Higher Risk of Repeat Stone Surgery in Stone Formers with Concomitant Bowel Disease: Single Center Long Term Analysis

OBJECTIVES

To identify the need for repeat stone surgery in patients with and without bowel disease. Few studies have compared risks between different types of bowel disease and whether their need for repeat stone surgery differs.

METHODS

From our IRB approved study, we identified patients with and without bowel disease. We categorized patients' bowel disease into 4 categories: inflammatory bowel disease (IBD), bypass procedures, bowel resection, and bowel disease not otherwise specified (e.g., irritable bowel syndrome, celiac disease). Differences between patient demographics, stone disease, and recurrent stone events for patients with and without bowel disease were compared using univariate and multivariate survival analyses (SPSS 25).

RESULTS

Of all surgical stone patients (2011), 484 (24%) had some type of bowel disease. Compared to patients without bowel disease, patients with bowel disease presented with stones at an older age (62.2±14.5 vs. 58.4±15.3 years; p<0.001) and were more likely to be female (56 vs. 46%; p<0.001). Patients with bowel disease required more repeat stone surgery than those without bowel disease (31 vs. 23%, p<0.001). In multivariate analysis, patients with bypass and bowel resection were associated with more repeat surgery than patients without bowel disease (p<0.001, p=0.002, respectively). Patients with IBD and bowel disease not otherwise specified did not have higher risk for repeat surgery than patients without bowel disease.

CONCLUSIONS

Surgical stone patients with bowel disease, specifically those with prior bowel resection and bypass, had a higher risk of repeat stone surgery over time than stone formers without bowel disease.

DATA AVAILABILITY

The data sets generated and analyzed during the current study are available from the corresponding author on reasonable request.

Wisely Choosing a Fast-Food Burger Meal Results in Meaningful Reduction in Sodium: Implications for Kidney Stone Patients

OBJECTIVE

Stone formers trying to limit dietary sodium may be unable to give up fast food. For the classic American hamburger, it is unclear if lower sodium preparations of this item are available and how this could affect sodium intake. We determined the impact of careful selection at national chains.

METHODS

Nutritional guides for 14 national chains were analyzed for all beef-based burgers and french fries. A meal was defined as 1 burger and an order of fries. The daily sodium limit (recommended daily sodium allowance [RDA]) was considered to be 2,300 mg. The maximal sodium reduction was defined as the difference between the highest and lowest sodium-containing meals. The Kruskal-Wallis test with Dunn's method was used to compare food items among the chains.

RESULTS

Of the total 263 different burgers and 74 different fries, median sodium was 1130 mg (range 180-3520) and 565 mg (range 30-1480), respectively. Mean sodium for burgers at individual chains ranged from a low of 590 mg to a high of 1721 mg (P < .001). The mean sodium for fries at individual chains ranged from a low of 245 mg to a high of 947 mg (P < .001). Post-hoc testing revealed 26 significant differences between pairs of restaurants for sodium content of burgers with P < .05 for each. The median maximal sodium reduction among the different chains was 1925 mg. Depending on the chain, sodium content of 1 meal could be reduced by as little as 830 mg (36% RDA) or as much as 3360 mg (146% RDA) by careful selection.

CONCLUSION

Stone formers should be aware of significant variation in sodium content of burgers and fries among chains and within a chain. Wisely selecting just 1 fast-food burger meal can significantly reduce sodium intake.

The Consecutive 200 Cases of Endoscopic-Combined Intrarenal Surgery: Comparison between Standard and Miniature Surgeries

Background and Objectives: Percutaneous nephrolithotomy (PCNL) is still the gold-standard treatment for large and/or complex renal stones. Endoscopic combined intrarenal surgery (ECIRS) was developed with the goal of minimizing the number of access tracts of PCNL while simultaneously improving the one-step stone-free rate (SFR). The aim of this study was to share the experience of the consecutive 200 cases of ECIRS in one institute and analyze surgical outcomes of mini-ECIRS and standard ECIRS. Materials and Methods: We performed ECIRS for 200 adult patients between July 2017 and January 2020. An ECIRS was performed with the patient under general anesthesia in the intermediate-supine position. Surgeries were finished using a tubeless technique with a simple ureteral stent insertion. Results: There were significant differences in the mean maximal stone length (MSL), the variation coefficient of stone density (VCSD), the linear calculus density (LCD), the Seoul National University Renal Stone Complexity (S-ReSC), and the modified S-ReSC scores in stone characteristics, and estimated blood loss (EBL) and operation time in peri-operative outcomes between conventional and mini-ECIRS. After propensity-score matching, there was only a difference in EBL between the two groups. In logistic regression models, MSL [odds ratio (OR) 0.953; 95% confidence interval (CI) 0.926-0.979; p < 0.001], LCD (OR 4.702; 95% CI 1.613-18.655; p = 0.013) were significant factors for the success rate after ECIRS. Conclusions: In patients who underwent a mini-ECIRS, the stones were relatively smaller and less complex, and the operation time was shorter. However, if the size of stones was similar, there was no difference in the success rate, but EBL was lower in mini-ECIRS than in standard surgery.

Single use flexible ureteroscopes: Current status and future directions

Introduction

Single use ureteroscopes are a technological innovation that have become available in the past decade and gained increased popularity. To this end, there are now an increasing number of both benchside and clinical studies reporting outcomes associated with their use. Our aim was to deliver a narrative review in order to provide an overview of this new technology.

Methods

A narrative review was performed to gain overview of the history of the technology's development, equipment specifications and to highlight potential advantages and disadvantages.

Results

Findings from preclinical studies highlight potenial advantages in terms of the design of single use ureteroscopes such as the lower weight and more recent modifications such as pressure control. However, concerns regarding plastic waste and environmental impact still remain unanswered. Clinical studies reveal them to have a non inferior status for outcomes such as stone free rate. However, the volume of evidence, especially in terms of randomised trials remains limited. From a cost perspective, study conclusions are still conflicting and centres are recommended to perform their own micro cost analyses.

Conclusions

Most clinical outcomes for single use ureteroscopes currently match those achieved by reusable ureteroscopes but the data pool is still limited. Areas of continued debate include their environmental impact and cost efficiency.

Chinese mini percutaneous nephrolithotomy for upper urinary calculi under local infiltration anesthesia

Percutaneous nephrolithotomy is generally performed under general or regional anesthesia; however, it is rarely performed under local infiltration anesthesia (LIA). This study aimed to assess the safety and effectiveness of Chinese mini percutaneous nephrolithotomy (MPCNL) for upper urinary calculi under LIA. A retrospective analysis of 52 patients with upper urinary stones who underwent MPCNL under LIA from April 2019 to May 2022 was performed. Pethidine and Phenergan were intramuscularly injected 30 minutes preoperatively. Oxybuprocaine hydrochloride gel was applied to the urethra for lubricating and mucosal anesthesia. Ropivacaine hydrochloride and lidocaine were injected into the whole percutaneous channel for local anesthesia. An 8/9.8F ureteroscope and an 18F vacuum-assisted access sheath were applied in MPCNL. All 52 patients tolerated procedures and underwent operations successfully; none of them converted the anesthesia method or required additional analgesia. The mean visual analogue scale scores intraoperatively and at 6 hours, 24 hours, and 48 hours after surgery were 3.25 ± 0.52, 3.13 ± 0.69, 2.25 ± 0.56, and 1.58 ± 0.50, respectively. The stone free rate was 84.6%. Complications were seen in 6 (11.5%) patients, including fever in 2 patients (Clavien I), renal colic in 1 patient (Clavien I), clinically insignificant bleeding in 2 patients (Clavien I), and urinary tract infection in 1 patient (Clavien II). No severe complications were observed in any patients. Chinese MPCNL under LIA was a feasible option and achieved good outcomes in appropriately selected patients, and it may become the routine procedure for general patients.

Flexible ureteroscopic lithotripsy with a suctioning ureteral access sheath for removing upper urinary calculi under local anesthesia

Objectives

We aimed to probe the safety and effectiveness of flexible ureteroscopic lithotripsy (FURL) with a suctioning ureteral access sheath (S-UAS) for removing upper urinary calculi under local anesthesia (LA).

Materials and methods

The clinical data of 56 patients with upper urinary calculi treated by FURL with an S-UAS under LA during the period between September 2019 and November 2022 were analyzed retrospectively. For LA, intramuscular pethidine (1.0-2.0 mg/kg) and phenergan (25 mg) were administered 30 min prior to surgery, and oxybuprocaine hydrochloride gel was administered through the urethra at the start of the surgery. The S-UAS and flexible ureteroscope were used for FURL. Demographic characteristics, stone-related parameters, and clinical outcomes were analyzed.

Result

A total of 66 procedures were performed successfully on 46 patients (Group A), who underwent unilateral surgeries, and on 10 patients (Group B) who underwent same-session bilateral surgeries. All 56 patients were operated upon without altering the anesthesia strategy, and none required additional analgesia. The mean stone sizes of the Group A and Group B patients were 20.24 ± 5.45 mm and 29.40 ± 3.89 mm, respectively. The mean operative times of the two groups were 53.04 ± 13.35 min and 90.00 ± 15.81 min, respectively. In Group A, the stone-free rates (SFRs) were 76.1% (35/46) and 85.1% (40/46) at postoperative day 1 and day 30, respectively. In Group B, the SFRs were 80.0% (16/20) and 85.0% (17/20), respectively. Four (8.7%) patients in Group A suffered complications such as fever, stent pain, urosepsis, and steinstrasse. In Group B, one (10%) patient suffered from fever.

