Kevin Stritt

Résumé: La métaphylaxie de la lithiase urinaire reste un défi clinique en raison de taux élevés de récidive. Traditionnellement, les stratégies préventives reposent sur des mesures diététiques et l’utilisation de diurétiques thiazidiques. Cependant, des études récentes remettent de plus en plus en question ces approches. L’étude randomisée NOSTONE n’a montré aucun bénéfice significatif de l’hydrochlorothiazide par rapport au placebo dans la prévention des récidives lithiasiques, malgré une réduction de l’excrétion calcique. L’étude INDAPACHLOR, actuellement en cours, évalue des diurétiques alternatifs tels que l’indapamide et la chlortalidone. Parallèlement, l’étude SWEETSTONE a démontré que l’inhibiteur de SGLT2, l’empagliflozine réduit significativement la sursaturation urinaire en substances lithogènes. L’étude EMPASTONE vise à confirmer ces résultats sur des critères cliniques. Dans l’ensemble, ces données suggèrent un possible changement de paradigme dans la métaphylaxie de la lithiase urinaire et ouvrent la voie à une prévention plus individualisée.

Urolithiasis is a highly prevalent condition influenced by environmental, dietary, and genetic factors. Recurrent unilateral stone formation raises the question of whether localized renal metabolic abnormalities contribute to lithogenesis. Conventional 24-hour urine analyses provide a global assessment of urinary solutes and may overlook kidney-specific differences. The objective of this study was to determine whether distinct urinary chemistry differences exist between stone-bearing and contralateral kidneys in patients with recurrent unilateral urolithiasis. This monocentric prospective study was conducted at the Department of Urology, Lausanne University Hospital (Switzerland). Adult patients undergoing elective ureteroscopy (URS) for recurrent unilateral urolithiasis were enrolled. Urine was collected separately from each kidney by selective ureteral catheterization, and samples were analyzed for urinary lithogenic parameters. Paired comparisons were performed using repeated measures ANOVA. Fifteen patients were included (median age 50 year; 67% male; median BMI 24.2 kg/m²), each with a median of three prior stone episodes. Surgical approaches included rigid (47%), flexible (27%), and combined (27%) URS, with a median operative time of 40 min. Calcium oxalate was the predominant stone type (60%), followed by mixed calcium oxalate–phosphate (27%) and uric acid stones (13%). No significant differences were found in urinary chemistry between stone-bearing and contralateral kidneys (all p > 0.10). Subgroup analyses by stone type suggested trends toward lower potassium excretion in mixed stones and reduced chloride in urate stones, though these were not statistically significant due to small subgroup sizes.Limitations include the small sample size and single-center design. No significant unilateral metabolic asymmetries were detected in urinary solute handling among patients with recurrent unilateral urolithiasis. This finding does not support the presence of clinically relevant kidney-specific metabolic defects in this cohort and supports the continued use of standard 24-hour urine testing as an adequate metabolic evaluation tool in most clinical scenarios. Kidney-specific urine sampling does not appear justified in routine practice based on the present data and should be limited to carefully selected cases or research settings.

Background: Kidney stones represent a growing global health concern, with a lifetime prevalence estimated at 7%–13% in North America and 1%–5% in Asia, but European data are scarce. We assessed the prevalences and incidence of kidney stones in the Swiss adult population and identified associated factors. Methods: The Swiss Kidney Project on Genes in Hypertension (SKIPOGH) is a multicenter cohort including 1128 participants recruited from the general population of Lausanne, Geneva and Bern (2009–12). All underwent renal ultrasound at baseline and completed a standardized questionnaire. Predefined demographic, lifestyle and clinical variables included age, sex, BMI, education, smoking, physical activity, hypertension, diabetes, history of kidney stones, laboratory and urinary parameters. A follow-up visit was performed 3 years later. Logistic regression analysis was performed to identify factors associated with kidney stone prevalence at baseline and 3-year incidence of newly formed stones. Results: Ultrasound-detected kidney stones were present in 5.6% (6.1% men and 5.1% women). The 3-year incidence of new stones was 4.3% (4.1% men, 4.6% women). In multivariable logistic regression analysis, diabetes mellitus [odds ratio (OR) 2.93, 95% confidence interval (CI) 1.05–8.21, P = .04], a family history of kidney stones (OR 9.96, 95% CI 4.53–21.91, P < .01) and higher serum creatinine (OR 1.02 per µmol/L, 95% CI 1.00–1.04, P = .02) were associated with the prevalence of kidney stones. Active smoking (OR 2.49, 95% CI 1.07–5.78, P = .03), lower physical activity score (OR 0.82, 95% CI 0.67–1.00, P = .05) and a personal history of kidney stones (OR 33.0, 95% CI 12.4–87.6, P < .01) were associated with the 3-year incidence of kidney stones. Conclusion: In this Swiss cohort, the prevalence of kidney stones was lower than that reported in North America but higher than in Asian populations. Diabetes mellitus, family history of kidney stones were the strongest risk factors for prevalent stones, while a personal history of kidney stones and low physical activity were predictors of incident stone formation. These data will help to inform prevention strategies.

