Stone Passage Research Articles

The diagnostic utility of cystoscopy in assessing patients with persistent microscopic abnormalities of urinalysis

BackgroundMicroscopic abnormalities are common findings on routine urinalysis performed for various clinical reasons. As a small proportion of these may indicate an underlying malignancy, a large number of patients with these abnormalities are referred for further investigations, which includes a cystoscopy. We aim to investigate the diagnostic utility of cystoscopy in detecting malignancy in this group of patients.MethodsA retrospective review of patients who underwent standard diagnostic workup for microscopic abnormalities of urinalysis (microscopic haematuria, sterile pyuria and bacteriuria) between January 2013 and December 2018 was performed. Patients with macroscopic haematuria, concurrent UTI, recent kidney stone passage, dysmorphic red cells, proteinuria and casts on urinalysis were excluded. Demographic information, age at diagnosis, smoking status and final diagnosis were extracted.ResultsIn total, 552 patients identified. 58% of the patients are males (319 patients). The mean age was 61 years with 35% patients having a history of smoking. 94% of the patients underwent pre-cystoscopy imaging. Twelve (2%) patients had a final diagnosis of genitourinary malignancy. Out of the 12 patients diagnosed with malignancy, pre-cystoscopy imaging detected a bladder lesion in 11 (92%) patients.ConclusionsThe incidence of genitourinary malignancy in patients with persistent microscopic abnormalities of urinalysis is low at 2%. In our cohort, flexible cystoscopy demonstrated little additional diagnostic value with only 1 malignancy (0.2%) detected by flexible cystoscopy alone. Hence, we may have to reconsider our current threshold in investigating this group of patients.

Spontaneous ureteral stone passage: a novel and comprehensive nomogram.

Ureteral stones pose a high economic and medical burden among Emergency Department (ED) admissions. Management strategies vary from expectant therapy to surgical interventions. Since predictors of ureteral spontaneous stone passage (SSP) are still not well understood, we sought to create a novel nomogram to guide management decisions. Charts were retrospectively reviewed for patients who presented to our institution's ED with non-febrile renal colic and received a radiological diagnosis of ureteral stone ≤10 mm. Demographic, clinical, laboratory, and non-contrast CT data were collected. This novel nomogram incorporates the serum neutrophil-to-lymphocyte ratio (NLR) as a potential predictor of SSP. The model was derived from a multivariate logistic regression and was validated on a different cohort. A receiver operator characteristic (ROC) curve was constructed and the area under the curve (AUC) was computed. A total of 1186 patients presented to our ED between January 2010 and October 2018. We randomly divided our population into a derivation and validation cohort in one to five ratio. A stone size ≥7 mm was the strongest predictor of SSP failure; OR=9.47; 95% CI: 6.03-14.88. Similarly, a NLR≥3.14 had 2.17; (1.58-2.98) the odds of retained stone. SSP failure was also correlated with proximal position, severe hydronephrosis, and leukocyte esterase ≥75, P=0.02, P=0.05, and P=0.006, respectively. The model had an AUC of 0.804 (0.776-0.832). The nomogram was also used to compute the risk of SSP failure (AUC 0.769 [0.709-0.829]). Our novel nomogram can be used as a predictor for SSP and can be used clinically in decision making.

Sphincter of Oddi dysfunction.

Sphincter of Oddi dysfunction (SOD) is a benign non-tumoral disorder of the major papilla. It occurs mainly after cholecystectomy but can also occur before surgery. Biliary pain and biliary colic are the most frequent symptoms although recurrent pancreatic pain or pancreatitis can also be presenting symptoms. In about half of the cases, there is a fibrotic stricture of the sphincter of Oddi, probably secondary to the passage of biliary stones, while in the remaining half, the syndrome is due to ampullary motility disorders. The diagnosis of SOD first requires exclusion of choledocholithiasis or ampullary tumor, by means of ERCP, endoscopic ultrasound or magnetic resonance imaging. Findings on biliary manometry will establish the diagnosis, but this technique is performed less and less often because its high risk of inducing pancreatitis discourages its use as a diagnostic procedure. Biliary scintigraphy offers a risk-free alternative albeit with lower sensitivity. Medical treatment relies on the administration of trimebutine and nitroglycerine when pain occurs. Their efficacy is moderate. Sometimes patients are referred for endoscopic sphincterotomy. Endoscopic treatment should be performed only for patients with biliary pain associated with hepatic function disorders and/or bile duct dilatation. Practicians and patients should be aware that endoscopic sphincterotomy in this clinical setting is associated with a high risk of pancreatitis and its efficacy is limited in patients with pain but without laboratory anomalies or dilatation of the biliary duct (type III Milwaukee classification). Patients with Milwaukee classification type III disorders have mostly functional complaints or psychosocial disabilities and require only medical management.

