An international delphi survey and consensus meeting to define the risk factors for ureteral stricture after endoscopic treatment for urolithiasis.

PURPOSE: Iatrogenic ureteral strictures (US) after endoscopic treatment for urolithiasis represent a significant healthcare concern. However, high-quality evidence on the risk factors associated with US is currently lacking. We aimed to develop a consensus statement addressing the definition, risk factors, and follow-up management of iatrogenic US after endoscopic treatment for urolithiasis. METHODS: Utilizing a modified Delphi method, a steering committee developed survey statements based on a systematic literature review. Then, a two-round online survey was submitted to 25 experts, offering voting options to assess agreement levels. A consensus panel meeting was held for unresolved statements. The predetermined consensus threshold was set at 70%. RESULTS: The steering committee formulated 73 statements. In the initial survey, consensus was reached on 56 (77%) statements. Following in-depth discussions and refinement of 17 (23%) statements in a consensus meeting, the second survey achieved consensus on 63 (86%) statements. This process underscored agreement on pivotal factors influencing US in endoscopic urolithiasis treatments. CONCLUSIONS: This study provides a comprehensive list of categorized risk factors for US following endoscopic urolithiasis treatments. The objectives include enhancing uniformity in research, minimizing redundancy in outcome assessments, and effectively addressing risk factors associated with US. These findings are crucial for designing future clinical trials and guiding endoscopic surgeons in mitigating the risk of US.

Application of AI in urolithiasis risk of infection: a scoping review.

INTRODUCTION: Artificial intelligence and machine learning are the new frontier in urology; they can assist the diagnostic work-up and in prognostication bring superior to the existing nomograms. Infectious events and in particular the septic risk, are one of the most common and in some cases life threatening complication in patients with urolithiasis. We performed a scoping review to provide an overview of the current application of AI in prediction the infectious complications in patients affected by urolithiasis. EVIDENCE ACQUISITION: A systematic scoping review of the literature was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses for Scoping Reviews (PRISMA-ScR) guidelines by screening Medline, PubMed, and Embase to detect pertinent studies. EVIDENCE SYNTHESIS: A total of 467 articles were found, of which nine met the inclusion criteria and were considered. All studies are retrospective and published between 2021 and 2023. Only two studies performed an external validation of the described models. The main event considered is urosepsis in four articles, urinary tract infection in two articles and diagnosis of infection stones in three articles. Different AI models were trained, each of which exploited several types and numbers of variables. All studies reveal good performance. Random forest and artificial neural networks seem to have higher AUC, specificity and sensibility and perform better than the traditional statistical analysis. CONCLUSIONS: Further prospective and multi-institutional studies with external validation are needed to better clarify which variables and AI models should be integrated in our clinical practice to predict infectious events.

Diversity, Equity, and Inclusion in Urolithiasis Clinical Trials: Representative Enrollment by Race, Ethnicity, and Sex.

INTRODUCTION: We sought to assess whether participant enrollment is appropriately representative of the overall urolithiasis population in published urolithiasis clinical trials. METHODS: PubMed was queried for urolithiasis US clinical trials published from 2000 to 2022. Trials were evaluated for reporting patient race/ethnicity and sex data. These were then compared to the stone prevalence reported by the National Health and Nutrition Examination Survey from 2015 to 2018. We calculated a representation quotient (RQ) to describe enrollment of patients and then stratified by geographic location, study type, and funding source. RESULTS: Of the 180 urolithiasis trials performed in the US, we identified 40 trials (22%) reporting race or ethnicity and 104 trials (58%) reporting sex. Male and female participants are well represented (RQ 0.97 and 1.02, respectively). Overall, the RQ of Black, Asian American and Pacific Islander, White, Hispanic, and mixed/other participants is 1.84, 1.06, 1.04, 0.46, and 0.34, respectively. Trials completed in the Western Section and multi-institutional trials have the most proportional enrollment, while trials in the South Central and Southeastern Sections have underrepresentation of mixed/other and Hispanic patients. Enrollment was similar among all trial subtypes. Government- and industry-funded trials had more diverse enrollment than academic-funded trials. CONCLUSIONS: Only 1 in 4 published US urolithiasis trials report race or ethnicity enrollment. Mixed race and Hispanic participants are consistently underrepresented, while Black participants are overrepresented. Government- and industry-sponsored multi-institutional trials have the most proportional representation. Investigators should prioritize inclusive recruitment and improve reporting practices to accurately reflect the diversity of the urolithiasis population.