Conclusion

FURL, combined with an S-UAS under LA, is a feasible option and provides satisfactory clinical outcomes for appropriately selected patients.

Plasma formation in holmium:YAG laser lithotripsy

OBJECTIVES

During holmium:yttrium-aluminum-garnet (holmium:YAG) laser lithotripsy to break urinary stones, urologists frequently see flashes of light. As infrared laser pulses are invisible, what is the source of light? Here we studied the origin, characteristics, and some effects of flashes of light in laser lithotripsy.

METHODS

Ultrahigh-speed video-microscopy was used to record single laser pulses at 0.2-1.0 J energy lasered with 242 µm glass-core-diameter fibers in contact with whole surgically retrieved urinary stones and hydroxyapatite (HA)-coated glass slides in air and water. Acoustic transients were measured with a hydrophone. Visible-light and infrared photodetectors resolved temporal profiles of visible-light emission and infrared-laser pulses.

RESULTS

Temporal profiles of laser pulses showed intensity spikes of various duration and amplitude. The pulses were seen to produce dim light and bright sparks with submicrosecond risetime. The spark produced by the intensity spike at the beginning of laser pulse generated a shock wave in the surrounding liquid. The subsequent sparks were in a vapor bubble and generated no shock waves. Sparks enhanced absorption of laser radiation, indicative of plasma formation and optical breakdown. The occurrence and number of sparks varied even with the same urinary stone. Sparks were consistently observed at laser energy >0.5 J with HA-coated glass slides. The slides broke or cracked by cavitation with sparks in 63 ± 15% of pulses (1.0 J, N = 60). No glass-slide breakage occurred without sparks (1.0 J, N = 500).

CONCLUSION

Unappreciated in previous studies, plasma formation with free-running long-pulse holmium:YAG lasers can be an additional physical mechanism of action in laser procedures.

Mortality due to urolithiasis in England and Wales: updated findings from a national database over a 23-year period

Introduction

Urolithiasis is a recognised disease of prevalence, and although not common, fatal sequelae can occur. There are few studies with population-based data that provide an overview of the mortality burden associated with this condition. Our aim was to perform an update based on national data from England and Wales.

Material and methods

A search was performed of the database available through the Office of National Statistics (ONS), which collates relevant information from all death certificates in England and Wales. The cause of death is classified according to the conditions listed in the International Classification of Diseases, Tenth Revision (ICD-10). The codes N 20-23 were utilised. Data were collected on gender, location in the upper or lower urinary tract, and age.

Results

Over the 23-year period, 3717 deaths caused by urolithiasis were recorded. The male-to-female ratio was 1:1.4. However, this gender gap steadily closed over time. The mean number of deaths per year was 161 (range: 98-308 year), and this gradually increased over the study period. By 2021, urolithiasis accounted for 0.1% of deaths in England and Wales. Over half of the deaths (64.9%) were in persons aged ≥75 years, while the mortality rate in persons under 50 years old was less than 4%. 0.1% of the deaths occurred in children under 15 years of age, and these were all females.

Conclusions

The number of deaths caused by urolithiasis has increased in England and Wales. Although mortality is higher among females, this gender gap is narrowing.

Effect of Cannabidiol Oil on Post-ureteroscopy Pain for Urinary Calculi: A Randomized, Double-blind, Placebo-controlled Trial

PURPOSE

Post-ureteroscopy stent placement carries significant morbidity which can interfere with daily life. This discomfort unfortunately leads to high utilization of opioid pain medications, which have a known risk of addiction. Cannabidiol oil represents an alternative analgesic that has proven anti-inflammatory and antinociceptive effects. The purpose was to evaluate the effect of a Food and Drug Administration-approved cannabidiol oil (Epidiolex) on pain control and opioid usage in the post-ureteroscopy setting.

MATERIALS AND METHODS

This was a prospective, randomized, double-blind, placebo-controlled trial at a tertiary care center. Ninety patients undergoing ureteroscopy with stent placement for urinary stone disease were randomized 1:1 to placebo or 20 mg cannabidiol oil daily for 3 days postoperatively. Both groups were prescribed a rescue narcotic, tamsulosin, oxybutynin, and phenazopyridine. Daily pain scores, medication usage, and ureteral stent symptoms using the validated Ureteral Stent Symptom Questionnaire were recorded postoperatively.

RESULTS

Both the placebo and cannabidiol oil groups were not different in pre- and perioperative characteristics. There was no difference in pain scores or opioid usage between groups postoperatively. The level of discomfort with ureteral stents was also not different between groups when comparing physical activity, sleep, urination, and activities of daily life.

CONCLUSIONS

This randomized, blinded, placebo-controlled trial showed that cannabidiol oil is safe but ineffective when compared to placebo in reducing post-ureteroscopic stent discomfort or opioid usage. Despite the availability of numerous analgesic agents, stent symptoms continue to be a dissatisfier for most patients, suggesting additional work needs to focus on novel interventions and pain control.

Potential of Unenhanced Ultra-Low-Dose Abdominal Photon-Counting CT with Tin Filtration: A Cadaveric Study

OBJECTIVES

This study investigated the feasibility and image quality of ultra-low-dose unenhanced abdominal CT using photon-counting detector technology and tin prefiltration.

MATERIALS AND METHODS

Employing a first-generation photon-counting CT scanner, eight cadaveric specimens were examined both with tin prefiltration (Sn 100 kVp) and polychromatic (120 kVp) scan protocols matched for radiation dose at three different levels: standard-dose (3 mGy), low-dose (1 mGy) and ultra-low-dose (0.5 mGy). Image quality was evaluated quantitatively by means of contrast-to-noise-ratios (CNR) with regions of interest placed in the renal cortex and subcutaneous fat. Additionally, three independent radiologists performed subjective evaluation of image quality. The intraclass correlation coefficient was calculated as a measure of interrater reliability.

RESULTS

Irrespective of scan mode, CNR in the renal cortex decreased with lower radiation dose. Despite similar mean energy of the applied x-ray spectrum, CNR was superior for Sn 100 kVp over 120 kVp at standard-dose (17.75 ± 3.51 vs. 14.13 ± 4.02), low-dose (13.99 ± 2.6 vs. 10.68 ± 2.17) and ultra-low-dose levels (8.88 ± 2.01 vs. 11.06 ± 1.74) (all p ≤ 0.05). Subjective image quality was highest for both standard-dose protocols (score 5; interquartile range 5-5). While no difference was ascertained between Sn 100 kVp and 120 kVp examinations at standard and low-dose levels, the subjective image quality of tin-filtered scans was superior to 120 kVp with ultra-low radiation dose (p < 0.05). An intraclass correlation coefficient of 0.844 (95% confidence interval 0.763-0.906; p < 0.001) indicated good interrater reliability.

CONCLUSIONS

Photon-counting detector CT permits excellent image quality in unenhanced abdominal CT with very low radiation dose. Employment of tin prefiltration at 100 kVp instead of polychromatic imaging at 120 kVp increases the image quality even further in the ultra-low-dose range of 0.5 mGy.

The changing composition of urinary calculi in Southern Thailand over the past 14 years

Objective

A worldwide increased incidence of urolithiasis has been observed over the past few decades. Insight into the composition of these stones can lead to enhanced medical treatment and outcomes. The objective of this study was to examine the distribution and chemical composition of urinary calculi in Southern Thailand over the past decade.

Materials and Methods

An analysis was conducted on 2611 urinary calculi submitted to the Stone Analysis Laboratory, Songklanagarind Hospital, a single stone analysis laboratory in Southern Thailand. The analysis was performed from 2007 to 2020 using Fourier-transform infrared spectroscopy. The demographic results were described using descriptive statistical analyses, and the Chi-square test for trends was performed to identify changes in urinary calculi composition.

Results

The patients' demographic data revealed a male-to-female ratio of 2.2:1; the most common age group of affected men was 50-69 years, whereas the most common age group of affected women was 40-59 years. The most common components found in the calculi were uric acid (30.6%), mixed calcium oxalate with calcium phosphate (29.2%), and calcium oxalate (26.7%). We noted a trend of increasing uric acid calculi for 14 years (P = 0.00493), whereas the trend for the other major components was decreasing.

Conclusion

The most common component of urinary calculi analyzed in Southern Thailand was uric acid, with a significant rising trend in proportion in the past decade; the trend of other major components, such as mixed calcium oxalate-calcium phosphate and calcium oxalate, decreased.

Spectrum of Bacterial Pathogens from Urinary Infections Associated with Struvite and Metabolic Stones

OBJECTIVE

The purposes of this multi-center study were to evaluate the rate of infection stones and to evaluate the urine cultures of patients with infection stones.

MATERIALS

Charts of adulpatients with urinary stones were reviewed and data on stone analyses and urine cultures were collected.