Emergency department non-contrast computed tomography for suspicion of obstructive urolithiasis: Yield and consequences.

We aimed to analyze patterns of referral, yield, and clinical implications of non-contrast computed tomography (NCCT) in the acute evaluation of flank pain suspected as obstructive urolithiasis (OU) in a high-volume emergency department (ED). The study comprised 506 consecutive NCCTs performed in the ED over four months. Detection rates of OU, incidental, and alternative findings were calculated. Imaging signs suspicious for recent passage of stones were considered positive for OU, while renal stones without signs of obstruction were considered unrelated to the acute presentation. OU, other findings requiring hospitalization, and incidental findings warranting further workup were considered situations in which NCCTs were warranted. NCCTs confirmed an OU diagnosis in 162 (32%) patients and non-clinically significant nephrolithiasis in 125 (25%). They revealed other findings in 108 (21%) patients, including 42 (8%) with clinically significant incidental findings and 26 (5%) with alternative diagnoses requiring hospitalization. NCCTs were entirely negative in 111 (22%) patients. Corroboration of these outcomes, together with overlapping of OU, incidental, and alternative significant findings in some patients resulted in an overall justified NCCT request rate of 44%. The yield of NCCT performed in acute presentations of flank pain suspected as OU is relatively low, and over one-half of the scans are unwarranted. The pattern of requesting NCCT in the ED needs refinement to avoid abuse that may lead to radiation overexposure, psychological burden, physical harm, and financial overload.

Efficacy of intravenous hydration during extracorporeal shock wave lithotripsy in improving ureteral stone treatment success rate.

The treatment efficacy of extracorporeal shock wave lithotripsy for urolithiasis depends on several factors. We aimed to evaluate the impact of intravenous hydration during shock wave lithotripsy on stone treatment success rate in patients with ureteral stones. We retrospectively evaluated patients with ureteral stones <2 cm in diameter treated with extracorporeal shock wave lithotripsy at two sites. Patients from one of the sites received intravenous hydration with 500 mL of 0.9% NaCl. Stone treatment success status was defined as stone-free or residual ureteral stones <0.4 cm in diameter 1 month after the procedure. Predictive factors associated with treatment success were evaluated using univariate and multivariate logistic regression. Overall, 146 consecutive patients with ureteral stones were included. Eighty (54.8%) patients received intravenous hydration. The overall stone treatment success rate was 66.4%. Those with intravenous hydration during the shock wave lithotripsy had significantly smaller stone size, lower serum creatinine levels, lower rate of alpha-blockers use, and higher rate of nonsteroidal anti-inflammatory drug use. Upon multivariate analysis, stone treatment success status postprocedure was significantly associated with stone size (odds ratio 4.118, 95% confidence interval 1.920-8.832, P < 0.0001) and intravenous hydration during the procedure (odds ratio 2.475, 95% confidence interval 1.176-5.208, P = 0.017). Besides small ureteral stone size, concomitant intravenous hydration with 500 mL of normal saline during extracorporeal shock wave lithotripsy was significantly associated with subsequent stone passage. Administering 0.9% NaCl may be a simple and effective measure to improve the treatment efficacy of extracorporeal shock wave lithotripsy.

Artificial intelligence in endourology: emerging technology for individualized care.

Artificial intelligence in medicine has allowed for efficient processing of large datasets to perform cognitive tasks that facilitate clinical decision-making, and it is an emerging area of research. This review aims to highlight the most pertinent and recent research in artificial intelligence in endourology, where it has been used to optimize stone diagnosis, support decision-making regarding management, predict stone recurrence, and provide new tools for bioinformatics research within endourology. Artificial neural networks (ANN) and machine learning approaches have demonstrated high accuracy in predicting stone diagnoses, stone composition, and outcomes of spontaneous stone passage, shockwave lithotripsy (SWL), or percutaneous nephrolithotomy (PCNL); some of these models outperform more traditional predictive models and existing nomograms. In addition, these approaches have been used to predict stone recurrence, quality of life scores, and provide novel methods of mining the electronic medical record for research. Artificial intelligence can be used to enhance existing approaches to stone diagnosis, management, and prevention to provide a more individualized approach to endourologic care. Moreover, it may support an emerging area of bioinformatics research within endourology. However, despite high accuracy, many of the published algorithms lack external validity and require further study before they are more widely adopted.