Percutaneous Nephrostomy versus Ureteral Stent for Severe Urinary Tract Infection with Obstructive Urolithiasis: A Systematic Review and Meta-Analysis.

Background and Objectives: The European Association of Urology guidelines on urolithiasis highlight the limited evidence supporting the superiority of percutaneous nephrostomy (PCN) over retrograde ureteral stent placement for the primary treatment of infected hydronephrosis secondary to urolithiasis. We, therefore, conducted a systematic review and meta-analysis comparing the effects of PCN and retrograde ureteral stent in patients with severe urinary tract infections secondary to obstructive urolithiasis. Materials and Methods: Meta-analyses were performed to compare four outcomes: time for the temperature to return to normal; time for the white blood cell (WBC) count to return to normal; hospital length of stay; and procedure success rate. After a full-text review, eight studies were identified as relevant and included in our systematic review and meta-analysis. Results: No significant difference was detected between PCN and retrograde ureteral stenting for the time for the temperature to return to normal (p = 0.13; mean difference [MD] = -0.74; 95% confidence interval [CI] = -1.69, 0.21; I2 = 96%) or the time for the WBC count to return to normal (p = 0.24; MD = 0.46; 95% CI = -0.30, 1.21; I2 = 85%). There was also no significant difference between methods for hospital length of stay (p = 0.78; MD = 0.45; 95% CI = -2.78, 3.68; I2 = 96%) or procedure success rate (p = 0.76; odds ratio = 0.86; 95% CI = 0.34, 2.20; I2 = 47%). Conclusions: The clinical outcomes related to efficacy did not differ between PCN and retrograde ureteral stenting for severe urinary tract infection with obstructive urolithiasis. Thus, the choice between procedures depends mainly on the urologist's or patient's preferences.

Comparative analysis of artificial intelligence chatbot recommendations for urolithiasis management: A study of EAU guideline compliance.

OBJECTIVES: Artificial intelligence (AI) applications are increasingly being utilized by both patients and physicians for accessing medical information. This study focused on the urolithiasis section (pertaining to kidney and ureteral stones) of the European Association of Urology (EAU) guideline, a key reference for urologists. MATERIAL AND METHODS: We directed inquiries to four distinct AI chatbots to assess their responses in relation to guideline adherence. A total of 115 recommendations were transformed into questions, and responses were evaluated by two urologists with a minimum of 5 years of experience using a 5-point Likert scale (1 - False, 2 - Inadequate, 3 - Sufficient, 4 - Correct, and 5 - Very correct). RESULTS: The mean scores for Perplexity and ChatGPT 4.0 were 4.68 (SD: 0.80) and 4.80 (SD: 0.47), respectively, both significantly differed the scores of Bing and Bard (Bing vs. Perplexity, P<0.001; Bard vs. Perplexity, P<0.001; Bing vs. ChatGPT, P<0.001; Bard vs. ChatGPT, P<0.001). Bing had a mean score of 4.21 (SD: 0.96), while Bard scored 3.56 (SD: 1.14), with a significant difference (Bing vs. Bard, P<0.001). Bard exhibited the lowest score among all chatbots. Analysis of references revealed that Perplexity and Bing cited the guideline most frequently (47.3% and 30%, respectively). CONCLUSION: Our findings demonstrate that ChatGPT 4.0 and, notably, Perplexity align well with EAU guideline recommendations. These continuously evolving applications may play a crucial role in delivering information to physicians in the future, especially for urolithiasis.

Xanthinuria in a familial group of Munchkin cats and an unrelated domestic shorthair cat.

