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Min Lei,1,2,&ast; Zheng Jiang,1,2,&ast; Peng Xu,1,2 Zhenglin Chang,1– 3 Yuyan Zhang,4 Shike Zhang,1,2 Lingyue An,1,2,5 Shujue Li,2,3 Tao Zeng,2,3 Hans-Göran Tiselius,6 Yuhao Zhou,1,2 Guohua Zeng,2,3 Wenqi Wu1,2 1Department of Urology, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, 510260, People’s Republic of China; 2Guangdong Key Laboratory of Urology, Guangzhou Medical University, Guangzhou, Guangdong, 510260, People’s Republic of China; 3Department of Urology, The First Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, 510260, People’s Republic of China; 4Guangzhou Institute of Dermatology, Guangzhou, Guangdong, 510095, People’s Republic of China; 5Department of Urology, Guizhou Provincial People’s Hospital, Guiyang, Guizhou, 550002, People’s Republic of China; 6Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institute, Stockholm, 14186, Sweden&ast;These authors contributed equally to this workCorrespondence: Wenqi Wu; Guohua Zeng, Email 2009681012@gzhmu.edu.cn; gzgyzgh@vip.sina.comBackground: The purpose of this study was to identify bacterial differences between urine cultures (UC) and stone cultures (SC) in patients with complex kidney stones and to determine any correlation with post-percutaneous nephrolithotomy Systemic Inflammatory Response Syndrome (SIRS).Methods: Perioperative data of 1055 patients with complex kidney stones treated with first-stage Percutaneous Nephrolithotomy (PCNL) from September 2016 until September 2021 were included. Preoperative mid-stream urine samples and surgically obtained stone material were subjected to bacterial culture and antibiotic sensitivity tests. Preoperatively, antibiotic usage was determined by the UC or local bacterial resistance patterns. After PCNL treatment, antibiotic selection was guided by stone bacterial culture result and clinical symptoms. The effect of different preoperative antibiotic regimens based on urine cultures and postoperative antibiotic treatment based on stone cultures were assessed.Results: Positive stone cultures (SC+) were significantly more common than positive urine cultures (UC+) (31.9% vs 20.9%, p < 0.05). Escherichia coli (E. coli) was the most common uropathogen in both urine (54.3%) and stones (43.9%). The difference was statistically significant (p < 0.05). Moreover, UC+SC-, UC-SC+, UC+SC+, and preoperative serum creatinine were independent risk factors of postoperative SIRS. The incidence of SIRS in the UC+SC+ patients with different bacteria in stones and urine (51.6%) was higher than that in other culture groups. The antibiotic resistance of E. coli inside the stone was increased when prolonged preoperative antibiotics were administered to UC+ patients.Conclusion: The bacterial spectrum and positive outcome of culture in urine and stones were significantly different. The incidence of postoperative SIRS was highest in patients with UC+SC+ but with different bacteria strains. Prolonged pre-surgical antibiotic treatment apparently induced higher drug resistance for bacteria inside the stone.Keywords: kidney stones, bacterial spectrum, antibiotic resistance, stone culture, urine culture

Different international associations have proposed their own guidelines on urolithiasis. However, the focus is primarily on an overview of the principles of urolithiasis management rather than step-by-step technical details for the procedure. The International Alliance of Urolithiasis (IAU) is releasing a series of guidelines on the management of urolithiasis. The current guideline on shockwave lithotripsy (SWL) is the third in the IAU guidelines series and provides a clinical framework for urologists and technicians performing SWL. A total of 49 recommendations are summarized and graded, covering the following aspects: indications and contraindications; preoperative patient evaluation; preoperative medication; prestenting; intraoperative analgesia or anesthesia; intraoperative position; stone localization and monitoring; machine and energy settings; intraoperative lithotripsy strategies; auxiliary therapy following SWL; evaluation of stone clearance; complications; and quality of life. The recommendations, tips, and tricks regarding SWL procedures summarized here provide important and necessary guidance for urologists along with technicians performing SWL. PATIENT SUMMARY: For kidney and urinary stones of less than 20 mm in size, shockwave lithotripsy (SWL) is an approach in which the stone is treated with shockwaves applied to the skin, without the need for surgery. Our recommendations on technical aspects of the procedure provide guidance for urologists and technicians performing SWL., (Copyright © 2022. Published by Elsevier B.V.)

The aim of this study was to construct the fourth in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis (IAU) that by providing a clinical framework for the metabolic evaluation, prevention, and follow-up of patients with urolithiasis based on the best available published literature. All recommendations were summarized following a systematic review and assessment of the literature in the PubMed database from January 1976 to June 2022. Each generated recommendation was graded using a modified GRADE methodology. Guideline recommendations were developed that addressed the following topics: initial evaluation, metabolic testing, dietary measures, medical management, and follow-up of recurrent stone formers. It was emphasized by the Panel that prevention of new stone formation is as important as the surgical removal of the stones. Although general preventive measures may be effective in reducing stone recurrence rates in some patients, specific medical and dietary management should be well considered and eventually applied in an individualized manner based on the outcomes of metabolic work-up, stone analysis and some certain patient related factors. A detailed follow-up of each case is essential depending on the metabolic activity of each individual patient., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Correct perioperative antibiotic strategies are crucial to prevent postoperative infections during percutaneous nephrolithotomy (PCNL). We aimed to compare the realistic antibiotic strategies applied in China with current urological guidelines., Methods: Between April and May 2020, urologists from China were invited to finish an online cross-sectional survey. The questionnaire was designed according to the current urological guidelines and literatures., Results: 3393 completed responses were received. 61.1% (2073/3393) respondents had urological experience of more than 10 years. 72.4% urologists chose multiple-dose antibiotics for patients with both negative urine culture (UC-) and negative urine microscopy (UM-) preoperatively. Respondents in central China (OR = 1.518; 95% CI 1.102-2.092; P = 0.011), east China (OR = 1.528; 95% CI 1.179-1.979; P = 0.001) and northeast China (OR = 1.904; 95% CI 1.298-2.792; P = 0.001) were more likely to prescribe multiple-dose antibiotic for UC-UM- patients. Notably, the respondents who finished PCNL exceeded 100 cases per year were in favor of single-dose administration (OR = 0.674; 95% CI 0.519-0.875; P = 0.003). There are only 8.3% urologists chose single-dose antibiotic for UC-UM+ patients, whereas 65.5% administered antibiotics for 1-3 days. Meanwhile, for UC+ patients, 59.0% of the urologists applied antibiotics shorter than 1 week, and only 26.3% of the urologists carried out routine re-examination of UC. Moreover, postoperative antibiotics were frequently prescribed for 3-6 days (1815; 53.5%). Finally, although 88.2% urologists considered stone culture important for management of postoperative antibiotics as the guideline recommended, only 18.5% performed it routinely., Conclusions: The antibiotic strategies are different between current practice in China and the urological guidelines. The dissimilarities suggested that further studies should be conducted to investigate the reasons of the differences and standardize the application of antibiotics., (© 2022. The Author(s).)