Comparison between Tamsulosin and Tadalafil Versus Tamsulosin alone to treat Lower Ureteric Stones Through Medical Expulsive Therapy: a comparative study

Aim: To compare between Tamsulosin and Tadalafil versus Tamsulosin alone to treat Lower Ureteric Stones through Medical Expulsive Therapy Study design: Comparative study Place and duration: This study was done at Ghulam Muhammad Mahar Medical college hospital Sukkur, Pakistan from February 2021 to July 2021. Methodology: This study was carried our in our institute for 6 months. Patients that were having stones of 5mm to 10mn were included in the study, because these stones are detected easily through CT scans and ultrasound. Patients were randomly divided into two groups each containing 86 persons. Prescription of tamsulosin of 0.3 mg and tadalafil of 8 mg was given to group A patients and 0.3mg, tamsulosin was prescribed to group B Results: The stone expulsion rate was 78.0% in group A and 61.5% in group B. The stone passage time was 1.55 vs. 2.22 weeks in group B. In 45 patients there was no stone expulsion at the end of 3rd week of treatment. So these patients were treated with laser lithotripsy. A comparison study of two groups showed that group B has more episodes of flatulent pain than group A. The average need for analgesia was more in group B than group A. Conclusion: It is found from this study that tamsulosin alone is less effective than tamsulosin and tadalafil combination therapy and they both give fewer emergency room visits and require less pain killers for the treatment of 5mm and 10mm ureteric stones.

What is the role of inflammatory markers in predicting spontaneous ureteral stone passage?

To investigate the role of inflammatory markers in predicting the spontaneous passage of ureteral stones. We retrospectively reviewed 279 patients with ureteral stones sized 4-10 mm that were managed conservatively. The patients were divided into two groups: Group 1 consisted of 137 patients who passed the stone spontaneously; Group 2 comprised 142 patients without spontaneous stone passage. The groups were compared using the Mann-Whitney U and chi-square tests. In addition, univariate and multivariate analyses were performed to identify the significance of the parameters. The mean age of the patients was 41.2 years. The patients in Group 1 had a significantly lower mean stone size, white blood cell count and neutrophil count. In addition, stone location, presence of hydronephrosis and history of urolithiasis were significantly different between the groups. Neutrophil percentage, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio were insignificantly lower in Group 1. In a multivariate analysis, stone size, distal location and hydronephrosis status significantly predicted the spontaneous stone passage. However, inflammatory markers including white blood cell count, neutrophil count and neutrophil-to-lymphocyte ratio could not determine the likelihood of spontaneous stone passage. Our results suggest that inflammatory markers are no meaningful parameters for the prediction of spontaneous stone passage.

Predictors of Stone-Related Events in Asymptomatic Untreated Intrarenal Calculi.

Purpose: There is a lack of data on the natural history of asymptomatic intrarenal calculi. In this study, we investigate stone-related events (SREs) in patients with untreated intrarenal calculi. We also investigate predictive factors for SREs. Methods: All patients found with an asymptomatic intrarenal calculus on CT kidney, ureter, bladder managed conservatively with interval imaging for ≥6 months were included. Patients were evaluated for any SRE. The rate of event according to calculus size, location, and number of calculi was also analyzed. Multivariate logistic regression analysis was performed to determine significant predictors for SREs. Results: In total, 266 renal units from 177 patients met inclusion criteria. The mean stone size was 4.44 mm (range 1-25 mm). Duration of follow-up was 43.78 ± 26.86 months (range 6-106 months). The overall rate of SREs, including intervention (n = 80) and spontaneous stone passage after ureteral colic (n = 40), was 45.1% (n = 120/266). Stones >5 mm were more likely to lead to an event compared with stones ≤5 mm (odds ratio [OR]: 2.94; p = 0.01). Interpolar stones and stones located in multiple calices were more likely to cause a SRE than lower pole stones (OR: 2.05; p = 0.05 and OR: 2.29; p = 0.03, respectively). Conclusion: In this large series of patients with asymptomatic intrarenal calculi, the incidence of a spontaneous SRE was 45.1% after 41 months. Stone size and stone location were significant predictors for a SRE. Information from this study will enable urologists to accurately risk stratify patients with asymptomatic renal stones.

