The Urological Association of Asia clinical guideline for urinary stone disease

Effect of alkalized urine on renal calculi in patients with gout: a protocol for a placebo-controlled, double-blinded randomized controlled trial

Background

The prevalence of renal calculi in patients with gout is high. Alkalized urine has been recommended by the 2020 European Association of Urology (EAU) guidelines to promote calculus dissolution. However, randomized controlled trials are lacking.

Methods

In the protocol of this randomized, placebo-controlled, double-blinded trial, patients with gout combined with renal calculi are randomized (1:1) to the placebo and sodium bicarbonate groups. The intervention would be performed for 24 weeks, the 1–12 weeks are double-blinded, and the 13–24 weeks are open-labeled. Sodium bicarbonate (1 g tid) will be performed for 24 weeks in the sodium bicarbonate group. The placebo will be performed for 12 weeks and not be performed from 13 weeks to 24 weeks in the placebo group. All subjects will be administered febuxostat (40 mg/day) for 24 weeks and receive concomitant anti-inflammatory prophylaxis therapy for 12 weeks. The primary outcome is the proportion of patients whose renal calculus volume will be reduced after 12 weeks of treatment. The secondary outcomes include the volume changes of renal calculi, uric acid changes, the proportion of patients with serum uric acid (sUA) levels < 360 μmol/L, the changes in estimated glomerular filtration rate (eGFR), the pH value of urine, and the incidence of adverse events after treatment for 12 and 24 weeks.

Discussion

This study will evaluate the efficacy and safety of sodium bicarbonate-alkalized urine on renal calculi in patients with gout.

Trial registration

ClinicalTrials.gov ChiCTR2100045183. Registered on April 7, 2021, with ChiCTR.

Nutritional status assessed by the Controlling Nutritional Status (CONUT) score as a predictor of recurrence of urolithiasis

PURPOSE

We aimed to determine the influence of nutritional status on urinary metabolic abnormalities and stone recurrence in patients with urolithiasis.

MATERIALS AND METHODS

We analyzed data for 464 stone-formers and 464 propensity-score-matched control patients that had been collected between 2003 and 2015. Nutritional status was evaluated by use of the Controlling Nutritional Status (CONUT) score, and patients were placed into two CONUT score categories (0-1 and ≥2). Serum and 24-hour urinary metabolites were evaluated in 464 stone-formers. Kaplan-Meier and multivariate Cox regression analyses were performed to assess the influence of nutritional status on stone recurrence. Stone recurrence was defined as radiographic appearance of new stones during the follow-up period.

RESULTS

Stone-formers showed a higher prevalence of poor nutrition (CONUT score ≥2) than did the propensity-score-matched control patients (p<0.001). Stone-formers who had poor nutritional status had significantly lower 24-hour urinary calcium but higher oxalate excretion (each p<0.05). Kaplan-Meier estimates demonstrated that stone-formers with poor nutritional status also experienced stone recurrence more rapidly (log-rank test, p=0.014). Multivariate Cox regression revealed that poor nutritional status was independently associated with stone recurrence (hazard ratio, 1.736; 95% confidence interval, 1.041-2.896; p=0.034).

CONCLUSIONS

The CONUT score, an easily measured immunonutritional biomarker, is independently associated with a higher risk for stone recurrence in patients with urolithiasis. This implies that not only dietary excess, but also undernourished status, may be associated with aberrations in urine physicochemistry and stone recurrence.

Guideline of the guidelines: urolithiasis

PURPOSE OF REVIEW

We reviewed the latest guidelines on urolithiasis to highlight the commonalities and differences in the most important recommendations.

RECENT FINDINGS

Most guidelines utilize systematic review of literature and grade evidence to generate the appropriate recommendations and statements. Only the latest versions of guidelines were included in this review.

SUMMARY

Four national and international guidelines were included in this review, including those of the EAU (European Association of Urology), the AUA (American Urological Association)/ES (Endourological Society), the UAA (Urological Association of Asia) and the NICE (National Institute for Health and Care Excellence) guidelines. There are general similarities in the most important recommendations. The EAU guidelines provide the latest evidence updates.

