Establishment and validation of a nomogram for predicting overall survival of upper-tract urothelial carcinoma with bone metastasis: a population-based study.

BACKGROUND: Bone metastasis (BM) carries a poor prognosis for patients with upper-tract urothelial carcinoma (UTUC). This study aims to identify survival predictors and develop a prognostic nomogram for overall survival (OS) in UTUC patients with BM. METHODS: The Surveillance, Epidemiology, and End Results database was used to select patients with UTUC between 2010 and 2019. The chi-square test was used to assess the baseline differences between the groups. Kaplan-Meier analysis was employed to assess OS. Univariate and multivariate analyses were conducted to identify prognostic factors for nomogram establishment. An independent cohort was used for external validation of the nomogram. The discrimination and calibration of the nomogram were evaluated using concordance index (C-index), area under receiver operating characteristic curve (AUC), calibration curve, and decision curve analysis (DCA). All statistical analyses were performed using SPSS 23.0 and R software 4.2.2. RESULTS: The mean OS for UTUC patients with BM was 10 months (95% CI: 8.17 to 11.84), with 6-month OS, 1-year OS, and 3-year OS rates of 41%, 21%, and 3%, respectively. Multi-organ metastases (HR = 2.21, 95% CI: 1.66 to 2.95, P < 0.001), surgery (HR = 0.72, 95% CI: 0.56 to 0.91, P = 0.007), and chemotherapy (HR = 0.37, 95% CI: 0.3 to 0.46, P < 0.001) were identified as independent prognostic factors. The C-index was 0.725 for the training cohort and 0.854 for the validation cohort, and all AUC values were > 0.679. The calibration curve and DCA curve showed the accuracy and practicality of the nomogram. CONCLUSIONS: The OS of UTUC patients with BM was poor. Multi-organ metastases was a risk factor for OS, while surgery and chemotherapy were protective factors. Our nomogram was developed and validated to assist clinicians in evaluating the OS of UTUC patients with BM.

Factors affecting the intraoperative calculi excretion during flexible ureteroscopy lithotripsy: an in vitro analysis.

OBJECTIVE: To explore the parameters influencing intraoperative calculi excretion (ICE) during flexible ureteroscopy lithotripsy (fURL) using in vitro simulation experiments. METHODS: 3D-printed human kidney models were used to simulate the elimination of gravel during fURL. The factors influencing the ICE during fURL were analyzed by comparing the effects of different degrees of hydronephrosis (mild, moderate, and severe), surgical positions (supine and lateral position), ratios of endoscope-sheath diameter (RESD) (0.625, 0.725, and 0.825), gravel sizes (0.50-1.00 mm, 0.25-0.50 mm, and 0.10-0.25 mm), and ureteral access sheaths (UASs) (traditional UAS and negative-pressure UAS) on ICE. RESULTS: The impacts of various UAS, RESD, degree of hydronephrosis, surgical positions, and gravel sizes on ICE were all significant (p < 0.05). We found no evidence of multicollinearity for all the independent variables, and the linear regression equation fitted as ICE ( g / min ) = 0.102 + 0.083 ∗ UAS grade - 0.050 ∗ RESD grade - 0.048 ∗ hydronephrosis grade + 0.065 ∗ position grade - 0.027 ∗ gravel size grade (R2 = 0.569). CONCLUSION: Employing negative-pressure UAS, smaller RESD, milder hydronephrosis, lateral position, and smaller gravel size contribute to improved ICE during fURL. Among them, the adoption of negative-pressure UAS had the most substantial effects.

The optimal ratio of endoscope-sheath diameter with negative-pressure ureteral access sheath: an in vitro research.