Purpose: To explore an appropriate duration of antibiotic therapy before percutaneous nephrolithotomy (PCNL) in patients with positive urine culture., Methods: From March 2016 to May 2018, consecutive patients with positive urine culture undergoing PCNL were prospectively registered. Initial preoperative antibiotics were given empirically. If needed, antibiotics were upgraded or adjusted to susceptible antibiotic after obtaining antibiotic-sensitivity test. Postoperative systemic inflammatory response syndrome (SIRS) was the primary outcome., Results: Among the 220 participants, the incidence of positive stone culture and SIRS were 85.5% and 36.8%. Escherichia coli (53.6%, 44.5%) and Proteus mirabilis (8.2%, 10.0%) were the top two bacteria in urine and stones. In univariable analysis, patients with postoperative SIRS had a higher rate of stone culture positivity (97.5% VS 78.4%, P < 0.001) and a shorter duration of preoperative antibiotics therapy (3.4 ± 2.7 days versus 4.2 ± 2.8 days, P = 0.037). The landscape of SIRS showed a declining trend as the elongation of preoperative antibiotics (P = 0.039). In a day-by-day comparison, SIRS was less prevalent in patients treated by pre-PCNL antibiotics ≥ 7 days than in those with antibiotics ≤ 6 days (21.7% VS 40.8%, P = 0.017). Multivariable logistic regression confirmed positive stone culture (P = 0.001, OR 11.115) as an independent risk factor and pre-PCNL antibiotics ≥ 7 days (P = 0.048, OR 0.449) as an independent protective factor for SIRS. Preoperative antibiotic ≥ 7 days decreased SIRS from 45.4 to 27.8% and from 9.1 to 0% in patients with a positive and negative stone culture, respectively., Conclusion: Exceeding seven days should be appropriate duration of antibiotic therapy before PCNL in patients with positive urine cultures., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The purpose of this study in a small group of non-stone-forming Chinese persons was to measure the levels of supersaturation with calcium oxalate and calcium phosphate and pH with the aim of confirming if any of the different short-term urine samples were better for risk evaluation than a 24-h sample. Nine normal men and 1 woman collected urine during 4 periods of the day. Period 1 between 08 and 12 h, Period 2 between 12 and 18 h, Period 3 between 18 and 22 h, and Period 4 between 22 and 08 h. Each sample was analysed for calcium, oxalate, citrate, magnesium and phosphate, and estimates of supersaturation with calcium oxalate (CaOx) and calcium phosphate (CaP) were expressed in terms of AP(CaOx) and AP(CaP) index. An estimate of the solute load of CaOx was also calculated. Urine composition for 24-h urine (Period 24) was obtained mathematically from the analysed variables. Urine composition corresponding to 14-h urine portions 22-12 h (Period 14N) and 08-22 h (Period 14 D) were calculated. The lowest pH levels were recorded in Period 1 urine. The highest level of AP(CaOx) index was recorded during Period 1, and the product AP(CaOx) index × 107 × hydrogen ion concentration was significantly higher in Period 1 urine than in 24-h urine (p = 0.02). Also, the product SL(CaOx) × 107 × hydrogen ion concentration was significantly higher in Period 1 urine (p = 0.02). Low AP (CaP) index levels were recorded in Period 4, but also in all periods following dietary loads of calcium and phosphate. With the important reservation that the analytical results were obtained from non-stone-forming persons, the conclusion is that analysis of urine samples collected between 08 and 12 h might be an alternative to 24-h urine. The risk evaluation might advantageously be expressed either in terms of the product AP(CaOx) index × 107 × hydrogen ion concentration or the product SL(CaOx) × 107 × hydrogen ion concentration., (© 2021 S. Karger AG, Basel.)