Ureteroscopy-assisted puncture for ultrasonography-guided renal access significantly improves overall treatment outcomes in endoscopic combined intrarenal surgery

OBJECTIVES

To assess the impact and availability of ureteroscopy-assisted puncture for percutaneous renal access during ultrasonography-guided miniaturized (mini)-endoscopic combined intrarenal surgery for large volume renal and/or proximal ureteral stones.

METHODS

We conducted a multi-institutional retrospective cohort study for urolithiasis treatment. Data from a total of 313 patients who underwent mini-endoscopic combined intrarenal surgery to treat renal and/or ureteral stones between January 2016 and April 2020 were collected. We compared the outcomes between ultrasonography-guided mini-endoscopic combined intrarenal surgery with and without ureteroscopy-assisted puncture (ureteroscopy-assisted puncture(+) group [n = 126] and ureteroscopy-assisted puncture(-) group [n = 187] group, respectively). The primary outcome was requirement for additional surgical intervention. Secondary outcomes were stone-free rate, complications and total procedure, fluoroscopy, hospital stay, and postoperative ureteral stent placement durations.

RESULTS

The ureteroscopy-assisted puncture(+) group had a lower additional surgical intervention rate and a higher stone-free rate immediately after and 3 months after surgery than the ureteroscopy-assisted puncture(-) group (5.6% vs 19.7%, P < 0.001; 82.5% vs 65.8%, P = 0.001; 59.5% vs 44.6%, P = 0.011). The median total procedure, fluoroscopy, and postoperative ureteral stent placement durations were 18 min, 3 min, and 5 days shorter, respectively, in the ureteroscopy-assisted puncture(+) group. Multivariate analyses showed that ureteroscopy-assisted puncture was associated with a decreased risk of additional surgical intervention (odds ratio 0.31, P = 0.011) and postoperative infection (odds ratio 0.34, P = 0.003) and decreased total procedure (estimate = -11 min; P = 0.011), fluoroscopy (estimate = -3 min; P = 0.034), and postoperative ureteral stent placement (estimate = -8 days; P = 0.011) durations. Female patients and those with smaller stone volumes or without hydronephrosis were identified as ideal ureteroscopy-assisted puncture candidates.

CONCLUSIONS

Ureteroscopy-assisted puncture during mini-endoscopic combined intrarenal surgery could provide favorable surgical outcomes, especially in female patients without collecting system obstruction.

Laparoscopic ureterolithotomy for large proximal ureteric stones: Surgical technique, outcomes and literature review

INTRODUCTION

We evaluated the efficacy and safety of laparoscopic ureterolithotomy (LPU) for the treatment of large proximal ureteric stone.

METHODS

A retrospective multicenter analysis for patients with solitary impacted proximal ureteric stone ≥15 mm who underwent LPU from 2016 to 2019 was performed. Primary outcome was to estimate the stone-free rate (SFR). SFR was defined as absence of residual stones on postoperative computed tomography scan. Secondary outcome was to assess the perioperative outcomes, as well as to review literature data of randomized controlled trials and meta-analyses comparing LPU to other treatment options.

RESULTS

Forty-four patients were included in our study. Mean stone size was 22.9 ± 5.8 mm and median follow-up was 14 months. Three patients had previous abdominal surgery, one patient had severe degree of scoliosis and six patients failed primary therapy. All stones were extracted successfully (SFR = 100%) without need of auxiliary treatments. Mean operative time and estimated blood loss were 86.6 ± 14.1 minutes. and 11.9 ± 14.7 mL, respectively. No intraoperative complications or conversion to open surgery were reported. No major postoperative complications (≥grade 3) were reported. Mean length of hospital stay was 2 ± 0.8 days.

CONCLUSIONS

For treatment of large ureteric stones, our study showed that LPU achieves 100% stone-free status. When performed by well-trained laparoscopic surgeons, it is safe and has no major perioperative complications. According to our results and literature data, when counseling patients with large impacted proximal ureteral stones, LPU should be advised as the procedure that has the higher SFR, lower auxiliary treatments, and comparable complication rates to other treatments.