RESULTS

In total, 1204 renal stone formers (RSFs) from 10 countries were included (776 males, 428 females). Fifty-six patients (4.6%) had struvite stones. The highest frequency of struvite stones was observed in India (23%) and Pakistan (18%). Lower rates were reported in Canada (2%), China (3%), Argentina (3%), Iraq (3%), Italy (3.5%) and Poland (3%), and intermediate rates in Egypt (5.5%) and Bulgaria (5.4%). Urine cultures were retrieved from 508 patients. Patients with struvite stones had a positive culture in 64.3% of the samples and patients with other stones, in 26.7%. In struvite stones, the most common isolates were Escherichia coli (27.7%) and Proteus spp. (27.7%), followed by Klebsiella spp. (16.7%); in other types of stone, it was Escherichia coli (47.6%), followed by Gram-positive bacteria (14.0%) Conclusions: The struvite stone composition was associated with a urinary infection, although an infection was not demonstrable with a conventional midstream urine culture in about 30%.

Feasibility of Laser Lithotripsy for Midsize Stones Using Robotic Retrograde Intrarenal Surgery System easyUretero in a Porcine Model

Purpose: To test the safety and feasibility of laser lithotripsy for midsize renal stones using a newly developed robotic retrograde intrarenal surgery (RIRS) system (easyUretero) in a porcine model. Materials and Methods: Three urologic surgeons representing three different RIRS experience levels (beginner, intermediate, and expert) participated. Four female pigs (aged 6 months) underwent manual or robotic RIRS. Under general anesthesia, a nephrostomy tract was created ventrally, and calcium stones (diameter, 1.0-1.5 cm) were inserted at renal calices. For manual RIRS, surgeons operated a flexible ureteroscope. For robotic RIRS, the ureteroscope was attached to the robotic slave device. The Auriga XL™ Holmium laser was used for lithotripsy. Lasering and stone retrieval time were measured. Kidneys and ureters were inspected for injury at the end of each session. Results: For the expert, both lasering and stone retrieval by manual RIRS were quicker than by robotic RIRS (22.8 ± 11.0 s/stone vs 234.5 ± 102.5 s/stone, p = 0.02; 41.5 ± 0.5 s/stone vs 79.3 ± 8.1 s/stone, p = 0.02). For the intermediate and beginner, lasering and stone retrieval times were not significantly different between manual and robotic procedures (127.8 ± 93.2 s/stone vs 284.8 ± 112.3 s/stone, p = 0.08; 86.0 ± 30.5 s/stone vs 84.1 ± 21.4 s/stone, p = 0.92). All stones were removed. Grade 1 ureteral and renal injuries occurred in both manual RIRS and robotic RIRS. Conclusions: The laser lithotripsy using the easyUretero robotic system is safe and feasible in a porcine model, even for less-experienced surgeons.

The First 100 Cases of Endoscopic Combined Intrarenal Surgery in Korea: Matched Cohort Analyses versus Shock-Wave Lithotripsy

PURPOSE

This study presents our initial experience with endoscopic combined intrarenal surgery (ECIRS) for large renal stones and compares the results of a propensity score-matched cohort of patients undergoing shock-wave lithotripsy (SWL).

MATERIALS AND METHODS

A total of 100 adults underwent ECIRS for renal stones between August 2017 and January 2019. For comparison, 2172 patients who underwent a first session of SWL between January 2005 and May 2018 were included in the SWL cohort. Propensity score matching was performed using maximal stone length (MSL), mean stone density (MSD), and stone heterogeneity index (SHI) scores. Stone-free rate (SFR) and success rate were compared between ECIRS and SWL.

RESULTS

In the ECIRS group, the mean MSL, mean MSD, and mean SHI were 28.7±15.2 mm, 1013.9±360.0 Hounsfield units (HU), 209.4±104.0 HU, respectively. The SFR was 70%, and the success rate was 82.0% in this group. Although the ECIRS group had larger, harder, and more homogeneous stones than the SWL group, ECIRS showed a higher SFR and success rate than SWL. After propensity-score matching, SFR and success rate remained higher with ECIRS than with SWL (both, p<0.001). In multivariate logistic regression, smaller stone size [odds ratio (OR): 0.947, 95% confidence interval (CI): 0.913-0.979, p=0.002] and lower Seoul National University Renal Stone Complexity score (OR: 0.759, 95% CI: 0.610-0.935, p=0.011) were independent predictors of successful ECIRS.

CONCLUSION

ECIRS showed a higher SFR and success rate than SWL for large renal stones. Smaller stone size and lower complexity of stones were associated with a higher likelihood of successful ECIRS.

Risk factors and predictive model for incidence of difficult ureter during retrograde ureteroscopic lithotripsy

OBJECTIVE

Difficult ureter can be a challenge for accessing upper urinary tract during lithotripsy. In this study, we evaluated the risk factors for the incidence of difficult ureter in retrograde ureteroscopic lithotripsy. Moreover, we aimed to develop a predictive model for the incidence of difficult ureter.

METHODS

We retrospectively reviewed consecutive retrograde ureteroscopic lithotripsies performed at our institution between 2009 and 2021. A total of 1010 renal units were evaluated: 449 units with renal stones only and 561 units with ureteral stones, with or without renal stones.

RESULTS

The overall incidence of difficult ureter was 5.9%, with a higher incidence in the renal alone stone group than in the ureteral stone group (7.8% vs 4.5%, P = 0.026). Multivariate regression analysis revealed three risk factors for the incidence of difficult ureter: absence of stone history (odds ratio 5.67, 95% confidence interval 2.40-13.4, and P < 0.001), age ≤45 years (odds ratio 3.61, 95% confidence interval 2.05-6.37, and P < 0.001), and renal stone only (odds ratio 2.11, 95% confidence interval 1.22-3.64, and P = 0.008). A simple model using these three risks enabled the stratification of the incidence rate of difficult ureter, with the incidence of high-risk cases being 12.7%.

CONCLUSIONS

The greatest risk factor for the incidence of difficult ureter was the absence of stone history, followed by age 45 years or younger, and having only renal stones. In high-risk cases of difficult ureter, the possibility of secondary lithotripsy should be explained to the patients.

The Economic Burden of Cystoscopy-Based Ureteral Stent Removal in the United States: An Analysis of Nearly 30,000 Patients

INTRODUCTION

Ureteral stents are commonly placed after ureteroscopy. We examined the rate of cystoscopy-based stent removal (CBSR) following ureteroscopy for stone disease and its economic burden in the United States.

METHODS

Adults undergoing ureteroscopy and stenting (index surgery) for stone disease between 2014 and 2018 were identified using the IBM® MarketScan® Commercial Database. Patients were categorized as those with CBSR or without CBSR within 6 months post-index surgery. Rate and location of CBSR were assessed. To estimate the economic burden of CBSR, medical costs (2019 U.S. dollars) paid by insurers were calculated at 6 months post-index surgery. A generalized linear model examined the association of CBSR with total costs adjusting for patient characteristics.

RESULTS

Among 29,535 patients meeting the inclusion criteria, 56.5% had CBSR within 6 months. Median time to CBSR was 9 days; 70% of patients with CBSR had their stent removed in the office. Medical costs for CBSR patients were significantly higher than those for nonCBSR patients ($7,808 vs $6,231; p <0.0001). The difference was driven by the cost of CBSR ($1,132 vs $0; p <0.0001) and health care utilization for stone disease ($2,464 vs $2,121; p <0.0001). CBSR was associated with a 17% increase in medical costs compared to nonCBSR (OR: 1.17; 95% CI 3.03, 3.46).

CONCLUSIONS

Over 50% of patients had CBSR within 6 months following ureteroscopy. Medical costs for patients undergoing CBSR were significantly higher and driven by the cost of CBSR and resource utilization for stone disease. Ureteral stents that avoid CBSR can lower medical costs to the health care system.

Prognostic Accuracy of the qSOFA Score for In-Hospital Mortality in Elderly Patients with Obstructive Acute Pyelonephritis: A Multi-Institutional Study

Prognostic accuracy of the quick sequential organ failure assessment (qSOFA) score for mortality may be limited in elderly patients. Using our multi-institutional database, we classified obstructive acute pyelonephritis (OAPN) patients into young and elderly groups, and evaluated predictive performance of the qSOFA score for in-hospital mortality. qSOFA score ≥ 2 was an independent predictor for in-hospital mortality, as was higher age, and Charlson comorbidity index (CCI) ≥ 2. In young patients, the area under the curve (AUC) of the qSOFA score for in-hospital mortality was 0.85, whereas it was 0.61 in elderly patients. The sensitivity and specificity of qSOFA score ≥ 2 for in-hospital mortality was 80% and 80% in young patients, and 50% and 68% in elderly patients, respectively. For elderly patients, we developed the CCI-incorporated qSOFA score, which showed higher prognostic accuracy compared with the qSOFA score (AUC, 0.66 vs. 0.61, p < 0.001). Therefore, the prognostic accuracy of the qSOFA score for in-hospital mortality was high in young OAPN patients, but modest in elderly patients. Although it can work as a screening tool to determine therapeutic management in young patients, for elderly patients, the presence of comorbidities should be considered at the initial assessment.