Introduction: Urinary tract infection (UTI) should be treated before percutaneous nephrolithotomy (PCNL). However, the most appropriate treatment strategy in patients with negative urine culture but positive urine dipstick infection test (positive urinary leukocyte or nitrite reaction) remains unclear. Materials and Methods: From August 2016 to February 2018, 806 consecutive patients who had undergone the first-stage PCNL with negative urine culture were included. Preoperative urinalysis, antibiotic treatment, intraoperative stone culture, and postoperative systemic inflammatory response syndrome (SIRS) were prospectively recorded. The primary outcome was SIRS. The impact of preoperative antibiotics on preoperative UTI, stone culture, and postoperative SIRS was studied. Results: Among the 806 participants, the rate of positive urine dipstick infection test and SIRS were 26.8% and 7.2%, respectively. In univariable analysis, positive urinary nitrite ( p  < 0.001), positive urinary leukocytes ( p  < 0.001), positive urine dipstick infection test ( p  < 0.001), longer duration of pre-PCNL antibiotics ( p  = 0.001), higher level of pre-PCNL antibiotics ( p  = 0.010), infection stones ( p  = 0.001), and positive stone culture ( p  < 0.001) were risk factors for SIRS. However, multivariable analysis showed that positive stone culture ( p  = 0.004) and prolonged preoperative treatment with antibiotics ( p  = 0.021) were independent risk factors for SIRS. Although preoperative antibiotics reduced the incidence of positive urine leukocyte ( p  < 0.001) or nitrite reactions ( p  < 0.001), prolonged or upgraded preoperative antibiotics did not affect the incidence of positive stone culture. Whether stone culture was positive ( p  = 0.023) or negative ( p  = 0.025), prolonged preoperative treatment with antibiotics was associated with a higher incidence of SIRS. Conclusions: Enhanced preoperative antibiotic treatment based on positive urine dipstick infection tests was insufficient to reduce the incidence of positive stone culture but increased the risk of SIRS after PCNL in patients with negative urine cultures.

Previous clinical studies have shown that Escherichia coli (E. coli) predominated in urine and stone culture from calcium oxalate (CaOx) stone disease. The characteristic and relationship between E. coli isolated from urine cultures (EUC) and stone cultures (ESC) are compared. 83 E. coli (33 EUC and 50 ESC, respectively) from 66 CaOx stone patients were recruited in the study. E. coli in urine and stones from those patients were assessed by antimicrobial susceptibility test, genotyping and phylogenetic grouping. Furthermore, whole genome sequencing and comparative genomic analysis in paired ESC and EUC isolated strains from eight patients were carried out. The E. coli strains from ESC and EUC were not only multidrug resistant (MDR), but also had the similar pattern of resistant genes. The dominant phylogenetic group was B2, which was found in 54.0% of the ESC samples and 69.7% of the EUC samples, respectively. The virulence genes of E. coli, which isolated from stones and urine in the same patients, were highly homologous and largely consistent. Meanwhile, these E. coli strains were located in the same clade originated from a common ancestor. ESC and EUC isolated from patients with CaOx stones had a high prevalence of phylogenetic groups B2. Bacterial strains isolated from urine and stones in the same patient had consistent antimicrobial susceptibility profiles, genotyping, phylogenetic groups, virulence and resistance genes, also with high sequence co-linearity and close relationships., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

Purpose: To evaluate the distribution and dynamic trends in constituents of urinary stones in China., Materials and Methods: The composition of 23,182 stones were analyzed and then recorded between January 2011 and December 2019. The characteristics in terms of stone patient's gender, age and calendar year were analyzed., Results: Most stones (22,172, 95.64%) had several crystal components, among which 40.25% (8925/22,172) were mixtures with infection components. Calcium oxalate (CaOx) and uric acid (UA) stones were more commonly encountered in men, but calcium phosphate (CaP), magnesium ammonium phosphate (MAP) and carbonate apatite (CA) stones were more prevalent in women (p < 0.05). In males, the proportion of CaOx stones increased up to the age of 40, but subsequently decreased (p < 0.001). Interestingly, females showed an inverse trend regarding CaOx stones (p < 0.001). The proportion of UA stones increased with age (p < 0.001), and CA stones most frequently were recorded at age 20-49. Over the past 9 years, UA, CA, and MAP stones increased over time, whereas there was a tendency for CaOx stones to decrease (p < 0.05)., Conclusions: The scarcity of pure stones and a certain proportion of mixtures with infection stone components (e.g., mixtures of CaOx and CA) suggest that treatment directed against a single stone component is insufficient for effective recurrence prevention. Age and gender were significant determinants of stone composition, and according to the observed chronological trends, it seems that in the future, more UA, CA and MAP stones and fewer CaOx stones may be encountered in the studied population., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: To evaluate the chemical composition of double-J stent encrustation and to assess risk factors associated with their development., Materials and Methods: Patients who had double-J stents removed between July 2016 and June 2017 were recruited for this study prospectively. The clinical features of the patients were recorded and the composition of encrustation material was analyzed by infrared spectroscopy., Results: Encrustments from a total of 372 double-J stents were collected. The mean age of patients was 50.4±13.1 years and deposits possible to analyze were obtained from 228 males (61.3%) and 144 females (38.7%). Calcium oxalate monohydrate was the most common constituent of stone and encrustments. The encrustation rate of vesical coils was significantly higher than that of renal coils (P<0.001). There was no significant difference in chemical composition between stone and encrustation regarding renal (P=0.086) and vesical coils (P=0.072). The only predictive risk factor for the development of encrustation on double-J stents was indwelling time. This phenomenon was observed in both renal (P<0.001) and vesical coils (P=0.021). Interestingly, patient with chronic kidney disease (CKD) was associated with less risk of encrustation on both renal (P<0.001) and vesical coils (P=0.001)., Conclusion: The chemical composition of double-J stent encrustation was the same as the urinary stone. The prevention strategy for stone composition is also suitable for the prevention of encrustation of double-J stent. The only predictive factor for double-J stent encrustation was the indwelling time. CKD patient was shown to be less at risk for the development of encrustation.