The Long-Term Follow-Up of Patients with Cystine Stones: A Single-Center Experience for 13 Years

Introduction: Cystine stone development is relatively uncommon among patients with urolithiasis, and most studies have reported only on small sample sizes and short follow-up periods. We evaluated clinical courses and treatment outcomes of patients with cystine stones with long-term follow-up at our center. Methods: We retrospectively analyzed 22 patients diagnosed with cystine stones between January 1989 and May 2019. Results: The median follow-up was 160 (range 6–340) months, and the median patient age at diagnosis was 46 (range 12–82) years. All patients underwent surgical interventions at the first visit (4 extracorporeal shockwave lithotripsy, 5 ureteroscopy, and 13 percutaneous nephrolithotripsy). The median number of stone events and surgical interventions per year was 0.45 (range 0–2.6) and 0.19 (range 0–1.3) after initial surgical intervention. The median time to stone events and surgical intervention was 2 years and 3.25 years, respectively. There was a significant difference in time to stone events and second surgical intervention when patients were divided at 50 years of age at diagnosis (p = 0.02, 0.04, respectively). Conclusions: Only age at a diagnosis under 50 was significantly associated with recurrent stone events and intervention. Adequate follow-up and treatment are needed to manage patients with cystine stones safely.

Nomograms predicting the outcomes of endoscopic treatments for pediatric upper urinary tract calculi

OBJECTIVES

To demonstrate the efficacy and safety of mini-percutaneous nephrolithotomy, micro-percutaneous nephrolithotomy, and flexible ureteroscopy for pediatric upper urinary tract calculi and to develop nomograms predicting surgical outcomes.

METHODS

A prospectively managed database containing children who were diagnosed with upper urinary tract calculi and treated with mini-percutaneous nephrolithotomy, micro-percutaneous nephrolithotomy, and flexible ureteroscopy between June 2014 and April 2019 was analysed. Patient demographics, intraoperative data, stone characteristics, stone-free rate, and complication rate were analysed and compared. Nomograms predicting the postoperative stone-free rate and complication rate were established based on predictors, and internal validation was performed. Calibration curves and decision curves were generated to assess the predictive efficacy and clinical benefit.

RESULTS

Forty-three children underwent mini-percutaneous nephrolithotomy on 56 sides in 47 operations, 30 children underwent micro-percutaneous nephrolithotomy on 30 sides in 30 operations, and 275 children underwent flexible ureteroscopy on 320 sides in 288 operations. The stone-free rates were 88.5% (282/320) for flexible ureteroscopy, 89.3% (50/56) for mini-percutaneous nephrolithotomy, and 90.0% (27/30) for micro-percutaneous nephrolithotomy (P = 0.94). And the complication rates were 19.8% (57/288), 36.2% (17/47), and 33.3% (10/30), respectively (P = 0.02). Nomograms based on stone characteristics, operation duration, and the physical condition of the child were shown to have good discrimination and calibration. The area under the curve of the models was 81% for stone-free rate and 73% for complication rate. The calibration curves showed that the nomogram might underestimate the probability of stone-free rate when the threshold was below 82% and might overestimate the risk of complication rate when the threshold was over 25%. The decision curves demonstrated that the Capital Medical University nomograms improved clinical risk prediction against threshold probabilities of stone-free rate ≤20% and complication rate ≤10%.

CONCLUSIONS

Both the percutaneous nephrolithotomy and flexible ureteroscopy procedures could have acceptable stone-free rates when treating pediatric stones. The Capital Medical University nomograms performed well in helping to predict stone-free and complication rates.

Comparison of antegrade and retrograde ureterolithotripsy for proximal ureteral stones: a systematic review and meta-analysis

Background

Antegrade percutaneous ureterolithotripsy (URSL) could be a treatment option for large and/or impacted proximal ureteral stones, which are difficult to treat. To review the current approach and treatment outcomes and to compare the efficacy of retrograde and antegrade URSL for large proximal ureteral stones, we evaluated the unique perspectives of both surgical modalities.