CASE SERIES SUMMARY: Four confirmed cases of xanthinuria in cats, and one suspected case based on pedigree analysis, were identified. Clinical presentations varied and included haematuria, pollakiuria, dysuria, and urethral and ureteral obstruction. All cats had upper urinary tract uroliths. Diagnosis was obtained through infrared mass spectrometry of uroliths or urine. Clinical signs commenced at 3-8 months of age and reduced in all cats in the medium to long term after the introduction of a protein-restricted diet. Four cats were castrated males and one was a spayed female. Cases consisted of four Munchkin pedigree cats and one unrelated domestic shorthair cat. All four affected Munchkin pedigree cats were related, with three cases full siblings and the fourth case a half-sibling. No connection to the Munchkin pedigree could be established for the domestic shorthair cat. A candidate causative genetic variant (XDH p.A681V) proposed for this cat was excluded in the Munchkin family. RELEVANCE AND NOVEL INFORMATION: All affected cats presented diagnostic challenges and routine urinalysis was insufficient to obtain a diagnosis. Cases of feline xanthinuria may be underdiagnosed due to situations where uroliths cannot be retrieved for analysis and there is an inability to make a diagnosis using crystal morphology alone on routine urinalysis. Metabolic screening of urine may provide an effective mechanism to confirm xanthinuria in suspected cases where uroliths are inaccessible or absent. In this case series, male cats were more common. Their anatomy may increase the risk of lower urinary tract signs and urethral obstruction developing secondary to xanthine urolithiasis. A protein-restricted diet appears to reduce clinical signs as part of long-term management. PLAIN LANGUAGE SUMMARY: Four closely related Munchkin cats and one domestic shorthair cat were found with a suspected genetic disease causing high levels of xanthine in their urine. The case series looks at similarities and differences in their clinical signs, as well as difficulties experienced in obtaining a correct diagnosis. All cats had upper urinary tract stones and required metabolic testing of the stones or urine to diagnose. All cats were young when their clinical signs started and were on a high-protein diet. Four cats were desexed males and one was a desexed female. A genetic variant that may have caused the disease in the domestic shorthair cat was ruled out in the Munchkin family. Cases of high xanthine levels in feline urine may be underdiagnosed as the stones may not be accessed for testing. In this case series, male cats were more common. Their anatomy may increase the risk of lower urinary tract signs. A protein-restricted diet appears to reduce clinical signs as part of long-term management.

Stone centers: a national survey on surgical techniques performed in Italy.

BACKGROUND: Recurrent and complex stone disease may be considered a challenging disease. In 2018, the Calculus group of the SIU (Italian Society of Urology) set itself the goal of establishing the minimum requirements for a center that could continuously manage urolithiasis pathology, named a Stone Center. In this study we present the results of a pilot survey carried out in 2019 with the aim of drawing a map of the situation of Italian urological centers dealing with urinary stones. METHODS: A total of 260 national urology departments dealing with urolithiasis surgery were contacted for this study. A survey was issued to each of the centers to determine the number of patients treated for urinary stones and the amount of procedures performed per year: 1) extracorporeal shock wave lithotripsy ESWL; 2) ureterorenoscopy URS; 3) retrograde intrarenal surgery RIRS; 4) percutaneous nephrolithotomy PCNL. RESULTS: Out of 260 centers contacted, 188 fulfilled the survey. Outcomes were quite variable, with approximately 37% of the centers lacking a lithotripter, and 46% of those that did have it performing fewer than 100 treatments per year. In terms of endoscopic procedures, more than 80% of the centers contacted performed URS or RIRS; however, when it came to percutaneous lithotripsy, these numbers dropped significantly; 33% of the centers contacted did not perform PCNL, and of those who did, 18% had less than 5 years of experience as a center. CONCLUSIONS: Our survey shows a very heterogeneous national picture about urolithiasis treatments. Our goal is to create national paradigms to be able to define stone centers where the patient suffering from complex urinary stones can find a network of professionals with an adequate armamentarium suitable for the management of their pathology.

URS for de-novo urolithiasis after kidney transplantation: a systematic review of the literature.

