Epidemiology of stone disease across the world

Role of Dual-Energy Computed Tomography in Characterization of Ureteric Calculi and Urinary Obstruction

Objective The present study was carried out to assess the accuracy of dual-energy computed tomography (DECT) in the morphological and chemical characterization of ureteric calculi along with the prediction of the grade of urinary obstruction. Methods This was a prospective observational study that included 100 cases with ultrasonography (USG)-diagnosed ureteric calculi that underwent surgery or had spontaneous expulsion of ureteric calculi. At enrolment, DECT was performed for an in vivo evaluation of volume, chemical composition, and grade of obstruction by subjective assessment of the perinephric edema. After surgical intervention, in vitro evaluation of volume was done by fluid displacement followed by infrared spectroscopy (IRS) for chemical composition. DECT findings were compared with the biochemical analysis and degree of obstruction was validated against excretory CT urograms. Sensitivity, specificity, and the positive predictive and negative predictive values of DECT were assessed. Results No significant difference was observed between the mean volume of stones by fluid displacement (65.1±77.61 mm³) and DECT assessment (66.09±81.78 mm³). IRS revealed the composition of stones as hydroxyapatite, uric acid, cysteine, oxalic acid, and mixed type in 48, 23, 15, five, and nine cases. The sensitivity and specificity of DECT for hydroxyapatite, uric acid, cysteine, oxalic acid, and mixed types were 89.6% and 88.5%, 82.6% and 97.5%, 86.7% and 96.5%, 80% and 98.9%, and 88.9% and 98.9%, respectively. On CT urography, a total of 35 had a high-grade and 65 had a low-grade obstruction, whereas DECT revealed high- and low-grade obstructions in 42 and 58 cases. The sensitivity and specificity of DECT for a high-grade obstruction were 94.3% and 86.2%. Conclusions The findings of the study showed that DECT provides comprehensive information regarding the morphological, chemical, and anatomical characterization of ureteric stones.

Composition of urinary calculi: Lessons from a French epidemiologic retrospective study

INTRODUCTION

Urolithiasis is a common urological disease whose incidence increases in developed countries. We studied relations between composition of urinary calculi, age and gender.

MATERIAL

An epidemiologic study was conducted in a French population of patients encountered analysis of urinary calculi between 2013 and 2017. This retrospective cohort study was performed from urinary calculi samples analysed in a clinical biochemistry laboratory of University Hospital of Lyon in France. A total of 5782 samples were included. Data, according to stone composition, presence of a papillary umbilication and a Randall's plaque, age and gender, were investigated. Statistical analyses used the Chi² test (R software).

RESULTS

The overall male to female sex ratio was equal to 1.76. The average and the median of age were 52.1 and 53.0 years, respectively. Whewellite was the most frequent main component in our population (44.4%). Carbapatite, weddellite and uric acid represented the main component in 14.0%, 13.4% and 13.0% of samples, respectively. Differences between genders were shown. Whewellite and uric acid were more frequent in men (P<0.001), while carbapatite and struvite were predominant in women (P<0.001).

CONCLUSIONS

Our study provided recent data on the composition of urinary calculi in a French population and the relations between composition of urinary calculi and age and gender.

LEVEL OF EVIDENCE

3.

Supine versus prone position in percutaneous nephrolithotomy: a systematic review and meta-analysis

Background: The decision for using supine or prone position in percutaneous nephrolithotomy (PCNL) is still debatable. The aim of this study is to compare the efficacy and safety profile of the supine and prone position when performing PCNL. Methods: A systematic electronic search was performed using the database from MEDLINE, Cochrane library and Google Scholar from January 2009 to November 2019. The outcomes assessed were stone free rate, major complication rate, length of hospital stay and mean operation time. Results: A total of 11 articles were included in qualitative and quantitative analysis. The efficacy of PCNL in supine position as determined by stone free rate is significantly lower than in prone position (OR: 0.74; 95% CI: 0.66 - 0.83; p<0.00001), However, major complication rate is also lower in the supine group compared with the prone group (OR: 0.70; 95% CI: 0.51 - 0.96; p=0.03). There is no statistically significant difference in the length of hospital stay and mean operation time between both groups. Conclusion: Prone position leads to a higher stone free rate, but also a higher rate of major complication. Thus, the decision of using which position during PCNL should be based on the surgeon's experience and clinical aspects of the patients.

Supine versus prone position in percutaneous nephrolithotomy: a systematic review and meta-analysis

Background: The decision for using supine or prone position in percutaneous nephrolithotomy (PCNL) is still debatable. The aim of this study is to compare the efficacy and safety profile of the supine and prone position when performing PCNL. Methods: A systematic electronic search was performed using the database from MEDLINE, Cochrane library and Google Scholar from January 2009 to November 2019. The outcomes assessed were stone free rate, major complication rate, length of hospital stay and mean operation time. Results: A total of 11 articles were included in qualitative and quantitative analysis. The efficacy of PCNL in supine position as determined by stone free rate is significantly lower than in prone position (OR: 0.74; 95% CI: 0.66 - 0.83; p<0.00001), However, major complication rate is also lower in the supine group compared with the prone group (OR: 0.70; 95% CI: 0.51 - 0.96; p=0.03). There is no statistically significant difference in the length of hospital stay and mean operation time between both groups. Conclusion: Prone position leads to a higher stone free rate, but also a higher rate of major complication. Thus, the decision of using which position during PCNL should be based on the surgeon's experience and clinical aspects of the patients.

Supine versus prone position in percutaneous nephrolithotomy: a systematic review and meta-analysis

Background: The decision for using supine or prone position in percutaneous nephrolithotomy (PCNL) is still debatable. The aim of this study is to compare the efficacy and safety profile of the supine and prone position when performing PCNL. Methods: A systematic electronic search was performed using the database from MEDLINE, Cochrane library and Google Scholar from January 2009 to November 2019. The outcomes assessed were stone free rate, major complication rate, length of hospital stay and mean operation time. Results: A total of 11 articles were included in qualitative and quantitative analysis. The efficacy of PCNL in supine position as determined by stone free rate is significantly lower than in prone position (OR: 0.74; 95% CI: 0.66 - 0.83; p<0.00001), However, major complication rate is also lower in the supine group compared with the prone group (OR: 0.70; 95% CI: 0.51 - 0.96; p=0.03). There is no statistically significant difference in the length of hospital stay and mean operation time between both groups. Conclusion: Prone position leads to a higher stone free rate, but also a higher rate of major complication. Thus, the decision of using which position during PCNL should be based on the surgeon's experience and clinical aspects of the patients.

Evaluation of a child with suspected nephrolithiasis

PURPOSE OF REVIEW

As the incidence of nephrolithiasis in children doubles every 10 years it is becoming a common disease associated with significant morbidity along with considerable economic burden worldwide. The aim of this review is to summarize current data on the epidemiology and causes of renal stones in children and to provide a frame for the first clinical evaluation of a child with suspected nephrolithiasis.

RECENT FINDINGS

Dietary and environmental factors are the driving force of changing epidemiology. Diagnosis should be based on medical history, presenting signs, examination, first laboratory and radiological workup. Ultrasound should be the initial diagnostic imaging performed in pediatric patients while low-dose computed tomography is rarely necessary for management. Metabolic factors including hypercalciuria, hypocitraturia, low fluid intake as well as specific genetic diseases should be explored after the resolution of initial signs and symptoms.

