Vascular calcification in kidney stone formers: the impact of age and stone composition.

An increased prevalence of vascular calcification (VC) has been reported in kidney stone formers (KSFs), along with an elevated cardiovascular risk. The aim of the current study is to assess whether VC in these patients develops at a younger age and is influenced by stone composition. This single-center, matched case-control study included KSFs with uric acid or calcium oxalate stones (diagnosed based on stone analysis) and age- and sex-matched controls without a history of nephrolithiasis. The prevalence and severity of abdominal aortic calcification (AAC) and bone mineral density (BMD) were compared between KSFs and non-KSFs. In total, 335 patients were investigated: 134 with calcium oxalate stones, 67 with uric acid stones, and 134 controls. Overall, the prevalence of AAC was significantly higher among calcium stone formers than among the controls (67.9% vs. 47%, p = 0.002). In patients under 60 years of age, those with calcium oxalate stones exhibited both a significantly elevated AAC prevalence (61.9% vs. 31.3%, p = 0.016) and severity (94.8 ± 15.4 vs. 30.3 ± 15.95, p = 0.001) compared to the controls. Within the age group of 40-49, osteoporosis was identified only in the KSFs. Multivariate analysis identified age, smoking, and the presence of calcium stones as independent predictors of AAC. This study highlights that VC and osteoporosis occur in KSFs at a younger age than in non-stone-formers, suggesting potential premature VC. Its pathogenesis is intriguing and needs to be elucidated. Early evaluation and intervention may be crucial for mitigating the cardiovascular risk in this population.

[Prevention of recurrence of urolithiasis]. / Rezidivprävention der Urolithiasis.

Urolithiasis is one of the most frequent urological diseases. Identifying the causes of stone formation forms the basis for successful prevention of recurrence. Metabolic diagnostics and measures for prevention of recurrence are based on the assignment of the patient to a low-risk or high-risk group. Analysis of the urinary calculi is an essential prerequisite for identifying patients at risk. The general recommendations on diet and lifestyle are considered to be the basis of treatment. Depending on the type of stone and the individual biochemical risk profile of a patient, these general measures should be supplemented by targeted medical nutrition therapy and pharmacological treatment. Mixed stones can pose a challenge for the treatment and prevention of recurrence. A personalized treatment decision that takes the various components of mixed stones into account could further improve the prevention of recurrence of urolithiasis.

Mixed stones: urinary stone composition, frequency and distribution by gender and age.

Proper analysis of urinary stone composition is a cornerstone for diagnosis, targeted treatment and recurrence prevention of urolithiasis. The aim of this study was to determine the composition, frequency and distribution of mixed stones according to gender and age of patients. A total of 42,519 urinary stones from 30,311 men and 12,208 women submitted between January 2007 and December 2020 were studied. Most urinary calculi consisted of two components (50.9%), followed by stones of a single constituent (27.1%) and three-component stones (21.9%), while four-component stones were only rarely identified (0.1%). Among all stones, 49.8% consisted of whewellite (COM), weddellite (COD), and mixtures of COM and COD, 33.8% were pure carbonate apatite (CA) and mixtures of CA with COM and/or COD, while 7.6% were composed of uric acid anhydrous (UAA), uric acid dihydrate (UAD), and mixed UAA and UAD. The remaining 8.8% of calculi were rare single-component stones and rare mixtures of various constituents. The number of stone components was inversely associated with age (p < 0.001). The proportion of men decreased significantly with the number of stone constituents, from 3.01:1 for single-component stones to 1.0:1 for four-component urinary calculi (p < 0.001). The vast majority of urinary calculi consisted of two or more components in varying proportions. While age was inversely associated with the number of stone constituents, the proportion of women increased significantly from single-component to four-component urinary calculi. A significant proportion of mixed stones could present a challenge for diagnosis and targeted recurrence prevention.

Comparison of the bone mineral density status of patients with kidney stones stratified by stone composition.