Learning retrograde intrarenal surgery as a sheathless and radiation-free technique

The aim of this study was to evaluate the learning curve of inexperienced surgeon who can perform the operation on their own for access sheatless and radiation-free retrograde intrarenal surgery (RIRS) technique. Results of 70 consecutive patients who have renal stones and underwent RIRS which performed by a single surgeon were evaluated retrospectively. Cumulative stone free rates and fragmentation efficacy were taken as the primary outcomes for the learning curve analyses. Stone free rate was 74% (52/70). The learning curve constructed with moving average of cumulative stone free rates showed that learning curve of sheathless RIRS consisted of three phases; rapid ascent (0-15: phase 1), slight decline (16-35: phase 2) and plateau (36-70: phase 3). The number of case needed to obtain a final plateau in stone free rates was about 35. Fragmentation efficacy reached a plateau after 50 cases. The learning curve of access sheatless and radiation-free RIRS reached plateau phase after 35-50 cases. This steep learning curve points out that surgeons do not need to experience the classical RIRS technique before starting to perform access sheatless and radiation-free technique.

The current status of preventive measures for urinary calculi in children

Urological calculus is a common disease in urology. Urological calculi are generally more common in adults but have become more common in children in recent years. Most existing studies focus on the prevention of urinary calculi in adults; there are relatively few articles on calculi in children. Reported preventive measures are not comprehensive enough, while the latest research progress has not been updated. The pathogenesis and preventive measures associated with urinary calculi have been the focus of research, but many preventive measures still need further clarification. This article reviews the progress on preventive measures for urinary calculi in children.

Spectrum of urological cases in a West African Tertiary Hospital

Context:

Urological diseases vary from one geographical location to another worldwide. The knowledge of their distribution in each location could determine local workforce and facility needs and as well guide the areas of subspecialization.

Aims:

The aim of this study is to document the annual frequency and distribution of urological diseases at the Usmanu Danfodiyo University Teaching Hospital, Sokoto.

Settings and Design:

A cross-sectional retrospective study from January 2016 to December 2016 of all new patients seen at the urology outpatient clinic, emergency department as well as inpatient referrals from other departments of Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria.

Materials and Methods:

The relevant records were extracted from the patient's case notes and entered into a semistructured questionnaire.

Statistical Analysis Used:

Data were analyzed using the SPSS software version 20.

Results:

A total of 607 new patients were seen over the study period. There were 576 (94.9%) males and 31 (5.1%) females, with a male-to-female ratio of 18.6:1. The median age was 45 years, with age range of 1–106 years. Urological emergencies were seen in 35.0% patients. Ninety-one percent of cases were acquired, whereas 8.2% were of congenital etiology. Overall, the most commonly diagnosed urologic diseases among new patients in order of decreasing frequency were benign prostatic enlargement (BPE) (18.6%), bladder tumor (11.8%), upper tract urinary calculi (10.3%), urethral stricture (8.9%), and prostate adenocarcinoma (7.4%).

Conclusions:

BPE, bladder tumor, upper tract urinary calculi, urethral stricture, and prostate adenocarcinoma are common in our environment. Knowledge of these diseases distribution may guide service expansion and workforce needs, inspire subspecialization as well as direct research and government policy in this community. Nongovernmental organizations wanting to have impact will be suitably directed.

Mechanism of Huayu Jianpi Fangshi decoction in urolithiasis prevention: a randomized trial

BACKGROUND

This study aims to explore the mechanism of the Huayu Jianpi Fangshi decoction in urolithiasis prevention.

METHODS

The present study was designed as a randomized, double-blinded, placebo-controlled clinical trial. Sixty patients with the qi stagnation and blood stasis, spleen deficiency, and dampness obstruction types of urolithiasis were randomly divided into two groups: the treatment group and the control group (n=30 in both groups). Patients in the treatment group were treated with the Huayu Jianpi Fangshi decoction, while patients in the control group were treated with the Huayu Fangshi placebo decoction. Both treatments were taken orally two times per day. All patients received treatment over the course of four weeks. The main outcome indicators included the Tamm-Horsfall protein (THP) expression levels, osteopontin, and inter-α-trypsin inhibitor heavy chain 3 (ITIH3) in the patients' urine as well as changes in 24-h urinary citric acid, urinary magnesium levels, and Traditional Chinese Medicine (TCM) syndrome scores.

RESULTS

The results of the present study revealed a significant increase in the total citric acid excretion level (244.75±59.62 vs. 297.48±57.91 mmol/L, P<0.01), significant decrease in the total urinary THP level (10.83±7.73 vs. 6.37±6.10 mg/L, P<0.05), significant decrease in the total ITIH3 level (9.51±6.32 vs. 6.14±4.46 mg/L, P<0.05) in the patients' 24-h urine, and a significant elevation of the total TCM syndrome score (5% vs. 23%, P<0.01) in the treatment group when compared with the control group.

CONCLUSIONS

The Huayu Jianpi Fangshi decoction can increase the excretion of urinary citric acid, decrease the expression levels of urinary THP and ITIH3 in patients with cured urolithiasis, and reduce the TCM syndrome score.

Role of Stone Heterogeneity Index in Determining Success of Shock Wave Lithotripsy in Urinary Calculi

INTRODUCTION

Various stone factors can affect the outcome of shock wave lithotripsy (SWL). A novel factor called the stone heterogeneity index (SHI) may have an impact on stone free rates. The objective of this study was to assess the role of SHI in SWL outcomes.

METHODS

Patients' medical records were reviewed for the collection of data variables. They were subjected to SWL, using an electromagnetic lithotripter machine (Storz Modulith SLX-MX). Computation of mean stone density (mean value of the Hounsfield units) and SHI was accomplished by generating elliptical regions of interest on the computed tomography (CT) scan images. Grouping was performed on the basis of stone free and failure outcomes. Relevant statistical tests were applied for continuous and categorical variables. P ≤ 0.05 was considered statistically significant.

RESULTS

Overall, 385 subjects were included having a mean age of 38.4 ± 14.7 years. The cohort comprised 276 (71.7%) males and 109 (28.3%) female patients. A total of 234 (60.8%) patients were rendered successful (stone free after one session) while 151 (39.2%) of the patients were declared to have failed the SWL procedure. Stone length, stone density, and SHI values were 13.7 ± 7.6 mm, 935 ± 404, and 201 ± 107, respectively. The stone density, SHI, and stone length were significantly different between the two groups (p-values of 0.001, 0.02, and 0.04, respectively).

CONCLUSIONS

SHI can be a helpful CT scan-based parameter to assess stone fragility. It can help clinicians in the judicious selection of patients before implementing SWL procedure.

RELEVANCE FOR PATIENTS

Non-contrast CT-based stone parameters have been found to be effective for predictions of outcomes. SHI can be a helping tool to better predict SWL success rates when treating the renal stones.

Loop-tail stents fail in reducing stent-related symptoms: results of a prospective randomised controlled trial

OBJECTIVE

To compare stent-related symptoms (SRS) of loop-tail (LT) and conventional double J (DJ) stents after uncomplicated flexible ureterorenoscopy (fURS), in a prospective randomised controlled single-blind parallel-group study.

PATIENTS AND METHODS

Patients undergoing fURS were randomised into two groups: the LT Group received LT stents (Polaris™ Loop) and the DJ Group received conventional DJ stents (Vortek^® ). The stent was removed after 4 weeks. The Ureteric Stent Symptom Questionnaire (USSQ) was administered at 2 days, 4 and 8 weeks (baseline evaluation) after stent insertion. The primary endpoint was to compare the Urinary Symptom Index Score of the LT vs DJ groups at 4 weeks after stent insertion. The secondary endpoints were to compare the USSQ domains' subscores at 2 days and 4 weeks after stent insertion, USSQ single answers at 4 weeks, and the 4-week USSQ domains' subscores adjusted for baseline.

RESULTS

A total of 68 patients were randomised (34 LT and 34 DJ). The answers given at 4 weeks were not significantly different between the two groups for the Urinary Symptom Index Score (P = 0.982), Pain Index Score (P = 0.169), visual analogue scale (P = 0.276), and all the other domains of the USSQ. At 4 weeks, the single-answer analysis did not find any differences between the groups; the urinary symptoms were all comparable, as was the requirement for pain painkillers (P = 0.684) and pain during sex (P = 0.496). There were also no significant differences for every single domain score for the responses given at 2 days. The same applied to USSQ subscores at 4 weeks adjusted for the 8-week baseline results, which were also comparable.

CONCLUSIONS

The study found no differences in terms of SRS between the LT and DJ groups, either at 2 days or 4 weeks after stent insertion, with or without baseline correction.

Gender differences in acute stone admissions - should we have a lower threshold for treatment in female patients?

OBJECTIVES

To examine the gender-related differences in the presentation, management and outcomes of patients admitted with acute renal colic at our institution.

PATIENTS AND METHODS

A retrospective analysis of 231 consecutive patients requiring inpatient admission for acute renal colic between October 2015 and March 2018. For each admission, data on demographics, admission blood results, stone characteristics, management and outcomes were collected. Differences between genders were compared using the chi-squared and Student's t-test.

RESULTS

Gender distribution was 35% female: 65% male. There was no significant difference in age, American Society of Anesthesiologists Physical Status Classification grade or history of diabetes. Women had a higher admission C-reactive protein level (89.3 vs 32.9 mg/L, P < 0.001) and neutrophil count (10.0 vs 8.8 × 10⁹ /L, P = 0.04) than men. They also had more positive cultures (34.1% vs 6.0%, P < 0.001) and were more likely to require percutaneous nephrostomy insertion (9.8% vs 0.7%, P = 0.005). Women had more intensive therapy unit (ITU) admissions (12.2% vs 0.6%, P < 0.001) and longer lengths of stay (4.4 vs 1.8 days, P < 0.001) than men. There was no mortality in our series.