SUMMARY

Appropriate initial evaluation, imaging technique, identification of risk factors and other abnormalities are essential for early diagnosis and prevention of stone-related morbidity in children with suspected nephrolithiasis.

Nephrocalcinosis, Renal Dysfunction, and Calculi in Patients With Primary Hypoparathyroidism on Long-Term Conventional Therapy

CONTEXT

There are concerns about the long-term safety of conventional therapy on renal health in patients with hypoparathyroidism. Careful audit of these would help comparisons with upcoming parathyroid hormone therapy.

OBJECTIVE

We investigated nephrocalcinosis, renal dysfunction, and calculi, their predictors and progression over long-term follow-up in patients with primary hypoparathyroidism (PH).

DESIGN AND SETTING

An observational study at a tertiary care center was conducted.

PARTICIPANTS AND METHODS

A total of 165 PH patients receiving conventional therapy were evaluated by radiographs, ultrasonography, and computed tomography. Their glomerular filtration rate (GFR) was measured by Tc-99m-diethylenetriamine penta-acetic acid clearance. Clinical characteristics, serum total calcium, phosphorus, creatinine, hypercalciuria, and fractional excretion of phosphorus (FEPh) at presentation and during follow-up were analyzed as possible predictors of renal complications. Controls were 165 apparently healthy individuals.

RESULTS

Nephrocalcinosis was present in 6.7% of PH patients but not in controls. Patients younger than 15 years at presentation and with higher serum calcium-phosphorus product were at higher risk. Nephrocalcinosis showed no significant association with cataract and intracranial calcification. Prevalence of renal calculi was comparable between hypoparathyroid patients and controls (5% vs 3.6%, P = .58). Fourteen percent of patients had a GFR less than 60 mL/min/1.73 m2. Increased FEPh during follow-up was the significant predictor of low GFR. Nephrocalcinosis developed in 9% of patients over 10 years of conventional therapy.

CONCLUSION

A total of 6.7% of PH patients had nephrocalcinosis, and 14% showed renal dysfunction. Prevalence of renal calculi was similar in patients and controls. Nine percent of patients developed nephrocalcinosis over 10 years of conventional therapy.

Preventing CKD in Developed Countries

Chronic kidney disease (CKD) is an important public health concern in developed countries because of both the number of people affected and the high cost of care when prevention strategies are not effectively implemented. Prevention should start at the governance level with the institution of multisectoral polices supporting sustainable development goals and ensuring safe and healthy environments. Primordial prevention of CKD can be achieved through implementation of measures to ensure healthy fetal (kidney) development. Public health strategies to prevent diabetes, hypertension, and obesity as risk factors for CKD are important. These approaches are cost-effective and reduce the overall noncommunicable disease burden. Strategies to prevent nontraditional CKD risk factors, including nephrotoxin exposure, kidney stones, infections, environmental exposures, and acute kidney injury (AKI), need to be tailored to local needs and epidemiology. Early diagnosis and treatment of CKD risk factors such as diabetes, obesity, and hypertension are key for primary prevention of CKD. CKD tends to occur more frequently and to progress more rapidly among indigenous, minority, and socioeconomically disadvantaged populations. Special attention is required to meet the CKD prevention needs of these populations. Effective secondary prevention of CKD relies on screening of individuals at risk to detect and treat CKD early, using established and emerging strategies. Within high-income countries, barriers to accessing effective CKD therapies must be recognized, and public health strategies must be developed to overcome these obstacles, including training and support at the primary care level to identify individuals at risk of CKD, and appropriately implement clinical practice guidelines.

Metabolic evaluation in urolithiasis - study of the prevalence of metabolic abnormalities in a tertiary centre

Introduction

Metabolic abnormalities are one of the most important risk factors for urinary stone disease. Our objective was to determine the prevalence of metabolic abnormalities in patients referred to the urolithiasis outpatient clinic of a tertiary centre.

Material and methods

We performed a cross-sectional study evaluating 67 patients referred to the urolithiasis outpatient clinic. Metabolic evaluation was performed, including one 24-hour urine sample.

Results

Metabolic abnormalities could be identified in 92.5% patients. Almost a quarter of the patients had only one metabolic abnormality and 67.6% had more than one abnormality. The most prevalent metabolic abnormalities were hypercalciuria (54.5%), hyperoxaluria (34.7%) and hyperuricosuria (32.3%). Patients with hypercalciuria were older (54.7 vs. 47.8 years, p = 0.018) and family history of stone disease was significantly more frequent among patients with hyperoxaluria (71.4% vs. 28.6%, p = 0.013). There was a positive linear relationship between body mass index (BMI) and urinary calcium (r = 0.247, p = 0.048) and a negative linear relationship between BMI and urinary pH (r = −0.254, p = 0.046).

Conclusions

Given the high prevalence of metabolic abnormalities, metabolic evaluation should be performed in every patient with urolithiasis evaluated in a tertiary setting.

Atorvastatin inhibits renal inflammatory response induced by calcium oxalate crystals via inhibiting the activation of TLR4/NF-κB and NLRP3 inflammasome

This study aimed to investigate the renal protective effect of atorvastatin (ATV) on the kidney inflammation induced by calcium oxalate (CaOx) crystals. A cell model of cell-crystal interactions and a rat model of CaOx kidney stone were established. The expressions of TLR4, NF-κB, NLRP3, and cleaved caspase-1 in cells and rat kidney tissues were detected using Western blot, immunohistochemical, and/or immunofluorescence. The concentrations of malondialdehyde (MDA), superoxide dismutase (SOD), reactive oxygen species (ROS) in cells, and lactic acid dehydrogenase (LDH) in the culture medium were measured. The secreted levels of interleukin (IL)-1β, IL-18, IL-6, and tumor necrosis factor-α (TNF-α) were examined by ELISA. The serum levels of creatinine (CRE) and blood urea nitrogen (BUN) were measured. von Kossa staining was used for the evaluation of renal lens deposition. The CaOx model group showed significantly decreased SOD level; increased concentrations of MDA; ROS and LDH; elevated expressions of TLR4, NF-κB, NLRP3, and cleaved caspase-1; and the elevated release of IL-1β, IL-18, IL-6, and TNF- α as compared to the control group. The treatment with ATV significantly inhibited the formation of CaOx kidney stone by increasing the level of SOD; downregulating MDA, ROS, and LDH; inhibiting the expressions of TLR4, NF-κB, NLRP3 and cleaved caspase-1; and blocking the secretion of inflammatory cytokines. In addition, the serum levels of CRE and BUN, and the intrarenal crystal deposition were also significantly decreased in ATV-treated rats. In summary, oxidative stress, TLR4/NF-κB, and NLRP3 inflammasome pathways are involved in renal inflammatory responses induced by CaOx crystals. ATV treatment significantly suppressed oxidative stress, inhibited the activation of TLR4/NF-κB and NLRP3 inflammasome pathways, and decreased the release of inflammatory mediators, thereby ameliorating CaOx crystal-induced damage and crystal deposition in HK-2 cells and rat kidney tissues.

Kidney Stone History and Adverse Outcomes After Percutaneous Coronary Intervention

OBJECTIVE

To determine whether kidney stone history is associated with adverse outcomes after percutaneous coronary intervention (PCI). Kidney stone formers have an increased risk of developing coronary artery disease; however, whether these patients have worse cardiac outcomes is unknown.