INTRODUCTION: There is a gap in the available literature and guidelines concerning the optimal approach for treating allograft stones, which currently include external shockwave lithotripsy, ureteroscopy and laser lithotripsy, or percutaneous nephrolithotomy. The objective of this systematic review was to evaluate the safety and effectiveness of URS as a treatment option for patients in this scenario. EVIDENCE ACQUISITION: A comprehensive search of the literature was conducted until August 2023. Only original articles written in English were considered for inclusion. This review has been registered in PROSPERO (registration number CRD42023451154). EVIDENCE SYNTHESIS: Eleven articles were included (122 patients). The mean age was 46.9±9.5 years, with a male-to-female ratio of 62:49. The preferred ureteral reimplantation technique was the Lich-Gregoire. The mean onset time was 48.24 months. Acute kidney injury, urinary tract infections and fever were the most frequent clinical presentations (18.3% each), followed by hematuria (10%). The mean stone size measured 9.84 mm (±2.42 mm). Flexible URS was preferred over semirigid URS. The stone-free rate stood at 83.35%, while the overall complication rate was 13.93%, with six (4.9%) major complications reported. Stones were mainly composed of calcium oxalate (42.6%) or uric acid (14.8%). Over an average follow-up period of 30.2 months, the recurrence rate was 2.46%. No significant changes in renal function or allograft loss were reported. CONCLUSIONS: URS remains an efficient choice for addressing de-novo allograft urolithiasis, offering the advantage of treating urinary stones with a good SFR and a low incidence of complications. Procedures should be performed in an Endourology referral center.

Exploring the association between multiple factors and urolithiasis: A retrospective study and Mendelian randomization analysis.

To investigate the relationship between several factors and urinary stone as well as different stone compositions. To guide the diagnosis, treatment, and prevention of urinary stone recurrence. We used bidirectional Mendelian randomization to analyze the causal relationship between hypertension and urinary stones, diabetes and urinary stones, and body mass index (BMI) and urinary stones. We retrospectively analyzed the medical records of patients with urinary stones admitted to a tertiary care hospital in Chongqing, China, from July 2015 to October 2022. Patients were included when they were first diagnosed with urinary stones. The odds ratio of calculi on hypertension estimated by inverse variance weighted was 8.46 (95%CI: 4.00-17.90, P = 2.25 × 10-8). The stone composition analysis showed that there were 3101 (67.02%) mixed, 1322 (28.57%) calcium oxalate monohydrate, 148 (3.20%) anhydrous uric acid, 16 (0.35%) magnesium ammonium phosphate hexahydrate, 11 (0.24%) dicalcium phosphate dihydrate, 10 (0.22%) carbonate apatite, 8 (0.17%) L-cystine, 4 ammonium uric acid (0.09%), and 7 other stone types (0.15%). Mendelian randomization studies have proven that urinary stones may be a potential risk factor for hypertension, while there is no causal relationship between diabetes and stones, BMI, and stones. Our retrospective study has shown that urinary stone components are closely associated with sex, age, hypertension, diabetes, and BMI. It is reasonable to suspect that treating a single stone component is ineffective in preventing recurrence. We also found that the peak incidence of urinary stones was at the most active stage of most people's working lives.

Flexible Ureteroscopic Guided Laparoscopic Ureteroplasty For The Treatment Of Ureteral Stricture.

INTRODUCTION: Ureteral stricture is often a consequence of urolithiasis or previous endourological procedures (1-3). Precisely delineating the stricture zone intraoperatively is crucial to minimize ureter shortening and target only the affected tissue (4, 5). Flexible ureteroscopy offers a significant advantage in this regard. OBJECTIVE: This video aims to demonstrate the step-by-step technique of flexible ureteroscopic guided laparoscopic ureteroplasty for treating ureteral stricture caused by urolithiasis and prior endourological interventions. PATIENT AND METHODS: We present a case of a 36-year-old male with a history of urolithiasis and unsuccessful endourological treatments, including endoureterotomy and balloon dilation, diagnosed with re-stenosis of the proximal ureter of 1 cm through ureteroscopy and pyelography. He underwent a successful laparoscopic ureteroplasty. While the lead surgeon performed the laparoscopy, an assistant conducted the flexible ureteroscopy. Intraoperatively, using transillumination facilitated by the flexible ureteroscope, we can precisely identify the narrowed area, allowing for resection of only the damaged segment. Subsequently, we perform the end-to-end ureteroplasty, confirming its patency through the seamless passage of the ureteroscope. Upon completion, we employ a fat patch to safeguard the anastomosis. RESULTS: The patient was discharged on the third postoperative day. Double J stent was removed six weeks after surgery. Symptoms resolved. Renal function improved: eGFR 49 to 67 ml/min. Furthermore, improvement was observed in the DTPA scan, and a decrease in hydronephrosis was noted on the follow-up tomography. CONCLUSION: Flexible ureteroscopy effectively identifies the stricture zone in laparoscopic ureteroplasty, enhancing surgical precision and outcomes. This approach is safe, effective, and reproducible, offering a valuable technique in the surgical treatment of ureteral strictures.

