Renal pelvic pressure generally remains lower than the backflow level (30 mm Hg) during MPCNL via a 14- to 18-French percutaneous tract. Any factors that brought about poor drainage would result in temporarily elevated RPP greater than 30 mm Hg, and many such occurrences of high pressure would have an accumulating effect, which means enough backflow to cause bacteremia and postoperative fever.

AIMTo compare the outcomes of retrograde intrarenal surgery (RIRS) and miniaturized percutaneous nephrolithotomy (mini-PCNL) in treating lower pole (LP) renal stones with a diameter of 1.5-2.5 cm.METHODSA total of 216 patients who underwent mini-PCNL (n = 103) or RIRS n = 113) for LP stones with a diameter of 1.5-2.5 cm were enrolled between December 2015 and April 2017 at the Urology Department of Ningbo Urology and Nephrology Hospital.RESULTSSignificant differences were found in the hospital stay (9.39 ± 4.01 vs 14.08 ± 5.26, P < 0.0001) and hospitalization costs (2624.5 ± 513.36 vs 3255.2 ± 976.5, P < 0.0001) between the RIRS and mini-PCNL groups. The mean operation time was not significantly different between the RIRS group (56.48 ± 24.77) and the mini-PCNL group (60.04 ± 30.38, P = 0.345). The stone-free rates at the first postoperative day (RIRS vs mini-PCNL: 90.2% vs 93.2%, P = 0.822) and the second month postoperatively (RIRS vs mini-PCNL: 93.8% vs 95.1%, P = 0.986) were not significantly different.CONCLUSIONRIRS and mini-PCNL are both safe and effective methods for treating LP stones with a diameter of 1.5-2.5 cm. RIRS can be considered as an alternative to PCNL for the treatment for LP stones of 1.5-2.5 cm.

The present study revealed the normal metabolic status for stone risk factors of the Chinese Han population. It is therefore necessary for each country or region to define their own reference intervals for comparison of stone risk factors between patients and healthy subjects.

Purpose: To explore the role and mechanism of curcumin (Cur) in reducing oxidative stress damage in rats with nephrolithiasis induced by ethylene glycol (EG). Methods: Thirty male rats were divided into normal control, model, positive (10% potassium citrate), Cur-10 (10 mg/kg curcumin) and Cur-20 (20 mg/kg curcumin) groups. Results: The results of kidney tissue section stained by hematoxylin-eosin and von Kossa showed that curcumin treatment can inhibit the formation of kidney stones. The biochemical test results showed that the urea (Ur), creatinine (Cr), uric acid (UA), inorganic phosphorus and Ca 2+ concentrations in urine decreased after being treated with curcumin. There were significant differences between different doses of curcumin (P < 0.05). Compared with the Cur-10 group, Cur-20 had a more significant inhibitory effect on malondialdehyde (MDA) (P < 0.05). In addition, reverse transcription polymerase chain reaction (PCR) detection and immunohistochemical results indicated that the osteopontin (OPN) in the kidney was significantly reduced after curcumin treatment. Conclusions: Curcumin could reduce the oxidative stress damage caused by EG-induced kidney stones.