MATERIALS AND METHODS

We identified adult patients who underwent first-time PCI in Vanderbilt University Medical Center (VUMC) Synthetic Derivative from 2008 to 2016 (n = 11,289) and in a nationwide database of Taiwan (NHIRD) from 2005 to 2012 (n = 155,762). Odds ratios (ORs) of 30-day in-hospital mortality and hazard ratios (HRs) of 1-year and 3-year adverse outcomes associated with kidney stone history were estimated using a propensity score approach.

RESULTS

Overall, 294 and 12,286 stone formers undergoing PCI were identified in the VUMC and NHIRD, respectively. After matching, stone formers at VUMC were at higher risks of 30-day in-hospital mortality (OR 2.79, 95% CI 1.15-6.69) and 1-year (HR 1.59, 95% CI 1.13-2.24) and 3-year (HR 1.36, 95% CI 1.02-1.81) myocardial infarction. In the NHIRD, kidney stone history was associated with 1-year (HR 1.12, 95% CI 1.03-1.21) and 3-year (HR 1.14, 95% CI 1.06-1.22) myocardial infarction. In a sensitivity analysis, stone formers undergoing kidney stone surgery were marginally associated with 30-day in-hospital mortality (OR 1.21, 95% CI 0.99-1.48) and were associated with 3-year myocardial infarction (HR 1.13, 95% CI 1.02-1.25).

CONCLUSION

Kidney stone history is associated with poorer cardiac outcomes after PCI. Improving secondary cardiac prevention strategies after PCI may be necessary for patients with a history of kidney stone disease.

The rs1256328 (ALPL) and rs12654812 (RGS14) Polymorphisms are Associated with Susceptibility to Calcium Nephrolithiasis in a Taiwanese population

Nephrolithiasis is a common disease affecting almost all populations, with an increasing prevalence over the past decades. Previous studies revealed several functional polymorphisms associated with the pathogenesis of nephrolithiasis. However, data on Asian populations are limited. In this study, three candidate polymorphisms were selected from previous studies to investigate the correlations with nephrolithiasis in a Taiwanese population. In total, 454 nephrolithiasis patients were recruited from Kaohsiung Medical University Hospital, with SNP frequency for 1513 subjects of general population from the Taiwan Biobank (TWB) as a genotypic reference. Results revealed that subjects with minor TT genotype at rs1256328 (alkaline phosphatase, liver/bone/kidney (ALPL)) have higher susceptibility to nephrolithiasis (odds ratio (OR) = 2.03, p = 0.0013). In addition, subjects carrying the minor AA genotype at rs12654812 (regulator of G protein signaling 14 (RGS14)) have higher susceptibility to nephrolithiasis (OR = 1.91, p = 0.0017). Among nephrolithiasis patients, subjects with GG at rs7627468 (calcium-sensing receptor (CASR)) have lower pH level in urine (p = 0.0088). Importantly, rs7627468 is associated with the expressions of IQCB1 and EAF2. rs12654812 could influence the expression of RGS14 itself, MXD3, and FGFR4. In summary, this study successfully validated the genetic roles of rs1256328 and rs12654812 in human nephrolithiasis.

Efficacy of extracorporeal shockwave lithotripsy with furosemide and hydration in renal stone management: A randomised controlled trial

Objective: To assess the effect of diuretics (furosemide) administered before extracorporeal shockwave lithotripsy (ESWL) followed by continuous infusion of 0.9% NaCl during the ESWL in patients with renal stones. Patients and methods: A tertiary care teaching hospital-based prospective randomised controlled trial was conducted from July 2015 to June 2017, including 714 patients who underwent ESWL. The patients were randomised in two groups: in Group-A, patients received 40 mg furosemide 30 min before each ESWL session and 1000 mL 0.9% NaCl intravenous hydration during the procedure. In Group-B, the patients only received 0.9% NaCl. All patients were followed-up every 2 weeks for 3 months with X-ray and ultrasonography of the kidney, ureter and bladder. Patients without a radio-opaque stone at follow-up were classified as successes. Results: After 2 months, the stone-free rate (SFR) was much higher in Group-A, at 77.0% vs 65.3% (P < 0.001). Further, for patients aged ≤40 years, the SFR was significantly higher in Group-A than Group-B, at 89.2% vs 71.4% (P < 0.001). The mean (SD) age of the patients was 34.4 (8.23) years. Amongst them, 441 (61.8%) were male and 273 (38.2%) were female. The mean (SD) stone size was 1.42 (0.21) cm in Group-A and 1.40 (0.20) cm in Group-B. Conclusion: We conclude that the efficacy of diuretics (furosemide) along with hydration is superior to hydration alone during ESWL for renal stone clearance. Abbreviations: BMI: body mass index; KUB: kidney, ureter and bladder; OPD: Outpatient Department; ESWL: extracorporeal shockwave lithotripsy; SFR, stone-free rate.

Single-Use Versus Reusable Digital Flexible Ureteroscopes for the Treatment of Renal Calculi: A Prospective Multicenter Randomized Controlled Trial

Objective: To compare the efficacy and safety of a single-use digital flexible ureteroscope (f-URS) and a reusable digital f-URS (URF-V) for the treatment of renal stones in adults. Patients and Methods: In this randomized open-label noninferiority trial, we randomly selected patients with renal stones to receive ureteroscopy through a single-use digital f-URS (ZebraScope^™; Happiness Workshop, Beijing, China) or a URF-V (Olympus, Tokyo, Japan). The primary endpoint was the 1-month postsurgical stone-free rate (SFR). The secondary efficacy endpoints assessed were the high-quality rate of images, the eligible rate of operability, the operative time, and the length of hospital stay. The safety outcomes assessed were the presence of postoperative complications, adverse events (AEs), and serious AEs (SAEs). The noninferiority margin was set at -10%. Results: In total, 126 patients completed the study (i.e., 63 patients in each group). The demographic and preoperative parameters were comparable between the two groups. The 1-month SFR was 77.78% for the ZebraScope group and 68.25% for the URF-V group (two-sided 95% confidence interval [CI]: -5.95 to 25.01). The high-quality rate of images and the eligible rate of operability were 100% in both groups (two-sided 95% CI: -5.27 to 5.35). There was no difference between the two groups in the operative time (p = 0.687), the length of hospital stay (p = 0.430), the presence of postoperative complications (p = 0.310), the presence of AEs (p = 0.709), and the presence of SAEs (p = 0.648). The most important and fatal SAE was acute urinary tract obstruction. Conclusion: The single-use digital f-URS (ZebraScope) appears to be at least noninferior to URF-V regarding the 1-month SFR, the high-quality rate of images, and the eligible rate of operability. Single-use digital f-URSs are an effective and safe alternative to URF-V.

Clinical Presentation of Primary Hyperparathyroidism in Older Adults

Background

The clinical presentation of primary hyperparathyroidism (PHPT) has changed greatly during the past few decades. Our aim was to evaluate whether the clinical presentation at diagnosis differed according to age.

Methods

We evaluated retrospectively a monocentric series of 462 consecutive patients with PHPT, dividing them according to a cutoff of 65 years of age.