Purpose: To explore the safety of multiple tract percutaneous nephrolithotomy (PNL) in terms of complication and draw a nomogram to predict the possibility of significant renal function decline (SRFD)., Materials and Methods: Patients with complex renal calculi appropriate for PNL at our institution between August 2016 and February 2018 were included in the study. The outcome of single and multiple tract PNL was analyzed retrospectively. A nomogram was created to predict the probability of SRFD., Results: 793 (88.4%) patients were treated with single tract PNL (Group 1) and 104 patients (11.6%) treated with multiple tract PNL (Group 2). Group 2 had a significantly greater hemoglobin reduction (16.0 ± 12.5 vs. 11.4 ± 11.8 g/L, p < 0.001), higher rate of postoperative fever (19.2% vs. 11.9%, p = 0.034) and longer duration of the operation (110.6 ± 39.6 vs. 97.8 ± 34.5 min, p < 0.001). A nomogram for predicting the probability of SRFD was constructed based on identified risk factors: patients' age, positive urine culture (UC +), hemoglobin reduction and embolization. The area of receiver operating characteristic (ROC) curve was 70%. Bootstrapping technique utilized to make the calibration plot showed a high reliability of the nomogram., Conclusions: Multiple tract PNL had a higher risk of hemoglobin reduction and postoperative fever than single tract PNL. Multiple tracts had no effect on SRFD, but old age, UC + , hemoglobin reduction and embolization were risk factors for SRFD. A nomogram with the aim of predicting the probability of SRFD based on these parameters demonstrated good uniformity in internal validation.

The Consensus Group deliberated on a number of questions concerning urine and stone analysis over a period of months, and then met to develop consensus. The Group concluded that analyses of urine and stones should be routine in the diagnosis and treatment of urinary stone diseases. At present, the 24-h urine is the most useful type of urine collection, and accepted methods for analysis are described. Patient education is also important for obtaining a proper urine sample. Graphical methods for reporting urine analysis results can be helpful both for the physician and for educating the patient as to proper dietary changes that could be beneficial. Proper analysis of stones is also essential for diagnosis and management of patients. The Consensus Group also agreed that research has shown that evaluation of urinary crystals could be very valuable, but the Group also recognizes that existing methods for assessment of crystalluria do not allow this to be part of stone treatment in many places.

Objective: To assess the relevance of urine test (UT), urine culture (UC) and stone culture (SC) for postoperative infections and to investigate the optimal perioperative antibiotic treatment strategy in association with percutaneous nephrolithotomy (PCNL) in patients with renal calculi., Materials and Methods: Between September 2016 and September 2018 1,060 patients treated with PCNL were included in the study. The results of UT, UC and SC were reviewed. The details of perioperatively administered antibiotics and postoperative infections were recorded., Results: A positive UT was associated with an increased incidence of infection; this was also the case in patients with negative UC (p < 0.05). There was no significant difference in incidence of infection between patients who were given a single dose of antibiotics compared with those given multiple doses when UC was negative, whether UT was positive or negative (all p > 0.05). The incidence of infection was decreased when pre-operative antibiotics were administered according to the sensitivity pattern based on UC (p < 0.05). This outcome was particularly evident when the treatment duration exceeded 7 days (p < 0.05). A positive SC was associated with increased incidence of infection, even if the patient had a negative UC and UT (p < 0.05). The incidence of infection was significantly decreased when antibiotic treatment was administered based on the results of SC (p < 0.05)., Conclusion: Pre-operative prophylaxis with a single-dose antibiotic was sufficient in patients with negative UC, whether UT was positive or negative. Pre-operative treatment with antibiotics according to the bacterial sensitivity pattern should be administered for ≥7 days in patients with positive UC. The postoperative antibiotic treatment strategy should be tailored according to the SC results., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The objective of this study is to explore the efficacy and safety of mechanical percussion combined with changed patient position (MPPP) on elimination of residual stones/fragments in the upper urinary tract. The study was a systematic review and meta-analysis. A systematic literature review using Pubmed, Embase, Medline, and Cochrane Library was conducted to obtain randomized-controlled trials (RCTs) evaluating the efficacy and safety of MPPP treatment of patients with residual stones/fragments in the upper urinary tract. The retrieval of data ended in October 2018. Statistical analysis was carried out using summarized unadjusted risk ratios (RRs) with 95% confidence intervals (CIs). Seven RCTs comprising 1132 patients were included. Compared with patients in the control group, patients treated with MPPP had higher stone-free rates (SFRs) with RR 1.55 (CI 1.11-2.18; p = 0.01) and lower complication rates with RR 0.48 (CI 0.25-0.94, p = 0.03). In subgroup analysis based on stone location, the SFR for the lower calyx was significantly higher in the intervention group than in the control group: RR 1.80 (CI 1.47-2.21, p < 0.00001). In subgroup analysis based on complication type, compared with the control patients, the intervention patients had lower hematuria rate with RR 0.46 (CI 0.28-0.74, p = 0.001) and lower leucocyturia rate with RR 0.33 (CI 0.12-0.89, p = 0.03). MPPP is a worthwhile non-invasive method for elimination of residual stones/fragments in the upper urinary tract. Furthermore, we recommend MPPP for patients with residual stones or fragments located in the lower calyces.

The aim of the study was to report the characteristics of urolithiasis in Uyghur patients from Xinjiang, China. The composition of stones collected from 1863 patients in the Uyghur region of Xinjiang was analyzed. The median age of patients was 17 years [25th and 75th percentiles: 2, 36]. The stones were delivered by 1299 males (69.7%) and 564 females (30.3%). Calcium oxalate was the predominant stone component in 42.1% of the patients, followed by ammonium urate in 20.6%. Females had formed more stones of magnesium ammonium phosphate 8.9 vs. 5.6% (p = 0.010) and carbonate apatite 6.2 vs. 3.3% (p = 0.004). In contrast uric acid was more common in males than in females; 21.6 vs. 15.1% (p = 0.001). In this series, pediatric patients (age range 0-18) were more likely to present with a stone (51.5%, p < 0.001). Moreover, the largest number of pediatric stones was recorded in children 1-2 years old (37.9%, p < 0.001). The occurrence of ammonium urate stones was extremely high (52.4%) in children with an age below 1 year. There was a downward trend for ammonium urate with age in both children and adults (p for trend < 0.001, respectively). In contrast the frequency of uric acid declined with age in pediatric patients, but increased in adults (p for trend < 0.001, respectively). This study provides a basis for further considerations on the management of Xinjiang Uyghur patients and emphasize the severity of pediatric stone problems.

