Urinary Calculi

IntroductionUreteroscopy serves as a minimally invasive surgical treatment option for ureteral and kidney stones but is not without technical challenges. Pre-stenting and medical therapies, such as alpha-blockers, may improve outcomes by facilitating ureteral access sheath placements and reducing complications. This systematic review and meta-analysis aimed to evaluate the effects of pre-stenting and preoperative pharmacological agents on ureteroscopy outcomes.MethodsWe conducted a systematic review and meta-analysis following PRISMA guidelines. A comprehensive literature search was performed across multiple databases, identifying randomized controlled trials comparing ureteroscopy outcomes with and without pre-stenting and pre-ureteroscopy medical therapy. Primary outcomes included failure rates in accessing the upper urinary tract, while secondary outcomes encompassed operative times, complications, and stone-free rates.ResultsThe analysis included 16 randomized controlled trials, revealing that pre-stenting and medical therapy significantly reduced failure rates (Relative Ratio 0.44, 95% CI 0.33-0.59, p ConclusionPreoperative alpha blockers enhance ureteroscopy success and reduces complications. The evidence supports their use before ureteroscopy for renal and ureteral stones, improving patient outcomes and procedural efficiency. Patients pre-stented for any reason demonstrated significantly improved ureteroscopic access and stone-free rates.

Gut microbial dysbiosis and the resultant metabolic disorder are intimately associated with calcium oxalate (CaOx) stone formation. Renal CaOx crystal deposition is one of the primary initiating factors of CaOx formation; however, the critical signaling metabolites communicating along the gut-kidney axis, and their regulation on renal CaOx crystal deposition remain unclear. Here, we investigate the role of gut microbiota-associated unconjugated bilirubin (UCB) metabolism in renal CaOx crystalline pathogenesis. The UCB was first distinguished as a significant risk factor of renal CaOx crystal deposition, by transplantation of fecal microbiota derived from healthy rat (healthy-FMT) to alleviate the renal CaOx crystal deposition in rat models, which was also testified in CaOx stone patients. Further experiments showed that UCB could increase renal CaOx crystal deposition significantly in both rat and Drosophila models. Mechanistically, UCB can promote apoptosis in renal tubular epithelial cells, enhance oxalate secretion by upregulating Slc26a6 expression, and facilitate CaOx crystal nucleation and aggregation, all of which contribute to renal CaOx crystalline pathogenesis. Furthermore, we identified significant gut microbiota dysbiosis in renal CaOx crystal deposition rats, particularly in β-glucuronidase (β-GD) and bilirubin reductase (BilR)-related dysbiosis, which modulate UCB levels and its enterohepatic circulation. These findings suggest that UCB is a novel regulator of renal CaOx crystal deposition, and targeting its metabolism via modulation of the gut microbiota may offer a promising therapeutic strategy for preventing renal CaOx crystal deposition-related nephropathy.

IntroductionNovel Direct-In-Scope-Suction ureteroscopes (DISS-U) have recently been introduced to facilitate removal of small stone fragments. The purpose of this study was to compare two novel DISS-U to a conventional ureteroscope to determine efficiency for suctioning fluid and stone dust at different deflection angles.MethodsThree disposable ureteroscopes were evaluated, including two DISS-U with 5.1-Fr and a 3.6-Fr channels, and were compared to a conventional ureteroscope with 3.6-Fr channel. For DISS-U trials, a conventional suction system was set at maximal settings and tested at deflection of 0, 90, and 140°, to simulate upper, interpolar, and lower pole kidney stone evacuation under 3 conditions (empty channel, 2.2-Fr basket, and 0.038 guidewire). For the conventional ureteroscope, suctioning was performed manually using a 60-mL Luer lock syringe. Five trials were performed to measure the time in seconds to remove 1 gram of CaOx density BegoStones (0.25, 0.5, and 1 mm) and 50-mL of saline.ResultsThe 5.1-Fr DISS-U was the only scope that evacuated 0.5 mm stone fragments and evacuated them significantly faster from the upper and interpole compared to the lower pole (111.0 ± 27.7, 128.0 ± 29.1, and 377.7 ± 63.4 s at 0, 90, and 140°, respectively; p ConclusionsThe DISS ureteroscopes significantly outperformed the conventional ureteroscope in both suction speed and dust evacuation efficiency. The 5.1-Fr DISS-U demonstrated superior performance and is able to evacuate stone particles up to 0.5 mm.

Background: Kidney stone disease (KSD) is a growing global health issue, while hyperuricemia has been linked to various health conditions. This study aimed to explore the association between hyperuricemia and KSD. Methods: This study analyzed the data of 118,963 generally healthy participants aged 30-70 years from the Taiwan Biobank. KSD was defined based on self-reported diagnoses, and hyperuricemia was defined as a serum uric acid level > 7 mg/dL in men and > 6 mg/dL in women. Key variables including age, sex, body mass index, lifestyle factors, presence of hypertension, diabetes, and chronic kidney disease were recorded. Statistical analysis was conducted using descriptive statistics and logistic regression to evaluate the association between hyperuricemia and KSD. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were reported, with statistical significance set at p Results: Among the 118,963 participants, 23,094 (19.4%) had hyperuricemia. Those with hyperuricemia were older, had a higher body mass index, and were more likely to smoke, consume alcohol, and have elevated blood pressure. They also had higher rates of comorbidities such as hypertension, diabetes, metabolic syndrome, chronic kidney disease, and gout, along with worse laboratory profiles. Multivariable analysis revealed that hyperuricemia was significantly associated with an increased risk of KSD (OR: 1.155, 95% CI: 1.089-1.224, p Conclusion: Hyperuricemia was an independent risk factor for KSD in this large Taiwanese cohort study, with a stronger association observed in females. Gout partially mediates this relationship, suggesting overlapping yet distinct pathways linking hyperuricemia to kidney stone formation. These findings underscore the importance of sex-specific management strategies for KSD. Routine monitoring of serum uric acid levels is recommended to mitigate KSD risk, especially among high-risk individuals. Future research should focus on elucidating the long-term impact of hyperuricemia on KSD and tailoring prevention strategies to regional and population-specific needs.