Results

No differences were found in the mean serum PTH, calcium, or vitamin D levels. In older patients (n = 212; 45.9%), the urinary calcium levels were significantly lower (median, 205 mg/24 hour; interquartile range, 220 mg/24 hour) compared with those in younger patients (median, 308 mg/24 hour; interquartile range, 233 mg/24 hour). In addition, renal involvement was significantly less frequent (25% vs 49.2%), and bone involvement significantly more frequent (58% vs 44%) in older patients compared with younger patients. The clinical presentation was significantly different between the two age groups, with a lower frequency of symptomatic forms and a greater frequency of asymptomatic forms not meeting surgical criteria in the older patients (44.4% vs 57.2% and 18.4% vs 5.6%, respectively). Osteoporosis was significantly more frequent in the older adults than in their younger counterparts. The most affected bone site was the forearm in older adults and the lumbar spine in younger ones (50.3% and 50.5%, respectively).

Conclusion

The clinical presentation of PHPT differs according to age, and this difference can affect the selection of management modalities.

[Modern nephrolithiasis in the complex setting of metaphylaxis : Latest epidemiological data and a nationwide survey in private practices]

The focus of this work is on aspects of the current management of recurrent nephrolithiasis in private practices and outpatient departments in Germany. We wanted to make a contribution to the epidemiological discourse as well as for an instrument for the self-reflection and complex classification of urolithiasis in everyday practice by a first-time determination of population-based, age- and gender-based data based on the full recording of urological diagnoses and treatments in the federal accounting setting. The analysis of the taken positions in this representative practice survey prove to some extent information and experience deficits in the handling of complicated nephrolithiasis. Therefor more than 90% of the interviewees demand a structured practical training initiative. In this context, nearly 65% of practices also support the establishment of regional consultation hours. A majority strongly welcomes the establishment of a National Register of Urolithiasis, but nearly 40% are skeptical about defining pending framework conditions.

Association of vitamin D receptor gene polymorphisms and risk of urolithiasis: results of a genetic epidemiology study and comprehensive meta-analysis

Polymorphisms of vitamin D receptor (VDR) gene have been associated with risk of urolithiasis, but, with inconsistent results and lack data from Pakistani population. Therefore, after including our indigenous study data, a comprehensive meta-analysis was performed to provide an evidence-based estimate of any association between VDR polymorphisms and urolithiasis risk. A total of 483 Pakistani subjects, comprising 235 urolithiasis patients and 248 healthy controls, were genotyped for 6 VDR polymorphisms. Additionally, a systematic literature search with subsequent meta-analysis was conducted and pooled odds ratios (ORs) were used to determine the strength of any existent associations. Trial sequential analysis (TSA) was also performed. Results revealed no significant association of any VDR polymorphism and urolithiasis risk in indigenous Pakistani patients. However, meta-analysis of 29 relevant studies indicated that VDR FokI polymorphism significantly increased the risk of urolithiasis in allelic (f vs. F: OR = 1.13; 95% CI = 1.05-1.22; p ≤ 0.01) and recessive (ff vs. FF + Ff: OR = 1.20; 95% CI = 1.05-1.38; p = 0.01) models with no significant heterogeneity. No associations were evident for VDR ApaI, BsmI and TaqI polymorphic variants and urolithiasis risk after correction for multiple testing. Subgroup analysis by ethnicity suggested significant association for FokI variant among Asians. The TSA results demonstrated that the evidence reflecting association of FokI polymorphism and urolithiasis risk was sufficient and conclusive. In conclusion, this meta-analysis suggests that VDR FokI polymorphism is significantly associated with urolithiasis risk, especially in Asians, whereas ApaI, BsmI and TaqI polymorphisms are not associated.

Exploiting the aiming beam to increase the safety of laser lithotripsy: Experimental evaluation of light reflection and fluorescence

BACKGROUND AND OBJECTIVES

In Holmium laser lithotripsy, usually, the surgeon is guided by a visible beam superimposing the infrared (IR) treatment radiation. It has been shown that a green aiming beam excites stone autofluorescence. This fluorescence signal can be used for calculi detection to check the correct fiber position before triggering the IR laser, thus preventing damage to soft tissue and application devices. However, also the directly reflected green light from the fiber tip gives valuable information on fiber position and its surface condition.

MATERIALS AND METHODS

An external fiber-fiber-coupling-box (fiber core diameter 365 µm) for pulsed holmium laser radiation (2.1 µm) was set up containing a green diode laser module (520 nm, average power on the sample <0.5 mW) and optics and detectors for measuring the reflected light of this aiming beam as well as the fluorescence excited with it. Measurements were done via a lock-in technique with more than 20 human calculi samples and porcine calix in vitro. After the implementation of automatic data storage signals during ongoing in vitro lithotripsy procedures were recorded with the fiber positioned on tissue, stone, or in/on medical equipment (working channel of an endoscope, stone retrieval basket).

RESULTS

Stone fluorescence signals measured were a factor of 7 to >100 higher than those of tissue. Stone fluorescence was detectable in "non-contact mode" with a linear signal decrease over a distance up to ~1 mm in front of the fiber tip (core diameter 365 µm) and with severely damaged fibers (max. decrease: 75% with pinched off fiber). Reflection signals of the fiber tip surface in air and water surrounding decreased significantly when the fiber was damaged; measured ratios of intact to damaged fiber found in the air were (5-17):1 and in water (1.6-3.7):1. Surfaces in front of the fiber aggravated the evaluation of fiber condition due to reflections but enabled to detect, for example, the working channel of a flexible endoscope in combination with the (missing) fluorescence signal.

CONCLUSIONS

Autofluorescence induced by a green aiming beam can be exploited for stone detection in laser lithotripsy. A reflection measurement can give further information on fiber condition and position. Implementing this kind of safety features for an automatic block of IR laser emission in case of weak or missing fluorescence and un-normal reflections can assist the surgeon by avoiding tissue perforation, and damage to medical devices such as endoscopes. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Simultaneous and synchronous bilateral endoscopic treatment of urolithiasis: a multicentric study

Introduction

The general prevalence of bilateral urolithiasis has risen to 15% and bilateral non-simultaneous treatment has been reported to have good outcomes. The objective of this study was to evaluate the effectiveness and safety of simultaneous bilateral endoscopic surgery (SBES).

Material and methods

An international multicenter analysis was performed between May 2015 and December 2017. All patients with bilateral stone disease that underwent SBES were included. Patients were treated under general anesthesia in either the supine or lithotomy position. Demographic, clinical, intraoperative and postoperative data were analyzed.

Results

A total of 47 patients were included. Mean age was 53.8 years and 70% of the patients were males. The mean American Society of Anesthesiology (ASA) score was 2. The mean diameter of right- and left-sided stones was 29.43 mm (2–83 mm) and 31.15 (4–102 mm), respectively. Staghorn stones were treated in 18 cases (8 right-sided and 10 left-sided), four of them were defined as complete staghorn. The procedures performed were 42 cases of bilateral URS and PCNL and ureteroscopy. Additionally, 5 bilateral flexible ureteroscopy (fURS) cases were described. Intraoperative complications occurred in five patients: four of them were classified as Clavien-Dindo (CD) I and one as CD II. Postoperatively, there were two cases with CD I, 6 with CD II and one CD IIIa.

The stone-free status was 70%. Residual stones (30%) were detected only on the side treated for high-volume (complete) staghorn calculi.