Background: To retrospectively compare the composition of urinary tract stones formed by Uyghur children from the southern (Kashgar) and northern (Urumchi) parts of the Xinjiang region., Methods: The chemical composition of urinary tract calculi formed by 855 Uyghur children from the two regions in Xinjiang (366 Kashgar and 489 Urumchi) was compared retrospectively. Stone composition was determined by infrared spectroscopy. Factors that might have been of relevance for the findings such as age, gender, stone location and geographic region were also considered., Results: Kashgar children were younger than Urumchi children (2.8 ± 2.7 vs. 4.3 ± 3.7 years, p < 0.001). Although ammonium urate was the dominant stone component in the whole population, calcium oxalate was most common in children from Urumchi. The mean occurrence of ammonium urate, calcium oxalate and uric acid differed significantly between stones formed by Kashgar and Urumchi children (52.5% vs. 29.2%, 18.9% vs. 29.4%, 12.3% vs. 20.9%; respectively, p < 0.001). Renal stones were less frequently recorded in Kashgar children than in Urumchi children (65.8% vs. 91.6%, p < 0.001). Interestingly, bladder stones were more common in children from Kashgar (28.4% vs. 3.7%; p < 0.001)., Conclusion: Uyghur children from the southern part of Xinjiang apparently had a more serious form of stone disease than children from the northern part and the occurrence of stones dominated by ammonium urate stones was extremely high in children from the southern part of the region., (Copyright © 2018. Published by Elsevier Taiwan LLC.)

Purpose: The characteristics and resistance patterns of urine bacteriology in patients with urinary tract stones have not been extensively studied. This study aims to investigate the microbial spectrum and antibiotic resistance of uropathogens isolated from urinary tract infections in patients with urinary stones and provide a basis for appropriate antimicrobial treatments., Methods: The results of positive bladder midstream urine cultures and their antimicrobial susceptibility were retrospectively analysed from hospitalised patients with diagnosis of urinary calculi and urinary tract infections between January 2010 and December 2015., Results: A total of 3892 samples were analysed during the study period: 2201 were female patients (56.6%) and 1691 were male patients (43.4%). The 4 most common uropathogens were Escherichia coli (48.7%), Klebsiella pneumoniae (10.4%), Enterococcus faecalis (8.7%) and Proteus mirabilis (5.2%). Both E. coli (60.8%) and Proteus mirabilis (7.5%) were higher in female patients than in male patients (32.8%; 2.3%; P < .05). ESBL-positive E. coli accounted for 59.5% of total number of E. coli, while ESBL-positive K. pneumoniae comprised 42.0% of total K. pneumoniae. The majority of uropathogens in patients with stones had high resistance to fluoroquinolones, ceftriaxone, ceftazidime, cefepime, penicillins, sulfonamides and monobactams (resistance >20%)., Conclusions: The microbial spectrum in patients with urinary stones had a complex pattern. The uropathogens showed marked multidrug resistance and a large proportion of the uropathogens were able to produce β-lactamase., (© 2018 John Wiley & Sons Ltd.)

It is well recognized that the popularity of extracorporeal shock wave lithotripsy (SWL), despite its non-invasive character, has decreased during recent years. This is partly explained by the technological achievements in endoscopy and urologists' enthusiasm for such procedures. Another explanation is that many urologists have been insufficiently successful with SWL. The latter effect might to some extent be a result of the performance of the lithotripter used, but in too many cases, it is evident that the principles of how shock wave lithotripsy should be carried out are poorly applied. The purpose of this article is to emphasize some important aspects on how SWL best should be used. Based on decades of experience, it stands to reason that success with SWL does not come automatically and attention has to be paid to all details of this technique.

Objective: To investigate the impact of green tea on urinary oxalate excretion in healthy male volunteers., Materials and Methods: The oxalate concentrations after different brewing times (2-60 min) of different qualities (2-8 g) of green tea were measured in in vitro experiment. In in vivo experiment, the effects on urine composition were assessed in 12 healthy men with an age of 24-29 years. Each subject was requested to collect two 24-h urine samples under normal dietary conditions. Green tea prepared from tea bags containing 2 g of tea leafs was consumed by the subjects for 7 consecutive days, and 24-h urine samples were collected and analyzed on days 6 and 7. After 3-week washout interval, all subjects consumed green tea containing 4 g of leaf tea for another 7 consecutive days. Two 24-h urine samples were collected on the last 2 days. Urine volume, pH, calcium, magnesium, sodium, phosphate, potassium, chloride, citrate, oxalate, urate and creatinine were measured., Results: In the in vitro experiments, oxalate in solution increased with brewing time (p < 0.05) and tea quality (p < 0.05). In the in vivo experiment, 24-h urinary oxalate increased significantly (0.24 ± 0.09 mmol to 0.32 ± 0.13 mmol, p = 0.045) when tea was prepared from 2-g bags of green leaf tea. Consumption of green tea containing 4 g of leaf tea resulted in 24-h urinary oxalate increase (0.25 ± 0.25 mmol to 0.34 ± 0.22 mmol, p = 0.041)., Conclusions: In vitro studies showed that there was a gradual increase in solution concentrations of oxalate that was associated with increased brewing time and increased quality of green tea. Studies in normal men showed that green tea consumption was associated with increased urinary exertion of oxalate.

