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Purpose: Early characterization of small (T1a, <4 cm) renal masses is imperative for patient care and treatment planning. Renal biopsy is a sensitive and specific procedure that can accurately differentiate small renal masses as malignant or benign. However, it is an invasive procedure with a nonnegligible complication rate and is not performed routinely at most institutions. In this study, we sought to apply the Retroperitoneal Vascularity Assessment and Scoring in Carcinoma (Re-VASC) scoring system to T1a renal masses and analyzed whether it could differentiate these masses as benign or malignant. Methods: We obtained Institutional Review Board approval to retrospectively examine the records of all patients who presented to our single, urban academic referral center for surgical treatment of renal cell carcinoma (RCC). For the malignant group, patients with a diagnosis of T1a RCC from pathologic evaluation were included. Additionally, patients with a histopathological diagnosis of a T1a nonmalignant renal mass (fat poor-angiomyolipoma or oncocytoma) were included in our benign group. Results: This study includes 57 benign and 69 malignant T1a renal tumors. Average size for benign and malignant masses were 2.47 and 2.63, respectively (p = 0.267). Analysis demonstrated no significant difference between both groups in terms of sex, laterality, or size. The average Re-VASC score of benign and malignant masses was 0.175 and malignant masses was 0.784, respectively (p < 0.001). Additionally, the Re-VASC score was independently associated with malignancy with an odds ratio of 2.223 (p = 0.0109). Conclusion: The Re-VASC scoring system exhibits significantly greater values for malignant T1a renal masses when compared to benign masses. As a result, it shows promise as an adjunctive tool to renal biopsy for clinical decision-making. Further assessment of Re-VASC's true efficacy as a diagnostic marker will include prospective evaluation of a larger multicenter population. [ABSTRACT FROM AUTHOR]

Purpose: Renal cell carcinoma (RCC) is the most common type of kidney cancer worldwide. Although radiologists assess enhancement patterns of renal tumors to predict tumor pathology report, to our knowledge, no formal scoring system has been created and validated to assess the level of neovascularity in RCC, despite its critical role in cancer metastases. In this study, we characterized and analyzed the level of angiogenesis in tumor-burdened kidneys and their benign counterparts. We then created and validated a scoring scale for neovascularity that can help predict tumor staging for RCC. Methods: After Institutional Review Board approval, the charts of patients who had undergone operation for RCC between January 13, 2014 and February 4, 2020 were retrospectively reviewed for inclusion in this study. Inclusion criteria were a diagnosis of RCC, simple/radical nephrectomy, preoperative contrast-enhanced CT scans, and complete pathology reports. Neovascularity was scored on a scale of 0–4 where 0 = no neovascularity detected, 1 = a single vessel <3 mm wide, 2 = a single vessel ≥3 mm wide, 3 = multiple vessels <3 mm wide, and 4 = multiple vessels ≥3 mm wide. Results: A total of 227 patients were included in this study. Most of the tumor pathology reports were clear cell carcinoma, regardless of tumor staging. The average neovascularity score was 1.07 for pT1x tumors, 2.83 for pT2x tumors, and 3.04 for pT3x tumors. There was a significant difference in neovascularity score between pT1x and pT2x tumors (p = 0.0046), pT1x and pT3x tumors (p < 0.0001), and benign kidneys and kidneys with RCC (p < 0.0001). Conclusion: Our novel vascular scoring system for RCC demonstrates significant correlation with RCC pathological tumor staging. This scoring system may be utilized as part of a comprehensive radiological assessment of renal tumors, potentially improving tumor characterization and clinical decision making. [ABSTRACT FROM AUTHOR]