Conclusions

SBES is a feasible, effective and safe procedure. It may potentially avoid repeated anesthetic sessions as needed for staged procedures and reduce the length of patients' hospital stay.

Method of alkalization and monitoring of urinary pH for prevention of recurrent uric acid urolithiasis: a systematic review

Uric acid (UA) urolithiasis comprises around 5-10% of all stones and can frequently recur. Due to the fact that UA stones form in acidic urine with a pH <5.5, these patients require special attention compared to other stone patients. The international guidelines suggest treatment and metaphylaxis by urinary alkalization. The objective of this review is to critically asses the available evidence concerning the method and efficacy of this treatment modality. A systematic review on the methods of metaphylactic therapy using oral alkalization of UA urolithiasis was conducted by two authors. Evidence was sought using a predefined search strategy in seven different databases. The provided evidence was critically evaluated using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Cochrane collaboration tool for assessing the risk of bias. Twelve manuscripts were included of which one was a randomised trial. They focussed on ways to alkalize urine and its effect on stone recurrence. Because of their methodology and heterogeneity, the evidence is presented in a narrative review. There were differences in medication used for alkalizing urine, ways of monitoring urine pH and evaluating its efficacy. The reported outcomes also differed between studies. There is currently a lack of clear evidence for the method of alkalization of urine and the method of pH measurement. Besides this, for an established treatment modality, there is lack of long term results for the alkalization therapy. In conclusion, urine alkalization is an established treatment modality for the metaphylaxis of UA urolithiasis despite the lack of evidence from high quality studies on the methods of alkalization and its treatment efficacy. The studies published on this topic are scarce and contain notable risks of bias which should be kept in mind when interpreting the stated results.

Handling and protecting your flexible ureteroscope: how to maximise scope usage

Flexible ureteroscopy is an important therapeutic and diagnostic procedure and has seen rapid rise in its utilisation in recent years. There have been numerous developments in flexible ureteroscope (fURS) technology but scope fragility, and the associated high maintenance costs, remains a concern. A comprehensive Medline search for related publications from the last 20 years was undertaken to identify common causes of fURS damage and ascertain practices to minimise this. Flexible ureteroscopy can be due to intraoperative causes (loss of the deflection mechanism, damage to the working channel due and fibreoptic bundle injury) and non-operative damage which occur during cleaning, sterilisation and handling of the fURS. The review summarises the available literature to help highlight common mechanisms of scope damage, and outlines evidence-based measures to reduce the risk of damage and maximise durability. Scope fragility remains a problem with significant associated cost implications. In a culture of rising fURS use and reducing re-imbursement for endourologists, prolonging the longevity of the fURS is imperative for maintaining profitability. There are simple and inexpensive practices which can be immediately adopted to maximise fURS use and reduce the need for repairs.

Acute renal impairment characterization using diffusion magnetic resonance imaging: Validation by histology

Diffusion magnetic resonance imaging has been demonstrated to be a simple, noninvasive and accurate method for the detection of renal microstructure and microcirculation, which are closely linked to renal function. Moreover, serum endothelin-1 (ET-1) was also reported as a good indicator of early renal injury. The aim of this study was to evaluate the feasibility and capability of diffusion MRI and ET-1 to detect acute kidney injury by an operation simulating high-pressure renal pelvic perfusion, which is commonly used during ureteroscopic lithotripsy. Histological findings were used as a reference. Fourteen New Zealand rabbits in an experimental group and 14 in a control group were used in this study. Diffusion tensor imaging and intravoxel incoherent motion diffusion-weighted imaging were acquired by a 3.0 T MRI scanner. Significant corticomedullary differences were found in the values of the apparent diffusion coefficient (ADC), pure tissue diffusion, volume fraction of pseudo-diffusion (fp) and fractional anisotropy (FA) (P < 0.05 for all) in both preoperation and postoperation experimental groups. Compared with the control group, the values of cortical fp_mean , medullary ADC_mean and FA_mean decreased significantly (P < 0.05) after the operation in the experimental group. Also, the change rate of medullary ADC_mean in the experimental group was more pronounced than that in the control group (P = 0.018). No significant change was found in serum ET-1 concentration after surgery in either the experimental (P = 0.80) or control (P = 0.17) groups. In the experimental group, histological changes were observed in the medulla, while no visible change was found in the cortex. This study demonstrated the feasibility of diffusion MRI to detect the changes of renal microstructure and microcirculation in acute kidney injury, with the potential to evaluate renal function. Moreover, the sensitivity of diffusion MRI to acute kidney injury appears to be superior to that of serum ET-1.

Delaying voiding, limiting fluids, urinary symptoms, and work productivity: A survey of female nurses and midwives

AIM

To examine the relationships between workplace bladder practices, urinary symptoms, and work productivity.

DESIGN

Cross-sectional observational survey.

METHODS

Surveys were distributed June-November 2016 to at least 600 female nurses and midwives at three urban hospitals in New South Wales, Australia. Nurses self-reported restricted workplace access to toilets, delaying voiding, limiting of fluid intakes and urinary symptoms at work. Logistic modelling was used to examine whether nurses' bladder practices impaired their time management, ability to concentrate or perform physical demands.

RESULTS

Of 353 useable surveys, one in five nurses (22.4%; N = 79) reported restricted access to toilets at work, most (77.1%; N = 272) delayed voiding and one in four (26.9%; N = 95) limited fluid intakes to delay voiding at work. Almost half the sample had urinary symptoms at work (46.7%; N = 165); delaying voiding increased the likelihood of impaired mental concentration and limiting fluid intakes increased the likelihood of impaired time management.

CONCLUSION

As workplace access to toilets and related bladder practices are modifiable, associated urinary symptoms and productivity loss may be preventable.

IMPACT

Nurses' often experience restricted accesses to amenities due to job demands and workplace environments. The impact of nurses' poor bladder practices in the workplace is not known. In this study most nurses delayed voiding and many purposefully limited fluid intakes at work. These behaviours impacted a nurse's ability to manage time and/or concentrate at work. Results have implications for nurses' personal health, the design of workplace environments, workforce management, occupational health policy, and patient care.

The evolution of percutaneous nephrolithotomy: Analysis of a single institution experience over 25 years

INTRODUCTION

Over time, the incidence of nephrolithiasis has risen significantly, and patient populations have become increasingly complex. Our study aimed to determine the impact of changes in patient demographics on percutaneous nephrolithotomy (PCNL) outcomes.

METHODS

A retrospective analysis of a prospectively collected database was carried out from 1990-2015. Patient demographics, comorbidities, stone and procedure characteristics were analyzed. Multivariate logistic regression was used to evaluate differences in operative duration, complications, stone-free rate, and length of stay.

RESULTS

A total of 2486 patients with a mean age of 54±15 years, body mass index (BMI) of 31±8, and stone surface area of 895±602 mm² were analyzed; 47% of patients had comorbidities, including hypertension (22%), diabetes mellitus (14%), and cardiac disease (13%). Complication rate was 19%, including a 2% rate of major complications (Clavien grade III-V). There was a statistically significant increase in patient age, BMI, and comorbidities over time, which was correlated with an increased complication rate (odds ratio [OR] 1.15; p=0.010). The overall transfusion rate was 1.0% and remained stable (p=0.131). With time, both OR duration (mean Δ 16 minutes; p<0.001) and hospital length of stay (mean Δ 2.4 days; p<0.001) decreased significantly. Stone-free rate of 1873 patients with available three-month followup was 87% and decreased significantly over time (OR 1.09; p<0.001), but was correlated with an increased use of computed tomography (CT) scans for followup imaging.

