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Tag: Urology

  • f-URS matched stone clearance with better short-term safety than mPCNL

    f-URS matched stone clearance with better short-term safety than mPCNL

    What the study found

    The study found that flexible ureteroscopy (f-URS, a scope-based procedure through the urinary tract) and mini-percutaneous nephrolithotomy (mPCNL, a small-keyhole kidney stone procedure) had comparable stone clearance in patients with a solitary kidney and 1.0–2.0 cm renal stones. The authors report that f-URS also had a better early safety profile and better short-term preservation of renal function.

    Why the authors say this matters

    The authors conclude that f-URS may be a viable nephron-sparing option, meaning a treatment intended to preserve kidney tissue, for this high-risk population. They also say the findings are hypothesis-generating and that more prospective, long-term studies are needed to test whether the functional benefits last.

    What the researchers tested

    This was a retrospective study of 50 solitary-kidney patients treated between June 2018 and April 2024. The researchers compared 26 patients who received mPCNL with 24 who received f-URS, using 3-month stone-free rate, Clavien–Dindo complication grading, hemoglobin change, hospital stay, serum creatinine, and estimated glomerular filtration rate (eGFR, a measure of kidney filtering function) at baseline, 72 hours, and 1 month.

    What worked and what didn't

    Stone-free rates were similar between groups: 96.2% for mPCNL and 91.7% for f-URS, with no statistically significant difference reported. f-URS showed less hemoglobin decline, shorter hospitalization, no Grade II complications, and greater improvement in short-term kidney function measures; all Grade II complications, which required transfusion, occurred in the mPCNL group.

    What to keep in mind

    The study was retrospective and included only 50 patients, so the authors treat the findings as preliminary. The abstract also states that longer-term durability of the renal function differences was not established and needs prospective follow-up.

    • Both procedures achieved high stone-free rates in solitary-kidney patients with 1.0–2.0 cm renal stones.
    • f-URS had less hemoglobin decline than mPCNL.
    • Hospital stay was shorter with f-URS than with mPCNL.
    • All Grade II complications, requiring transfusion, occurred in the mPCNL group.
    • At 1 month, f-URS showed greater improvement in serum creatinine and eGFR.
  • Residual stones and urine culture predict early stone recurrence

    Residual stones and urine culture predict early stone recurrence

    What the study found

    The study found that three factors were independently associated with 6-month recurrence after surgery for infection-related upper urinary tract stones: residual stones, a positive urine culture during follow-up, and higher CT attenuation values. A nomogram is a risk-prediction chart was built from these factors and showed acceptable internal performance.

    Why the authors say this matters

    The authors say the findings may help support individualized follow-up after surgery for infection-related stones. They conclude that the nomogram could be useful in practice, but note that it still needs external validation.

    What the researchers tested

    The researchers did a retrospective single-center study of 148 patients with infection-related upper urinary tract stones confirmed by infrared spectroscopy. They split the patients into a modeling cohort and a validation cohort, then used multivariable logistic regression to identify predictors and build a nomogram, which they evaluated with discrimination, calibration, and decision curve analysis.

    What worked and what didn't

    Recurrence within 6 months was common in both cohorts, with rates of 44.2% in the modeling group and 70.5% in the validation group. Patients with recurrence more often had residual stones, renal atrophy, and positive urine cultures at follow-up, and they had higher median CT values. Residual stones, positive follow-up urine culture, and CT value remained independent predictors, and the nomogram had an area under the curve of 0.86 in the modeling group and 0.75 in the validation group.

    What to keep in mind

    This was a retrospective study from one center, and the validation was internal only. The authors state that the nomogram requires external validation before broader use.

    • Residual stones were an independent predictor of 6-month recurrence.
    • Positive urine culture during follow-up was also independently linked to recurrence.
    • Higher CT attenuation values were associated with recurrence.
    • The nomogram reached an AUC of 0.86 in the modeling group and 0.75 in the validation group.
    • The study used a retrospective single-center sample of 148 patients.

  • RIRS and mini-PCNL were similarly effective for pediatric high-density renal stones

    What the study found

    Both retrograde intrarenal surgery (RIRS, a stone-removal procedure using a flexible scope passed through the urinary tract) and mini-percutaneous nephrolithotomy (mini-PCNL, a smaller-keyhole kidney stone surgery) worked well and were safe in children with single renal pelvic stones under 2 cm and high density on CT. The study found comparable stone-free rates, with some recovery measures favoring RIRS.

    Why the authors say this matters

    The authors conclude that both procedures are useful for managing pediatric kidney stones in this group. They also suggest that RIRS may offer less invasiveness, shorter recovery, and lower radiation exposure, while mini-PCNL remains a valuable option in anatomically complex or lower-calyceal cases.

    What the researchers tested

    The researchers conducted a prospective randomized clinical trial at Beni-Suef University Hospitals. They enrolled 70 children aged 3–14 years with a single renal pelvic stone smaller than 2 cm and density above 1000 HU on low-dose non-contrast CT, then randomized them equally to RIRS or mini-PCNL.