Prospective long-term evaluation of incomplete distal renal tubular acidosis in idiopathic calcium nephrolithiasis diagnosed by low-dose NH4CL loading – gender prevalences and impact of alkali treatment

PurposeProspective evaluation of the prevalence of incomplete distal renal tubular acidosis (idRTA) in idiopathic calcium stone formers (ICSF) diagnosed by half-dose ammonium chloride loading (NH4Cl, 0.05 g/kg body weight/day) and impact of alkali treatment of idRTA.MethodsEvaluation of 386 consecutive idiopathic calcium stone formers (ICSF) (280 males, 106 females) for idRTA. If screening fasting urine pH was > 5.80, 1-day NH4Cl loading was performed without severe adverse effects. Normally, urine pH falls below 5.45.ResultsSixty-four idiopathic calcium stone formers exhibited idRTA, one complete dRTA. Prevalence was higher in women (25.4%) than in men (13.6%). Thus, for more equilibrated comparisons, we formed pairs of 62 idiopathic calcium stone formers (ICSF) with and 62 without idRTA, matched for gender, age, BMI and serum creatinine. Idiopathic calcium stone formers with idRTA more often had hypercalciuria (p < 0.025) and urine citrate < 2 mmol/d (p < 0.05), formed calcium phosphate stones more frequently, exhibited higher numbers of stones/year (1.4 ± 1.5 vs. 0.9 ± 0.8, p = 0.034) and 2.5 times more intrarenal calcifications (4.6 ± 5.9 vs. 1.8 ± 3.6, p = 0.002). All idiopathic calcium stone formers with idRTA were recommended chronic alkali therapy. After 4–15 years of follow-up, stone events /years follow-up (stone passage or urologic intervention) were higher in patients non-adherent to alkali therapy (0.61 ± 0.92) than in patients adherent to treatment (0.11 ± 0.21, p = 0.006).Conclusion Incomplete distal renal tubular acidosis is 1.8-fold more prevalent among female idiopathic calcium stone formers, predicts more stone recurrences, predisposes to calcium phosphate stones and is associated with 2.5 times more intrarenal calcifications vs. non-idRTA patients. Chronic alkali treatment reduces clinical stone recurrences by 5.5 times.Graphical abstract

Effectiveness of α&lt;sub&gt;1A&lt;/sub&gt;-adrenoreceptor antagonist in the passage of middle stones from the ureter: the role of receptors coupled with G-protein

Effectiveness of α&lt;sub&gt;1A&lt;/sub&gt;-adrenoreceptor antagonist in the passage of middle stones from the ureter: the role of receptors coupled with G-protein

Is it possible to predict spontaneous passage of a ureteral stone? An up-to-date comment on the current problem with new concepts concerning the patient and the stone.

The aim of this article was to determine a predictive factor by examining the patient's characteristics and the stone to predict the ureteral stone spontaneous passage. A total of 200 patients aged 18-55 who were referred with middle and distal ureter ureteral stones between 5-7 mm were analyzed retrospectively. Patients were randomized as 50 spontaneous stone passage positive (SSPP) and 50 negative patients. Body mass index (BMI), waist-to-hip ratio (WHR), stone size, ureter length, ureter diameter, stone Hounsfield unit value (SHU), ureteral wall thickness (UWT), kidney parenchymal thickness (KPT), kidney parenchymal density, neutrophil-lymphocyte ratio (NLR) and thrombocyte-lymphocyte ratio (TLR) values were recorded. The average SHU of the SSPP group was 579 and 970 in the negative group (p: 0.000). While the mean was 1.7 mm in the UWT SSPP group, it was 2.4 mm in the negative group (p: 0.000). SHU and UWT were statistically significantly different in univariate and multivariate logistic regression analyses. WHR values were 39.6 and 29.3 for SSPP and the negative group, respectively (p: 0.032). The ureter diameter was 7.6 mm for the SSPP group and 8.9 mm in the negative group (p: 0.01). Low SHU value is related to the ureteral stone's positive spontaneous passage, and the increase of UWT is inversely related to the spontaneous passage. WHR is higher in people who can passage ureteral stones. A narrow ureter diameter is correlated with spontaneous stone passage. Ureter length, KPT, and kidney parenchymal density were not associated with spontaneous passage.