Urologists' opinion on treating asymptomatic stones: Would we treat ourselves as we treat our patients? Survey from European Association of Urology, Young Academic Urologists, Endourology and Urolithiasis working party.

Background/aim: Management of asymptomatic kidney stones is an ongoing debate with follow-up and treatment guidelines based on low-level evidence. Our aim was to evaluate current management of asymptomatic urinary stones. Materials and methods: A 70-question survey was designed in collaboration with European Association of Urology, Young Academic Urologists, Section of Uro-Technology and Section of Urolithiasis groups and distributed. Responders filled out hypothetical scenarios from 2 perspectives, either as treating physicians, or as patients themselves. Results: A total of 212 (40.01%) responses were obtained. Median responder age was 39 years. 75% of responders were interested in "urolithiasis". 82.5% had never experienced a renal colic, 89.6% had never undergone urolithiasis treatment.Overall, as the kidney stone scenarios got more complicated, the invasiveness of the treatment preference increased. As "the physician", responders preferred the conservative option in all situations more than they would choose as "the patient". For ureteral stones, conservative approach was most preferred for small stones and ureteroscopy became more preferred as the stone size increased.For smaller kidney stones, the most preferred follow-up schedule was 4-6 monthly, whereas for larger and complicated stones it was 0-3 monthly from both perspectives respectively. For all ureteral stone scenarios, 0-4 weekly follow-up was mostly preferred.Interestingly, having had a renal colic was an independent predictor of an interventional approach, whereas having had an intervention was an independent predictor of a conservative approach. Conclusion: Current treatment and follow-up patterns of asymptomatic urinary stones are in agreement with international guidelines on symptomatic stones.In most of the urolithiasis situations urologists chose a conservative approach for their patients compared to what they would prefer for themselves. Conversely, urologists, in the scenarios as "the patient", would like to have a more frequent follow-up schedule for their stones compared to how they would follow-up their patients.

Risk factors of early infectious complications after ureterorenoscopy for stone disease: a prospective study.

PURPOSE: To prospectively evaluate the rate and associated risk factors of early infectious complications after ureterorenoscopy for urolithiasis. METHODS: After ethical committee approval, 400 therapeutic retrograde ureterorenoscopy procedures between August 3, 2020 and November 24, 2021 were included for analysis in a single-center study. Postoperative infection was defined as an afebrile urinary tract infection, fever (≥ 38 °C) with pyuria (≥ 300 WBC/µL) or proven urinary pathogen, and urosepsis. The primary outcome was the rate of infectious complications after ureterorenoscopy. Secondary outcomes were the perioperative factors that increased the risk of infectious complications within 30 days of surgery using univariate and multivariate logistic regression analysis. RESULTS: Twenty-nine of four hundred (7.3%) patients developed an infectious complication within 30 days after ureterorenoscopy. Ten (2.5%) patients developed an afebrile urinary tract infection, eight (2.0%) developed fever with pyuria, five (1.3%) febrile urinary tract infection, and six (1.5%) urosepsis. On univariate analysis, preoperative stent-type JFil® pigtail suture stent was significantly associated with the dependent variable (p < 0.001). On multivariate logistic regression analysis, older age (OR 1.035; 95% CI 1.006-1.070; p = 0.02) was found to be significantly associated with developing a postoperative infectious complication. CONCLUSIONS: A 7.3% rate of postoperative infectious complications and 1.5% urosepsis rate were observed after therapeutic ureterorenoscopy, without the need of intensive care admission. The only significant risk factors were preoperative stent type (JFil® pigtail suture stent) on univariate analysis, and older age on multivariate logistic regression analysis. Further multicentric prospective observational data are needed in this field.

