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. ResultsA 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. ConclusionKidney 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.

Objective To present a novel miniature endoscopic system designed to improve the safety and efficacy of percutaneous nephrolithotomy, named the ‘super‐mini percutaneous nephrolithotomy’ (SMP). Patients and Methods The endoscopic system consists of a 7‐F nephroscope with enhanced irrigation and a modified 10–14 F access sheath with a suction‐evacuation function. This system was tested in patients with renal stones of <2.5 cm, in a multicentre prospective non‐randomised clinical trial. In all, 146 patients were accrued in 14 centres. Nephrostomy tract dilatation was carried out to 10–14 F. The lithotripsy was performed using either a Holmium laser or pneumatic lithotripter. A nephrostomy tube or JJ stent was placed only if clinically indicated. Results SMP was completed successfully in 141 of 146 patients. Five patients required conversion to larger nephrostomy tracts. The mean (sd) stone size was 2.2 (0.6) cm and the mean operative duration was 45.6 min. The initial stone‐free rate (SFR) was 90.1%. The SFR at the 3‐month follow‐up was 95.8%. Three patients required auxiliary procedures for residual stones. Complications occurred in 12.8% of the patients, all of which were Clavien grade ≤II and no transfusions were needed. In all, 72.3% of the patients did not require any kind of catheter, while 19.8% had JJ stents and 5.7% had nephrostomy tubes placed. The mean hospital stay was 2.1 days. Conclusions SMP is a safe and effective treatment for renal stones of <2.5 cm. SMP may be particularly suitable for patients with lower pole stones and stones that ae not amenable to retrograde intrarenal surgery.

Compared with the prone position, the PCNL in the supine position has a slightly lower rate of stone clearance, albeit shorter mean operative time, and lower incidence of blood transfusions. The meta-analysis suggests that the PCNL in the supine position is a promising alternative.

Mini-PCNL under USG is as safe and effective as FG or CG in the treatment of simple kidney stones (S.T.O.N.E. scores 5-6) but with no radiation exposure. FG or CG is more effective for patients with S.T.O.N.E. scores of 7-8, where multiple percutaneous tracts may be necessary.