Objectives: To investigate the prevalence and associated factors of kidney stones among adults in China. Subjects and Methods: A nationwide cross‐sectional survey was conducted among individuals aged ≥18 years across China, from May 2013 to July 2014. Participants underwent urinary tract ultrasonographic examinations, completed pre‐designed and standardised questionnaires, and provided blood and urine samples for analysis. Kidney stones were defined as particles of ≥4 mm. Prevalence was defined as the proportion of participants with kidney stones and binary logistic regression was used to estimate the associated factors. Results: A total of 12 570 individuals (45.2% men) with a mean (sd, range) age of 48.8 (15.3, 18–96) years were selected and invited to participate in the study. In all, 9310 (40.7% men) participants completed the investigation, with a response rate of 74.1%. The prevalence of kidney stones was 6.4% [95% confidence interval ( CI ) 5.9, 6.9], and the age‐ and sex‐adjusted prevalence was 5.8% (95% CI 5.3, 6.3; 6.5% in men and 5.1% in women). Binary logistic regression analysis showed that male gender, rural residency, age, family history of urinary stones, concurrent diabetes mellitus and hyperuricaemia, increased consumption of meat, and excessive sweating were all statistically significantly associated with a greater risk of kidney stones. By contrast, consumption of more tea, legumes, and fermented vinegar was statistically significantly associated with a lesser risk of kidney stone formation. Conclusion: Kidney stones are common among Chinese adults, with about one in 17 adults affected currently. Some Chinese dietary habits may lower the risk of kidney stone formation.

Retrograde intrarenal surgery (RIRS) is the main treatments for upper urinary tract stones. The Ureteral Access Sheath (UAS) serves as a supplementary tool, facilitating direct kidney access during RIRS. High quality of evidence comparing tip bendable suction ureteral access sheath (S-UAS) with traditional UAS in RIRS for the treatment of renal and ureteral stones is lacking. The purpose of the study is to compare the efficacy and safety of S-UAS with traditional UAS in RIRS for the treatment of renal or ureteral stones ≤30 mm. An international, multicenter, and superiority randomized controlled trial included 320 intention-to-treat patients across 8 medical centers in China, the Philippines, Malaysia and Turkey from August 2023 to February 2024. The inclusion criteria were patients ≥18 years old with renal or ureteral stones ≤30 mm. RIRS was performed using either S-UAS or traditional UAS. The primary outcome was the immediately stone-free rate (SFR). Secondary outcomes included SFR 3 months after operation, operating time, hospital stay, auxiliary procedures, complications (using the Clavien–Dindo grading system), and improvement in the Quality of Life (QoL) score. Differences between proportions [risk difference (RD)]/means [mean difference (MD)] and 95% confidence intervals (CI) were presented. This study is registered at ClinicalTrials.gov: NCT05952635. The S-UAS group demonstrated a significantly higher immediately SFR (81.3% versus 49.4%; RD 31.9%; 95% CI 22.5%–41.7%; p = 0.004) compared to the traditional UAS group, as determined by the one-side superiority test. Additionally, the S-UAS group exhibited a higher SFR at 3 months post-operation (87.5% versus 70.0%; RD 17.5%; 95% CI 8.7%–26.3%; p < 0.001), lower postoperative fever rate (RD −11.9%; 95% CI −18.7% to −4.9%; p < 0.001), reduced use of stone baskets (RD −70.6%; 95% CI −77.8% to −63.5%; p < 0.001), and better QoL improvement (MD 7.25; 95% CI 2.21–12.29; p = 0.005). No statistically significant differences were observed in operation time, hospital stay, or the need for second-stage RIRS. In RIRS for upper urinary tract stones ≤30 mm, S-UAS exhibited superior performance compared to traditional UAS, demonstrating higher SFR, reduced postoperative fever rate, and improved QoL outcomes. S-UAS emerges as a prudent and advantageous alternative to traditional UAS for RIRS. 10.13039/501100001809 National Natural Science Foundation of China and Guangdong Province, and Zhejiang Medicine and Health Program.

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.

Objectives. To describe our novel modified technique of ultra-mini-percutaneous nephrolithotomy (UMP) using of a novel 6 Fr mininephroscope through an 11–13 Fr metal sheath to perform holmium: YAG laser lithotripsy.Methods. The medical records of 36 patients with moderate-sized (<20 mm) kidney stones treated with UMP from April to July 2012 were retrospectively reviewed. Patients were assessed at the 1st day and 1st month postoperatively by KUB and US to assess stone-free status.Results. The mean stone size was 14.9 ± 4.1 mm (rang: 6–20). The average operative time was 59.8 ± 15.9 (30–90) min. The stone-free rate at postoperative 1st day and 1st month was 88.9% and 97.2%. The mean hospital stay was 3.0 ± 0.9 (2–5) days. Complications were noted in 6 (16.7%) cases according to the Clavien classification, including sepsis in 2 (5.6%) cases (grade II), urinary extravasations in 1 (2.8%) case (grade IIIa), and fever in 3 (8.3%) cases (grade II). No patients needed blood transfusion.Conclusions. UMP is technically feasible, safe, and efficacious for moderate-sized renal stones with an advantage of high stone-free rates and low complication rates. However, due to the limits of its current unexplored indications, UMP is therefore a supplement to, not a substitute for, the standard mini-PCNL technology.