    What worked and what didn't

    At one month, stone-free rates were 91.4% for RIRS and 94.3% for mini-PCNL, and this difference was not significant. RIRS had shorter operative time, hospital stay, catheterization time, and radiation exposure; mini-PCNL had a greater hemoglobin drop, while complication rates were similar between groups.

    What to keep in mind

    The abstract does not describe longer-term follow-up beyond one month. It also focuses on children with a single high-density renal pelvic stone under 2 cm, so the findings may not apply to other stone types or locations.

    • The study compared RIRS with mini-PCNL in 70 children aged 3–14 years.
    • Both treatments had high one-month stone-free rates: 91.4% for RIRS and 94.3% for mini-PCNL.
    • RIRS had shorter operative time, hospital stay, catheterization time, and lower radiation exposure.
    • Mini-PCNL produced a greater hemoglobin drop, while complication rates were similar.
    • The authors say mini-PCNL may still be useful in anatomically complex or lower-calyceal cases.

  • Open cystolithotomy removed giant neobladder stones after long follow-up loss

    What the study found

    The study reports a 78-year-old man who developed two very large stones in an ileal neobladder after 18 years without urological follow-up. Open cystolithotomy, a surgical procedure to remove bladder stones through an incision, removed both stones successfully.

    Why the authors say this matters

    The authors conclude that this case shows the need for lifelong structured follow-up for people with urinary diversions such as a neobladder, an intestinal bladder substitute created after bladder removal. They also state that preventive measures are important to avoid severe stone formation.

    What the researchers tested

    This is a case report, so the researchers described one patient’s history, imaging findings, surgery, stone analysis, and follow-up. Computed tomography was used to measure the stones, and the removed stones were analyzed for composition.

    What worked and what didn't

    The patient had two stones measuring 10×8×6 cm and 9×7×8 cm, with a combined weight of 950 grams. Open cystolithotomy removed both stones in 90 minutes with minimal blood loss and no complications, and the patient had symptom resolution, stone-free imaging, and stable renal function during 12 months of follow-up.

    What to keep in mind

    This is a single case report, so it describes one person rather than a larger group. The abstract also notes that the patient was later lost to follow-up again, and it does not provide comparative data on other treatments.

    • A 78-year-old man developed two giant stones in an ileal neobladder after 18 years without urological follow-up.
    • The stones measured 10×8×6 cm and 9×7×8 cm and weighed 950 grams together.
    • Open cystolithotomy removed both stones with minimal blood loss and no complications.
    • Stone analysis showed pure struvite-carbonate apatite, linked in the abstract to chronic Proteus mirabilis infection.
    • The authors emphasize lifelong structured follow-up and preventive care for urinary diversion patients.

  • Flexible ureteroscopy matched stone clearance with fewer early complications

    What the study found

    In patients with a solitary kidney and 1.0–2.0 cm renal stones, flexible ureteroscopy (f-URS) and mini-percutaneous nephrolithotomy (mPCNL) had similar stone-free rates. The study reports that f-URS was associated with less bleeding, shorter hospital stays, and better short-term kidney function measures.

    Why the authors say this matters

    The authors conclude that f-URS may be a viable nephron-sparing option, meaning a treatment intended to preserve kidney tissue, for this high-risk population. They also state that the findings are preliminary and suggest the need for further prospective, long-term studies.

    What the researchers tested

    This was a retrospective study of 50 solitary-kidney patients treated between June 2018 and April 2024. The researchers compared mPCNL in 26 patients with f-URS in 24 patients, measuring 3-month stone-free rate, complications by Clavien–Dindo classification, and renal function using serum creatinine and estimated glomerular filtration rate (eGFR), a measure of how well the kidneys filter blood.

    What worked and what didn't

    Stone-free rates were comparable between the two procedures: 96.2% for mPCNL and 91.7% for f-URS, with no statistically significant difference reported. f-URS showed significantly smaller hemoglobin decline, shorter hospitalization, and all grade II complications, which required transfusion, occurred in the mPCNL group. At 1 month, f-URS was associated with greater improvement in serum creatinine and eGFR than mPCNL.

    What to keep in mind

    The study is retrospective and included only 50 patients, so the authors treat the results as hypothesis-generating. The abstract says longer-term durability of the kidney function differences has not been established, and the findings may not apply beyond solitary-kidney patients with 1.0–2.0 cm renal stones.

    • The study compared mini-percutaneous nephrolithotomy and flexible ureteroscopy in 50 solitary-kidney patients.
    • Stone-free rates were similar between the two treatments.
    • Flexible ureteroscopy had less hemoglobin decline and shorter hospital stays.
    • All grade II complications, which required transfusion, occurred in the mini-percutaneous nephrolithotomy group.
    • At 1 month, flexible ureteroscopy showed greater improvement in creatinine and eGFR.

  • Urinary calcium-to-citrate ratio helps identify stone risk in infants

    What the study found

    The urinary calcium-to-citrate (Ca/Cit) ratio, a measure of calcium relative to citrate in urine, showed moderate ability to distinguish stone-forming from non-stone-forming children under 24 months old. A higher ratio was seen in hypercalciuric stone-formers than in the other groups.