Diagnosis and treatment of urolithiasis in a Toy Poodle dog.

Background: Urolithiasis in dogs is a disorder of the urinary tract caused by the development of crystals. These crystals are composed of minerals such as phosphates, oxalates, urates, cystine, carbonates, and silica. It can be fatal if the diagnosis and treatment are inaccurate. This report aims to report a case of urolithiasis in a Toy Poodle dog. Case Description: A 2-year-old male Toy Poodle dog weighing 4.2 kg with black hair, and having trouble urinating was presented to Prof. Soeparwi Animal Hospital, Universitas Gadjah Mada, Indonesia. The dog is examined physically and, in the laboratory, diagnosed and continued with operative therapy. The history and physical examination revealed that the dog had been experiencing hematuria, stranguria, and oliguria for 2 months, with the last few days accompanied by decreased appetite. The dog exhibited decreased skin turgor, a capillary refill time (CRT) of less than 2 seconds, signs of pain and distress during urination, and palpation of distended urinary vesicles. Ultrasound scans revealed uroliths in the urinary vesica, which were identified by an acoustic shadow. Blood tests indicated a decrease in hematocrit and erythrocytes along with an increase in leukocytes. Urolithiasis was diagnosed in the case dog based on anamnesis, physical examination, hematological examination, and ultrasonography. Subsequently, a cystotomy was performed, and uroliths located in urinary vesicles were removed. The dog received ceftriaxone injections at 15 mg/kg body weight and vitamin B-complex injections at a concentration of 10 mg/kg body weight for 5 days. Four days post-surgery, the case dog was able to successfully urinate and pass clean urine. Conclusion: The Toy Poodle dog was diagnosed with silica urolithiasis in the urinary vesicles and the urolith is quite large. Cystotomy was performed to remove the urolith. Postoperative care were included the administration of antibiotics and vitamins to facilitate the healing process. The condition of the Poodle toy dog improved.

Trends in Emergency Department Admissions Due to Renal Colic in the Pediatric Population: A Multicenter Study.

BACKGROUND: Pediatric urolithiasis is relatively uncommon and is generally associated with predisposing anatomic or metabolic abnormalities. In the adult population, emergency department (ED) admissions have been associated with an increase in ambient temperature. The same association has not been evaluated in the pediatric population. OBJECTIVES: To analyze trends in ED admissions due to renal colic in a pediatric population (≤ 18 years old) and to assess the possible effect of climate on ED admissions. METHODS: We conducted a retrospective, multicenter cohort study, based on a computerized database of all ED visits due to renal colic in pediatric patients. The study cohort presented with urolithiasis on imaging during their ED admission. Exact climate data was acquired through the Israeli Meteorological Service (IMS). RESULTS: Between January 2010 and December 2020, 609 patients, ≤ 18 years, were admitted to EDs in five medical centers with renal colic: 318 males (52%), 291 females (48%). The median age was 17 years (IQR 9-16). ED visits oscillated through the years, peaking in 2012 and 2018. A 6% downward trend in ED admissions was noted between 2010 and 2020. The number of ED admissions in the different seasons was 179 in autumn (30%), 134 in winter (22%), 152 in spring (25%), and 144 in summer (23%) (P = 0.8). Logistic regression multivariable analysis associated with ED visits did not find any correlation between climate parameters and ED admissions due to renal colic in the pediatric population. CONCLUSIONS: ED admissions oscillated during the period investigated and had a downward trend. Unlike in the adult population, rates of renal colic ED admissions in the pediatric population were not affected by seasonal changes or rise in maximum ambient temperature.

Predictors of Recurrent Urolithiasis in Iran: Findings from a Nationwide Study.