PURPOSE: Bone loss has been found to occur frequently in patients with particular metabolic disorders that are likely associated with certain kidney stone composition. Thus, we compared the bone mineral density (BMD) of patients with different kidney stone compositions. PATIENTS AND METHODS: A total of 204 consecutive patients who exhibited stone formation with calcium oxalate (CaOx), calcium phosphate (CaP), uric acid (UA), and magnesium ammonium phosphate (MAP) underwent 24 h urine test and BMD measurement. BMD was measured by dual X-ray absorptiometry at the lumbar spine (LS) and femoral neck (FN). The Z-score was used to express BMD. A BMD Z-score ≤ - 2 was defined as a diagnostic threshold for bone loss. RESULTS: Amongst the patients, 38 had an LS BMD Z-score of ≤ - 2, but only 2 had FN BMD Z-score of ≤ - 2. The group with an LS BMD Z-score of ≤ - 2 exhibited significantly larger male - female ratio, higher frequency of hypercalciuria and CaP, and lower frequency of MAP than the group with an LS BMD Z-score of > - 2. Reduced LS BMD was most remarkable in the CaP group, followed by the CaOx, UA, and MAP groups. The LS BMD Z-score of hypercalciuric patients was significantly lower than that of normocalciuric patients only in the CaP group. CONCLUSION: Patients with different kidney stone compositions presented different BMD status. Using this information may facilitate medical decision-making in patients with kidney stone who should undergone BMD earlier.

The first epidemiology of urolithiasis in Northern Vietnam: Urinary stone composition, age, gender, season, and clinical features study.

OBJECTIVES: The aim of this study is to analyze the compositions of urinary stones and investigate their distributions in different ages, genders, seasons, and clinical features of Northern Vietnamese patients. METHODS: A total of 231 patients with urinary stones from Northern Vietnam were collected and analyzed composition from 1/2021-12/2022. For all patients, age, sex, stone location, stone side, urine pH, and hospitalized date (month) were collected. RESULTS: Kidney stones are more frequently found in men than women with the male: female urinary stones ratio in this study being 1.96:1. The highest stone prevalence appeared between 60 and 69 years old. The most common stone composition was calcium oxalate, followed by calcium phosphate, uric acid, struvite, and cysteine. Mix stones of CaOx and CaP were more prevalent than pure stones. Males submitted more CaOx, CaP, and UA stones, whereas females were susceptible to infectious stones. Stones were more frequently found on the left side of the upper urinary tract (51.9%) than on the right side (27.3%) and lower urinary tract (7.8%). Cultural tendency leads to a smaller number of stones during the Lunar new year (February), and Ghost month (August).

Epidemiology and composition of upper urinary tract lithiasis in Senegalese population: a multicenter retrospective study.

Urolithiasis is a major public health issue due to its increasing prevalence. The objective of this study was to describe the spectrophotometric profile of upper urinary tract stones (UTS) in Senegal. We conducted a multicenter retrospective study of all patients treated for upper UTS whose chemical composition was analyzed from January 2014 to January 2020 in eight regions of Senegal. Socio-demographic, clinical, paraclinical, and prognosis data were collected and analyzed. Three hundred and thirty-four patients were included in this study with a mean age of 46.3 ± 18.4 years and a sex ratio of 1.38. About one-third of patients (31.1%) had a body mass index > 25 kg/m2 and 74.2% presented with lumbar pain was the main clinical symptom. Calcium oxalate and calcium phosphate stones were the predominant types found, respectively, in 37.7% and 24.5% of patients. Uric acid was the main stone constituent in 18.6% of patients and struvites represented 14.7% of cases. Stones were located in the renal calyces and pelvis in 71.2% of cases. Surgical lithotomy was performed in 62.7% of patients for UTS extraction. Upper UTS are frequent condition in Senegalese with predominance of males and young adults. Calcium and uric acid stones are the main types. Preventive dietary and lifestyle measures are needed to reduce their burden.

Automatic Kidney Stone Composition Analysis Method Based on Dual-energy CT.

