Purpose of review The limited adoption of percutaneous nephrolithotomy (PCNL) among urologists can be explained by the steep learning curve and limited structured training in several residency programs. This review provides a summary of emerging technologies and techniques designed to assist with percutaneous renal access, focusing on their clinical applicability and available outcome data. Recent findings A literature review was conducted in January 2025, searching for studies describing emerging renal access technologies and techniques. Recent guidance developments include electromagnetic systems, retrograde and direct visualization, fusion of different image modalities with ultrasound, robot-assisted needle positioning and navigation, robot-assisted ultrasound needle guidance, and laser alignment radiation reduction technique. Available data suggest ongoing efforts focused on improved puncture accuracy, ease of technology adoption, and reduction in radiation exposure. Summary The number of emerging technologies to assist with percutaneous renal access has significantly increased during the last decade. While the cost-effectiveness of most innovations is yet to be elucidated, they may help democratize renal access and lower technical barriers, potentially facilitating broader adoption of this technique, particularly in lower-volume or less experienced centers.

The American Urological Association (AUA) provides guidance on primary prevention for nephrolithiasis; however, patient compliance is often poor. The role of healthy literacy in the primary prevention of nephrolithiasis is not well understood. Understanding kidney stone formers’ perceptions and knowledge of primary prevention is critical to evaluating their health literacy. This study aimed to assess these perceptions and explore how they relate to counseling intensity and quality of life among patients with nephrolithiasis. A cross-sectional web-based survey was administered to a random sample of adult volunteers. Disease specific information was queried for stone formers and all participants were asked a series of questions based on the AUA Metabolic Stone Management Guidelines (2016) regarding primary prevention. Receipt of dietary counseling was categorized by comprehensiveness. Patient quality of life was assessed using the Wisconsin Stone Quality of Life questionnaire (WisQOL). Multivariable linear regression was used to identify predictors of stone-specific health literacy. Of the 2482 participants, 429 (17

Introduction and Objective:Totally tubeless percutaneous nephrolithotomy (PCNL) has been demonstrated to be feasible and safe, particularly for mini-PCNL. Having an objective test to guide patient selection could improve confidence in this practice and facilitate broader adoption. The purpose of this study was to evaluate the utility of an intraoperative methylene blue test to determine candidacy for totally tubeless PCNL. Methods:Adult patients undergoing PCNL at four institutions were included in this study. Patients with prior reconstructive surgery, chronic pain, or requiring ureteral dilation were excluded. After stone clearance, 10 mL methylene blue (MB) dye was injected into the percutaneous access tract. A positive test ("pass") was defined as visualization of blue dye in the bladder catheter within two minutes of injection. In some standard PCNL cases, totally tubeless management was simulated by placement of a capped nephrostomy tube. Post-operative complications within 7 days were evaluated as the primary outcome. Results:The intraoperative MB test was performed in 91 PCNL cases: 60 mini-PCNLs (16 Fr access) and 31 standard PCNLs (24+ Fr access). Mini-PCNL cases were more likely to pass the MB test compared to standard PCNL cases (75% vs 38.7%, p = 0.001). Of the 45 mini-PCNL subjects who passed, 40 were left totally tubeless, resulting in two minor complications (urinary retention, obstructing ureteral stone fragment). In the standard PCNL cohort, 12 passed the MB test. Five were left totally tubeless and 3 simulated totally tubeless management with capped nephrostomy tubes; one subject had a transient postoperative creatinine elevation, and one required uncapping for steinstrasse. There were no other obstructive or infectious complications, and no surgical reintervention was required. Conclusions:An intraoperative methylene blue test is a simple test with high positive-predictive value to determine candidacy for totally tubeless PCNL in real time for both mini and standard PCNLs.

PURPOSE:The purpose of this Guideline is to provide a framework for the medical evaluation, treatment, and follow-up of patients with a history of kidney stones in order to reduce the likelihood of recurrent disease. The summary presented herein represents Part I of the two-part series dedicated to Medical Management of Kidney Stones. Please refer to Part II for additional information on this topic. MATERIALS AND METHODS:The systematic review utilized in the creation of this Guideline is based on research conducted by the Research Triangle Institute (RTI) International-University of North Carolina at Chapel Hill Evidence-based Practice Center (EPC) under contract to the Agency for Healthcare Research and Quality (AHRQ) and funded by the Patient-Centered Outcomes Research Institute (PCORI). The EPC extracted and synthesized comparative effectiveness and harms outcomes for preventive treatment with diet or pharmacologic agents and surveillance imaging strategies in nonpregnant adults and children with a history of nephrolithiasis from 30 publications. RESULTS:A series of Guideline statements were developed that addresses the identification of individuals at high-risk of stone recurrence, the metabolic evaluation of high-risk and interested patients, treatment with dietary measures and pharmacologic therapy, and follow-up for assessment of therapeutic effects. The statements were developed based on the evidence base for this Guideline. CONCLUSIONS:Using the best available evidence and the expert opinions of the Panel, this Guideline offers recommendations for the initiation of dietary measures and drug therapy to allow for active treatment of motivated and high-risk patients with the goal of reducing the risk of stone recurrence.