CONCLUSION

In the present study, women admitted with acute renal colic were more likely to have an associated infection than men and require rapid decompression. Although there was no difference in mortality, women experienced greater morbidity as evidenced by the higher rate of ITU admissions and longer length of stay. These differences are important to consider when assessing the suitability of conservative management for female patients.

Ureteral Stent Placement following Ureteroscopy Increases Emergency Department Visits in a Statewide Surgical Collaborative

PURPOSE

Ureteral stents are commonly placed after ureteroscopy. Although studies indicate that stents are associated with patient discomfort, their impact on downstream health services use is unclear. We examined patterns of stent utilization in Michigan and their association with unplanned health care encounters.

MATERIALS AND METHODS

We used the Michigan Urological Surgery Improvement Collaborative's Reducing Operative Complications from Kidney Stones (MUSIC ROCKS) clinical registry to identify ureteroscopy cases between 2016 and 2019. Factors associated with stent placement were examined using bivariate and multivariable statistics. Using multivariable logistic regression, we evaluated whether stent placement was associated with emergency department visits and hospitalizations within 30 days.

RESULTS

We identified 9,662 ureteroscopies and a stent was placed in 7,025 (73%) of these. Frequency of stent use across the 137 urologists varied (11%-100%, p <0.001) and was not associated with total case volume. Factors associated with stent use included age and stone size. Pre-stented cases and renal stones had a decreased odds of stent placement. On multivariable analysis after adjusting for risk factors, stent placement was associated with a 1.25 higher odds of emergency department visit (OR 1.25, 95% CI 1.01-1.54, p=0.043) but not hospitalization (OR 1.28, 95% CI 0.94-1.76, p=0.12). In a single high volume practice, 0.5% of cases that omitted a stent required urgent stenting postoperatively.

CONCLUSIONS

There is substantial variation in the use of stents in Michigan, irrespective of case volume. Stent placement significantly increased the odds of an emergency department visit after surgery. Importantly, stent omission rarely required subsequent urgent stent placement.

Urinary Stones and Intervention Quality of Life (USIQoL): Development and Validation of a New Core Universal Patient-reported Outcome Measure for Urinary Calculi

BACKGROUND

Urolithiasis has a significant impact on patients' health-related quality of life (HRQoL).

OBJECTIVE

To develop a core patient-reported outcome measure (PROM) using modern psychometric methods to quantify the impact of urolithiasis and different treatments.

DESIGN, SETTING, AND PARTICIPANTS

Adult patients with urinary calculi, attending urology departments, covering all index categories and treatment spectrum, participated during different development phases. The pilot instrument was created from potential items (phases 1 and 2) within the conceptual framework. The instrument was pretested (phase 3) and then underwent psychometric evaluation in two parts (phases 4 and 5).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The validity and reliability of the new PROM were assessed using Rasch measurement theory (RUMM 2030 statistical software) and traditional analyses.

RESULTS AND LIMITATIONS

In total, 683 patients (median age 51 yr, range 18-92 yr) participated during different phases. The initial 60-item draft (five scales) was completed by 212 patients (phase 4). A revised 25-item draft was produced after removal of unstable items. In the second field test, the revised version was evaluated by 369 patients. This led to the final Urinary Stones and Intervention Quality of Life (USIQoL; 15 items) with summated logit scores. The PROM includes three scales: pain with physical health (six items), psychosocial health (seven items) and work performance (two items). Lower scores indicate better outcomes. Results demonstrate that USIQoL is reliable (r ≥ 0.8) and internally consistent (α ≥ 0.7), and has good construct validity (good hypothesised correlations, r > 0.3) and satisfactory sensitivity to change (p < 0.01). All scales demonstrated unidimensionality with good item fit and person separation indices. A limitation is that USIQoL was developed in the English language within the UK population.

CONCLUSIONS

USIQoL is a short, unidimensional, valid, and reliable PROM for assessing the HRQoL impact of urinary calculi and treatments. It is expected to serve as a core PROM across the entire spectrum of urolithiasis.

PATIENT SUMMARY

Kidney stones are a common condition for which various treatment options are available. The condition and treatments have a significant impact on a patient's quality of life. This can be measured objectively using a valid and reliable patient-reported outcome measure (PROM) developed using modern methods. We have developed a PROM that provides helpful and accurate measurement useful for all stakeholders.

Preliminary study of prevalence of urolithiasis in North-Eastern city of India

Introduction:

Urinary tract stone is one of the major urological problems globally and has changed significantly in the last few decades. The epidemiology differs according to geography, socioeconomic status, and diet. The primary care physicians are initially consulted rather than urologists because of increase in the prevalence of urolithiasis and saturation of health facilities.

Objectives:

To study the prevalence of urolithiasis in the urology department of a tertiary care centre, Manipur, India.

Methods:

A total 621 patients of urolithiasis were studied. After history and physical examination of each patient, urolithiasis was confirmed by X-ray Kidney Ureter Bladder (KUB) or Ultrasound (USG) KUB.

Results:

The male to female ratio was 1.01:1. 30.8% patients came from Imphal West district. 63.1% of studied population had single stone and commonly seen in the 31–40 years of age, whereas multiple stones (n = 59) were found most commonly in the 41–50 years of age group. The difference of number of stones according to age group was statistically significant (P = 0.000). The most common location of stones was in kidneys (67.4%) and stones in urethra were the least common (P = 0.000).

Conclusion:

In this preliminary study, we report the prevalence of urolithiasis in Manipur, India. The better understanding of the epidemiology of urolithiasis is important to plan the effective treatment and prevention strategies in general practice. There is a shift in gender distribution of urolithiasis. Aging demographics, number of stones, obesity; all were associated with increased prevalence of urolithiasis.

Clinician Versus Nomogram Predicted Estimates of Kidney Stone Recurrence Risk

Purpose: Kidney stone recurrence rates vary between patients. A patient's risk informs the frequency and intensity of preventative interventions. Clinicians routinely use clinical experience to estimate risk. We sought to compare clinician estimated recurrence risk with the recurrence of kidney stones (ROKS) nomogram. Materials and Methods: We surveyed members of the Endourological Society with clinical expertise in kidney stones. Respondents estimated the risk of recurrence for patients in three clinical vignettes corresponding to low, intermediate, and high recurrence risk from the nomogram. Clinician estimates were compared with ROKS estimates. Results: The majority of the 318 respondents were from North America (n = 127, 40%). The most commonly estimated recurrence was 50% at 5 years. The respondents' estimates were significantly different from the ROKS predicted recurrence rate for all cases (Case 1, 50% vs 93% p < 0.0001; Case 2, 50% vs 60% p < 0.0001; Case 3, 60% vs 22% p < 0.0001). The ROKS predicted estimates ranged from 22% to 93%, whereas the median urologist-derived 5-year risk estimates for each case ranged from 50% to 60%. The median range of estimates by respondents across cases was 20%, narrower than the 71% for the ROKS nomogram. The majority of respondents (95%) do not use nomograms in practice, mostly because of lack of awareness of useful nomograms (59%). Conclusions: This study suggests that clinicians may not be able to distinguish those with high and low recurrence risk when compared with peers and when compared with a nomogram. Clinical decision support tools are needed to enable clinicians to better estimate stone recurrence risk.

Urinary stone management during the COVID-19 pandemic: a suggested approach and review of literature

COVID-19 is now the major health concern of the century in many countries. Prolonged homestay has various undesirable consequences for people, such as physical inactivity and weight gain, which potentially could put people at risk of urinary stone formation. With regard to the prevention and treatment strategy for urinary stones during this COVID-19 pandemic period, patients can be divided into two groups. The first group comprises those for whom urological intervention is not indicated and where general dietary and lifestyle recommendations are helpful. The second group comprises those patients where urological intervention is indicated. This group can be divided into emergent and nonemergent subgroups. Patients with urinary stones and concomitant uremia, sepsis, anuria, or refractory pain and vomiting make up the emergent group, where intervention is necessary. The preferred option during the novel coronavirus crisis for these patients is percutaneous nephrostomy tube insertion under local anesthesia. The second subgroup is made up of those patients with asymptomatic and noncomplicated renal and ureteral stones where urologic intervention is indicated in the usual time scale. However, we suggest conservative treatment for 3 months during the COVID-19 outbreak after which re-evaluation of the patient should be carried out. Thus the operation could be chosen carefully based on the patient’s and urologist’s preference and the rate of infection in that center.

Gender and side distribution of urinary calculi using ultrasound imaging

Introduction:

Urinary calculi constitute a significant medical problem worldwide. Due to lack of previous studies on gender and side distribution of urinary calculi, the current study was conducted.

Patients and Methods:

This retrospective study involved 590 urinary calculi from the electronic reports of 266 patients. Gender and side distribution were compared using Chi-square test. Relationship between gender and side of urinary calculi was analyzed using cross tabulation test.