BACKGROUND: The composition of kidney stones is related to the hardness of the stones. Knowing the composition of the stones before surgery can help plan the laser power and operation time of percutaneous nephroscopic surgery. Moreover, patients can be treated with medications if the kidney stone is compounded by uric acid before treatment, which can relieve the patients of the pain of surgery. However, although the literature generally reports the kidney stone composition analysis method base on dual-energy CT images, the accuracy of these methods is not enough; they need manual delineation of the kidney stone location, and these methods cannot analyze mixed composition kidney stones. OBJECTIVE: This study aimed to overcome the problem related to identifying kidney stone composition; we need an accurate method to analyze the composition of kidney stones. METHODS: In this paper, we proposed the automatic kidney stone composition analysis algorithm based on a dual-energy CT image. The algorithm first segmented the kidney stone mask by deep learning model, then analyzed the composition of each stone by machine learning model. RESULTS: The experimental results indicate that the proposed algorithm can segment kidney stones accurately (AUC=0.96) and predict kidney stone composition accurately (mean Acc=0.86, mean Se=0.75, mean Sp=0.9, mean F1=0.75, mean AUC=0.83, MR (Exact match ratio)=0.6). CONCLUSION: The proposed method can predict the composition and location of kidney stones, which can guide its treatment. Experimental results show that the weighting strategy can improve kidney stone segmentation performance. In addition, the multi-label classification model can predict kidney stone composition precisely, including the mixed composition kidney stones.

On the rocks: can urologists identify stone composition based on endoscopic images alone? A worldwide survey of urologists.

PURPOSE: As part of the management of nephrolithiasis, determination of chemical composition of stones is important. Our objective in this study is to assess urologists' accuracy in making visual, intraoperative determinations of stone composition. MATERIALS AND METHODS: We conducted a REDCap survey asking urologists to predict stone composition based on intraoperative images of 10 different pure-composition kidney stones of 7 different types: calcium oxalate monohydrate (COM), calcium oxalate dihydrate (COD), calcium phosphate (CP) apatite, CP brushite, uric acid (UA), struvite (ST) and cystine (CY). To evaluate experience, we examined specific endourologic training, years of experience, and number of ureteroscopy (URS) cases/week. A self-assessment of ability to identify stone composition was also required. RESULTS: With a response rate of 26% (366 completed surveys out of 1,370 deliveries), the overall accuracy of our cohort was 44%. COM, ST, and COD obtained the most successful identification rates (65.9%, 55.7%, and 52.0%, respectively). The most frequent misidentified stones were CP apatite (10.7%) and CY (14.2%). Predictors of increased overall accuracy included self-perceived ability to determine composition and number of ureteroscopies per week, while years of experience did not show a positive correlation. CONCLUSIONS: Although endoscopic stone recognition can be an important tool for surgeons, it is not reliable enough to be utilized as a single method for stone identification, suggesting that urologists need to refine their ability to successfully recognize specific stone compositions intraoperatively.

A Novel Infrared Spectroscopy Method for Analysis of Stone Dust for Establishing Final Composition of Urolithiasis.

Background: The introduction of the holmium laser for lithotripsy and minimally invasive techniques in endoscopy increased the popularity of stone dusting techniques. Retrieving stone pieces for an analysis increases the economic burden of surgery and operative time. Novel methods are needed for the analysis of convenient urolithiasis composition. Objective: This study aims to assess the efficacy of the stone dust Fourier transform infrared spectroscopy coupled with attenuated total reflection (FTIR ATR) method for accurate stone composition determination from the dust specimens compared with simultaneously retrieved standard stone fragments. Design setting and participants: From July 2021 to March 2022, a total of 75 patients who received endoscopic treatment for urolithiasis were included in this study. Outcome measurements and statistical analysis: The accuracy of the FTIR ATR method was assessed via estimates of sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV). The results were compared between samples of stone dust and the final stone composition. Results and limitations: Total or partial biochemical composition agreement was observed in 92.7% of cases and total agreement in 82.4% of cases when stone dust was compared with stone fragments. The highest accuracy rates were obtained for uric acid stones: sensitivity 100%, specificity 98.3%, PPV 90.9%, and NPV 100%. Identification of other types of stones was also of high accuracy, reaching up to 83.3% sensitivity and 100% specificity. Conclusions: The application of FTIR ATR spectroscopy for a stone dust analysis allows obtaining easy and cost-effective final composition of urolithiasis without a stone fragment analysis. This technique was shown to be feasible, and there is substantial potential for clinical practice. Patient summary: This study investigates a novel method that determines accurate stone composition without acquiring the pieces of stone during surgery. The results have shown that stone dust Fourier transform infrared spectroscopy coupled with attenuated total reflection provides accurate stone composition.