Methods

This systematic literature review and meta-analysis was performed in July 2020. Articles on human studies and treatment of ureteral stones with URSL were extracted from the PubMed, MEDLINE, Embase, Cochrane Library, Scopus, and the Japan Medical Abstracts Society databases without any language restrictions. The risks of bias for randomized controlled trials (RCTs) and non-randomized controlled trials (non-RCTs) were assessed using the Cochrane risk of tool and the Risk of Bias in Non-randomized Studies- of Interventions tool, respectively.

Results

A total of 10 studies, including seven RCTs and three non-RCTs, were selected for the analysis; 433 and 420 cases underwent retrograde and antegrade URSL, respectively. The stone-free rate (SFR) was significantly higher in antegrade URSL than in retrograde URSL (SFR ratio: 1.17, 95% CI: 1.12-1.22; P<0.001), while the hospital stay was significantly longer in antegrade URSL than in retrograde URSL (standardized mean difference: 2.56, 95% CI: 0.67-4.46; P=0.008). There were no significant differences in the operation time and the overall complication rate between the two approaches.

Conclusions

Despite the heterogeneity of data and bias limitations, this latest evidence reflects real practice data, which may be useful for decision making.

Endoscopic lithotripsy with a SuperPulsed thulium-fiber laser for ureteral stones: A single-center experience

OBJECTIVES

To estimate the efficacy and safety of SuperPulsed thulium-fiber laser ureteral lithotripsy and to identify optimal laser settings.

METHODS

Patients with solitary stones were prospectively included. Lithotripsy was performed with a SuperPulsed thulium-fiber laser (NTO IRE-Polus, Fryazino, Russia) using a rigid ureteroscope 7.5 Ch (Richard Wolf, Knittlingen, Germany). We analyzed the efficacy of lithotripsy by measuring total energy required for stone disintegration, "laser-on" time, ablation speed, ablation efficacy, and energy consumption. Stone retropulsion and visibility were assessed using a three-point Likert scale. Complications were assessed using the Clavien-Dindo classification system.

RESULTS

A total of 149 patients were included. The mean stone density was 985 ± 360 Hounsfield units, the median (interquartile range) stone volume was 179 (94-357) mm3 . The median (interquartile range) total energy was 1 (0.4-2) kJ, and laser-on time 1.2 (0.5-2.7) min. The median (interquartile range) stone ablation speed was 140 (80-279) mm3 /min, energy for ablation of 1 mm3 was 5.6 (3-9.9) J/mm3 and energy consumption was 0.9 (0.6-1) J/min. A correlation was found between retropulsion and the energy used (r = 0.5, P < 0.001). Multivariable analysis showed energy to be a predictor of increased retropulsion (odds ratio 65.7, 95% confidence interval 1.6-2774.1; P = 0.028). No predictors for worse visibility were identified.

CONCLUSION

The SuperPulsed thulium-fiber laser provides effective and safe lithotripsy during ureteroscopy regardless of stone density. Fiber diameter and laser frequency do not influence visibility or safety. Optimal laser settings are 0.5 J × 30 Hz for fragmentation and 0.15 J × 100 Hz for dusting.

Prospective Randomized Controlled Trial to Evaluate the Effectiveness of Watching Movies to Decrease Anxiety During Extracorporeal Shock Wave Lithotripsy

Background

Extracorporeal shock wave lithotripsy (ESWL) is the only non-invasive treatment for urolithiasis; however, it can cause anxiety and pain for patients. Several new nonpharmacological adjuvant approaches have been developed to reduce adverse events.

Objective

To analyze the efficacy of watching movies during ESWL to relieve anxiety and pain.

Methods

A total of 84 patients were randomly divided into two groups. The experimental group consisted of 42 patients who watched their own selected movies during the ESWL session, while the control group included 42 patients who did not watch movies. Basic characteristics, hemodynamic parameters, State-Trait Anxiety Inventory, Visual Analog Scale for pain, willingness to repeat the procedure, and patient satisfaction rates were collected and analyzed.