Introduction: We sought to compare the safety, efficacy, efficiency, and surgeon experience during upper urinary tract stone management with single-lumen (SLFU) vs dual-lumen flexible ureteroscopes (DLFU). Materials and Methods: Seventy-nine patients with proximal ureteral or renal stone burden <2 cm were randomized to a SLFU or DLFU. We recorded times for ureteroscopy (URS), laser lithotripsy, stone basketing, as well as intraoperative and postoperative complications. The rate of stone clearance and stone free status were calculated using CT imaging. Surgeons completed a survey after each procedure rating various metrics regarding ureteroscope performance. Results: Thirty-five patients from the single-lumen group and 44 patients from the dual-lumen group had comparable median URS time (37 vs 35 minutes, p = 0.984) and basketing time (12 vs 19 minutes; p = 0.584). Median lithotripsy time was decreased in the dual-lumen group (single: 6 vs dual: 2 minutes, p = 0.017). The stone clearance rate was superior in the dual-lumen group (single: 3.7 vs dual: 7.1 mm3/min, p = 0.025). The absolute stone-free rate (SFR) was superior for the dual-lumen group (single: 26% vs dual: 48%, p = 0.045). No differences in intraoperative (single: 0% vs dual: 2%; p = 0.375) and postoperative complications (single: 7% vs dual: 11%, p = 0.474) were observed. Surgeons' ratings of the dual-lumen ureteroscope was superior for visibility, comfort, ease of use, and overall performance. Conclusions: The use of the dual-lumen ureteroscope in patients with renal and proximal ureteral stones <2 cm provided shorter lithotripsy time, higher stone clearance rates, improved SFR, and superior surgeon ratings when compared with SLFUs. [ABSTRACT FROM AUTHOR]

Introduction and Objectives: Conventional renal stone dusting is challenging; the holmium (Ho:YAG) laser and holmium with MOSES effect (Ho:YAG-MOSES) fail to uniformly produce fragments ≤100 μm (i.e., dust). The superpulse thulium fiber laser (sTFL) may more effectively render uroliths into "dust," and may thus improve stone-free rates. Accordingly, we performed ex vivo evaluations with all three laser modalities, assessing stone fragments and stone clearance. Methods: Seventy-two ex vivo porcine kidney-ureter models were divided into 12 groups of 6: laser type (Ho:YAG, Ho:YAG-MOSES, sTFL), ureteroscope with and without applied suction, and the presence or absence of a 14F ureteral access sheath (UAS). Calcium oxalate stones were preweighed and implanted into each kidney via a pyelotomy. Stones were treated at 16W using dusting settings of 0.4J × 40Hz (Ho:YAG), 0.2J × 80Hz (Ho:YAG-MOSES), and 0.2J × 80Hz (sTFL) for up to 20 minutes. No stone basketing was performed. Kidneys were bivalved and residual fragments were collected, dried, weighed, and sieved to determine fragment size and stone clearance. Results: Initial stone mass (mg), procedure time (seconds), and laser energy expenditure (kJ) were similar in all 12 groups. The greatest stone clearance was seen with sTFL + suction + UAS (94%) compared with a conventional technique (Ho:YAG + no suction + no UAS) (65%, p < 0.01). The use of sTFL provided greater stone clearance than Ho:YAG or Ho:YAG-MOSES. Aspiration improved stone clearance for sTFL (p = 0.01), but not for Ho:YAG or Ho:YAG-MOSES, consistent with the creation of smaller fragments with sTFL. Presence of a 14F UAS improved stone clearance in all scenarios (p < 0.01). Conclusions: In this ex vivo study, stone clearance was optimized under the following conditions: sTFL, 14F UAS, and aspiration. This combination resulted in 94% of stone fragments being cleared; the 6% remaining fragments were all <2 mm. In all scenarios, deployment of a 14F UAS improved stone clearance. [ABSTRACT FROM AUTHOR]

Introduction: A detailed understanding of renal tumor anatomy is required to perform partial nephrectomy. We evaluated the utility of a CT-based interactive virtual reality (iVR) display to assist surgeons' understanding of the precise location of the renal tumor. Methods: CT scans and iVR models of 11 patients with a mean R.E.N.A.L. nephrometry score of 6.9 were evaluated. Seven faculty urologists and six urology residents reviewed CT scans and positioned each tumor onto a digital three-dimensional model of the same kidney, although without the tumor present. A week later, participants repeated the session using both iVR models and CT scans. For both time points, the overlap between the surgeon-inserted tumor and the actual tumor location was calculated. Participants answered a 1 to 10 Likert scale survey to gauge their understanding of renal and tumor anatomy based on CT alone vs CT+iVR. Results: Median tumor overlap for the entire cohort was 28% after CT review and 42% after CT+iVR (p = 0.05); among faculty urologists, for CT+iVR vs CT alone, percentage overlap improved (47% vs 33%, p = 0.033) and the incidence of 0% overlap decreased (19%–4%, p = 0.024), respectively. Among residents, there was no significant difference for either percentage overlap or 0% overlap for CT vs CT+iVR. The percentage overlap for the two tumors with high R.E.N.A.L. nephrometry scores (i.e., 10) increased from 51% to 67% after using CT+iVR (p = 0.039). The combination of CT+iVR was an independent predictor of improved overlap vs CT alone (odds ratio 2.22, 95% confidence interval 1.04–4.78, p = 0.039). Faculty surgeons' survey responses showed an improved understanding of the tumor location and shape with the addition of iVR (p < 0.05). Conclusions: The addition of patient-specific iVR models to standard CT imaging improved the ability of faculty urologists to accurately configure the location of a renal tumor, and improved their understanding of tumor anatomy. [ABSTRACT FROM AUTHOR]

