Management of large renal stones with super-mini percutaneous nephrolithotomy: an international multicentre comparative study.

OBJECTIVES: To comparatively evaluate the clinical outcomes of super-mini percutaneous nephrolithotomy (SMP) and mini-percutaneous nephrolithotomy (Miniperc) for treating urinary tract calculi of >2 cm. PATIENTS AND METHODS: An international multicentre, retrospective cohort study was conducted at 20 tertiary care hospitals across five countries (China, the Philippines, Qatar, UK, and Kuwait) between April 2016 and May 2019. SMP and Miniperc were performed in 3525 patients with renal calculi with diameters of >2 cm. The primary endpoint was the stone-free rate (SFR). The secondary outcomes included: blood loss, operating time, postoperative pain scores, auxiliary procedures, complications, tubeless rate, and hospital stay. Propensity score matching analysis was used to balance the selection bias between the two groups. RESULTS: In all, 2012 and 1513 patients underwent SMP and Miniperc, respectively. After matching, 1380 patients from each group were included for further analysis. Overall, there was no significant difference in the mean operating time or SFR between the two groups. However, the hospital stay and postoperative pain score were significantly in favour of SMP (both P < 0.001). The tubeless rate was significantly higher in the SMP group (72.6% vs 57.8%, P < 0.001). Postoperative fever was much more common in the Miniperc group (12.0% vs 8.4%, P = 0.002). When the patients were further classified into three subgroups based on stones diameters (2-3, 3-4, and >4 cm). The advantages of SMP were most obvious in the 2-3 cm stone group and diminished as the size of the stone increased, with longer operating time in the latter two subgroups. Compared with Miniperc, the SFR of SMP was comparable for 3-4 cm stones, but lower for >4 cm stones. There was no statistical difference in blood transfusions and renal embolisations between the two groups. CONCLUSIONS: Our data showed that SMP is an ideal treatment option for stones of <4 cm and is more efficacious for stones of 2-3 cm, with lesser postoperative fever, blood loss, and pain compared to Miniperc. SMP was less effective for stones of >4 cm, with a prolonged operating time.

The status and characteristics of urinary stone composition in China.

OBJECTIVES: To explore characteristics of urinary stone composition in China, and determine the effects of gender, age, body mass index (BMI), stone location, and geographical region on stone composition. PATIENTS AND METHODS: We prospectively used Fourier-transform infrared spectroscopy to analyse stones from consecutive patients presenting with new-onset urolithiasis at 46 hospitals in seven geographical areas of China, between 1 June 2010 and 31 May 2015. Chi-squared tests and logistic regression analyses were used to determine associations between stone composition and gender, age, BMI, stone location, and geographical region. RESULTS: The most common stone constituents were: calcium oxalate (CaOx; 65.9%), carbapatite (15.6%), urate (12.4%), struvite (2.7%), and brushite (1.7%). CaOx and urate stones occurred more frequently in males, whereas carbapatite and struvite were more common in females (P < 0.01). CaOx and carbapatite were more common in those aged 30-50 and 20-40 years than in other groups. Brushite and struvite were most common amongst those aged <20 and >70 years. The detection rate of urate increased with age, whilst cystine decreased with age. Obese patients were more likely to have urate stones than carbapatite or brushite stones (P < 0.01). CaOx, carbapatite, brushite, and cystine stones were more frequently found in the kidney than other types, whereas urate and struvite were more frequent in the bladder (P < 0.01). Stone composition varied by geographical region. CONCLUSIONS: The most common stone composition was CaOx, followed by carbapatite, urate, struvite, and brushite. Stone composition differed significantly in patients grouped by gender, age, BMI, stone location, and geographical region.

Prevalence of kidney stones in China: an ultrasonography based cross-sectional study.

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.

Failure of initial renal arterial embolization for severe post-percutaneous nephrolithotomy hemorrhage: a multicenter study of risk factors.

PURPOSE: Severe hemorrhage after percutaneous nephrolithotomy is a rare but alarming event. If local tamponade fails to control bleeding, the current treatment of choice is superselective renal arterial embolization. If initial embolization is unsuccessful, repeat embolization or nephrectomy is often required. To our knowledge we report the first study of risk factors for failed initial superselective renal arterial embolization. MATERIALS AND METHODS: We retrospectively reviewed the records of 17,619 patients who underwent a total of 19,185 percutaneous nephrolithotomies from January 2007 to April 2012 at 6 centers. Study inclusion criteria were percutaneous nephrolithotomy and severe postoperative renal hemorrhage requiring superselective renal arterial embolization. Data on patients in whom initial embolization failed were compared to those on patients with successful embolization on univariate and multivariate analysis. RESULTS: Of the 17,619 patients 117 (0.6%), met study inclusion criteria, including 90 males and 27 females. Initial treatment failed in 12 patients (10.3%), 8 underwent repeat superselective renal arterial embolization, 3 required 3 embolizations and 1 underwent nephrectomy. Complete bleeding cessation was achieved in all 11 repeat embolization cases. We identified 3 risk factors for failure of initial superselective renal arterial embolization, including multiple percutaneous access sites, more than 2 bleeding sites identified on renal angiogram and gelatin sponge alone used as the embolic material. CONCLUSIONS: Carefully selecting patients for multitract percutaneous nephrolithotomy, making an extra effort to identify all bleeding vessels during angiography and not using gelatin sponge as the only embolic material could potentially decrease the risk of failure of initial superselective renal arterial embolization after percutaneous nephrolithotomy.