Analysis of stone composition and clinical characteristics of urinary calculi in infants in Xinjiang / 国际外科学杂志

Objective:To analyze the composition and clinical characteristics of urinary calculi in infants in Xinjiang.Methods:The clinical data of 75 infants with urinary calculi admitted to the People′s Hospital of Xinjiang Uygur Autonomous Region from January 2016 to December 2021 were retrospectively analyzed, including the general situation of the children, stone-related parameters, random urine pH value, urine culture and biochemical examination results. The serum uric acid, serum calcium, urine pH value, positive rate of urine culture, and stone length between infants with and without ammonium urate stones were compared. Measurement data conforming to normal distribution were expressed as mean ± standard deviation ( ± s), and independent sample t-test was used for inter-group comparison. Measurement data that did not conform to the normal distribution were expressed as the median (interquartile distance) [ M ( Q1, Q3)], and Mann-Whitney U test was used for comparison between groups. The Chi-square test, continuity-corrected Chi-square test or Fisher exact probability method were used for the comparison of count data. Results:The median age of infants with urinary calculi was 23.04 months, and the ratio of male to female was 3.2∶1. More than half of the infants (81.3%, 61/75) came from rural areas, 57.3% (43/75) were malnourished, 33.3% (25/75) were complicated with urinary tract infection, and 8.0% (6/75) were combined with urinary system congenital malformation. The calculi were found in 53 cases (70.67%) of kidney, 27 cases (36.0%) of ureter, 17 cases (22.67%) of urethra and 16 cases (21.33%) of bladder. The analysis of calculi composition showed that there were 44 cases (58.67%) of ammonium urate, 39 cases (52.0%) of calcium oxalate, 14 cases (18.67%) of apatite carbonate and 7 cases (9.33%) of uric acid. Kidney calculi was more common in female infants ( P=0.011). Compared with the infant group ( n=19), calcium oxalate stones were more common in the preschooler group ( n=56) ( P=0.039), but there were not statistical difference in the incidence of ammonium urate, apatite carbonate and uric acid stones. There were not statistical difference in gender, age, place of residence, nutritional status, serum uric acid, serum calcium, urine pH value, positive rate of urine culture, stone maximum diameter and incidence of bladder stones between ammonium urate group and non-ammonium urate group. Conclusions:The incidence of urinary calculi in infants is higher in boys, and the most common site of calculi is the upper urinary tract, especially in female kidney calculi. Ammonium urate is the main component of urinary calculi in infants. Calcium oxalate stones are more common in preschooler group. Infants with urinary calculi are mostly rural residents, and malnutrition and urinary tract infection are more common.

Predictive value of dual-source stone energy spectrum CT for uric acid stones / 中华泌尿外科杂志

Objective:To investigate the predictive value of stone composition prediction method based on dual-source stone energy spectrum CT for uric acid stones.Methods:The clinical data of 204 patients with urinary stones, 159 males and 45 females, admitted to Shanghai Sixth People's Hospital from July 2020 to July 2022 were retrospectively analyzed. The average age was (50.7±14.3) years. There were 187 cases of upper urinary tract (kidney, ureter) stones and 17 cases of lower urinary tract (bladder, urethra) stones. All patients underwent preoperative dual-source stone energy spectroscopy CT, measuring CT values at 150 kV and 100 kV, respectively, and the calculated dual energy ratio (Ratio) was used to predict stone composition. Of the 204 cases in this group, 33 cases underwent percutaneous nephrolithotomy and 171 cases underwent ureteroscopic lithotripsy. Postoperative stone specimens were analyzed for stone composition by infrared spectroscopy. Subject work characteristic (ROC) curves were used to analyze the efficacy of preoperative dual-source stone energy spectrum CT to predict uric acid stones.Results:In 204 patients, preoperative CT predicted 28 cases of uric acid stones and 176 cases of non-uric acid stones, including 136 cases of calcium oxalate stones, 38 cases of hydroxyapatite, and 2 cases of cystine stones. Postoperative IR spectral analysis detected 26 cases of uric acid stones and 178 cases of non-uric acid stones, including 129 cases of calcium oxalate stones, 47 cases of hydroxyapatite, and 2 cases of cystine stones. Compared with the preoperative CT results, there were 2 false positives and no false negatives in the classification of uric acid stones. The ROC curve showed that the sensitivity of the CT value for predicting uric acid stones at 100 kV was 96.2%, the specificity was 99.5%, and the area under the ROC curve (AUC) was 0.995, with the best prediction value of 620 HU.The sensitivity of the CT value for predicting uric acid stones at 150 kV was 96.2%, specificity was 85.5%, AUC was 0.916, and the best predictive value was 597.5 HU. The sensitivity of using Ratio values for predicting uric acid stones was 100.0%, specificity was 97.9%, AUC was 0.996, and the best predictive value was 1.14. The CT values for uric acid stones at 100 kV and 150 kV were (558.58±77.07) HU and (521.12±83.54) HU, CT values for calcium oxalate stones were (1 335.26±301.82) HU and (878.21±200.21) HU, CT values for hydroxyapatite were (1 104.09±203.61) HU and (710.38±178.44) HU, respectively.The CT values of cystine stones were (684.5±67.18) HU and (573.5±67.10) HU, respectively, and the differences between uric acid stones and other components were statistically significant ( P<0.01). The Ratio values of uric acid stones, calcium oxalate stones, hydroxyapatite, and cystine stones were 1.08±0.06, 1.52±0.08, 1.62±0.40, and 1.19±0.02, respectively, and the differences were statistically significant ( P<0.01) when comparing uric acid stones with other components. Conclusion:The CT and Ratio values of dual-source stone energy spectrum CT can effectively distinguish uric acid stones from other types of stones, and the accuracy, sensitivity, and specificity of this method for predicting uric acid stones are high.