Epidemiology and composition of nephrolithiasis in a Lebanese tertiary care center: A descriptive study.

Introduction:Nephrolithiasis is a common affliction with a prevalence of 12% in men and 7% in women. The incidence rate diverges with geographic location. Arab countries report high nephrolithiasis prevalence rates, with Saudi Arabia being the highest (20.1%). To date, there is little knowledge about the demographics and composition of stones in Lebanon.Methods:A retrospective chart review was performed on stone composition at the American University of Beirut Medical Center, between 2005 and 2018. Patients’ demographics and stone characteristics were obtained from electronic medical records. Analysis of frequencies and Chi-square test were adopted for potential risk factor correlations by the Statistical Package for the Social Sciences (SPSS).Results:A total of 626 stone analyses were performed. Male patients predominated (69%). The mean age was 46.58 ± 16.5 years, and mean body mass index was 28.63 ± 5.6, for both sexes. Calcium oxalate was the most predominant stone in both sexes (70%). Uric acid stones followed (~16%), and calcium oxalate phosphate stones were the third most common (5%). Incidence of kidney stones peaks in the summer, with 11.86% presenting in July. Around 60% presented with flank pain to the Emergency Department, and 32% ended up with spontaneous passage of stones by medical expulsive therapies alone, with no further surgical intervention. Diabetes and hypertension were significantly correlated with stone recurrence in our cohort.Conclusion:There is a significant gender disparity in stone prevalence in Lebanon. Calcium oxalate is the most common type in both sexes. Future investigations of dietary and environmental factors are recommended from our region.

Development of a spontaneous stone passage renal simulator using a physiological 3D renal model

Urolithiasis is a disease in which calcium oxalate crystallizes in the urinary tract, and has a high recurrence rate. It is necessary to consider the burden on the body by surgical treatment, therefore, treatment methods that effectively promote spontaneous stone passage are required. In this study, we investigated the effects of angular velocity on spontaneous stone passage and established the parameters needed to develop a working accelerated renal pelvis and calyx simulator. According to analysis from experiments, it was confirmed that the simulator using our established parameters is able to reproduce spontaneous stone passage similar to our experiment results. By establishing a spontaneous stone passage prediction simulator, it will be possible to devise a method to effectively promote spontaneous stone passage in patients. By reducing the morbidity of urinary lithiasis that requires surgery, it is expected to reduce the burden on patients and medical sites.

POSTOPERATIVE INFECTIOUS COMPLICATIONS OF PERCUTANEOUS NEPHROLITHOTOMY INFLUENCING FACTORS: A SINGLE CENTER EXPERIENCE

Objective: The major objective was to determine how percutaneous nephrolithotomy in patients with chronic renal disease affected their long-term prognosis. Method: Prospective data collection involved 208 individuals who received percutaneous nephrolithotomy between October 2020 to October 2021. A 4-variable variation of the diet in renal disease equation was used to retroactively determine the predicted glomerular filtration rate for each patient. According to National Kidney Foundation recommendations, individuals were graded for chronic renal disease. Result: Preoperative glomerular filtration rate was less than 50 ml per minute/1.72 m2 in a total of 140 patients (12.7%). The analysis included those who had been watched for at least six months. The average ± SD age of the 140 patients in the research was 54.2 ± 12.0 years. 15.1% of patients had perioperative and postoperative problems. The renal function had improved in 29.3% of patients at a mean follow-up of 43.3± 22.6 months, although it had remained stable or worsened in 54.1% and 16.3% of patients, respectively. Diabetic and preoperative or surgical comorbidities indicated renal function in multivariate regression analysis. At 4 months after surgery, the stone-free rate was 80.1%. 35 of these patients (25.2%) experienced stone recurrence during long-term follow-up. 10 of the 35 patients (34.1%) with residual stones showed spontaneous stone passage, however 7 (22.7%) of these patients also had larger residual stones. Conclusion: More than 81% of people suffering from chronic kidney disease who received percutaneous nephrolithotomy had their renal function preserved or enhanced at long-term follow-up. About 24% of these individuals experienced stone recurrence or stone development.