The Objective of this study is to analyze the difference in renal stone composition between Uyghur and Han children with urolithiasis in China and possible reasons. From May 2011 to September 2013, we analyzed the stone compositions of 274 Chinese children with urolithiasis, including 151 Uyghur children from Xinjiang Province and 123 Han children from Guangdong Province. All the stone components were determined by Infrared spectroscopy and the main components were recorded. We also evaluated the data, including age, gender and geographic region of the patients. The mean age of Uyghur children was less than Han children (5.3 ± 4.2 vs 8.6 ± 5.7 years, p < 0.001). Calcium oxalate (CaOx) was the main stone composition in both Uyghur (35.1 %) and Han (64.2 %) children, but was more common in Han children (p < 0.0001). Cystine stone was also more abundant in Han children (8.9 % vs 0.7 %, p = 0.001). While, both uric acid (20.5 % vs 3.3 %, p < 0.0001) and magnesium ammonium phosphate (16.6 % vs 2.5 %, p < 0.0001) stones were more common in Uyghur. Interestingly, the significant differences in stone composition between the two groups were only observed in males. When the pediatric patients were further divided into three age groups which were 0-5, 6-12 and >12, the prevalence of calcium oxalate stones increased with age in both groups and was higher in Han children at each age level. The compositions of urinary stones were significantly different between Uyghur and Han children with urolithiasis, factors such as diet habit, life style, genetic diversity, environmental and medical conditions may all contribute to the variances.

Protein supplements are consumed for an expected increase in muscle mass and improved exercise performance, but as their impact on lithogenic parameters are unknown, we aimed to evaluate the effects of Whey protein (WP) and Albumin upon the risk factors for nephrolithiasis. WP or Albumin supplements (one scoop/day) were administered for 3 days to 18 healthy volunteers, with 1-week washout period between them. Serum and 24-h urine samples were collected at baseline and after completing each intervention. All participants were asked to replicate their baseline diet during the subsequent urine collection. After WP or albumin, mean protein equivalent of nitrogen appearance (PNA) was significantly higher (p < 0.001), as the result of the consumption of each of the supplements, but mean urinary calcium, phosphorus, sodium, potassium, uric acid, citrate, oxalate, magnesium, creatinine, pH, and urinary saturation indices did not differ from baseline. However, individual increases higher than 50% in urinary calcium were observed in 39% of the individuals and variable decreases in urinary pH in 44 and 67% of them, respectively, after WP or Albumin. Increases higher than 50% in urinary sodium occurred in one-third of them after Albumin. A short-term consumption of WP or albumin by healthy subjects, under controlled diet, did not significantly change the mean lithogenic parameters. Nevertheless, the wide individual variation and relevant increases/decreases observed for urinary calcium, sodium, and pH suggest the need of a closer surveillance of these parameters and adequacy of diet in case of supplementation by stone formers.

Urinary stones and urine composition are the first steps in the process of recurrence prevention, but data concerning the association between the two compositions are scarce in Chinese children with urolithiasis. We retrospectively analyzed the records of children (age range 0-18 years) with urolithiasis in our center between March 2004 and December 2013. Stone analysis was carried out in 382 children and 24-hour urine analysis in 80 children. Analysis of both stone and 24-hour urine composition was completed in 56 children. Stone samples were analyzed by Fourier transform-infrared spectrometry. The major stone constituents were calcium oxalate (78.8 %). Of 80 children with 24 h urine analysis, only 2.5 % were without urinary metabolic abnormalities. Hypocitraturia was recorded in 97.5 %, high sodium excretion in 50.0 %, cystinuria in 48.7 %, hypercalciuria in 18.8 %, small urine volumes in 12.5 %, hyperoxaluria in 5.0 % and hyperuricosuria in 1.3 %. Interestingly, higher urine volumes were recorded in girls than in boys (73.2 ± 58.5 vs 51.3 ± 45.3 mL/kg, p = 0.036). Urine sodium (p = 0.002) and oxalate (p = 0.004) were significantly higher in children >9 year old. Moreover, compared with calcium oxalate stone formers, the urine volume (p = 0.040), citrate (p = 0.007) and cystine (p = 0.004) were higher in patients with cystine stones. Hypocitraturia was the common abnormality among Chinese children with urolithiasis. The surprisingly high incidence of cystinuria is of note.

Context: The incidence of urinary tract stone disease is increasing and the risk of recurrent stone formation is high. Appropriate therapeutic procedures with the aim of counteracting the progress of stone formation are highly desirable. Metabolic work-up is considered essential as a base for optimal design and follow-up of effective recurrence prevention., Objective: To scrutinize the current literature with regard to principles of metabolic work-up for this heterogeneous group of patients., Evidence Acquisition: Relevant articles in PubMed, guideline documents, consensus reports, and the Cochrane Library published during the past 20 yr were consulted., Evidence Synthesis: Grades of recommendation were used according to the principles applied in the European Association of Urology and American Urological Association guidelines. Medical efforts to prevent recurrent stone formation should be part of the care of patients with urinary tract stone disease (grade of recommendation A). A careful medical history and imaging together with analysis of stone composition, blood, and urine provide the basis for appropriate measures, but the treatment has to be individualized (grade of recommendation D). Whenever possible, stone analysis should be carried out at least once for every patient or each time when a long time has elapsed between two stone episodes because the risk factors explaining stone formation may have changed (clinical principle). The medical history, including information on dietary and drinking habits as well as lifestyle, is necessary for appropriate advice (grade of recommendation C). The medical history, together with imaging and stone composition, is used to estimate the severity of the disease (clinical principle). Identification of specific medical conditions should be supported by blood and/or urine analysis (grade of recommendation B). Pharmacological agents associated with an increased risk of stone formation should be identified (grade of recommendation C). Patients who have formed noncalcium stones should always be given recurrence preventive treatment. Analysis of urine composition for these patients is optional, but might be of value in the follow-up to support decisions on appropriate dosage regimens (grade of recommendation C). For patients with idiopathic calcium stone disease information from 24-h urine samples should be used, although the number of samples to be taken is debated (grade of recommendation C). Information from 24-h urine analysis should be used for selective dietary and drinking advice as well as for selection of the most appropriate pharmacological agent (grade of recommendation B). The treatment effects on the risk of stone formation can be followed by estimates of supersaturation based on urine composition (grade of recommendation C)., Conclusions: It is clear that the metabolic work-up of patients with urinary tract stone disease should be individualized according to stone type and severity of the disease, and that the different therapeutic approaches are closely associated with the availability of therapeutic tools and motivation by the patient., Patient Summary: Effective prevention of recurrent stone formation is determined by several factors such as the current and previous stone episodes and surgical procedures, stone composition, medical history, dietary and drinking habits, lifestyle, and ongoing pharmacological therapy. Analysis of blood and urine is an important part of the metabolic evaluation, but how extensive the risk evaluation should be is determined by the type of stone and the severity of the disease., (Copyright © 2017 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Kidney stones are mineral deposits in the renal calyces and pelvis that are found free or attached to the renal papillae. They contain crystalline and organic components and are formed when the urine becomes supersaturated with respect to a mineral. Calcium oxalate is the main constituent of most stones, many of which form on a foundation of calcium phosphate called Randall's plaques, which are present on the renal papillary surface. Stone formation is highly prevalent, with rates of up to 14.8% and increasing, and a recurrence rate of up to 50% within the first 5 years of the initial stone episode. Obesity, diabetes, hypertension and metabolic syndrome are considered risk factors for stone formation, which, in turn, can lead to hypertension, chronic kidney disease and end-stage renal disease. Management of symptomatic kidney stones has evolved from open surgical lithotomy to minimally invasive endourological treatments leading to a reduction in patient morbidity, improved stone-free rates and better quality of life. Prevention of recurrence requires behavioural and nutritional interventions, as well as pharmacological treatments that are specific for the type of stone. There is a great need for recurrence prevention that requires a better understanding of the mechanisms involved in stone formation to facilitate the development of more-effective drugs.