BACKGROUND: Prevention of urinary stone recurrence is the ultimate goal in urolithiasis patients. In this study, we aimed to investigate the national prevalence rate and possible determinants of increased urolithiasis recurrence risk in a nationwide study in Iran. METHODS: All data regarding stone occurrence and recurrence episodes were extracted from the cross-sectional Iran National Stone Survey (INSS) study, and the possible determinants of recurrence were evaluated in the subset of 2913 patients who had a positive history of at least one episode of urolithiasis. RESULTS: The national prevalence rate of recurrent urolithiasis was 2.6% (95% CI: 2.5, 2.8) in Iran. Moreover, the relative ratio of recurrent stone formers to all stone formers was 39.8% (95% CI: 38.0, 41.6). Our univariable truncated negative binomial regressions suggested that a positive history of urolithiasis in the patient's father (prevalence ratio [PR] [95% CI]=1.83 [1.39, 2.41], P<0.001), mother (PR [95% CI]=1.92 [1.39, 2.66], P<0.001) or brother (PR [95% CI]=1.32 [1.03, 1.69], P=0.026); and residence in urban areas (PR [95% CI]=1.27 [1.04, 1.55], P=0.016) were significant predictors of repetitive recurrence episodes. However, when incorporated into a multivariable truncated negative binomial regression model, the only significant predictors of more frequent recurrence episodes were a positive history in father (PR [95% CI]=1.66 [1.24, 2.22], P<0.001) and mother (PR [95% CI]=1.68 [1.20, 2.36], P=0.002); and urban residence (PR [95% CI]=1.24 [1.01, 1.51], P=0.031). CONCLUSION: Our results indicate that a positive family history of urolithiasis in mother and father and residence in urban areas are the significant predictors of recurrence risk in urolithiasis patients in Iran.

A nomogram clinical prediction model for predicting urinary infection stones: development and validation in a retrospective study.

PURPOSE: This study aimed to develop a nomogram prediction model to predict the exact probability of urinary infection stones before surgery in order to better deal with the clinical problems caused by infection stones and take effective treatment measures. METHODS: We retrospectively collected the clinical data of 390 patients who were diagnosed with urinary calculi by imaging examination and underwent postoperative stone analysis between August 2018 and August 2023. The patients were randomly divided into training group (n = 312) and validation group (n = 78) using the "caret" R package. The clinical data of the patients were evaluated. Univariate and multivariate logistic regression analysis were used to screen out the independent influencing factors and construct a nomogram prediction model. The receiver operating characteristic curve (ROC), calibration curves, and decision curve analysis (DCA) and clinical impact curves were used to evaluate the discrimination, accuracy, and clinical application efficacy of the prediction model. RESULTS: Gender, recurrence stones, blood uric acid value, urine pH, and urine bacterial culture (P < 0.05) were independent predictors of infection stones, and a nomogram prediction model ( https://zhaoyshenjh.shinyapps.io/DynNomInfectionStone/ ) was constructed using these five parameters. The area under the ROC curve of the training group was 0.901, 95% confidence interval (CI) (0.865-0.936), and the area under the ROC curve of the validation group was 0.960, 95% CI (0.921-0.998). The results of the calibration curve for the training group showed a mean absolute error of 0.015 and the Hosmer-Lemeshow test P > 0.05. DCA and clinical impact curves showed that when the threshold probability value of the model was between 0.01 and 0.85, it had the maximum net clinical benefit. CONCLUSIONS: The nomogram developed in this study has good clinical predictive value and clinical application efficiency can help with risk assessment and decision-making for infection stones in diagnosing and treating urolithiasis.

Impacto del uso de la vaina de acceso ureteral durante la ureteroscopia flexible: estudio comparativo de eficacia y seguridad / Impact of ureteric access sheath use during flexible ureteroscopy: A comparative study on efficacy and safety