Which Factors Affect the Spontaneous Stone Passage After Flexible Ureteroscopic Lithotripsy for Renal Stones?

Objectives: The aim of this study was to investigate factors predicting spontaneous stone passage after Flexible Ureteroscopic Lithotripsy (fURS) for renal stones. Materials and Methods: This study included 239 patients with renal stones who underwent fURS using the dusting technique. The final outcome was evaluated 3 months postoperatively and the Residual Fragment status (RFs) was defined as any residual stone fragments greater than 2 mm. Univariate and multivariate analyses of possible predictive factors associated with spontaneous clearance of residual renal fragments were performed. Results:186 patients (77.8%) had achieved an Stone-Free status (SFs) and 53 patients (22.2%) were considered with RFs. Univariate analysis showed the stone location, stone number, stone size, stone CT value, IPA degree, the presence of hydronephrosis and stone covered with purulent substance were all associated with RFs (P&lt;0.05). Multivariate logistic regression analysis showed that larger stone size (P=0.001), multiple stones (P=0.038), the IPA of &lt;45° (P=0.035), the presence of hydronephrosis (P=0.045), the stone CT value ≥ 1000 (P=0.047) were all significantly associated with higher rates of residual stone after fURS. The stone covered with purulent substance was found to be the strongest predictor of RFs (P=0.027). However, the presence of lower pole stone had no significant influence on stone clearance after fURS (P=0.263). Conclusions: Stone number, stone size , an IPA of &lt;45°, stone CT value ≥ 1000 HU, stone covered with purulent substance and presence of hydronephrosis are all predictive factors of the spontaneous clearance of residual renal fragments after fURS.

Failure of ureteral access sheath insertion in primary flexible ureteroscopy for renal stones: is there any relation with inflammation?

To investigate the relationship between failure to insert a ureteral access sheath (UAS) with inflammation and other clinical parameters in patients treated with flexible ureteroscopy for renal stones. This study included patients who underwent flexible ureteroscopy for the treatment of renal stones in our centre between 2015 and 2020. Patients who underwent any surgical procedure on the ipsilateral ureter and had a history of spontaneous stone passage were excluded. Patients were divided into two groups based on UAS insertion success (group 1) or failure (group 2). Both groups were compared with a view to clinical characteristics, preoperative neutrophil, lymphocyte, monocyte and platelet counts and ratios of these counts, all being considered inflammatory markers. A multivariate logistic regression analysis was performed to determine the independent variables affecting UAS insertion success. There were 113 (59.1%) patients in group 1, while group 2 consisted of 78 (40.9%) patients. The rates of male gender, coronary artery disease and preoperative ipsilateral hydronephrosis were significantly higher in group 2, while platelet counts and platelet-lymphocyte ratios were significantly lower. Our analysis revealed four independent predictors for UAS insertion failure: female gender (odds ratio [OR]=2.1) increased the rate of UAS insertion success, while hydronephrosis (OR=1.6), low platelet counts and PLR increased the rate of UAS insertion failure (OR=0.99, OR=0.98, respectively). Our results suggest that male gender and ipsilateral hydronephrosis are associated with increased UAS insertion failure. Although we found a relationship between relatively low platelet levels and UAS insertion failure, we think that further studies are needed to investigate this matter.

Development of prediction models of spontaneous ureteral stone passage through machine learning: Comparison with conventional statistical analysis.

ObjectivesTo develop a prediction model of spontaneous ureteral stone passage (SSP) using machine learning and logistic regression and compare the performance of the two models. Indications for management of ureteral stones are unclear, and the clinician determines whether to wait for SSP or perform active treatment, especially in well-controlled patients, to avoid unwanted complications. Therefore, suggesting the possibility of SSP would help make a clinical decision regarding ureteral stones.MethodsPatients diagnosed with unilateral ureteral stones at our emergency department between August 2014 and September 2018 were included and underwent non-contrast-enhanced computed tomography 4 weeks from the first stone episode. Predictors of SSP were applied to build and validate the prediction model using multilayer perceptron (MLP) with the Keras framework.ResultsOf 833 patients, SSP was observed in 606 (72.7%). SSP rates were 68.2% and 75.6% for stone sizes 5–10 mm and <5 mm, respectively. Stone opacity, location, and whether it was the first ureteral stone episode were significant predictors of SSP. Areas under the curve (AUCs) for receiver operating characteristic (ROC) curves for MLP, and logistic regression were 0.859 and 0.847, respectively, for stones <5 mm, and 0.881 and 0.817, respectively, for 5–10 mm stones.ConclusionSSP prediction models were developed in patients with well-controlled unilateral ureteral stones; the performance of the models was good, especially in identifying SSP for 5–10-mm ureteral stones without definite treatment guidelines. To further improve the performance of these models, future studies should focus on using machine learning techniques in image analysis.