Urinary stone composition in Germany: results from 45,783 stone analyses.

PURPOSE: Stone composition can provide valuable information for the diagnosis, treatment and recurrence prevention of urolithiasis. The aim of this study was to evaluate the distribution of urinary stone components and the impact of different crystal forms according to gender and age of patients in Germany. METHODS: A total of 45,783 urinary stones submitted from 32,512 men and 13,271 women between January 2007 and December 2020 were analyzed by infrared spectroscopy. Only the first calculus obtained per patient was included in the analysis. RESULTS: The most common main stone component was calcium oxalate (CaOx) (71.4%), followed by carbonate apatite (CA) (10.2%) and uric acid (UA) (8.3%). Struvite (2.1%), brushite (1.3%), protein (0.5%) and cystine (0.4%) stones were only rarely diagnosed. CaOx (75%) and UA stones (81%) were more frequently obtained from men than women (p < 0.001). Weddellite (COD) and uric acid dihydrate (UAD) were more common in younger ages than whewellite (COM) and anhydrous uric acid (UAA), respectively, in both men and women. The ratios of COM-to-COD and UAA-to-UAD calculi were approximately 4:1 and 8:1, respectively. The peak of stone occurrence was between the ages of 40 and 59 years. CONCLUSION: Stone composition is strongly associated with gender and age. The peak incidence of calculi in both women and men was in the most active phase of their working life. The distinction between different crystal forms could provide clues to the activity and mechanisms of lithogenesis. Further research is needed in understanding the causative factors and the process of stone formation.

How Reliable Is Endoscopic Stone Recognition? A Comparison Between Visual Stone Identification and Formal Stone Analysis.

Objective: To assess the diagnostic accuracy and intra-observer agreement of endoscopic stone recognition (ESR) compared with formal stone analysis. Introduction: Stone analysis is a corner stone in the prevention of stone recurrence. Although X-ray diffraction (XRD) and infrared spectroscopy are the recommended techniques for reliable formal stone analysis, this is not always possible, and the process takes time and is costly. ESR could be an alternative, as it would give immediate information on stone composition. Materials and Methods: Fifteen endourologists predicted stone composition based on 100 videos from ureterorenoscopy. Diagnostic accuracy was evaluated by comparing the prediction from visual assessment with stone analysis by XRD. After 30 days, the videos were reviewed again in a random order to assess intra-observer agreement. Results: The median diagnostic accuracy for calcium oxalate monohydrate was 54% in questionnaire 1 (Q1) and 59% in questionnaire 2 (Q2), whereas calcium oxalate dihydrate had a median diagnostic accuracy of 75% in Q1 and 50% in Q2. The diagnostic accuracy for calcium hydroxyphosphate was 10% in Q1 and 13% in Q2. The median diagnostic accuracy for calcium hydrogen phosphate dihydrate and calcium magnesium phosphate was 0% in both questionnaires. The median diagnostic accuracy for magnesium ammonium phosphate was 20% in Q1 and 40% in Q2. The median diagnostic accuracy for uric acid was 22% in both questionnaires. Finally, there was a diagnostic accuracy of 60% in Q1 and 80% in Q2 for cystine. The intra-observer agreement ranged between 45% and 72%. Conclusion: Diagnostic accuracy of ESR is limited and intra-observer agreement is below the threshold of acceptable agreement.