Background: The clinical benefit of preoperative ureteric double J (JJ) stenting prior to ureterorenoscopy (URS) for uncomplicated urolithiasis remains debated. In cases requiring urgent decompression or delayed definitive treatment, JJ stenting is frequently employed. However, prolonged indwelling time may increase the risk of bacterial colonization and subsequent infectious complications, though evidence remains limited. Methods: We conducted a retrospective, single-center study including 350 adult patients who underwent URS at the Department of Urology, Lausanne University Hospital (CHUV) between January and December 2023. The primary outcome was infectious complication, defined as the occurrence of ≥ 1 of the following within 30 days postoperatively: fever > 38.0 °C, systemic inflammatory response, hospitalization > 3 days with documented signs of infection, or readmission for urinary infection. Ten predefined clinical variables were analyzed using univariable and multivariable logistic regression to identify independent predictors of infectious failure. Results: Most patients (83%) had a stent in place at the time of surgery, and 78% received cefuroxime as prophylaxis. Infectious complications occurred in 29 patients (8.3%). Patients with infectious complications had significantly longer JJ stent dwell times (mean 63.9 vs. 36.3 days, p < 0.001). Multivariable analysis identified prolonged stent dwell time (OR 0.984 per day; 95% CI 0.973–0.995; p < 0.001) and neurogenic bladder (OR 0.871; 95% CI 2.196–6.739; p < 0.001) as independent risk factors for infectious failure. Subgroup analysis revealed a significant increase in infection rates when dwell time exceeded 60 days ( p < 0.001). Conclusion: Prolonged JJ stent dwell time and neurogenic bladder are independently associated with increased postoperative infectious complications after URS. Our findings support implementing fast-track surgical protocols to reduce stent duration, particularly avoiding delays beyond 60 days, to minimize infection-related morbidity.

Background/Objectives: To compare postoperative infectious complication rates after ureteroscopy (URS) in patients with anatomical anomalies of the urinary tract and neurogenic bladder to those in patients without these conditions, and to analyze associated risk factors, urine culture profiles, and stone composition in these special populations. Methods: This retrospective cohort study included patients undergoing URS at a single tertiary referral center. Patients were stratified into three groups: anatomical anomalies of the urinary tract (n = 23), neurogenic bladder (n = 30), and controls (n = 297). Demographic data, perioperative details, preoperative urine culture results, stone composition, and postoperative complications were collected and compared. Univariable analyses and chi-square or Kruskal–Wallis tests were used as appropriate. Results: Patients with anatomical anomalies of the urinary tract and neurogenic bladder had significantly higher rates of postoperative infectious complications compared to controls (30.4% and 33.3% vs. 4.0%; p < 0.001). Preoperative urine cultures were more frequently positive in these groups, with Escherichia coli, Enterococcus faecalis, and Pseudomonas aeruginosa being the most common pathogens. Stone analysis revealed a higher proportion of struvite and mixed calcium phosphate stones in the anatomical anomalies of the urinary tract and neurogenic bladder groups compared to controls, who predominantly formed calcium oxalate stones (75%). Conclusions: Patients with anatomical anomalies of the urinary tract or neurogenic bladder are at higher risk of postoperative infectious complications following URS, likely due to more frequent colonization and anatomical or functional urinary tract abnormalities. These findings underscore the importance of tailored perioperative management, including targeted antimicrobial strategies and careful surgical planning, to mitigate risks in these high-risk populations.

