Urolithiasis最新文献

The primary aim was to assess how various flexible ureteroscopes and ureteral access sheath size combinations affected intra-cavity pressures, under excessive irrigation pressures with a pressure bag. The secondary aim was to determine the maximum irrigation pressure that could be applied while still maintaining safe intra-cavity pressures, when a certain sheath-scope combination had resulted in an unsafe intra-cavity pressure in the initial experiment. An in-vitro setup was used to measure intra-cavity pressures across different flexible ureteroscope (6.3-9.6 Fr; Hugemed, Innovex and WiScope) and sheath size (ClearPetra; inner lumen diameter 9.5-12 Fr, lengths 40 and 50 cm) combinations. A steady irrigation pressure was delivered via a pressure bag pressurised to 360 mmHg, and a urodynamic machine provided real-time readings of intra-cavity pressure. For each combination, the steady-state intra-cavity pressure was recorded. Combinations generating an unsafe intra-cavity pressure (i.e. intra-cavity pressure of more than 30 mmHg) were re-assessed by gradually reducing the irrigation pressure, until intra-cavity pressure recorded reached 30 mmHg. The corresponding irrigation pressure was then recorded, and the experiment was then repeated with this established safe irrigation pressure to confirm that a safe intra-cavity pressure had been achieved. An intra-cavity pressure of 30 mmHg was taken to be the determined safe threshold for intra-cavity pressure. High intra-cavity pressures were observed with smaller sheaths and larger scopes, exceeding 100 mmHg in some combinations. Longer sheaths tended to generate higher pressures than shorter ones. The use of 12 Fr sheaths or 6.3 Fr scopes appeared to be safe regardless of the paired scope or sheath, even under extreme inflow pressure. Scope and sheath combinations have a significant impact on intra-cavity pressure, and inappropriate combinations may lead to unsafely elevated pressures. Larger sheaths and smaller scopes offer safer pressure profiles, even under high flow or high-pressure irrigation.

To determine whether retrograde pyeloperfusion (RP) during percutaneous nephrolithotomy (PCNL) decreases antegrade ureteral stone fragment migration, normal, moderately, and severely hydronephrotic silicone kidney and ureter models were created using deidentified CT images. Two techniques to prevent fragment migration, ureteral access sheath (UAS) and RP via a ureteroscope, were compared to an empty ureter. Two grams of stone fragments were placed into the renal pelvis. Antegrade irrigation and suction were applied for 5 min. The weights of ureteral stone fragments were compared using the Kruskal-Wallis test (p < 0.05 significant). In the normal ureter model, RP significantly reduced ureteral stone fragment migration (0.06±0.03 g) compared to both the UAS (0.32±0.19 g; p = 0.047) and control (0.42±0.11 g; p = 0.009). Similarly, in the moderate hydroureter model, RP significantly reduced ureteral stone fragment migration (0.11±0.06 g) compared to both the UAS (0.68±0.18 g; p = 0.009) and control (0.48±0.15 g; p = 0.016). In the severe hydroureter model, RP reduced ureteral stone fragment migration (0.17±0.12 g) compared to the UAS (1.04±0.29 g; p = 0.026) but was similar to the control (0.65±0.37 g; p = 0.169). RP showed an 85.7% and 81.1% reduction compared to the control and UAS conditions in the normal model, 76.2% and 83.3% reduction in the moderate hydroureter model, and 73.3% and 83.2% reduction in the severe hydroureter model, respectively. Thus, compared to an empty ureter and a UAS, in all ureter models, RP reduced ureteral stone fragment migration by 73.3-85.7%. Retrograde pyeloperfusion should be considered to reduce ureteral stone fragment migration during PCNL when endoscopic combined intrarenal surgery is employed.