    Why the authors say this matters

    The authors conclude that the Ca/Cit ratio may serve as a practical adjunctive marker of stone risk in infants and toddlers evaluated for suspected urinary stone disease. They also say the findings provide an age-appropriate reference distribution for children without stones and normal urinary calcium excretion.

    What the researchers tested

    The researchers did a retrospective single-center study of 181 children aged 1-24 months who had metabolic testing and ultrasonography at first visit to a tertiary pediatric nephrology clinic between 2012 and 2024. They grouped children as normocalciuric stone-free controls, hypercalciuric stone-formers, or non-hypercalciuric stone-formers, and used receiver operating characteristic (ROC) analysis to assess how well the spot urine Ca/Cit ratio predicted stones.

    What worked and what didn't

    The Ca/Cit ratio differed significantly across groups, with the highest values in hypercalciuric stone-formers (0.46 mg/mg) compared with controls (0.17 mg/mg) and non-hypercalciuric stone-formers (0.31 mg/mg). A threshold above 0.23 mg/mg had moderate diagnostic performance, with an area under the curve of 0.695, sensitivity of 66.1%, and specificity of 63.2%.

    What to keep in mind

    This was a retrospective study from a single center, so the findings may not generalize broadly. The abstract says larger prospective studies are needed to validate reference intervals and refine cut-off values for this age group.

    • The urinary calcium-to-citrate ratio was higher in stone-forming children than in stone-free controls.
    • Hypercalciuric stone-formers had the highest Ca/Cit ratio among the groups studied.
    • A Ca/Cit cutoff above 0.23 mg/mg showed moderate ability to detect stones.
    • Age did not show a meaningful correlation with Ca/Cit values in this study.
    • The authors call for larger prospective studies to confirm reference ranges and cut-off values.

  • Kidney stones were found in 5.6% of adults in a Swiss cohort

    What the study found

    In this Swiss adult cohort, ultrasound-detected kidney stones were present in 5.6% of participants, and 4.3% developed new stones over 3 years. The authors report that the prevalence was lower than in North America but higher than in Asian populations.

    Why the authors say this matters

    The authors conclude that these data will help inform prevention strategies. The findings indicate that kidney stone patterns and associated factors in Switzerland add information where European data are described as scarce.

    What the researchers tested

    The Swiss Kidney Project on Genes in Hypertension (SKIPOGH) is a multicenter cohort of 1,128 adults recruited from Lausanne, Geneva, and Bern between 2009 and 2012. Participants had renal ultrasound at baseline, completed a standardized questionnaire, and returned for follow-up 3 years later; the researchers used logistic regression to examine factors associated with kidney stone prevalence and new stone formation.

    What worked and what didn't

    At baseline, diabetes mellitus, family history of kidney stones, and higher serum creatinine were associated with prevalent kidney stones. For 3-year incidence, active smoking, lower physical activity score, and a personal history of kidney stones were associated with new stones. The abstract does not report other variables as associated with prevalence or incidence.

    What to keep in mind

    The summary provided does not describe limitations beyond noting that European data are scarce. The results come from one Swiss cohort, so the abstract does not state how far the findings extend beyond this population.

    • Ultrasound-detected kidney stones were present in 5.6% of participants overall.
    • New kidney stones appeared in 4.3% of participants over 3 years.
    • Diabetes mellitus and family history were linked to prevalent kidney stones.
    • Active smoking, lower physical activity, and a personal history of stones were linked to new stones.
    • The authors say the prevalence was lower than in North America and higher than in Asia.
  • Urolithiasis prevalence is similar across Europe and lower in Latin America

    Urolithiasis prevalence is similar across Europe and lower in Latin America

    What the study found

    The study found that the prevalence of urolithiasis, or urinary stones, was not detectably different across the European regions examined and had stayed stable over the last 20 years. It also found that prevalence in Latin America appeared lower than in Europe.

    Why the authors say this matters

    The authors say this matters because the epidemiology of urolithiasis may vary by geographical area in relation to environmental factors, so reviewing prevalence and incidence across countries can help summarize the available information.

    What the researchers tested

    The researchers conducted an updated systematic review and meta-analysis of population-based studies on urinary calculi prevalence and incidence in Europe and Latin America. They searched EMBASE and PubMed for studies published from January 1, 1981, to February 28, 2026, and included children and adults with population-based estimates.

    What worked and what didn't

    For Europe, 66 studies were included in the systematic review, and the pooled prevalence of kidney stones was 7.2%. For Latin America, 17 studies were included, and the pooled prevalence was 6.02%; incidence values were described as highly variable depending on study design and population, and in three pediatric studies incidence ranged from 1.8 to 6.5 cases per year per 100,000 inhabitants.

    What to keep in mind

    The study reports considerable heterogeneity in both Europe and Latin America, meaning the study estimates varied widely across studies. The overall risk of bias was low to moderate, and the available summary does not provide more detailed limitations.

    • The pooled prevalence of kidney stones in Europe was 7.2%.
    • The pooled prevalence in Latin America was 6.02%.
    • The study found no detectably different prevalence between Northern and Southern Europe.
    • Prevalence in Europe appeared stable before and after the year 2000.
    • Incidence estimates varied strongly by study design and population.