Results

After watching movies during ESWL, patients had a significantly lower anxiety level (p = 0.001) and a higher satisfaction rate (p = 0.021). No statistically significant differences were found in terms of demographic data, hemodynamic parameters, pain scores, or willingness to repeat the procedure.

Conclusion

Watching self-selected movies during an ESWL can effectively reduce anxiety and improve satisfaction.

A high basal metabolic rate is an independent predictor of stone recurrence in obese patients

Purpose

Basal metabolic rate (BMR) is an indicator of overall body metabolism and may portend unique aberrations in urine physico-chemistry and stone recurrence. The present study examined the effect of predicted BMR on 24 hours urinary metabolic profiles and stone recurrence in obese stone patients.

Materials and Methods

Data from 308 obese patients (body mass index [BMI] ≥30 kg/m²) diagnosed with urinary stone disease between 2003 and 2015 were analyzed retrospectively. BMR was calculated using the Harris–Benedict equation, and patients were classified into two predicted BMR categories (<1,145 kcal/day, ≥1,145 kcal/day). Urinary metabolic parameters and risk of stone recurrence were compared between the two groups.

Results

The high BMR group was more likely to be younger and female, and to have a high BMI and lower incidence of diabetes than the low BMR group (each p<0.05). There was a positive correlation between BMR and 24 hours urinary sodium, uric acid, and phosphate excretion. The amounts of stone-forming constituents such as calcium and uric acid were significantly higher in the high BMR group. Kaplan–Meier estimates showed that the high BMR group had a significantly shorter stone recurrence-free period than the low BMR group (log-rank test, p<0.001). Multivariate Cox regression analyses revealed that predicted BMR was an independent factor of stone recurrence (hazard ratio, 2.759; 95% confidence interval, 1.413–5.386; p=0.003).

Conclusions

BMR may be an easily measured parameter that can be used to identify risk of stone recurrence in obese stone patients.

The First Case Report of Robot-Assisted Fluoroscopy-Guided Renal Access During Endoscopic Combined Intrarenal Surgery

Background: During percutaneous nephrolithotomy (PCNL) and endoscopic combined intrarenal surgery (ECIRS), obtaining renal access is the most critical step to achieving effective treatment without major intraoperative complications. Among a variety of methods attempted to improve the access, robot-assisted fluoroscopy-guided (RAFG) renal access has been introduced to mitigate technical human errors and overcome challenging learning curves. In this study, we present our first experience with an automated needle targeting with an X-ray (ANT-X) device for minimally invasive (mini-) ECIRS. Case Presentation: A 75-year-old healthy woman with a 6.0 cm³ left kidney stone was referred to our hospital for surgical treatment. The patient underwent mini-ECIRS utilizing RAFG renal access without complication, and the stone was completely removed. The ureteral stent and transurethral catheter were removed on postoperative day 2, and the patient was discharged on postoperative day 3. There were no residual fragments detected by CT as of 3 months after the surgery. Conclusion: To our knowledge, this is the first report of the effective use of RAFG mini-ECIRS for a kidney stone. The overall outcome was positive, indicating the feasibility of ANT-X use for PCNL and ECIRS.

Low bone mineral density is a potential risk factor for symptom onset and related with hypocitraturia in urolithiasis patients: a single-center retrospective cohort study

Background

Patients with urolithiasis have a lower bone mineral density (BMD) than those without stones, suggesting a potential correlation between calcium stone formation and bone resorption disorders, including osteopenia and osteoporosis.

Methods

To investigate the influence of BMD on clinical outcomes in urolithiasis, we performed a single-center retrospective cohort study to analyze patients with urolithiasis who underwent both BMD examination and 24-h urine collection between 2006 and 2015. Data from the national cross-sectional surveillance of the Japanese Society on Urolithiasis Research in 2015 were utilized, and additional data related to urinary tract stones were obtained from medical records. The primary outcome was the development of stone-related symptoms and recurrences during follow-up. A total of 370 patients were included in this 10-year study period.