Results:

This study involved 590 urinary calculi reported in 266 patients. Among 590 calculi; 565 (95.8%) were in adults, and 25 (4.2%) were in children. Urinary calculi were in male in 397 (67.3%) and in female in 193 (32.7%). Calculi were 304 (51.5%) in right side, and 286 (48.5%) in left side. Exactly 507 (85.9%) of calculi were in the kidneys, and 83 (14.1%) in the ureters. No significant relationship between gender and side of the calculi (P = 0.238), (Odds ratio 0.869, 95% Confidence interval 0.615-1.226).

Conclusion:

Urinary calculi affect male more than female and adults more than children. No significant relationship between calculi and right or left side of the body.

Urinary stone composition analysis of 3684 patients in the eastern Shandong region of China

OBJECTIVE

There has not been a study that analyzed the composition of urinary stones from patients in the eastern Shandong region of China. Thus, we explored the composition of urinary stones in the eastern Shandong region of China and discuss the clinical significance of the findings.

METHODS

A total of 3684 urinary calculi from the eastern Shandong region were collected in our study. Compositions of the stones were analyzed using an Automatic Infrared Spectrum Analysis System (type LIIR-20). The results were verified through manual analysis of the spectrograms, which was accompanied by polarizing microscopy and chemical analysis if necessary.

RESULTS

Among the 3684 specimens, there were 1767 single-component stones and 1917 mixed-component stones. According to the main components of the stones, the stones were divided into the following types: calcium oxalate monohydrate stones (1779, 48.3%), anhydrous uric acid stones (1105, 30.0%), carbonate apatite stones (590, 16.0%), ammonium magnesium phosphate hexahydrate stones (143, 3.9%), calcium oxalate dihydrate stones (36, 1.0%), and cystine stones (31, 0.8%).

CONCLUSIONS

There was a relatively high rate of uric acid stones in patients from the eastern Shandong region of China.

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.

Urinary Stone Disease in Pregnancy: A Claims Based Analysis of 1.4 Million Patients

PURPOSE

Urinary stone disease during pregnancy is poorly understood but is thought to be associated with increased maternal and fetal morbidity. We determined the prevalence of urinary stone disease in pregnancy and whether it is associated with adverse pregnancy outcomes.

MATERIALS AND METHODS

We identified all pregnant women from 2003 through 2017 in the Optum® national insurance claims database. We used diagnosis claims to identify urinary stone disease and assess medical comorbidity. We established the prevalence of urinary stone disease during pregnancy stratified by week of pregnancy. We further evaluated associations among urinary stone disease, maternal complications and pregnancy outcomes in univariable and multivariable analyses.

RESULTS

Urinary stone disease affects 8 per 1,000 pregnancies and is more common in white women and women with more comorbid conditions. In fully adjusted models pregnancies complicated by urinary stone disease had higher rates of adverse fetal outcomes including prematurity and spontaneous abortions. This analysis is limited by its retrospective, administrative claims design.

CONCLUSIONS

The rate of urinary stone disease during pregnancy is higher than previously reported. Urinary stone disease is associated with adverse pregnancy outcomes.

Twenty-Four Hour Urine Testing and Prescriptions for Urinary Stone Disease-Related Medications in Veterans

BACKGROUND AND OBJECTIVES

Current guidelines recommend 24-hour urine testing in the evaluation and treatment of persons with high-risk urinary stone disease. However, how much clinicians use information from 24-hour urine testing to guide secondary prevention strategies is unknown. We sought to determine the degree to which clinicians initiate or continue stone disease-related medications in response to 24-hour urine testing.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We examined a national cohort of 130,489 patients with incident urinary stone disease in the Veterans Health Administration between 2007 and 2013 to determine whether prescription patterns for thiazide diuretics, alkali therapy, and allopurinol changed in response to 24-hour urine testing.

RESULTS

Stone formers who completed 24-hour urine testing (n=17,303; 13%) were significantly more likely to be prescribed thiazide diuretics, alkali therapy, and allopurinol compared with those who did not complete a 24-hour urine test (n=113,186; 87%). Prescription of thiazide diuretics increased in patients with hypercalciuria (9% absolute increase if urine calcium 201-400 mg/d; 21% absolute increase if urine calcium >400 mg/d, P<0.001). Prescription of alkali therapy increased in patients with hypocitraturia (24% absolute increase if urine citrate 201-400 mg/d; 34% absolute increase if urine citrate ≤200 mg/d, P<0.001). Prescription of allopurinol increased in patients with hyperuricosuria (18% absolute increase if urine uric acid >800 mg/d, P<0.001). Patients who had visited both a urologist and a nephrologist within 6 months of 24-hour urine testing were more likely to have been prescribed stone-related medications than patients who visited one, the other, or neither.

CONCLUSIONS

Clinicians adjust their treatment regimens in response to 24-hour urine testing by increasing the prescription of medications thought to reduce risk for urinary stone disease. Most patients who might benefit from targeted medications remain untreated.

Metabolic syndrome and the composition of urinary calculi: is there any relation?

Introduction

Epidemiologic studies demonstrate that obesity and diabetes increase the prevalence of urinary lithiasis. Most of these studies did not stratify the chemical composition of calculi and the physiological mechanisms responsible for this increased risk are not well understood. This study aims to investigate the relation between the metabolic syndrome and the composition of the urinary calculi.

Material and methods

Observational and retrospective study of all urinary calculi analysis performed at the Centro Hospitalar do Tâmega e Sousa, Portugal – from January 2009 to September 2015. Calculi were analyzed by infrared spectroscopy.

Results

302 analyses of urinary calculi were identified. Metabolic syndrome was diagnosed in 20.5% of patients. A total of 7 different mineral compounds were identified: 51.6% (N = 156) contained calcium oxalate, 41% (N = 124) calcium phosphate, 37.7% (N = 114) uric acid, 22.1% (N = 67) ammonium urate, 9.6% (N = 29) ammonium magnesium phosphate, 6.3% (N = 19) sodium urate and 1.3% (N = 4) contained cystine. Patients with metabolic syndrome presented a higher proportion of uric acid calculi (66.1% vs. 0%, p <0.001) and ammonium urate calculi (38.7% vs. 17%, p = 0.001). Patients without metabolic syndrome had a higher proportion of calcium oxalate calculi (58.8% vs. 24.2%, p <0.001) and calcium phosphate (46.7% vs. 19.4%, p <0.001).

Conclusions

There is a statistically significant relation between metabolic syndrome and uric acid and ammonium urate calculi. Metabolic syndrome may be considered risk factor for this calculi and the diagnosis and treatment of this syndrome must be considered for urolithiasis prevention. Further studies are needed to better the understanding of physiological mechanisms underlying this relationship to improve our strategy of prevention of urinary lithiasis.

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.

The laser of the future: reality and expectations about the new thulium fiber laser-a systematic review

The Holmium:yttrium-aluminum-garnet (Ho:YAG) laser has been the gold-standard for laser lithotripsy over the last 20 years. However, recent reports about a new prototype thulium fiber laser (TFL) lithotripter have revealed impressive levels of performance. We therefore decided to systematically review the reality and expectations for this new TFL technology. This review was registered in the PROSPERO registry (CRD42019128695). A PubMed search was performed for papers including specific terms relevant to this systematic review published between the years 2015 and 2019, including already accepted but not yet published papers. Additionally, the medical sections of ScienceDirect, Wiley, SpringerLink, Mary Ann Liebert publishers, and Google Scholar were also searched for peer-reviewed abstract presentations. All relevant studies and data identified in the bibliographic search were selected, categorized, and summarized. The authors adhered to PRISMA guidelines for this review. The TFL emits laser radiation at a wavelength of 1,940 nm, and has an optical penetration depth in water about four-times shorter than the Ho:YAG laser. This results in four-times lower stone ablation thresholds, as well as lower tissue ablation thresholds. As the TFL uses electronically-modulated laser diodes, it offers the most comprehensive and flexible range of laser parameters among laser lithotripters, with pulse frequencies up to 2,200 Hz, very low to very high pulse energies (0.005-6 J), short to very long-pulse durations (200 µs up to 12 ms), and a total power level up to 55 W. The stone ablation efficiency is up to four-times that of the Ho:YAG laser for similar laser parameters, with associated implications for speed and operating time. When using dusting settings, the TFL outperforms the Ho:YAG laser in dust quantity and quality, producing much finer particles. Retropulsion is also significantly reduced and sometimes even absent with the TFL. The TFL can use small laser fibers (as small as 50 µm core), with resulting advantages in irrigation, scope deflection, retropulsion reduction, and (in)direct effects on accessibility, visibility, efficiency, and surgical time, as well as offering future miniaturization possibilities. Similar to the Ho:YAG laser, the TFL can also be used for soft tissue applications such as prostate enucleation (ThuFLEP). The TFL machine itself is seven times smaller and eight times lighter than a high-power Ho:YAG laser system, and consumes nine times less energy. Maintenance is expected to be very low due to the durability of its components. The safety profile is also better in many aspects, i.e., for patients, instruments, and surgeons. The advantages of the TFL over the Ho:YAG laser are simply too extensive to be ignored. The TFL appears to be a real alternative to the Ho:YAG laser and become a true game-changer in laser lithotripsy. Due to its novelty, further studies are needed to broaden our understanding of the TFL, and comprehend the full implications and benefits of this new technology, as well its limitations.