To evaluate the safety and efficacy of the tip-flexible negative pressure suction ureteral access sheath (FUAS) in retrograde intrarenal surgery (RIRS) for pediatric patients with renal calculi, a retrospective analysis was performed on clinical data of 75 pediatric patients (aged 2-14 years) with renal calculi who underwent RIRS at Hetian County People's Hospital from January 2023 to August 2025. After 1-month preoperative double-J stent placement, patients were allocated to the FUAS group (n = 25) or conventional UAS (CUAS) group (n = 50), with groups matched for age, stone characteristics, and sheath size (10/12F). Indicators including operation time, stone basket utilization, complications, postoperative hospital stay, and stone clearance were compared. Baseline data were balanced between groups (P > 0.05). The FUAS group had shorter operation time than the CUAS group [(48.6 ± 19.8) min vs. (69.2 ± 22.1) min, P < 0.001], a significantly lower proportion of stone basket usage [32.0% (8 cases) vs. 72.0% (36 cases), P < 0.001], lower postoperative fever incidence (4.0% vs.12.0%, P < 0.05), and shorter postoperative hospital stay [(2.2 ± 0.8) d vs. (3.8 ± 1.1) d, P < 0.001]. Overall complication rates were comparable (12.0% vs.20.0%, P = 0.531), with all complications classified as Clavien-Dindo grade I-II, and stone-free rates showed no significant difference (96.0% vs.88.0%, P = 0.214). In the preschool subgroup (2-6 years, FUAS n = 8 vs. CUAS n = 12), the FUAS group also exhibited advantages: shorter operation time [(46.9 ± 17.8) min vs. (74.1 ± 21.3) min, P = 0.008], lower stone basket usage (25.0% vs. 83.3%, P = 0.005), shorter postoperative hospital stay [(2.3 ± 0.7) d vs. (3.6 ± 1.0) d, P = 0.006], and a 100% stone-free rate (vs. 83.3% in the CUAS group, P = 0.236). In conclusion, RIRS using a 7.5 F disposable flexible ureterorenoscope with 10/12F FUAS shows significant advantages for pediatric renal calculi management in Hotan County, with only mild complications. It significantly shortens operation time and postoperative hospital stay, lowers postoperative fever, and is worthy of promotion in urological centers equipped with proper instruments and experienced surgeons.

This study aimed to quantify the ablation volume per laser pulse (AVP, µm³) and the energy required to ablate 1 mm³ of stone material (RE, J/mm³) using the RevoLix HTL pulsed Thulium: YAG (p-Tm: YAG) laser (OmniGuide©, USA). Results were compared with those obtained using a Holmium: YAG (Ho: YAG) laser (MH1, Rocamed©, Monaco) and a Thulium Fiber Laser (TFL) system (IPG©, Russia). Experiments were conducted on pure human urinary stones composed of calcium oxalate monohydrate (COM), uric acid (UA), and cystine (CYS). Each sample was submerged in saline and lasered in contact mode with a 272-µm fiber. The p-Tm: YAG and TFL lasers were tested at 0.5, 0.8, and 1 J, while the Ho: YAG was evaluated at 0.6, 0.8, and 1 J, all using the shortest pulse setting available. After treatment, stone craters were imaged and segmented using 3D Slicer software to compute AVP, from which RE values were derived. All measurements were based on three repetitions per condition. Across multiple energy settings, Ho: YAG showed superior ablation performance in CYS and UA stones, particularly at 0.6 and 1 J, while no significant differences were noted among lasers for COM stones. TFL outperformed p-Tm: YAG in ablating UA stones at both 0.5 and 1 J. Regarding energy efficiency, Ho: YAG consumed less energy than TFL for CYS (at 0.8 and 1 J) and UA stones (all energies), and less than p-Tm: YAG for CYS (0.5 J) and UA (1 J). Conversely, both TFL and p-Tm: YAG were more efficient than Ho: YAG for COM stones. TFL also required significantly less energy than p-Tm: YAG at 0.5 J for COM and at 0.8 and 1 J for CYS stones. Our findings suggest that TFL and p-Tm: YAG may be less effective than Ho: YAG for cystine and uric acid stones. Stone composition should be carefully considered when selecting the laser source, as it may impact procedural efficiency and outcomes.

The global rise in urolithiasis poses significant health risks. However, the formation mechanisms and environmental influences of kidney stones remain poorly understood. Investigating the elemental composition of kidney stones provides a critical approach to exploring these factors. This study analyzed kidney stones from Yunnan Province, a region with high nephrolithiasis prevalence, classifying them into three types: calcium oxalate (CO), uric acid (UA), and mixed CO and carbonate apatite (CA) stones. The long-term accumulation of calcium salts results in significantly higher concentrations of Ca, Zn, and Se in calcium stones compared to the crustal average. The concentrations of most elements in UA stones are generally lower than those in calcium stones. Mg, Zn, and Sr show significant correlations with multiple elements and inhibit stone crystallization, whereas Cu and Se appear to act only in apatite-containing stones. Additionally, the heavy metal characteristics of kidney stones exhibit notable regional differences. Kidney stones from Yunnan show significantly lower Zn and Sr levels than those from other regions, displaying unique geochemical features influenced by regional environmental and dietary factors. The heavy metal characteristics of kidney stones in Yunnan elucidate the mechanistic roles of individual elements and their associated environmental influences.