Results

Half of the patients had recurrent stones, and the two-thirds were symptomatic stone formers. While only 9% of patients had hypercalciuria, 27% and 55% had hyperoxaluria and hypocitraturia, respectively. There was a positive correlation between T-scores and urinary citrate excretion. Both univariate and multivariate analyses demonstrated that female sex was associated with recurrences (odds ratio = 0.44, p = 0.007), whereas a T-score < − 2.5 and hyperoxaluria were associated with symptoms (odds ratio = 2.59, p = 0.037; odds ratio = 0.45, p = 0.01; respectively).

Conclusion

These results revealed that low T-scores might cause symptoms in patients with urolithiasis, suggesting the importance of BMD examination for high-risk Japanese patients with urolithiasis having hypocitraturia.

Pre-operative Percutaneous Nephrolithotripsy Characterisation of Kidney Stones with Second-Generation Dual-Source Dual-Energy Computed Tomography

Background: The current clinical practice to manage kidney stone requires knowledge of the stone composition. However, it is often difficult to determine the actual stone composition before a stone is operatively removed from the patient. Dual-energy computed tomography (DECT) can predict urinary stone composition, but it is not widely adopted. The purpose of the study was to investigate the use of a second-generation DECT with tin or stannum (Sn) filter for characterising the kidney stones composition. Methods: Thirty-three kidney stones were scanned ex vivo using a dual-source (DS)DECT scanner with dual-energy (DE) mode of 80/140 kVp with and without 4 mm Sn filtration. DE ratio was calculated to determine the kidney stones composition (uric acid, calcium oxalate, calcium phosphate and cystine). The median DE ratio of the stones was compared using Wilcoxon signed rank test and the results were further correlated with semi-quantitative Fourier transform infrared (FTIR) spectroscopy analysis using Kendall’s Tau test with P < 0.05 deemed to be statistically significant. Results: Second-generation DS-DECT could significantly discriminate the stones composition with and without Sn filtration (P < 0.001). The median DE ratio of uric acid, calcium oxalate and cystine stones were significantly higher with Sn filtration than those without filtration (P < 0.05). DECT results revealed significant correlation with FTIR spectroscopy analysis (r = 0.716, P < 0.001). DECT with Sn filtration showed increased performance (100% sensitivity, 0% specificity) than those without filtration (48.5% sensitivity, 0% specificity) in the detection of the kidney stone subtypes. Conclusion: In the second-generation DECT with additional Sn filtration, DECT has shown a significant performance in characterising and discriminating the kidney stone composition. This may improve diagnostic and therapy management in kidney stones cases.

Urine and stone analysis for the investigation of the renal stone former: a consensus conference

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.

Signal Feature Analysis of Contact Force at the Tip of a Flexible Ureteroscope

This paper presents a signal analysis approach to identify the contact objects at the tip of a flexible ureteroscope. First, a miniature triaxial fiber optic sensor based on Fiber Bragg Grating(FBG) is devised to measure the interactive force signals at the ureteroscope tip. Due to the multidimensional properties of these force signals, the principal components analysis(PCA) method is introduced to reduce dimensions. The signal features are then extracted from the representative principal component signals using the wavelet transform(WT) method. Experimental results show that the contact objects at the tip of a ureteroscope are readily discriminated from the measured force signals with the proposed approach.Clinical Relevance-This work commits to analyze the contact force signals at the tip of a flexible ureteroscope for the purpose of contact objects identification.