In this review, aspects on the importance of information on urine composition and selection of the most appropriate regimen for prevention of recurrence are discussed. For patients with urolithiasis the treatment is facilitated by urine analysis with estimates of supersaturation levels. Despite lack of strong scientific evidence for the benefit of selective versus non-selective prevention of recurrence in patients with calcium stone disease, there is currently both convincing and logical information in support of tailored/selective treatment regimens aiming at correction of abnormal target variables. Such an approach is also recommended in the EAU and AUA guidelines. It is important, however, that every preventive regimen is balanced between the effects on urine composition and patients' tolerance to the treatment in order to achieve satisfactory compliance. It is possible that future improved understanding of the causes of calcium stone formation might provide a different therapeutic approach.

At a time when there is an almost unlimited enthusiasm and preference among urologists for endoscopic stone removal, we have found it essential to meet some of the frequently presented arguments on why extracorporeal shockwave lithotripsy (SWL) should not be used. We have based our considerations in this brief article on our 30-35 years' experience with the non-invasive or least invasive technique that SWL represents. Stone disintegration, requirement of repeated treatment sessions, the concern of residual fragments, complications and economic aspects are some points that are discussed.

Although shock wave lithotripsy (SWL) remains an excellent non-invasive method for active removal of stones from the ureter and kidney, its popularity has decreased during recent years and the arguments for choosing endoscopic procedures rather than the only non-invasive surgical procedure are usually based on the opinion that SWL results are inferior to those obtained with endoscopic methods. It is considered that slow technical progress has not sufficiently met the requirements of disintegration, reduced need of repeated treatments, shorter treatment duration and less negative effects on tissues. This article summarises some recently published articles that address these problems and have the aim of improving the function of lithotripters. Modification of the shock wave geometry, elimination or control of cavitation bubbles, and different techniques of disintegration studied in in vitro and in animal experiments suggest several possible future directions that might provide a basis for development of a new "gold standard" lithotripter.

Objective: To evaluate how different methods for storage and preservation of urine samples affected the outcome of analysis of risk factors for stone formation., Methods: Spot urine samples were collected from 21 healthy volunteers. Each fresh urine sample was divided into ten 10-mL aliquots: 2 without preservative, 2 with thymol, 2 with toluene, 2 with hydrochloric acid (HCl), and 2 with sodium azide. One sample of each pair was stored at 4 °C and the other at room temperature. The concentrations of calcium, magnesium, sodium, phosphate, urate, oxalate, citrate, and pH in each urine sample were analyzed immediately after collection (0 hour) and after 24 and 48 hours., Results: There were no significant differences in calcium, oxalate, magnesium, phosphate, sodium, urate or pH (without acidification) between samples with different preservation methods (P >.05). Urinary citrate, however, was significantly lower in the urine collected with HCl than when other preservatives were used, both at room temperature and at 4 °C. Urine pH was significantly higher after 48 hours than after 24 hours, whether the samples were stored at room temperature or at 4 °C., Conclusion: Antibacterial preservatives (eg, thymol or toluene) can be recommended as preservatives for 24-hour urine collections. Ideally, the samples should be stored at 4 °C. When HCl is used as a preservative, it seems essential to neutralize the samples before analysis. This is particularly obvious with the chromatographic method used for analysis of citrate that was used in this study., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Prevention of recurrent calcium oxalate (CaOx) stone formation in the urinary tract is important to avoid negative effects on renal function, patient suffering and to reduce health care cost. Present shortcomings in this regard can be explained both by insufficient understanding of the mechanisms of stone formation and by poor patient compliance to those regimens that nevertheless have proven effective. During the past years, we have got increased insights in the nature of CaOx stone formation and it is suggested that the improved understanding of this process can be used for a more dynamic risk evaluation and treatment regimen directed to specific risk periods that can be identified in the individual patients. Some of the possibilities with regard to the important role of calcium phosphate are discussed in this article.