The combination of mean and maximum Hounsfield Unit allows more accurate prediction of uric acid stones.

Based on mean Hounsfield Unit (HuMean), we aimed to evaluate the additional use of standard deviation of Hounsfield Unit (HuStd), minimum Hounsfield Unit (HuMin), and maximum Hounsfield Unit (HuMax) in noncontrast computed tomography (NCCT) to evaluate uric acid (UA) stones more accurately. The data of patients who underwent the NCCT examination and infrared spectroscopy in our hospital from August 2017 to December 2021 were analyzed retrospectively. Based on CT scans, the HuMean, HuStd, HuMin, and HuMax of all patients were measured. The patients were divided into groups according to the stone composition. The attenuation value of mixed stones was in the middle of their pure stones. Except for Str, statistically significant differences between UA stones and other pure stones were observed for HuMean, HuStd, HuMin, and HuMax. A moderate correlation was found between HuMean, HuStd, HuMin, and HuMax and UA stones (rs showed -0.585, -0.409, -0.492, and -0.577, respectively). Receiver operator characteristic (ROC) curve showed that the area under the curve (AUC) of HuMean and HuMax were higher than those of HuStd and HuMin (AUC = 0.896, AUC = 0.891 vs. AUC = 0.777, AUC = 0.833). Higher AUC (0.904), specificity (0.899) and positive predictive value (PPV) (0.712) can be obtained by combining HuMean and HuMax in the diagnosis of UA stones. In conclusion, HuMean and HuMax can better predict UA stones than HuStd and HuMin. The combined use of HuMean and HuMax can lead to higher accuracy.

Do outcomes of ureteroscopic stone treatment vary with stone composition? A prospective analysis.

Introduction: Urinary tract calculi are commonly treated with ureteroscopy and laser stone fragmentation (URSL). The composition of calculi depends on underlying patient factors. Stones associated with metabolic or infectious conditions are sometimes thought to be more difficult to treat. This analysis explores whether the composition of calculi impacts on stone-free and complication rates. Material and methods: A prospectively maintained database of patients undergoing URSL between 2012-2021 was used to explore records for patients with uric acid (Group A), infection (Group B) and calcium oxalate monohydrate (Group C) calculi. Patients who had undergone URSL to treat ureteric or renal calculi were included. Patient demographics, stone parameters and operative details were collected, with the principal outcomes being stone-free rate (SFR) and associated complications. Results: A total of 352 patients were included (58 Group A, 71 Group B and 223 Group C patients) and had their data analysed. SFR was >90% for all three groups and a single Clavien-Dindo grade III complication was noted. No significant differences were found between the groups for complications, SFR and day case rates. Conclusions: This cohort of patients demonstrated that outcomes were similar for three different types of urinary tract calculi, which form for differing reasons. URSL appears to be an effective, safe treatment for all stone types with comparable results.

Epidemiological and clinical characteristics of stone composition: a single-center retrospective study.

The aim of the study was to investigate the epidemiological characteristics of stone components in patients with urolithiasis and analyze the associations between stone components with patients' clinical characteristics. A total of 7126 patients with urolithiasis between July 2005 and June 2020 were retrospectively analyzed. In this research, calcium oxalate stones (74.6%) accounted for the highest proportion, followed by infection stones (11.8%), uric acid (10.6%), brushite (2.0%), and others (1.1%). The change in trend in the composition of urinary stones revealed that the proportion of uric acid declined steadily, while the content of infection stones increased gradually over 15 years. The results also suggested that stone composition was significantly associated with PM2.5, gender, age, BMI, diabetes, hypertension, CCVD, alcohol consumption, albumin, creatinine, WBCHP, leukocyte, urine pH, nitrite and urine culture (P < 0.05). However, there was no significant correlation between stone composition with smoking, WBC and NEU% (P > 0.05). Our study concluded that calcium oxalate represented the highest proportion, followed by infection stones, uric acid, brushite, and others. The proportion of uric acid declined steadily, while the infection stones increased gradually. Furthermore, the factors influencing the formation of urinary calculi are PM2.5, gender, age, BMI, diabetes, hypertension, CCVD, alcohol consumption, albumin, creatinine, WBCHP, leukocyte, urine pH, nitrite and urine culture. Collectively, these results may provide clues to establish effective prevention and management strategies for urinary calculi.