Vaporizing Effect of the Popcorn Technique for Laser Lithotripsy: Comparing the Different Settings of High Energy in a Caliceal Model

Objective: To assess the effectiveness of laser lithotripsy in different holmium:yttrium aluminum garnet (Ho-YAG) laser settings with a wide range of energies, frequencies, and power. Materials and Methods: Two types of phantom stones were utilized, including soft stone, which mimics uric acid stone, and hard stone, which mimics calcium oxalate monohydrate stone. The stones were made into a round shape measuring 10 mm in diameter. The lithotripsy settings were 1 J × 20 Hz, 2 J × 10 Hz, 1.5 J × 20 Hz, 3 J × 10 Hz, and 2 J × 20 Hz. The lithotripsy was conducted in a caliceal model with a 2-mm filter. All stone vanishing from the artificial calix was an end point of the experiment. All fragments that passed through the filter of each setting were dried and weighed to calculate the vaporizing effect as well as to compare among the different settings. Laser fiber degradation was compared by using these settings. Results: Disintegration efficiency was determined by time consumption and the amount of vaporized stone. The best time consumption was 8 min 51 sec for 2 J × 20 Hz for hard stone and 5 min 13 sec for this setting for soft stone. The most vaporizing effect for hard stone was 92.19% for 2 J × 20 Hz and 87.30% for this setting for soft stone. The most fiber tip degradation was 28 mm for 3 J × 10 Hz for hard stone and 4 mm for 1.5 J × 20 Hz for soft stone. Conclusion: The study revealed that the best setting for hard stone was 2 J × 20 Hz, which was the fastest for achieving maximum vaporization, whereas fiber degeneration was comparable to others. For soft stone, there was no difference among the settings.

A Novel Laser Lithotripsy System with Automatic Real-Time Urinary Stone Recognition: Computer Controlled Ex Vivo Lithotripsy is Feasible and Reproducible in Endoscopic Stone Fragmentation

PURPOSE

Urinary stone treatment has been strongly influenced by advances in technology. Nevertheless, the photonic characteristics of stones as the treatment target have been neglected. Monitoring fluorescence spectra is sufficient for automatic target differentiation and laser feedback control as previously described. We investigated the characteristics of fluorescence signals and the clinical practicability of real-time laser feedback control during lithotripsy.

MATERIALS AND METHODS

Fluorescence excitation light was superimposed on a holmium laser beam into the treatment fiber. Spectra were recorded and signal amplitude changes were analyzed during increases in distance between the fiber tip and the stone to identify the optimal threshold level for stone recognition. Ho:YAG lithotripsy was performed under in vitro surgical conditions in porcine tissue while our feedback system autonomously controlled the laser impulse release during lithotripsy. The tissue was then endoscopically and macroscopically examined for laser induced lesions.

RESULTS

Mean ± SD autofluorescence signal amplitudes from urinary stone samples varied between 142 ± 29 and 1,521 ± 152 ADU while tissue and endoscope coating emission was negligible. Signal amplitude decreased rapidly at distances larger than 1 to 2 mm. Clinically reliable threshold values for target recognition could be set to prevent laser pulse emission if the stone was out of range or urothelial tissue might be harmed by laser irradiation. We observed no incorrectly released laser pulse or injury to tissue during autonomously controlled holmium laser lithotripsy.

CONCLUSIONS

Our laboratory study strengthens the evidence that tracking real-time autofluorescence spectra during endoscopic stone surgery via automatic feedback control of the laser impulse release may become a potentially useful clinical tool for surgeons who navigate in the upper urinary tract.

Medical management of urolithiasis in the Middle Ages: Thesaurus Pauperum of Pope John XXI

BACKGROUND/OBJECTIVE

This paper will present a brief description of medicine in the Middle Ages, and more comprehensive analysis of the medical management of urolithiasis in Thesaurus Pauperum, the main text of Pedro Hispano.

METHOD

An in-depth reading of the Italian translation of Thesaurus Pauperum, and a review of the literature of the life of Pedro Rebuli Guiliani, known as Pedro Hispano, was performed.

RESULT

Pedro Hispano was born in Portugal around 1205. He studied philosophy, theology and medicine in Paris. He was named professor of medicine at the University of Siena in 1247 and was elected Pope, as John XXI, in 1276. His primary medical book was Thesaurus Pauperum ('Treasure of the Poor'), a prescription handbook for common diseases, directed not only to physicians but also to ordinary people. We focused on the description of medical management of urolithiasis in Thesaurus Pauperum.

CONCLUSION

This text is interesting not so much on account of the pharmacopoeia used, but instead, because it is, probably, one of the first medical text reporting therapeutics close to the modern evidence-based medicine.

Predictors of Uric Acid Stones: Mean Stone Density, Stone Heterogeneity Index, and Variation Coefficient of Stone Density by Single-Energy Non-Contrast Computed Tomography and Urinary pH

We analyzed the capacities of pertinent parameters (determined by single-energy non-contrast computed tomography [NCCT]) and urinary pH to predict uric acid stones. We reviewed the medical records of 501 patients whose stones were removed surgically or passed spontaneously between December 2014 and April 2016. Qualifying participants (n = 420) were stratified by the nature of the stone (calcium oxalate, uric acid, or infectious). Based on NCCT, we determined maximal stone length (MSL), mean stone density (MSD), and stone heterogeneity index (SHI) using Hounsfield units (HU) and calculated the variant coefficient of stone density (VCSD = SHI/MSD × 100). Urinary pH was also ascertained. Mean patient age was 55.55 ± 15.46 years. MSD (448.59 ± 173.21 HU), SHI (100.81 ± 77.37 HU), and VCSD (22.58 ± 10.55) proved to be significantly lower in uric acid versus other types of stones, as did urinary pH (5.33 ± 0.56; all p < 0.001). Receiver operating characteristic (ROC) curves depicting predictability of uric acid stones yielded area under ROC curve (AUC) values for MSD, SHI, VCSD, and urinary pH of 0.806 (95% CI: 0.761⁻0.850), 0.893 (95% CI: 0.855⁻0.931), 0.782 (95% CI: 0.726⁻0.839), and 0.797 (95% CI: 0.749⁻0.846), respectively, with corresponding cutpoints of 572.3 HU, 140.4 HU, 25.79, and 6.0. Among these four parameters, SHI was verifiably (DeLong's test) the most effective predictor of uric acid stones (all p < 0.001). Compared with MSD, VCSD, and urinary pH, SHI may better predict uric acid stones, using a cutpoint of 140.4 HU.

Routine Preoperative Electrocardiograms in Patients at Low Risk for Cardiac Complications During Shockwave Lithotripsy: Are They Useful?

INTRODUCTION

Routine preoperative electrocardiogram (ECG) before shockwave lithotripsy (SWL) is frequently performed despite recommendations against its use in asymptomatic patients undergoing low-risk surgical procedures. This study assesses whether routine preoperative ECG before SWL is useful in patients at low risk for cardiac complications.

MATERIALS AND METHODS

A retrospective study of SWL at our center (2003-2013) reviewed all cardiac-related preoperative cancellations, intraoperative complications, postoperative admissions, and emergency department presentations in patients at low risk for cardiac complications. Patients received SWL with sedation and continuous five-lead ECG monitoring.

RESULTS

Of 30,892 referrals, preoperative ECG triggered 13 (0.04%) cancelations in low-risk patients (1 with new atrial fibrillation and 12 with ischemia/previous infarction). Of these patients, 1 had a subsequent abnormal cardiac work-up and 11 underwent uncomplicated SWL without cardiac intervention (2 had unknown history). Of 27,722 treatments, 5 (0.02%) were stopped prematurely in low-risk patients because of arrhythmia (3 had normal preoperative ECG, 1 had abnormal ECG, and 1 did not complete ECG). Three patients developed an arrhythmia with sedation and 2 patients were admitted postoperatively because of cardiac complications (1 for atrial fibrillation and 1 for hypertension), of whom all had normal preoperative ECG. No patients presented to our emergency department with cardiac complications after SWL.

CONCLUSIONS

In patients at low risk for cardiac complications, preoperative ECG triggered very few cancellations and did not predict early termination of treatment or cardiac complications after SWL. These findings suggest that in low-risk patients, routine preoperative ECG has little effect on treatment or complication rate and should be omitted.

Comparison of Scoring Systems in Predicting Success of Percutaneous Nephrolithotomy

Background:

Scoring systems are useful to inform the patients about the success and complication rates of the operation prior the surgery.

Aims:

To determine the applicability of the popular scoring systems (Guy’s, stone size, tract length, obstruction, number of involved calices, and essence/stone density and Clinical Research Office of the Endourological Society) by means of examining preoperative data of patients treated with percutaneous nephrolithotomy.

Study Design:

Cross sectional study.

Methods:

We retrospectively reviewed files of the patients who had undergone percutaneous nephrolithotomy in our center between 2011 and 2015. Excluded from the study were patients aged <18 years, and those who were not assessed preoperatively with computed tomography. Preoperative computed tomography images of all patients were assessed by a single observer, and patients were graded based on three scoring system. Demographic data were analyzed along with perioperative data (operation, fluoroscopy, length of hospital stay, changes in hematocrit values, location, and number of access sites, stone-free and complication rates).

