Antegrade flexible ureteroscopy-assisted percutaneous nephrolithotomy for staghorn calculi: a prospective randomized controlled study.

The aim is to compare the efficacy and safety between single percutaneous nephrolithotomy (sPNL) and antegrade flexible ureteroscopy-assisted percutaneous nephrolithotomy (aPNL) for the treatment of staghorn calculi. A prospective randomized controlled study was conducted at the Second Hospital of Tianjin Medical University. A total of 160 eligible patients were included, with 81 in the sPNL group and 79 in the aPNL group. The study first compared the overall differences between sPNL and aPNL. Then, the patients were divided into two subgroups: Group 1 (with less than 5 stone branches) and Group 2 (with 5 or more stone branches), and the differences between the two subgroups were further analyzed. The results showed that aPNL had a higher stone-free rate (SFR) and required fewer percutaneous tracts, with a shorter operation time compared to sPNL (P < 0.05). Moreover, aPNL significantly reduced the need for staged surgery, particularly in patients with 5 or more stone branches. Moreover, there were no significant differences in the changes of hemoglobin levels and the need for blood transfusions between the sPNL and aPNL groups, and the incidence of multiple tracts was lower in the aPNL group. The two groups showed comparable rates of perioperative complications. We concluded that aPNL resulted in a higher SFR for staghorn calculi, and required fewer multiple percutaneous tracts, reduced the need for staged surgery, and had a shorter operative time than PNL alone, especially for patients with 5 or more stone branches. Furthermore, aPNL did not increase the incidence of surgical complications.

Development and validation of a nomogram to predict impacted ureteral stones via machine learning.

BACKGROUND: To develop and evaluate a nomogram for predicting impacted ureteral stones using some simple and easily available clinical features. METHODS: From June 2019 to July 2022, 480 patients who underwent ureteroscopic lithotripsy (URSL) for ureteral calculi were enrolled in the study. From the eligible study population between June 2019 and December 2020, a training and validation set was randomly generated in a 7:3 ratio. To further evaluate the generalization performance of the nomogram, we performed an additional validation using the data from January 2021 to July 2022. Lasso regression analysis was used to identify the most useful predictive features. Subsequently, a multivariate logistic regression algorithm was applied to select independent predictive features. The predictive performance of the nomogram was assessed using Receiver Operating Characteristic (ROC) curves, calibration curves and decision Curve Analysis (DCA). The Hosmer-Lemeshow Test was utilized to evaluate the overall goodness of fit of the nomogram. RESULTS: Multivariate logistic regression analysis showed that flank pain, hydronephrosis, stone length/width, HU below (Hounsfield unit density of the ureter center below the stone), HU above/below (HU above divided by HU below) and UWT (ureteral wall thickness) were ascertained as independent predictors of impacted ureteral stones. The nomogram showed outstanding performance within the training dataset, with the area under the curve (AUC) of 0.907. Moreover, the AUC was 0.874 in the validation dataset. The ROC curve, calibration curve, DCA curve and Hosmer-Lemeshow Test suggested that the nomogram maintains excellent clinical applicability and demonstrates commendable performance. Similar results were achieved in the test dataset as well. CONCLUSIONS: We established a nomogram that can be effectively used for preoperative diagnosis of impacted ureteral stones, which is of great significance for the treatment of this disease.

Oxalate­induced renal pyroptotic injury and crystal formation mediated by NLRP3­GSDMD signaling in vitro and in vivo.

Calcium oxalate kidney stone has become an urgent issue due to its high incidence and recurrence rate. Thus, it is necessary to explore for mechanisms of calcium oxalate stones formation. Previous studies demonstrated that oxalate crystals could induce the activation of nucleotide­binding domain and leucine­rich repeat­containing family pyrin domain­containing 3 (NLRP3) inflammasome and change the renal tubular epithelium adhesion. However, the type and molecular mechanism of NLRP3 inflammasome­mediated calcium oxalate stones formation still need to be further investigated. In the present study, it was confirmed that the NLRP3­gasdermin D (GSDMD) signaling was involved in oxalate­induced cell injury in vitro and in vivo. Inhibition of reactive oxygen species production could effectively prevent the NLRP3 inflammasome formation in oxalate­treated HK­2 cells. NLRP3 gene silence could inhibit the DNA damage and cellular membrane injury of HK­2 cells treated with oxalate. The ultrastructural changes of several organelles and particular structures, similar to typical cell pyroptosis, were observed in oxalate­stimulated HK­2 cells. NLRP3 gene silence could antagonize the oxalate­induced injury and ultrastructure changes. Additionally, NSA (GSDMD inhibitor) could prevent the oxalate­induced injury of membrane integrity in HK­2 cells. Moreover, oxalate crystals were significantly decreased in GSDMD­/­ mice compared with wild­type mice with glyoxylic acid. Together, NLRP3­GSDMD pathway was involved in the oxalate­induced pyroptotic injury in HK­2 cells. GSDMD and its cleavage form GSDMD­N played an important role in the oxalate­induced renal cell injury and oxalate calcium crystals formation in vitro and in vivo. This provided a new target for prevention and treatment of oxalate nephropathy and oxalate calcium stones.