CONCLUSIONS

Despite an increasingly complex patient population, PCNL remains a safe and effective procedure with a high stone-free rate and low risk of complications.

Efficacy of Obcordata A from Aspidopterys obcordata on Kidney Stones by Inhibiting NOX4 Expression

Obcordata A (OA) is a polyoxypregnane glycoside derived from the Dai medicine Aspidopterys obcordata vines. This study aims to investigate the efficacy of OA on renal tubular epithelial cells exposed to calcium oxalate crystals. We incubated renal tubular cells with 28 μg·cm2 calcium oxalate crystals for 24 h with and without OA, GKT137831, phorbol-12-myristate-13-acetate (PMA), and tocopherol. The MTT [3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, microscopic examination, flow cytometry, and immunofluorescence staining revealed that calcium oxalate crystals decreased cell viability and elevated reactive oxygen species (ROS) levels. OA, GKT137831, and tocopherol protected cells and decreased ROS levels. However, OA did not exhibit direct DPPH scavenging ability. In addition, immunoblotting illustrated that OA inhibited the NOX4 (nicotinamide adenine dinucleotide phosphate oxidases 4) expression and downregulated the protein expression in the NOX4/ROS/p38 MAPK (p38 mitogen-activated protein kinase) pathway. The findings suggest that the cytoprotective and antioxidant effects of OA can be blocked by the NOX4 agonist PMA. In conclusion, OA could be used as a NOX4 inhibitor to prevent kidney stones.

Hydroxycitric Acid Tripotassium Inhibits Calcium Oxalate Crystal Formation in the Drosophila Melanogaster Model of Hyperoxaluria

Background

Hydroxycitric acid is a potential lithontriptic agent for calcium oxalate (CaOx) stones in the kidneys. This study aimed to evaluate the safety and efficiency of hydroxycitric acid tripotassium (K-HCA) against CaOx crystal formation using Drosophila melanogaster hyperoxaluria models.

Material/Methods

Wild-type D. melanogaster were fed standard medium with ethylene glycol or sodium oxalate added to induce hyperoxaluria. Their Malpighian tubules were dissected and observed under a microscope every 3 days. Crystal deposit score of each Malpighian tubule were evaluated under a magnification of ×200. Using hyperoxaluria Drosophila models, we investigated the inhibitory efficiency of hydroxycitrate acid tripotassium and citric acid tripotassium (K-CA) against CaOx crystal formation. The survival rate of each group was also assessed.

Results

When fed with 0.05% NaOx, the CaOx formation in Malpighian tubules increased significantly, without reduction of life span. Therefore, we selected 0.05% NaOx-induced hyperoxaluria models for the further investigations. After treatment, the stone scores showed that K-CA and K-HCA both significantly inhibit the formation of CaOx crystals in a dose-dependent manner, and with smaller dosage (0.01%), K-HCA was more efficient than K-CA. Moreover, after treatment of K-CA or K-HCA, the life span in different groups did not change, reflecting the safety to life.

Conclusions

The hyperoxaluria Drosophila models fed on 0.05% NaOx diet might be a useful tool to screen novel agents for the management of CaOx stones. K-HCA may be a promising agent for the prevention CaOx stones, with satisfying efficiency and acceptable safety.

The Effect of Operative Field Instrument Clutter During Intraoperative Fluoroscopy on Radiation Exposure

Introduction and Objectives: Fluoroscopy units are routinely operated in the automatic brightness control (ABC) mode to optimize image quality. During ureteroscopy, objects may be placed within the fluoroscopy beam and the effect upon radiation exposure is unknown. The purpose of this study is to investigate the effects of equipment within the fluoroscopy beam during simulated ureteroscopy. Methods: ABC fluoroscopy of a cadaver was performed in eight clinical scenarios, including a control (no equipment), and seven groups with different equipment within the fluoroscopy beam. Equipment tested included electrocardiogram (EKG) leads, a Kelly clamp, camera and light cords (straight and coiled configurations), flexible ureteroscope, rigid cystoscope, and the lateral table support beam. Ten 145-second fluoroscopy trials were performed for each arm. The primary outcome was radiation dose (mGy) compared using the Mann-Whitney test with p < 0.05 considered significant. Results: Compared with control (18.5 mGy), radiation exposure was significantly increased with the presence of a straight camera and light cords (19.3 mGy), Kelly clamp (19.4 mGy), coiled camera and light cords (20.2 mGy), a flexible ureteroscope (21.0 mGy), a rigid cystoscope (21.2 mGy), and when the lateral table support beam was in the path of the X-ray (25.0 mGy; a 35% increase; p < 0.007 for all). The EKG leads did not affect the radiation dose. Conclusions: Avoiding equipment within the fluoroscopy beam using ABC mode can reduce radiation exposure. Adjusting the table and patient position to exclude the lateral table support beam will reduce radiation exposure by 35%.

Acute Urinary Retention in the Male Child from Urethral Calculi: A Report of Three Cases

Urinary stones are uncommon in children. Urethral location of calculi can give rise to various clinical manifestations. We report three cases of urethral lithiasis presenting with acute urinary retention in children.

Kidney stone compositions and frequencies in a Norwegian population

Objectives: The aim of this study was to investigate frequencies of kidney stone constituents in a Norwegian population and examine trends over time by comparing with an earlier study of this population. Materials and methods: Upper urinary tract calculi consecutively collected from patients who underwent stone surgery at Akershus University Hospital from July 2014 to December 2017, in total 1252 calculi, were analysed by infrared spectroscopy. The results were compared with a study of 500 calculi collected from June 1975 to September 1980 at the same hospital. Results: The male:female ratio was 1.83:1. Single-component stones constituted 39%, 35% were binary, and 25% ternary. Main stone component frequencies were oxalate 71.3%, calcium oxalate monohydrate 53.7% with higher occurrence in males, calcium oxalate dihydrate 17.6%, carbonate apatite 10.8% and struvite 5.7%, both with higher occurrence in females, uric acid 8.9% with a non-significant male predominance, brushite 1.6% and cystine about 1%. Over four decades the frequency of UA stones increased by 4.6-times, whereas struvite and pure carbonate apatite stones decreased and no change was observed for brushite stones. Conclusion: Frequencies of kidney stone types in this Norwegian population are mainly in accordance with other studies, except a large increase in UA stones over four decades, partly caused by a particularly low frequency of UA stones in the old study, a decreased carbonate apatite frequency over four decades, and an unaltered brushite frequency. Also, in contrast to other studies, a relatively small and non-significant male UA stone predominance was found.

Sonographic twinkling artifact for diagnosis of acute ureteral calculus

OBJECTIVE

We compared the performance of color Doppler twinkling artifacts with B-ultrasound and computed tomography (CT) for diagnosis of ureteral calculus in patients with acute renal colic.

METHODS

The location and size of ureteral stones in 2268 patients with acute renal colic were determined using the two ultrasound methods and CT. All cases were followed up for 2-8 weeks.