Diet and Kidney Stones: The Ideal Questionnaire

Diet frequently contributes to patients' urinary stone disease. It is important to determine when this is the case and when it is not, as failure to do so may delay the implementation of other, more appropriate therapies. When diet is thought to be involved, one of two approaches may be taken: (1) provide a general list of all possible dietary factors that influence the risk for all types of stones and let the patient decide which dietary change(s) are needed; or (2) prescribe specific modifications that address each patient's need for change and their personal characteristics (i.e., urinary risk factors, type(s) of stones they have formed, dietary preferences, nutrient needs, etc.). The latter of these approaches is "minimally invasive" and is thus consistent with the goal of other therapies. However, this approach requires a rigorous appraisement of each patient's diet and linkage, when possible, to urinary and other stone risk factors. When the collaboration of a registered dietitian nutritionist or other nutrition professional experienced in dietary assessment is not available, screeners or questionnaires may be useful. Unfortunately, there is no such tool that is validated for identifying dietary stone risk factors. The development of a brief, 40-item, stone-specific food screener is described. While further validation is needed, it may provide the basis for a standardized instrument that could be used more broadly; desired features of such an instrument are described. Patient Summary: Personalized nutrition therapy is useful in mitigating the effects or recurrence risk of many chronic diseases. It is also useful in stone disease, a condition with highly variable risk expression, even among patients who form the same types of stones. A standardized and validated stone-specific dietary assessment tool would be valuable in clinical management and in research studies involving the description of patients' diets and dietary intervention.

Statins significantly alter urinary stone-related urine biochemistry in calcium kidney stone patients with dyslipidemia

OBJECTIVE

To investigate whether the use of statins would alter 24-h urine biochemistry in male patients with calcium kidney stones.

METHODS

We prospectively recruited 78 male patients with calcium kidney stones between May 2017 and December 2017, and 30 male controls with matching sex and age, but without kidney stones. All patients were classified into higher- and lower-risk groups of atherosclerotic cardiovascular disease according to the American College of Cardiology/American Heart Association guidelines. Atorvastatin 20 mg per day was prescribed for 12 weeks to the higher risk patients. For kidney stone group, 24-h urine collections were carried out before and after statin therapy.

RESULTS

A total of 78 patients and 30 controls were included. Higher-risk patients had significantly higher urine uric acid and calcium levels than lower-risk patients. After atorvastatin treatment for 12 weeks, urine citrate significantly increased (P < 0.001) accompanied with increased urine pH (P < 0.001), whereas urine uric acid significantly decreased after treatment. Although urine oxalate significantly increased after treatment (P = 0.037), we did not find any significant difference in urine calcium, ion activity product of calcium oxalate and ion activity product of calcium phosphate.

CONCLUSION

These findings suggest that atorvastatin administration might increase urinary citrate and decrease urinary uric acid in patients with calcium kidney stones and dyslipidemia.

Surgical Management of Urolithiasis of the Upper Tract - Current Trend of Endourology in Africa

Urolithiasis is a global pathology with increasing prevalence rate. The lifetime recurrence of urolithiasis ranges from 10–75% creating a public health crisis in affected regions. The epidemiology of urolithiasis in most parts of Africa and Asia remains poorly documented as incidence and prevalence rates in these settings are extrapolated from hospital admissions. The surgical management of kidney and ureteral stones is based on the stone location, size, the patient’s preference and the institutional capacity. To date, the available modalities in the management of urolithiasis includes external shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL), ureterorenoscopy (URS) including flexible and semirigid ureteroscopy. However, regarding the lack of endourological equipment and expertise in most parts of Sub-Saharan Africa (SSA), most urological centers in these regions still consider open surgery for kidney and ureteral stones. This review explores the current trend and surgical management of upper tract urolithiasis in SSA with insight on the available clinical guidelines.

Formation of a calcium oxalate urethral stone in a 3-year-old boy due to hypocitraturia

INTRODUCTION

Urolithiasis in children is often due to metabolic abnormalities (e.g. hypocitraturia) and hence recurs frequently.

CASE PRESENTATION

A 3-year-old boy presented with gross hematuria. Computed tomography detected a urethral calculus. The calculus was removed surgically. The stone was composed of calcium oxalate. Although oxalate and uric acid levels in the urine were within normal ranges, urine calcium was moderately elevated and urine citrate was substantially low. Urinalyses of the parents revealed that the father had acidic hypocitraturic urine, containing oxalate crystals, and the mother had hypercalciuria. Administration of oral citrate acid normalized urine citrate levels and eliminated the oxalate crystals, from the boy and his father.

CONCLUSION

Although preventing urolithiasis using oral citrate is common in the adult population, this preventive measure is not well recognized in children, thus warranting further study.