PURPOSE:The ASPiration to Improve Renal Calculi Removal Effectiveness study showed steerable ureteroscopic renal evacuation (SURE) with CVAC that significantly reduced residual stone volume at 30 days vs standard ureteroscopy (URS). This report presents 2-year health care consumption and stone events (SE) and their link to residual stone volume and other variables (n = 101 at primary end point; n = 93 at 2 years). MATERIALS AND METHODS:Logistic regression identified predictors of health care consumption events (HCEs), that is, emergency department visits, hospitalization, surgical retreatment, and SE across the study population. Incidence was compared between the treatment groups with Kaplan-Meier survival analysis. RESULTS:At 2 years, residual stone volume was significantly associated with both HCEs and SE. For every 100 mm3 increase in residual stone volume, the HCE risk increased by 50% to 54%, and the SE risk increased by 70%. Stone-free rate, the number of residual fragments (RFs), and RF total stone burden (based on diameter) were not predictors. Significantly fewer HCEs occurred in the SURE group (3 vs 20 events, p = 0.0004). Survival analysis confirmed this (4.3% vs 20%, log-rank p = 0.02), with a 73% risk reduction (hazard ratio 0.27, 95% Cl 0.09-0.80, p = 0.02). Fewer SE occurred in the SURE group, although not statistically significant. These subjects also had longer event-free survival. CONCLUSION:High-quality volumetric analysis supports evaluation of stone removal therapies, as residual stone volume predicts HCEs and SE. SURE significantly reduces the downstream incidence and risk of HCEs compared with standard URS.

PURPOSE:The purpose of this Guideline is to provide a framework for the treatment and follow-up of patients with a history of kidney stones in order to reduce the likelihood of recurrent disease. The summary presented herein represents Part II of the two-part series dedicated to Medical Management of Kidney Stones. Please refer to Part I for additional information on this topic. MATERIALS AND METHODS:The systematic review utilized in the creation of this Guideline is based on research conducted by the Research Triangle Institute (RTI) International-University of North Carolina at Chapel Hill Evidence-based Practice Center (EPC) under contract to the Agency for Healthcare Research and Quality (AHRQ) and funded by the Patient-Centered Outcomes Research Institute (PCORI). The EPC extracted and synthesized comparative effectiveness and harms outcomes for preventive treatment with diet or pharmacologic agents and surveillance imaging strategies in nonpregnant adults and children with a history of nephrolithiasis from 30 publications. RESULTS:A series of Guideline statements were developed that addresses the identification of individuals at high-risk of stone recurrence, the metabolic evaluation of high-risk and interested patients, treatment with dietary measures and pharmacologic therapy, and follow-up for assessment of therapeutic effects. The statements were developed based on the evidence base for this Guideline. CONCLUSIONS:Using the best available evidence and the expert opinion of the Panel, this Guideline offers recommendations for the initiation of dietary measures and drug therapy are provided to allow for active treatment of motivated and high-risk patients with the goal of reducing the risk of stone recurrence.

Benign prostatic hyperplasia (BPH) is characterized by excessive cell proliferation and inflammation and affects most aging men. The development of new therapies for BPH requires a deeper understanding of the underlying pathophysiology and cellular components of BPH. Single-cell RNA-sequencing was performed on prostate tissue from 15 patients undergoing holmium laser enucleation of the prostate for treatment of BPH. Clustering and differential expression analysis on aligned single-cell RNA-seq data was performed to annotate all cell types. 16,234 cells were analyzed and specific stromal, epithelial, and immune subgroups were found to be strongly associated with inflammation. A rare luminal subgroup was identified and pseudotime analysis indicated this luminal subgroup might give rise to other luminal cells. Using a gene set derived from epithelial stem cells, we found that this luminal subgroup had a significantly higher stem cell signature score than all other epithelial subgroups, suggesting this subgroup is a luminal precursor state. Ligand-receptor interactions between stromal, epithelial, and immune cells were explored with CellPhoneDB. Significant interactions involving MIF, a pro-inflammatory cytokine that promotes epithelial cell growth and inflammatory response in the prostate, were identified between the progenitor-like luminal subgroup and both fibroblasts and macrophages. Our single-cell profiling of BPH provides a roadmap for investigating inflammation-linked cell subgroups and highlights a progenitor-like luminal subgroup interacting with other cell groups via MIF that may contribute to the inflammation and cell proliferation phenotype associated with BPH.

PURPOSE:The efficacy of ureteroscopy to treat urinary stones is often less than 60%. Acoustic Enhancer is an investigational device of microparticles with a tag designed with an affinity for calcium. We evaluated safety and efficacy of ureteroscopic laser lithotripsy with and without Acoustic Enhancer Microbubble Cavitation in a randomized clinical trial. MATERIALS AND METHODS:Patients with urolithiasis were randomized to ureteroscopic laser lithotripsy with or without Acoustic Enhancer. The end points were the proportion of patients without residual fragments ≥ 2 mm on CT 30 days post procedure (fragment-free rate) and adverse events (AEs). RESULTS:There were 103 and 93 patients in the investigational and control groups, respectively. There was no statistical superiority between the 2 groups. The fragment-free rate was 41% and 47% in the investigational and control groups, respectively (P = .46). Residual fragment size was similar, 5.55 mm vs 5.70 mm for the investigational and control groups, respectively (P = .71). Among investigational patients treated with higher average powers ≥ 12 W, the fragment-free rate was 51% compared with 32% (n = 47) for the low-power group (P = .06). AEs were noted in 35% and 46% of patients in the investigational and control groups, respectively (P = .11). The total number of AEs was less for the investigational arm (P < .001). CONCLUSIONS:Although laser lithotripsy with microbubble cavitation did not increase efficacy, it was associated with significantly fewer AEs. Efficacy of microbubble cavitation may depend on laser power used. The low efficacy and high rates of AEs with ureteroscopy highlight the need for novel management approaches for urinary stones.