Relationship of urinary pathogenic bacteria and stone composition in patients with infectious stones / 中华泌尿外科杂志

Objective:To study the relationship of pathogenic bacteria in midstream urine culture and stone composition of patients characteristics with infection stones.Methods:Between January 2016 and December 2020, 989 patients with infectious stones who attended Tsinghua Chang Gung Hospital, affiliated with Tsinghua University, for surgical treatment were enrolled in the study. There were 545 male and 444 female patients, with the mean age (48±14) years. The left and right side stones were 396 and 333, respectively. There were 260 bilateral stones, 264 single stones, 334 multiple stones, and 391 deer-stalker-shaped stones. The maximum diameter of stones was (33.4±26.5)mm, combined with diabetes in 109 cases and hypertension in 235 cases. Clean middle-urine was collected for bacterial culture, and intraoperative stone specimens were collected by percutaneous nephrolithotomy (PCNL). Personal characteristics of the patient such as gender, age, body mass index, clinical information such as stone size, location, comorbidities, results of urine culture and stone composition were recorded. The differences of infectious stone composition was analyzed between urease-producing, non-urease-producing bacteria.Results:Among the 989 patients with infectious stones, 259 were pure infectious stones, 131 were mixed infectious stones, and 599 were combined with infectious stone components. Urine cultures were positive in 627(63.4%) patients with infectious stones. The predominant urease-producing bacteria included Ureaplasma urealyticum(94 case), Proteus mirabilis(58 case), and Staphylococcus spp.(36 case). Pure infectious stones were common in Proteus mirabilis, while combined with infectious stone components were common in Ureaplasma urealyticum and Staphylococcus spp. The predominant non-urease-producing bacteria included Escherichia coli(175 case), Enterococcus spp.(76 case) and Streptococcus spp.(35 case). Escherichia coli commonly contained in infectious stone components and pure infectious stones, whereas Enterococcus spp. and Streptococcus spp. commonly contained in infectious stone components. Escherichia coli (61 case), Proteus mirabilis (44 case) and Enterococcus spp.(20 case) were the most common bacteria in 259 cases of pure infectious stones. Escherichia coli (36 case), Enterococcus spp. (14 case) and Ureaplasma urealyticum (10 case) were the most common bacteria in 131 cases of mixed infectious stones. The most common bacteria in 599 cases of combined infectious stones were Escherichia coli (78 case), Ureaplasma urealyticum (68 case) and Enterococcus spp. (42 case).Conclusions:Urease producing bacteria were not common in infectious stones. It was common for the Ureaplasma urealyticum in combined infectious stone components, while Escherichia coli was common in pure and combined infectious stone components.

Analysis of children urinary stone composition in 592 cases in a single-center / 中华泌尿外科杂志

Objective:To investigate the characteristics of urinary stones composition in children and the differences in their distribution among different sexes and age groups.Methods:The clinical data of 592 children with urinary stones who underwent stone composition analysis using infrared spectroscopy at Hunan Children's Hospital from October 2015 to October 2019 were retrospectively analyzed. There were 430 males and 162 females.The median age was 4.0 (0.3 to 18.0) years old. The stone composition and the differences in its distribution in different sex and age groups were analyzed.Results:A total of 643 urinary stones were analyzed in 592 cases, with 419 (65.2%) single-component stones and 224 (34.8%) mixed-component stones. The main stone components were calcium oxalate in 361 cases (56.1%), ammonium hydrogen urate in 130 cases (20.0%), cystine in 56 cases (8.7%), calcium phosphate in 33 cases (5.1%), uric acids in 33 cases (5.1%), magnesium ammonium phosphate in 25 cases (3.9%), and xanthine in 5 cases (0.8%). The percentage of calcium oxalate stones was higher in women than in men [65.6% (118/180) vs. 52.5% (243/463), P<0.05]. The proportion of upper urinary tract stones was higher in girl than in boy[93.4%(168/180) vs. 73.2%(339/463), P<0.05]. The differences in the composition ratios of calcium oxalate stones, ammonium hydrogen urate, cystine, and magnesium ammonium phosphate stones in different age groups were statistically significant ( P<0.05), with the highest proportion of calcium oxalate stones (35.6%) at 6 to 10 years of age, ammonium hydrogen urate and cystine stones at 1 to 2 years of age (45.4% and 42.9%), and magnesium ammonium phosphate stones at 3 to 5, 6 to 10, and 11 to 18 years of age, the percentage of urinary stones in children was 24%. Conclusions:The main component of urinary stones in children is calcium oxalate, followed by ammonium hydrogen urate and cystine. Age and gender correlate with the distribution of stone components. Calcium oxalate stones are common in females and in children aged 6 to 10 years, ammonium hydrogen urate and cystine stones are common in children aged 1 to 2 years, and magnesium ammonium phosphate stones are more common in children aged 3 to 5 years, 6 to 10 years, and 11 to 18 years.