RESULTS

Color Doppler twinkling artifacts had a sensitivity of 96.98%, specificity of 90.39%, positive predictive value (PPV) of 99.77%, and negative predictive value (NPV) of 41.23%. B-Ultrasound had a sensitivity of 96.39%, specificity of 80.77%, PPV of 99.53%, and NPV of 34.43%. CT had a sensitivity of 99.59%, specificity of 94.23%, PPV of 99.86%, and NPV of 84.48%. The area under the receiver operating characteristic curve was 0.925 for color Doppler twinkling artifacts, 0.863 for B-ultrasound, and 0.963 for CT.

CONCLUSION

For the diagnosis of ureteral calculus, the sonographic twinkling artifact had a similar performance as CT. We suggest use of the sonographic twinkling artifact instead of CT for patients with acute renal colic to reduce the examination time and exposure to radiation, and to provide earlier access to treatment.

The Urological Association of Asia clinical guideline for urinary stone disease

The Urological Association of Asia, consisting of 25 member associations and one affiliated member since its foundation in 1990, has planned to develop Asian guidelines for all urological fields. The field of stone diseases is the third of its guideline projects. Because of the different climates, and social, economic and ethnic environments, the clinical practice for urinary stone diseases widely varies among the Asian countries. The committee members of the Urological Association of Asia on the clinical guidelines for urinary stone disease carried out a surveillance study to better understand the diversity of the treatment strategy among different regions and subsequent systematic literature review through PubMed and MEDLINE database between 1966 and 2017. Levels of evidence and grades of recommendation for each management were decided according to the relevant strategy. Each clinical question and answer were thoroughly reviewed and discussed by all committee members and their colleagues, with suggestions from expert representatives of the American Urological Association and European Association of Urology. However, we focused on the pragmatic care of patients and our own evidence throughout Asia, which included recent surgical trends, such as miniaturized percutaneous nephrolithotomy and endoscopic combined intrarenal surgery. This guideline covers all fields of stone diseases, from etiology to recurrence prevention. Here, we present a short summary of the first version of the guideline - consisting 43 clinical questions - and overview its key practical issues.

Leave no stone unturned: defining recurrence in kidney stone formers

PURPOSE OF REVIEW

Established guidelines provide recommendations on the management of kidney stones to prevent recurrence. However, clear and clinically useful terminology for recurrence of kidney stones is needed. This review describes the various manifestations of kidney stone recurrence and the reported rates of kidney stone recurrence in various clinical settings.

RECENT FINDINGS

Kidney stone recurrence has a wide range of symptomatic and radiographic presentations. Symptomatic recurrence may include characteristic symptoms of stone passage via the ureter (renal colic and gross hematuria). This may be self-managed or result in clinical care, with or without confirmation of an obstructing stone on imaging. Radiographic recurrence has been variably defined as new stone formation, stone growth, or stone disappearance (from passage with or without symptoms). Studies have used inconsistent definitions of recurrence, and recurrence rates vary substantially. Stone free rates and residual stone fragment size after surgical interventions are useful predictors of symptomatic recurrence.

SUMMARY

The recurrence rate of kidney stones has been assessed in stone formers from sub-specialty clinics, the general community, and clinical trials. The definition of recurrence is quite heterogenous between studies, but the rate of recurrence generally increases as more manifestations are included in the definition.

Metabolomic analysis reveals a protective effect of Fu-Fang-Jin-Qian-Chao herbal granules on oxalate-induced kidney injury

Nephrolithiasis is one of the world’s major public health burdens with a high incidence and a risk of persistent renal dysfunction. Fu-Fang-Jin-Qian-Chao granules (FFJQC), a traditional Chinese herb formula, is commonly used in treatment of nephrolithiasis. However, the therapeutic mechanism of FFJQC on kidney stone has still been a mystery. The objective of the present study is to explore the therapeutic mechanism of FFJQC on kidney injury and identify unique metabolomics patterns using a mouse model of kidney stone induced by a calcium oxalate (CaOx) deposition. Von Kossa staining and immuno-histopathological staining of osteopontin (OPN), cluster of differentiation 44 (CD44) and calbindin-D28k were conducted on renal sections. Biochemical analysis was performed on serum, urine, and kidney tissues. A metabolomics approach based on ultra-HPLC coupled with quadrupole-TOF-MS (UHPLC-Q-TOF/MS) was used for serum metabolic profiling. The immunohistopathological and biochemical analysis showed the therapeutic benefits of FFJQC. The expression levels of OPN and CD44 were decreased while calbindin-D28k increased after the CaOx injured mice were treated with FFJQC. In addition, total of 81 serum metabolites were identified to be associated with protective effects of FFJQC on CaOx crystal injured mice. Most of these metabolites were involved in purine, amino acid, membrane lipid and energy metabolism. Potential metabolite biomarkers were found for CaOx crystal-induced renal damage. Potential metabolite biomarkers of CaOx crystal-induced renal damage were found. FFJQC shows therapeutic benefits on CaOx crystal injured mice via regulation of multiple metabolic pathways including amino acids, purine, pyrimidine, glycerolipid, arachidonic acid (AA), sphingolipid, glycerophospholipid, and fatty acid.

Sirt3 suppresses calcium oxalate-induced renal tubular epithelial cell injury via modification of FoxO3a-mediated autophagy

High oxalic acid and calcium oxalate (CaOx)-induced renal tubular epithelial cell (TEC) injury plays a key role in nephrolithiasis. However, the mechanism remains unknown. Gene array analysis of the mice nephrolithiasis model indicated significant downregulation of sirtuin 3 (Sirt3) and activation of mitogen-activated protein kinase (MAPK) pathway. Kidney biopsy tissues of renal calculi patients also showed decreased Sirt3 expression. Silencing Sirt3 exacerbated oxidative stress and TEC death under CaOx stimulation. Restoring Sirt3 expression by overexpression or enhancing its activity protected renal function and reduced TEC death both in vitro and in vivo. Inhibiting the MAPK pathway resulted in upregulation of Sirt3 expression, preservation of renal function and decreased cell death both in vitro and in vivo. Furthermore, Sirt3 could upregulate FoxO3a activity post-translationally via deacetylation, dephosphorylation and deubiquitination. FoxO3a was found to interact with the promoter region of LC3B and to increase its expression, enhancing TEC autophagy and suppressing cell apoptosis and necrosis. Taken together, our results indicate that the MAPK/Sirt3/FoxO3a pathway modulates renal TEC death and autophagy in TEC injury.

Uncovering a Novel Stone in 27 Patients: Calcium Tartrate Tetrahydrate

OBJECTIVE

To further analyze calcium tartrate tetrahydrate stones after a recent case report described this novel stone. Prior to this, there was only one previously reported occurrence of this stone in a human. This unusual stone composition is not tested for routinely. True prevalence and possible causes of this stone are unknown.

MATERIALS/METHODS

During the previous case report, micro-CT and Fourier-transform infrared spectroscopy were used to identify a calcium tartrate tetrahydrate stone. This information was applied to urinary stones with previously unidentified compositions in the Mayo Metals laboratory database between 2010 and March 2018. Two additional stones were identified at our institution. Three patients had medical records available for analysis.

RESULTS

Between 2010 and March 2018, 35 calcium tartrate stones in 25 patients were identified in the Mayo database as well as 2 at our institution (37 stones in 27 patients). Thirty stones were pure calcium tartrate with the remainder having elements of more common stones. The average age was 46.3 (±14.7) with a slightly higher incidence in females (17 vs 10). Of the 3 medical records investigated, all 3 were males (average age 48.7), and each reported consumption of an energy supplement (Spark) routinely.