Objetivos Este estudio evalúa el impacto del uso de una vaina de acceso ureteral (VAU) durante la ureteroscopia flexible (URSf) para el tratamiento de la litiasis urinaria, centrándose en resultados como la tasa libre de litiasis, el tiempo quirúrgico y las complicaciones. Métodos Este estudio prospectivo y aleatorizado se llevó a cabo en el Hospital de Badr en la Universidad de Helwan y en los hospitales de la Universidad de Ain Shams, desde agosto de 2021 hasta agosto de 2022. Los pacientes se aleatorizaron sistemáticamente a 2 grupos (URSf con VAU: 33 pacientes y URSf sin VAU: 31 pacientes), y se sometieron a evaluaciones preoperatorias y postoperatorias, incluyendo pruebas de laboratorio y de imagen. Se controlaron los posibles riesgos asociados al procedimiento, como el fracaso en el acceso al cálculo, el dolor, el sangrado y la sepsis. Resultados Se observó que los 2 grupos eran comparables en cuanto a características demográficas o hallazgos preoperatorios de la litiasis (p>0,05 para todos). Sin embargo, el tiempo quirúrgico fue menor en el grupo tratado sin VAU (79,4±15,3 vs. 90,4±16,7min en el grupo tratado con VAU; p=0,008). Las tasas de complicaciones intraoperatorias, incluidos el fracaso del acceso, la interrupción de la operación, las lesiones ureterales y el sangrado, fueron comparables en ambos grupos (p>0,05). No se observaron diferencias significativas en cuanto a la tasa libre de litiasis postoperatoria (78,8 vs. 71,0%; p=0,305) y el tamaño litiásico residual medio (2,7±3,5 vs. 3,1±3,1mm; p=0,687). Conclusiones El presente estudio sugiere que URSf sin VAU puede ofrecer una opción eficiente e igualmente efectiva para el tratamiento de los cálculos renales y de uréter superior. Sin embargo, se necesitan más estudios con muestras de mayor tamaño y periodos de seguimiento más largos para validar estos resultados y establecer indicaciones más precisas para este procedimiento. (AU)

Objectives This study evaluates the impact of using an access sheath (AS) during flexible ureteroscopy (fURS) for urolithiasis treatment, focusing on outcomes such as stone-free rate, operation time, and complications. Methods This prospective, randomized study was carried out at Badr Hospital, Helwan University, and Ain Shams University hospitals from August 2021 to August 2022. Patients were systematically randomized into two groups (fURS with AS: 33 patients and without AS: 31 patients) and underwent preoperative and postoperative assessments, including lab tests and imaging. Possible procedure-associated risks, such as failed stone access, pain, bleeding, and sepsis, were monitored. Results The two groups were found to be comparable in terms of demographic characteristics or preoperative stone findings (P>.05 for all). However, operation duration was shorter in the No Sheath group (79.4±15.3minutes vs. 90.4±16.7minutes in the Sheath group, P=.008). Intraoperative complication rates, including failed access, operation termination, ureteric injury, and bleeding, were comparable in both groups (P>.05). Postoperative stone-free rates (78.8% vs. 71.0%, P=.305) and mean residual stone size (2.7±3.5mm vs. 3.1±3.1mm, P=.687) showed no significant differences. Conclusions The present study suggests that fURS without an access sheath may offer an efficient and equally effective option for managing upper ureteric and renal stones. However, more studies with larger sample sizes and longer follow-up periods are required to validate these findings and to establish more precise indications for this approach. (AU)

Proof-of-concept for a novel nanotechnology-based treatment for urolithiasis.

Proof-of-concept of photonic lithotripsy in an in vitro setting and its ability to fragment the most common stone types is demonstrated. Effectiveness of different classes of photonic nanoparticles in fragmenting human stones is assessed. De-identified human stones were collected after institutional approval. Stones of a size range between 2-4 mm were rehydrated in simulated urine for 24 h. Stones were then coated with a solution of nanoparticles prior to activation with either a 785 nm or 1320 nm near-infrared energy source. Photonic lithotripsy achieved greater than 70% success rate in fragmentating calcium oxalate monohydrate stones using carbon-based nanoparticles for both near-infrared wavelengths. For gold-based nanoparticles, there was a similar success rate with the 785 nm wavelength but a significant decrease when using the 1320 nm wavelength energy source. All stones fragmented with the energy source at a distance ≥ 20 mm from the stone's surface. Limitations include the use of mixed-composition stones, a lack of complete stone immersion in liquid during treatment, and smaller stone size. Different classes of nanoparticles when excited with a near-infrared energy source can fragment common stone types in vitro. This technology has the potential to change the way we approach and treat patients with urolithiasis in a clinical setting.