration port. We aimed to evaluate the clinical outcomes and effectiveness of Aspiration-Assisted UAS (ClearPETRA) in the RIRS procedure. Methods: One thousand six hundred twenty patients who underwent RIRS between January 2021 and January 2024 were evaluated retrospectively and 512 patients were included in the study. According to stone size, patients with stones less than 2 cm and those with stones between 2 and 3 cm were analyzed separately. Patient's demographic data, stone size, body mass index, Extracoporeal Shockwave Lithotripsy (ESWL) history, stone side, stone density (Hounsfield Unit), operation time, stone-free rate (SFR), and the number of patients with sepsis were recorded. SFR was evaluated with kidney urinary bladder 3 months after surgery for opaque calculi. Nonopaque calculi patients were evaluated with noncontrast computed tomography 3 months after surgery. In the postoperative evaluation, patients with stones less than 4 mm were evaluated as SFR. P value of <0.01 was considered statistically significant. Results: Patient's demographic data, stone characteristics, and history of ESWL were similar in the ClearPETRA and UAS groups ( P  > .05). A total of 328 patients who underwent RIRS for stones less than 2 cm were included (80 ClearPETRA, 248 UAS). Length of hospital stay, operation time, SFR, secondary intervention, or postoperative sepsis ( P  ≥ .01) were similar in both groups. The incidence of postoperative fever was statistically significantly lower in the ClearPETRA group ( P  = .006). A total of 184 patients who underwent RIRS for stones between 2 and 3 cm were included (42 ClearPETRA, 142 UAS). In the ClearPETRA group, operation time was statistically significantly shorter ( P  = .002), SFR was statistically significantly higher ( P  = .003), and the number of fever and sepsis were statistically significantly less ( P  = .003 and 0.002, respectively). Conclusion: We found that ClearPETRA reduces the likelihood of postoperative fever after RIRS surgeries. Moreover, we can say that the use of ClearPETRA in RIRS, especially for stones larger than 2 cm, reduces the operation time, increases the SFR, and also reduces sepsis rates.

Introduction: The Karl Storz FLEX-XC1 is a novel single-use flexible ureteroscope that uses the same videographics platform as its reusable digital counterpart. We evaluated the technical performance of the FLEX-XC1 in its initial clinical use., Methods: We reviewed a series of consecutive ureteroscopy procedures performed by 2 endourologists using the FLEX-XC1 for indications for which we typically use a single-use device: total stone burden > 15 mm or > 10 mm in the lower pole, anticipated case duration > 60 minutes, bilateral procedure, or upper tract urothelial cancer procedures. We assessed device tip deflection, intraoperative mechanical failure, and clinical outcomes for each case. Surgeons rated visual clarity, image quality, and maneuverability on a 1 to 5 Likert scale., Results: Of 29 procedures using FLEX-XC1, 27 (93%) were successfully completed. Preoperative upward deflection was < 270° in 6 (21%) cases, and downward deflection was < 270° in 9 (31%) cases. Three types of intraoperative malfunctions occurred: rotational twisting of deflectable tip (4 cases, 13%), device not advancing through distal ureter (1 case, 3%), and working channel not accommodating a 365-μm laser (1 case, 3%). Visual clarity, image quality, and maneuverability were rated as 5 "very good" or 4 "good" in 100%, 100%, and 97% of cases, respectively. No device-specific or general 30-day complications were observed., Conclusions: The FLEX-XC1 showed comparable image quality and maneuverability to reusable digital devices. We observed incomplete deflection in up to 31% of cases and mechanical failure in 2 cases. The FLEX-XC1 may be advantageous in prolonged cases where maintaining visual clarity is paramount.

Background: This study aimed to assess the feasibility, safety, and efficacy of an endoscopic parapelvic renal cyst (PRC) incision using flexible ureterorenoscopy (fURS)., Material and Methods: We retrospectively reviewed data concerning 16 patients in whom PRC incisions had been performed using fURS between January 2016 and January 2022. Two patients were excluded from the study owing to a lack of follow-up information. The cysts of all the patients were evaluated preoperatively by computed tomography. The patients' age, gender, cyst size, presenting symptoms, postoperative complications, and pre- and post-treatment visual analogue scale (VAS) scores were evaluated. Surgical success was defined as a reduction of more than half of the cyst size in the sixth postoperative month., Results: A total of 14 patients were included in this study. The patients' mean age was 52.6 ± 8.8 years, and the mean cyst size was 69.1 ± 15.5 mm. Twelve (85.7%) patients presented with flank pain. Clavien-Dindo grade 1 complications were observed in two patients (14.3%), and grade 2 complications were observed in one (7.1%). The median VAS scores were significantly lower after treatment than before in patients who presented with flank pain (2 (1-2.8) vs 8 (7-8), respectively; p = 0.002). Surgical success rate was detected in 11 patients (78.6%) six months after the treatment., Conclusions: Endoscopic incision of the PRC is a feasible treatment modality with high success rates and low complication rates. However, multicentre studies with larger populations and longer follow-ups are needed to evaluate the lasting effects., Competing Interests: The authors declare no conflict of interest., (© 2024 The Author(s).)

Objective: To report the initial results of an randomized clinical trail comparing the safety and efficacy between 7.5F and 9.2F flexible ureteroscope (FUS) in the management of renal calculi <2 cm. Materials and Methods: Eighty patients were enrolled and received retrograde intrarenal surgery (RIRS) with a different size FUS. The operation results and complications were compared. Results: Two cases in the 7.5F group and four cases in the 9.2F group failed to insert the 12/14F ureteral access sheath (UAS), respectively, and no significant difference ( p  = 0.396) was noted. However, 10/12F UAS was inserted in the 7.5F group, but not available in the 9.2F group, and thus, the 10/12F UAS inserting rate in the 7.5F group was higher than in the 9.2F group (100% vs 0%, p  = 0.014), and the UAS insertion failure rate in 9.2F group was higher than in the 7.5F group (10% vs 0%, p  = 0.040). The operation time in 7.5F group was shorter than the 9.2F group (35.60 ± 7.86 vs 41.05 ± 8.14, p  = 0.003). Less irrigation was required in 7.5F group (813.93 ± 279.47 mL vs 1504.18 ± 385.31 mL, p  = 0.000). The postoperative fever rate in 9.2F group was higher than 7.5F group (20% vs 5%, p  = 0.043). There was no significant difference in sepsis (0% vs 2.5%, p  = 0.314) between the two groups. No significant difference was noted in hospital stay (0.93 ± 0.49 days vs 1.14 ± 0.64 days, p  = 0.099) between the two groups. The final stone-free rate (SFR) in 7.5F group was higher than 9.2F group (95% vs 80%, p  = 0.043). Conclusion: The latest 7.5F mini FUS was a reliable instrument in RIRS to keep a good visualization with low requirement of irrigation, low postoperative infection complication, and also a high SFR when compared with the conventional 9.2F FUS. Clinical Trial Registration: NCT05231577.