PURPOSE: To maintain safe intrarenal pelvic pressure (IPP), the combination of flexible ureteroscope (fURS) and traditional ureteral access sheath (T-UAS) should maintain a basic rule that is the ratio of endoscope-sheath diameter (RESD) ≤ 0.75. However, the negative-pressure ureteral access sheath (NP-UAS) may break the rule of negative pressure suction. This study aimed to examine the effect of NP-UAS on IPP and flow rate (FR) with varying RESD. METHODS: In a 3D-printed renal model, flexible ureteroscopy lithotripsy (fURL) was replicated. Six sizes of fURS paired with 12Fr T-UAS and NP-UAS resulted in six distinct RESDs of 0.63, 0.78, 0.87, 0.89, 0.90, and 0.91. While the irrigation pressure (IRP) was set between 100 and 800 cmH2O and the sucking pressure (SP) was set between 0 and 800 cmH2O, the IPP and FR were measured in each RESD. RESULTS: NP-UASs can reduce the IPP and increase the FR at the same RESD compared to T-UASs. The IPP decreased with increasing SP with NP-UAS. When RESD ≤ 0.78, T-UAS and NP-UAS can maintain IPP < 40 cmH2O in most circumstances. When RESD = 0.87, it is challenging for T-UAS to sustain IPP < 40 cmH2O; however, NP-UAS can do so. When RESD ≥ 0.89, it is difficult to maintain an IPP < 40 cmH2O even with NP-UAS. CONCLUSION: NP-UAS can decrease IPP and increase FR compared with T-UAS. To maintain a safe IPP, it is recommended that RESD < 0.85 when utilizing NP-UAS.

Effect of Aging on Healing Capacity of Bituminous Composites Containing Polyphosphoric Acid.

This study examines how aging affects the healing capacity of bituminous composites containing polyphosphoric acid (PPA). PPA is commonly used in bituminous composites to enhance its elasticity, however, PPA effectiveness highly depends on other constituents on the matrix and the environmental (internal and external) factors. In terms of internal factors, the interplay between PPA and various bitumen modifiers have been extensively studied. Here, we study how external factors such as exposure to ultraviolet radiation affect PPA's efficacy, measured in terms of change in bitumen's healing index. The study results showed that the introduction of PPA to bituminous composites significantly increases the bitumen healing index, however, the change in the healing index becomes less pronounced as aging progresses. The presence of additives such as taconite were found to affect the effect of PPA on bitumen's healing index. For instance, bitumens containing 30% taconite showed the highest increase in their healing index in the presence of PPA among studied scenarios. Overall, bitumen containing PPA had a higher healing index than those without PPA regardless of the extent of aging and dosage of modifiers. This, in turn, indicates that PPA is highly effective for enhancing bitumen healing. This can be attributed to the role of PPA in promoting intermolecular interactions within the bitumen matrix.

What is the appropriate gravel size during ureteroscopy lithotripsy? An in vitro evaluation.

To propose the suitable diameter of calculus debris produced during flexible ureteroscopy lithotripsy (fURL). A glass tube was used to simulate the stone excretion process during Furl. Different stone diameters (0.50-1.00 mm, 0.25-0.50 mm, and 0.10-0.25 mm) with three sizes of flexible ureteroscopy (fURS) (7.5Fr, 8.7Fr, and 9.9Fr) and ureteral access sheath (UAS) (12/14Fr) with or without negative pressure suction were employed in the experiment. The intraoperative calculi excretion (ICE) was recorded according to the stones discharged from the gap between fURS and UAS. The ICE raised significantly in thinner fURS and UAS due to the smaller Ratio of Endoscope-Sheath Diameter (RESD). The gravel size ≤ 0.25 mm was conducive to drainage with traditional UAS, while using fURS with negative-pressure UAS could significantly improve ICE. The gravel size ≤ 0.5 mm was conducive to expulsion. We clarify that ICE during ureteroscopy relates to RESD and negative pressure suction. The proper size of the stone fragment is critical in ensuring the expulsion during fURL, ≤ 0.25 mm in traditional UAS and ≤ 0.50 mm in negative-pressure UAS, respectively.