Kinetic Study on the Crystal Transformation of Fe-Doped TiO2 via In Situ High-Temperature X-ray Diffraction and Transmission Electron Microscopy.

Titanium dioxide (TiO2) is widely used in various major industries owing to its different crystal forms and functions. Therefore, fabricating suitable crystalline TiO2 through reasonable processes is necessary. In this study, Fe-doped TiO2 precursors were prepared via hydrolysis. Further, in situ high-temperature X-ray diffraction and transmission electron microscopy were used to transform the synthesized precursor in its crystal form. The Rietveld full-spectrum fitting method could accurately yield two different crystal forms at instant temperatures. Additionally, the rate relation between the crystal form transformation and reaction conditions was obtained. Results showed that the addition of Fe increased the temperature of phase transition of TiO2 anatase to rutile and accelerated the anatase → rutile transformation process. Further, crystal phase transition kinetic analysis showed that the phase transition kinetic model of Fe-doped TiO2 matched the Johnson-Mehl-Avrami-Kohnogorov (JMAK) model and that its phase transition was affected by crystal defects. Finally, Fe3+ in Fe-doped TiO2 was reduced to Fe2+ to generate oxygen vacancies, thus promoting the rate of transformation from titanium ore to rutile.

[Effects of finasteride on hematuria associated with benign prostatic hyperplasia: a meta-analysis].

OBJECTIVE: To systematically evaluate the effects of finasteride on hematuria associated with benign prostatic hyperplasia (BPH). METHODS: We electronically searched MEDLINE (December 1966-April 2009), EMBASE (December 1974-April 2009), The Cochrane Library (Issue 1, 2009), CNKI (December 1994-April 2009), VIP (December 1989-April 2009) and CBM (December 1978-April 2009) , and handsearched several relevant journals as well. Randomized controlled trials were assessed with the methods recommended by the Cochrane Collaboration. The data were screened and systematically analyzed by at least two reviewers independently using the RevMan 5.0 software. RESULTS: Compared with the placebo control group, the finasteride group showed a significantly decreased incidence of hematuria during the 12 months follow-up period (OR 0.11, 95% CI: 0.06-0.21, P < 0.05). CONCLUSION: Finasteride has desirable therapeutic and preventive effects on BPH-associated hematuria. More well-designed multicentered randomized controlled trials of large sample size are invited to provide further evidence for this conclusion.

Efficacy and Safety of Tamsulosin in Medical Expulsive Therapy for Distal Ureteral Stones with Renal Colic: A Multicenter, Randomized, Double-blind, Placebo-controlled Trial.

BACKGROUND: Recent large high-quality trials have questioned the clinical effectiveness of medical expulsive therapy using tamsulosin for ureteral stones. OBJECTIVE: To evaluate the efficacy and safety of tamsulosin for distal ureteral stones compared with placebo. DESIGN, SETTING, AND PARTICIPANTS: We conducted a double-blind, placebo-controlled study of 3296 patients with distal ureteral stones, across 30 centers, to evaluate the efficacy and safety of tamsulosin. INTERVENTION: Participants were randomly assigned (1:1) into tamsulosin (0.4mg) or placebo groups for 4 wk. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary end point of analysis was the overall stone expulsion rate, defined as stone expulsion, confirmed by negative findings on computed tomography, over a 28-d surveillance period. Secondary end points included time to stone expulsion, use of analgesics, and incidence of adverse events. RESULTS AND LIMITATIONS: Among 3450 patients randomized between September 1, 2011, and August 31, 2013, 3296 (96%) were included in the primary analysis. Tamsulosin benefits from a higher stone expulsion rate than the placebo (86% vs 79%; p<0.001) for distal ureteral stones. Subgroup analysis identified a specific benefit of tamsulosin for the treatment of large distal ureteral stones (>5mm). Considering the secondary end points, tamsulosin-treated patients reported a shorter time to expulsion (p<0.001), required lower use of analgesics compared with placebo (p<0.001), and significantly relieved renal colic (p<0.001). No differences in the incidence of adverse events were identified between the two groups. CONCLUSIONS: Our data suggest that tamsulosin use benefits distal ureteral stones in facilitating stone passage and relieving renal colic. Subgroup analyses find that tamsulosin provides a superior expulsion rate for stones >5mm, but no effect for stones ≤5mm. PATIENT SUMMARY: In this report, we looked at the efficacy and safety of tamsulosin for the treatment of distal ureteral stones. We find that tamsulosin significantly facilitates the passage of distal ureteral stones and relieves renal colic.