Objective: To assess urine composition in Chinese patients with urolithiasis., Methods: Five hundred seven Chinese patients with urolithiasis from our center in southern China were included in this study. Analysis of stone composition was performed using infrared spectrometry. From all patients, 24-hour urine samples were collected for analysis of urinary variables. Some ion activity product risk indices were also calculated., Results: The major stone constituents in the 507 analyzed stones were as follows: calcium oxalate (78.3%), infection stone components (14.6%), uric acid (3.6%), and calcium phosphate (3.4%). Only 1 stone was composed of cystine (0.2%). Of all patients, 504 (99.4%) had 1 or several urinary metabolic abnormalities. Hypocitraturia was recorded in 93.9%, high sodium excretion in 58.6%, small urine volume in 45.6%, hyperoxaluria in 31.0%, hypercalciuria in 26.0%, hyperuricosuria in 19.3%, and hyperphosphaturia in 2.8%. Moreover, high sodium excretion was more frequent in men than women (59.2% vs 49.3%, P = .027), whereas hypercalciuria was more common in women (34.5% vs 20.4%, P <.001). High levels of urine sodium (187.7 ± 86.9 vs 179.8 ± 107.7 mmol/24h, P = .038) and phosphate (18.26 ± 8.36 vs 15.69 ± 11.14 mmol/24h, P <.001) were found in men than in women. Infection stones were significantly (P <.004) more common in women. Compared with noninfection stone formers, the occurrence of hypomagnesuria (P = .040) was more common in patients with infection stones., Conclusion: The results of urinary risk factors for stone formation in this study might serve as a basis for design of recurrence prevention. It is of interest to note that some of the demonstrated abnormalities differ from that in reports from other countries., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Results of research carried out during recent years have shown that papillary subepithelial and intratubular deposits of calcium phosphate have important roles in the formation of calcium oxalate stones. In this article, the mechanisms of calcium oxalate stone formation are briefly reviewed and the background to formation of Randall's plaques type I and II discussed. Although some of the conclusions are difficult to prove, it stands to reason that improved understanding of how calcium phosphate is deposited in the interstitial tissue as well as in the collecting ducts will be of great importance for design of rational and individualized recurrence prevention.

Cadmium exposure is associated with increased urinary calcium excretion. Hypercalciuria is recognised as a major risk factor for kidney stone formation. Increased prevalence of kidney stones among those occupationally exposed to cadmium has previously been suggested. Food is the main source of cadmium exposure in the general population with tobacco representing an important additional source among smokers. We aimed to assess the association between dietary cadmium exposure and kidney stone incidence in two large population-based, prospective cohorts of men (Cohort of Swedish Men; COSM) and women (The Swedish Mammography Cohort; SMC). Those with a history of kidney stones were excluded. At baseline 1997, men (45-79yrs) and women (48 to 83yrs), completed a self-administered questionnaire on diet and lifestyle. During 12years of follow-up, we ascertained 707 cases of kidney stones in men and 290 in women through linkage of the cohorts to the national inpatient and outpatient registers. Individual dietary cadmium exposure was estimated using dietary data and concentrations of cadmium in food. Hazard ratios (HR) were calculated using the Cox proportional hazards regression models with adjustment for other risk factors. Estimated dietary cadmium exposure was not associated with increased kidney stone incidence among men HR 0.97 (95% confidence interval (CI): 0.77-1.23) or women HR 0.99 (95% CI: 0.89-1.43), comparing the highest tertile with the lowest. In conclusion, our results do not support a strong association between dietary cadmium and kidney stone risk at the exposure levels seen in the general population., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Objective: To evaluate the effects of oral sodium bicarbonate (NaBic) supplementation upon urinary citrate excretion in calcium stone formers (CSFs)., Methods: Sixteen adult calcium stone formers with hypocitraturia were enrolled in a randomized, double-blind, crossover protocol using 60 mEq/day of NaBic during 3 days compared to the same period and doses of potassium citrate (KCit) supplementation. Blood and 24-hour urine samples were collected at baseline and during the third day of each alkali salt., Results: NaBic, similarly to KCit supplementation, led to an equivalent and significant increase in urinary citrate and pH. Compared to baseline, NaBic led to a significant increase in sodium excretion without concomitant increases in urinary calcium excretion, whereas KCit induced a significant increase in potassium excretion coupled with a significant reduction in urinary calcium. Although NaBic and KCit both reduced calcium oxalate supersaturation (CaOxSS) significantly vs baseline, KCit reduced calcium oxalate supersaturation significantly further vs NaBic. Both KCit and NaBic significantly reduced urinary phosphate and increased calcium phosphate supersaturation (CaPSS) compared to baseline. Finally, a significantly higher sodium urate supersaturation (NaUrSS) was observed after the use of the 2 drugs., Conclusion: This short-term study suggests that NaBic represents an effective alternative for the treatment of hypocitraturic calcium oxalate stone formers who cannot tolerate or afford the cost of KCit. In view of the increased sodium urate supersaturation, patients with pure uric acid stones and high urate excretion may be less suited for treatment with NaBic., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The purpose of this study is to derive approximate estimates of ion-activity products of CaOx (APCaOx) and CaP (APCaP) useful for spot urine or other less well defined short-term urine collections. In accordance with previously applied and described principles for estimating ion-activity products, the intention was to derive simplified estimates of AP(CaOx)CONC and AP(CaP)CONC by using urine concentrations of the most important determinants of APCaOx and APCaP. A comparison thus was made between estimates derived in that manner and AP(CaOx) index and AP(CaP) index obtained from calculations based on analysis of 24 h urine samples. The best fit between estimates of AP(CaOx) index in 24 h urine and AP(CaOx) indexCONC was obtained with the following formula (r = 0.99; p = 0.0000): [Formula in text] The corresponding formula for AP (CaP) indexCONC was derived from comparison with the corresponding calculations of AP(CaP) index in 24 h urine (r = 0.91; p = 0.0000): [Formula in text] The proposed simplified formulas enable calculation of approximate estimates of APCaOx and APCaP in spot-urine samples or any kind of urine collection for which duration of the collection period is less well known and by using the concentrations (c) of the variables in mmol/L in the two formulas.