Results:

A total of 298 patients who had been treated with 300 procedures were enrolled into the study. Mean age, stone burden, number of stones, and density were 48.1±12.9 years, 663.5±442.8 mm², 1.8±1.1 and 888.3±273 HU respectively. Scores of the cases based on Guy’s, stone size, tract length, obstruction, number of involved calices, and essence/stone density, and Clinical Research Office of the Endourological Society scoring system were calculated as 2, 7.6, and 222.1 points respectively. 81.6% of the patients were stone-free. Complications were detected in 30 (9.9%) patients. Based on receiver operating characteristic curve analysis a positive correlation was detected between success rate and scoring systems, i.e., Guy’s (p=<0.001, r=-0.309), stone size, tract length, obstruction, number of involved calices, and essence/stone density (p=<0.001, r=-0.295), and Clinical Research Office of the Endourological Society (p=<0.001, r=0.426). The Clinical Research Office of the Endourological Society scoring system had the highest predictive value. The sensitivity rates rates for Guy’s, Clinical Research Office of the Endourological Society and Stone scoring system were as 78.78%, 80% and 82.34% respectively.

Conclusion:

All of scoring systems predicted correctly the success of the percutaneous nephrolithotomy procedures. The Clinical Research Office of the Endourological Society scoring system had the highest predictive value.

Prone percutaneous nephrolithotomy: its advantages and our technique for puncture

Percutaneous nephrolithotomy (PCNL) is considered the treatment of choice for large urinary calculi and staghorn lithiasis. The approach for this surgery may be either supine or prone, and different access techniques are described in the literature with the use of ultrasound, fluoroscopy, or both combined. We believe that prone PCNL offers to the urologist key advantages, such as the possibility of puncturing anatomically abnormal urinary tracts, to perform multiple percutaneous tracts in the same kidney, experiencing the vacuum cleaner effect, ease of exploring the upper calyx through the inferior calyx, possibility to perform endoscopic combined intrarenal surgery (ECIRS) and bilateral simultaneous surgery, and to performed over local anesthesia. An adequate training for the endourologist should include both the prone and supine techniques for PCNL and to know which patient can benefit the most from each one.

Variables of initial examination and clinical management associated with survival in small ruminants with obstructive urolithiasis

BACKGROUND

Obstructive urolithiasis is a common disease associated with a guarded prognosis in small ruminants.

HYPOTHESIS/OBJECTIVE

The results of physical examination, laboratory analyses, and clinical management of male small ruminants presented to 2 referral clinics were investigated to identify variables significantly associated with disease outcome, so as to provide better recommendations to animal owners regarding the management of these patients.

ANIMALS

Two-hundred ten small ruminants (130 sheep and 80 goats) with confirmed diagnosis of obstructive urolithiasis.

METHODS

Clinical findings (including diagnostic imaging) and laboratory results of the 210 animals were reviewed, and relevant information regarding clinical and laboratory variables recorded upon admission and clinical management was retrieved. The association of the different variables with nonsurvival was investigated by univariable and multivariable logistic regression models.

RESULTS

Only 39% of all patients considered for treatment and 52% of those undergoing tube cystostomy survived to be released from the clinic. Nonsurvival was strongly associated with a very poor clinical condition upon presentation, obesity, castration, and evidence of uroperitoneum. Among blood variables, abnormal PCV, severely increased serum creatinine concentrations, and increased activity of the creatine kinase were associated with increased risk of nonsurvival. Presence of signs of colic or macroscopic appearance of urine was not significantly associated with outcome.

CONCLUSIONS AND CLINICAL IMPORTANCE

The prognosis of obstructive urolithiasis was guarded with survival rates of 39% (overall) to 52% (after tube cystostomy). Intact young males with normal body condition presented early in the course of disease had the best chances of survival.

Chemical analysis of uroliths: A two-center study of doctors' practice and perspective in South-East, Nigeria

Introduction

Urolithiasis is a global disease condition secondary to a variety of factors, and sometimes associated with serious complications. Determination of stone composition is important in delineating causative factors. Knowledge of causative and precipitating factors aids patient management and prevention of recurrence.

Objective

The authors' aim was to evaluate the practice and perspective of doctors regarding chemical analysis of stones in management of urolithiasis.

Materials and Methods

This comparative cross-sectional study was done between December 2016 and May 2017 in two teaching hospitals in South-East, Nigeria. Data were collected using self-administered questionnaires.

Results

In all, 88 doctors with mean (standard deviation) age of 37.3 (9.5) years participated in the study. Urinary bladder stones were the most frequently managed, 51 (58.0%); 45 (51.1%) participants do not routinely send stones for chemical analysis. All respondents (100%) agreed that stone analysis is beneficial to patient management.

Conclusion

This study showed that in spite of all respondents affirming that chemical analysis of uroliths is beneficial to patient management, more than half of respondents do not routinely send stones for analysis.

Urology Consultation and Emergency Department Revisits for Children with Urinary Stone Disease

PURPOSE

We determined the association between urology consultation and emergency department revisits for children with urinary stones.

MATERIALS AND METHODS

This retrospective cohort study included patients 18 years old or younger who presented to an emergency department in South Carolina with a urinary stone from 1997 to 2015. The primary exposure was urology consultation during the index emergency department visit. The primary outcome was a stone related emergency department revisit occurring within 180 days of discharge from an index emergency department visit. Secondary outcomes included computerized tomography use, inpatient admission and emergent surgery.

RESULTS

Of 5,642 index emergency department visits for acute urinary stones 11% resulted in at least 1 stone related emergency department revisit within 180 days. Of revisits 59% occurred within 30 days of discharge and 39% were due to pain. The odds of emergency department revisit were highest within the first 48 hours of discharge home (OR 22.6, 95% CI 18.0 to 28.5) and rapidly decreased thereafter. Urology consultation was associated with a 37% lower adjusted odds of emergency department revisit (OR 0.63, 95% CI 0.44 to 0.90) and 68% lower odds of computerized tomography use across all emergency department visits (OR 0.32, 95% CI 0.15 to 0.69). Among patients who revisited the emergency department the frequency of pain complaints was 27% in those with a urological consultation at the index visit and 39% in those without.

CONCLUSIONS

Urology consultation was associated with decreased emergency department revisits and computerized tomography use in pediatric patients with urinary stones. Future studies should identify patients who benefit most from urology consultation and ascertain processes of care that decrease emergency department revisits among high risk patients.

Obstruction of bifid ureter by two calculi: A case report

RATIONALE

The duplex ureter is a common anomaly of urinary tract, but preoperative sonography, plain abdominal radiography, or nonenhanced computed tomography (CT) often overlooked it when involved with urinary tract obstruction. In this report, We present a rare case of left Y-shaped bifid ureter and both ureter of upper moiety and common stem were obstructed respectively by 2 calculi.

PATIENT CONCERNS

A 47-year-old woman was admitted due to 3-day history of left-sided loin pain and low-grade fever. The patient was diagnosed with right renal atrophy and 2 calculi of left ureter associated with severe left hydronephroureterosis, and underwent left percutaneous nephrostomy and left ureterolithotomy without identification of the upper calculus in left ureter in another hospital.

DIAGNOSES

After transfer of the patient to our hospital, preoperative contrast-enhanced CT detected the left Y shaped bifid ureter and the calculus in upper moiety ureter.

INTERVENTIONS

The migrated calculus was extracted by left ureterolithotomy.

OUTCOMES

The patient discharged uneventfully.

LESSONS

Contrast-enhanced CT should be recommended prior to any surgical procedures involved with upper urinary tract to exclude duplex ureter.

Clinical findings and diagnostic procedures in 270 small ruminants with obstructive urolithiasis

Background

Details of the clinical signs of obstructive urolithiasis in male small ruminants have not been documented in a large population.

Objective

To describe the clinical presentation and diagnostic procedures in a large group of small ruminants with urolithiasis.

Animals

Two hundred and seventy small ruminants (158 sheep and 112 goats).

Methods

Retrospective study of 270 cases identified based on clinical records.

Results

81.2% affected goats were castrated and 91.7% sheep were intact males; 65.5% of the animals had been sick ≤2 days before referral. Common abnormalities included dysuria (93.6%), indigestion (84.4%), reduced general state of health (79.5%), signs of pain (73%), increased heart and respiratory rates (53.6% and 39.1%), and azotemia (89.4%). Blood urea nitrogen (BUN) and creatinine concentrations were strongly correlated (r² = 0.81). Hypochloremia (52.2%), hyponatremia (43.3%), hypophosphatemia (52.4%), and abnormal potassium concentrations (26.2% hypokalemia and 24.5% hyperkalemia) were the most common serum electrolyte imbalances. Packed cell volume (PCV), plasma proteins, potassium, BUN, and creatinine concentrations were significantly increased in animals with uroperitoneum. Ultrasonography allowed for confirmation of diagnosis in 83.9% of the cases (135/161 with sufficient available information), uroliths were visible on 34 of 56 plain radiographs.

Conclusions and Clinical Importance

Our study confirmed that clinical and ultrasonographic examinations are sufficient to diagnose urolithiasis. Clinical signs can be divided into an early stage with discrete unspecific clinical signs, a painful stage with frequent straining, expression of pain and moderately reduced general condition, and an advanced stage with a markedly reduced general condition and eventually recumbency.