Risk factors for subsequent stone events in pediatric nephrolithiasis: A multi-institutional analysis

Children with nephrolithiasis have a 50% risk of recurrence 3 years following an index urinary stone event. The American Urological Association guidelines for medical management of nephrolithiasis suggest metabolic evaluations be stratified according to risk of future stone events. However, no such risk stratification exists across the pediatric population with urinary stone disease. We aim to assess the risk factors among pediatric patients for a subsequent stone event (SSE). A retrospective review for children <17 years of age with a diagnosis of nephrolithiasis and at least one completed follow-up at two tertiary-care children's hospitals within our state between 2012 and 2017 was performed. Children with known monogenic stone disease were excluded as well as those with follow-up less than 1 year. SSEs following initial diagnosis and treatment for nephrolithiasis were defined as follows: subsequent surgical intervention, new stone on imaging, reported stone passage, or ED evaluation for renal colic. Clinical and demographic factors were compared between patients with and without SSEs and analyzed using univariate and multivariate analyses via Cox proportional hazard models. Survival curves for significant associations for SSEs were generated and evaluated using Log-Rank and Wilcoxon comparisons. A total of 200 patients with median clinical follow-up of 2.9 years were analyzed. Median age was 11.5 years (IQR: 6.0-15.5), with 109 (54.5%) males and 91 (45.5%) females, 94 (47%) of whom had a relevant comorbidity. An SSE occurred in 82 patients (41.0%). Age >12 (HR 2.21, 95%CI 1.42-3.45), reported stone event prior to enrollment encounter (i.e. personal history of nephrolithiasis) (HR 1.82, 95%CI 1.14-2.89), and family history of nephrolithiasis (HR 1.62, 95%CI 1.05-2.51) were associated with SSE on univariate analysis while age >12 (HR 2.09, 95%CI 1.33-3.27) and personal history of nephrolithiasis (HR 1.63, 1.02-2.6) retained significance on multivariable analysis. Survival analysis shows increased risk of recurrence with accumulation of risk factors (Summary Figure). Sensitivity analysis accounting for missing family history data retained significance for all three variables. Adolescent age and a personal history of nephrolithiasis are independent risk factors for SSE in children. Understanding these risk factors and the nature of SSE among the pediatric population can potentially enhance counseling for further metabolic work-up and tailored clinical follow-up.

A Giant Vesical Calculus in a Woman with Utero-Vaginal Prolapse: A Rare Case Report

Urinary bladder stone is usually defined as a giant calculus when it weighs 100g. The incidence of female urolithiasis is very low. According to literature, fewer than 2% of all bladder calculi occur in female subjects and thus, their presence should provoke careful assessment of the etiology. H. A. is a 70 year old P10+2 2 alive woman from a rural community who presented to the Obstetrics and Gynecology Department of Usmanu Danfodiyo University Teaching Hospital Sokoto with 10 years history of protruding mass through the vagina and pain in passing urine of 1 year duration. No history of haematuria, fever or passage of stones in urine. Vaginal examination show an irreducible third degree uterine decent. Laboratory investigations revealed pus cells in urine and urine culture yielded growth of Escherichia Coli after overnight incubation. The electrolyte, urea and creatinine levels were normal. On ultrasound, a large curvilinear echogenic structure that cast posterior acoustic shadowing consistent with calculus was demonstrated within the urinary bladder. It measured 4.5x3.7cm in size and showed marginal irregularities. The surrounding urine in the bladder show mobile internal echoes. Intravenous urogram showed a dense oval radio opaque calculus in the pelvis measuring about 4.5cm in diameter with normal upper urinary tract. She had open cystolithotomy with total abdominal hysterectomy. The stone weighs 142g.