Key Points: Asymptomatic stone passage was common in patients with recurrent calcium-containing kidney stones. Higher the number of stones at presentation, more likely it was that a kidney stone would spontaneously pass over time without causing any symptoms. Background: Kidney stones are a common health problem and are characterized by a high risk of recurrence. A certain number of kidney stones pass asymptomatically. Data regarding the frequency of asymptomatic spontaneous stone passages are limited. Methods: To assess the frequency of asymptomatic spontaneous stone passage and its covariates, we conducted a post hoc analysis of the prospective randomized NOSTONE trial. All asymptomatic spontaneous stone passages were identified by comparing the total number of kidney stones on low-dose noncontrast computed tomography (CT) imaging at the beginning and end of the study, considering symptomatic stone passages and surgical stone removal. The statistical analysis focused on the association of independent variables and the number of asymptomatic spontaneous stone passages using linear regression analyses. Results: Of the 416 randomized patients, 383 with both baseline and end-of-study CT were included in this analysis. The median follow-up period was 35 months, the median patient age was 49 years (interquartile range [IQR], 40–55), and 20% of the patients were female. A total of 442 stone events occurred in 209 of 383 (55%) patients: 217 of 442 (49%) were symptomatic spontaneous stone passages, 67 of 442 (15%) were surgically removed stones, and 158 of 442 (36%) were asymptomatic spontaneous stone passages. The median size of asymptomatic stones (2.4 mm; IQR, 1.95–3.4) and the size of symptomatic stones (2.15 mm; IQR, 1.68–2.79) that passed spontaneously were not significantly different (P = 0.37). The number of asymptomatic spontaneous stone passages was significantly associated with a higher number of stones on CT at randomization (P = 0.001). Limitations include the lack of data on stone size at the time of passage and overrepresentation of White men. Conclusions: Asymptomatic stone passage was common in patients with recurrent calcium-containing kidney stones. The higher the number of stones at presentation, the more likely it was that a kidney stone would spontaneously pass over time without causing any symptoms. Clinical Trial registry name and registration number: NOSTONE trial and: NCT03057431.

Background: Cystectomy with urinary diversion (CUD) is a highly morbid surgery. Despite implementing an enhanced recovery after surgery (ERAS^®) protocol, postoperative respiratory complications (PRC) within 30 days after surgery remain frequent. This study aims to identify patients at higher risk of developing PRC after CUD. Methods: We conducted a retrospective analysis of 242 patients who underwent CUD at Lausanne University Hospital from 2012 to 2022, adhering to ERAS^® guidelines. Data on postoperative complications, including pneumonia, respiratory failure, pulmonary embolism, lobar atelectasis, and pleural effusion, were analyzed. Chi-square and Mann–Whitney U tests compared patients with and without PRC. A multivariable Cox model identified independent prognostic factors. Results: PRC occurred in 41 patients (17%). Those with PRC experienced longer hospital stays and higher 30-day mortality rates. Poor ERAS^® compliance was a significant risk factor. Multivariable analysis showed pneumonia was associated with postoperative ileus, while pulmonary embolism correlated with infectious and cardiovascular complications. Conclusions: PRC result in extended hospitalization and decreased survival. Rigorous adherence to ERAS^® protocols, including early mobilization, respiratory physiotherapy, and avoiding nasogastric tubes, is essential for preventing PRC.

Lower urinary tract dysfunction is frequently observed in individuals with multiple sclerosis (MS), significantly impacting their quality of life and increasing the risk of upper urinary tract (UUT) damage. Magnetic resonance imaging (MRI) serves as the gold standard imaging technique for identifying demyelinating lesions and aiding in the clinical diagnosis of MS. However, despite its diagnostic utility, the precise relationship between MRI lesions and bladder dysfunction remains poorly established. We aimed to examine the correlation between MRI lesion localizations and both urodynamic parameters and risk factors for UUT damage. In this retrospective study, we conducted a comprehensive review of 201 patients diagnosed with MS who were referred for primary neurourological evaluation, including a videourodynamic study (VUDS). To explore potential significant relationships between the independent variable of MRI lesion localization and the dependent outcome variables, we conducted a multivariate analysis of variance (MANOVA) regression. A significant correlation was observed between the presence of a brainstem lesion and specific urodynamic parameters, including lower maximum cystometric bladder capacity and higher bladder compliance. Similarly, an increased number of diverse MRI lesion localizations demonstrated a significant correlation with these urodynamic parameters. In conclusion, MRI findings did not exhibit a significant association with urodynamic risk factors for UUT damage, thereby limiting their utility in stratifying MS patients for subsequent neurourological assessment and treatment.

Lower urinary tract dysfunction is often observed in patients with multiple sclerosis (MS) and may be responsible for an increased risk of upper urinary tract (UUT) damage. Although there are well-known urodynamic risk factors for UUT damage, no clinical prediction parameters are clearly identified. We aimed to confirm the accuracy of the Expanded Disability Status Scale (EDSS) in predicting urodynamic risk factors for UUT deterioration and to assess other clinical parameters potentially predicting urodynamic risk factors. We retrospectively reviewed 201 patients with MS referred for primary neuro-urological work-up, including a video-urodynamic study (VUDS) from August 2009 to February 2020. Multivariate modeling revealed EDSS, male gender, and a number of LUTS as clinical parameters significantly associated with urodynamic risk factors for UUT damage (p = 0.06, p = 0.01, p = 0.02, respectively). A nomogram combining EDSS, male gender, and a number of different LUTS was created to predict the presence of at least one urodynamic risk factor for UUT damage. In conclusion, the presence of high EDSS combined with male gender and several different LUTS is significantly associated with urodynamic risk factors and can be used to stratify MS patients for further neuro-urological assessment and treatment.