CONCLUSION

The true prevalence of this relatively unknown stone remains unclear and additional investigation is warranted. We believe all stone laboratories should have access to the IR spectra for calcium tartrate tetrahydrate. Attention should be paid to possible causes of this stone, particularly with relation to oral supplements, to aid with future prevention and treatment.

Impact of LUTS on urine volume in stone formers The impact of lower urinary tract symptomatology on urine volumes in stone formers

INTRODUCTION

We aimed to determine if there is a correlation between International Prostate Symptom scores (IPSS) and 24-hour urine collection volumes, as patients experiencing lower urinary tract symptoms (LUTS) may have impaired ability to increase fluid intake for stone prevention.

METHODS

We conducted a single-centre, retrospective review was performed of stone-formers presenting from 2014-2016. Inclusion criteria were completion of an IPSS questionnaire and a 24-hour urine collection. Exclusion criteria included symptomatic stone or urinary tract infection at time of IPSS completion, inadequate 24-hour collection, or incomplete IPSS questionnaire.

RESULTS

A total of 131 patients met inclusion criteria. Stratification by IPSS severity into mild (0-7), moderate (8-19), and severe (20-35) yielded groups of n=96, 28, and 7, respectively. Linear regression modelling did not reveal a correlation between IPSS score and volume (p=0.10). When compared to those with adequate urine volumes (>2 L/day, n=65), low-volume patients (<1 L/day, n=10) had a significantly higher total IPSS (11.7 vs. 6.1; p=0.036). These groups showed significant differences in their responses to questions about incomplete emptying (p=0.031), intermittency (p=0.011), and stranguria (p=0.0020), with higher scores noted in the low urine output group.

CONCLUSIONS

This study is the first to examine the correlation between IPSS and 24-hour urine volume. Though our data does not show a linear relationship between urine output and IPSS, those with lower urine volumes appear to have worse self-reported voiding symptoms when compared to those with adequate volumes (>2 L/day) for stone prevention. The overall number of patients in our study is relatively small, which may account for the lack of a relationship between IPSS and 24-hour urine volumes.

Comparison among the available stone treatment techniques from the first European Association of Urology Section of Urolithiasis (EULIS) Survey: Do we have a Queen?

PURPOSE

The miniaturization of instruments has had an impact on stone management. The aims of this study were to highlight surgeon preferences among Retrograde Intra Renal Surgery (RIRS), Regular, Mini-, UltraMini- and Micro- Percutaneous Nephrolithotomy (PCNL) for urolithiasis and to compare the effectiveness and safety of these techniques in a real-life setting.

METHODS

A 12-item survey regarding endourological techniques was conducted through Survey Monkey among attendees of the 2013 European Association of Urology Section of Urolithiasis meeting. We asked responders to share data from the last 5 cases they performed for each technique. Procedures were stratified according to stone size and the centres' surgical volume. Techniques were compared in terms of effectiveness and safety. Analyses were performed on the overall group and a subgroup of 1-2 cm stones.

RESULTS

We collected data from a total of 420 procedures by 30, out of 78, urologists who received the survey (response rate 38%): 140 RIRS, 141 Regular-PCNL (>20 Ch), 67 Mini-PCNL (14-20 Ch), 28 UltraMini-PCNL (11-13 Ch) and 44 Micro-PCNL (4,8-8 Ch). Techniques choice was influenced by stone size and the centre's surgical volume. Effectiveness and safety outcomes were influenced by stone size, independently of the technique. The stone-free rate was significantly lower in Micro-PCNL compared to Regular-PCNL. This was not confirmed for 1-2 cm stones. All techniques presented a lower complication rate than Regular-PCNL, with Mini-PCNL being the most protective technique compared to Regular-PCNL.

CONCLUSIONS

Stone size seems to drive treatment choice. Miniaturized PCNL techniques are widely employed for 1-2 cm stones, in particular in higher surgical volume centres. Mini-PCNL and RIRS are growing in popularity for stones > 2 cm. Mini-PCNL seems to be a good compromise, being the most effective and safe procedure among PCNL techniques. RIRS is characterized by satisfactory stone-free and low complication rates.

THE CLINICAL PRESENTATION OF PRIMARY HYPERPARATHYROIDISM: A SOUTHERN EUROPEAN PERSPECTIVE OVER THE LAST 2 DECADES

OBJECTIVE

The clinical presentation of primary hyperparathyroidism (PHPT) has changed widely in developed countries in the last few decades. We evaluated its variations in our series over a 20-year period (i.e., 1997-2016).

METHODS

A retrospective survey was conducted in our series of 364 well-characterized consecutive patients, arbitrarily divided into 4 consecutive 5-year periods at diagnosis.

RESULTS

In the overall series, only estimated glomerular function (eGFR) and urinary calcium (UCa) showed a significant upward trend ( P = .032 and .039, respectively), whereas demographic and clinical characteristics were stable. The UCa upward trend was also confirmed for the subgroup of symptomatic patients ( P = .013). No difference was observed in the demographic, clinical, or biochemical characteristics of asymptomatic patients or in the fraction of patients meeting surgical criteria.

CONCLUSION

The clinical presentation of PHPT was stable over 20 years in our large series.

ABBREVIATIONS

Ca = calcium; eGFR = estimated glomerular filtration rate; 25OHD = 25-hydroxyvitamin D; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone; UCa = urinary calcium.

Epidemiology of urolithiasis in Asia

In Asia, about 1%-19.1% of the population suffer from urolithiasis. However, due to variations in socio-economic status and geographic locations, the prevalence and incidence have changed in different countries or regions over the years. The research for risk factors of urinary tract stones is of predominant importance. In this review, we find the prevalence of urolithiasis is 5%-19.1% in West Asia, Southeast Asia, South Asia, as well as some developed countries (South Korea and Japan), whereas, it is only 1%-8% in most part of East Asia and North Asia. The recurrence rate ranges from 21% to 53% after 3-5 years. Calcium oxalate (75%-90%) is the most frequent component of calculi, followed by uric acid (5%-20%), calcium phosphate (6%-13%), struvite (2%-15%), apatite (1%) and cystine (0.5%-1%). The incidence of urolithiasis reaches its peak in population aged over 30 years. Males are more likely to suffer from urinary calculi. Because of different dietary habits or genetic background, differences of prevalence among races or nationalities also exist. Genetic mutation of specific locus may contribute to the formation of different kinds of calculi. Dietary habits (westernized dietary habits and less fluid intake), as well as climatic factors (hot temperature and many hours of exposure to sunshine) play a crucial role in the development of stones. Other diseases, especially metabolic syndrome, may also contribute to urinary tract stones.

Medical therapy for nephrolithiasis: State of the art

The prevalence of nephrolithiasis is increasing worldwide. Understanding and implementing medical therapies for kidney stone prevention are critical to prevent recurrences and decrease the economic burden of this condition. Dietary and pharmacologic therapies require understanding on the part of the patient and the prescribing practitioner in order to promote compliance. Insights into occupational exposures and antibiotic use may help uncover individual risk factors. Follow-up is essential to assess response to treatment and to modify treatment plans to maximize therapeutic benefit.