Urinary stone composition analysis of 1 972 cases in Chongqing / 国际外科学杂志

Objective:To investigate the composition characteristics of urolithiasis patients in Chongqing.Methods:From May 2017 to July 2021, clinical data of 1 972 urinary stone patients treated in the Second Affiliated Hospital of Chongqing Medical University was retrospectively analyzed. Among 1 972 patients, there were 1 323 males and 649 females, the average age was (52.7±13.8) years (aged 14-92 years). In this study, all of the patients were first divided into the central and western areas of Chongqing group ( n=1 532) and southeastern areas of Chongqing group ( n=440) according to regional differences; then according to the difference of economic development level, all patients were divided into the more developed area of Chongqing group ( n=1 491) and the less developed area of Chongqing group ( n=481). To study and analyze the influence of gender, age, region and economic development level on stone composition in patients. The distribution characteristics of urinary calculi constituents in different groups of region, gender and age were analyzed by Chi-square test, and analysis of the proportion of various urinary calculi with age were conducted by Cochran-Armitage trend test. Results:The results of stone composition analysis showed that, among the 1 972 cases, the mixed urinary stones were dominant in the urinary stones [92.9%(1 832/1 972)], in which, the most component was the calcium oxalate monohydrate+ calcium oxalate dehydrate [40.8%(805/1 972)]; among the pure stones, the most component was the calcium oxalate dehydrate [2.5%(50/1 972)]. The proportion of carbonated apatite stones [53.6%(348/649) vs 43.5%(576/1 323), P<0.05], hydroxyapatite stones [25.1%(163/649) vs 17.2%(228/1 323), P<0.05] and magnesium ammonium phosphate stones [20.6%(134/649) vs 6.3%(83/1 323), P<0.05] in female patients were significantly higher than those in male patients, but the proportion of calcium oxalate stones [91.4%(1 209/1 323) vs 80.7%(524/649), P<0.05] and uric acid stones [9.4%(125/1 323) vs 1.5%(10/649), P<0.05] in male patients were significantly higher than those in female patients. Compared with patients aged 40-70 years and ≥70 years, the proportion of carbonated apatite stones [39.6%(155/391) vs 48.4%(673/1 391), 50.5%(96/190), P<0.05], magnesium ammonium phosphate stones [6.1% (24/391) vs 12.0% (167/1 391), 13.7% (26/190), P<0.05] and uric acid stones [3.3% (13/391) vs 7.4% (103/1 391), 10.0% (19/190), P<0.05] was significantly lower for patients aged <40 years; but the proportion of calcium oxalate stones in patients aged < 40 years was significantly higher [93.6%(366/391) vs 87.2%(1 213/1 391), 81.0%(154/190), P<0.05]. In this study, there were no significant difference in stone composition between the central and western areas of Chongqing and the southeastern areas of Chongqing, and between the more developed areas of Chongqing and the less developed areas of Chongqing ( P>0.05). Conclusions:There are gender and age differences in the distribution of urinary stone components in Chongqing, but the regional and economic development level differences are not particularly obvious. Carbonated apatite stones, hydroxyapatite stones and magnesium ammonium phosphate stones were more prevalent in females, calcium oxalate stones and uric acid stones were more common in males. Calcium oxalate stones were the most common in patients aged< 40 years, carbonate apatite, magnesium ammonium phosphate and uric acid stones were more common in patients aged ≥40 years.