Introduction: Encrustation of implanted urinary tract devices is associated with significant morbidity. Pellethane ® is a polyether-based compound noted for its strength, porosity, and resistance to solvents. We assessed Pellethane thermoplastic polyurethane (TPU) with and without surface coatings 2-hydroxyethyl methacrylate (HEMA) and tetraethylene glycol dimethyl ether (TETRA) for the potential to resist encrustation in an artificial urine environment. Materials and Methods: Samples of Pellethane TPU, HEMA Pellethane TPU, TETRA Pellethane TPU, and hydrogel-coated ureteral stent (Cook ®) were suspended in a batch-flow model with an artificial urine solution (AUS). Every 48 hours for 90 days, 40% of the solution was replaced with fresh AUS. All samples were stored in a 37℃ incubator. Subsequently, the samples were thoroughly dried for 48 hours before weighing. Scanning electron microscopy was used to assess the degree of encrustation. Nu-Attom Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to determine the precise compositions of the encrustation specifically with regard to calcium, magnesium, and phosphate. Results: At the conclusion of the 90-day trial, the samples were analyzed, and the average mass changes were as follows: stent 63.78%, uncoated Pellethane TPU 11.50%, HEMA-coated Pellethane TPU 2.90%, and TETRAcoated Pellethane TPU 0.60%. Pellethane TPU products, and specifically those coated with HEMA and TETRA, exhibited less average mass increase and a lesser propensity to form encrustation than the traditional urinary tract stent. The mass increases noted on coated Pellethane devices were primarily ionic, whereas that of the stent was not. Conclusion: Pellethane, particularly with an HEMA-based preventative coating, may serve as a favorable alternative to traditional urinary stent material, providing its improved resistance to encrustation. [ABSTRACT FROM AUTHOR]

Introduction: Herein we provide the first report regarding in vivo porcine renal forniceal, papillary, and infundibular blood flow at the urothelial level using a novel ureteroscopic Doppler transducer. Materials and Methods: Nephroureteroscopy was performed on 11 female Yorkshire pigs to map the forniceal, papillary, and infundibular blood flow. A Doppler transducer was mounted to a 3F 120 cm catheter; the probe was passed through the working channel of a flexible ureteroscope. Blood flow was categorized from 0 (no flow) to 3 (highest flow) based on auditory intensity. At each site, a holmium laser probe was activated until it penetrated ∼1 cm into each of the examined areas; bleeding times were recorded. Results: The frequency of the Doppler transducer signal was proportional to the blood velocity within the vessel with expected increased bleeding times confirmed after puncture with a holmium laser. Analysis demonstrated that the 6 o'clock position of the fornix had significantly greater blood flow than any other forniceal location (p < 0.001). The center of each papilla had the least blood flow (p < 0.001). Blood flow was significantly higher at the infundibular level compared with the caliceal fornices at all locations (anterior, posterior, upper pole, midkidney, and lower pole) (p < 0.001). Conclusions: In a porcine model, a miniaturized Doppler ultrasound probe used during ureteroscopy demonstrated that the renal papilla had the least amount of blood flow whereas the infundibula had the highest blood flow. These data may serve to inform site selection during percutaneous nephrostomy placement. [ABSTRACT FROM AUTHOR]

Introduction: The objective of this study was to determine if use of an automated irrigation pump (AIP) during ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL) affects circulating nurse labor, irrigation-related issues, and surgeon and nurse satisfaction when compared to manual hand pump (HP) irrigation. Methods: Eighty consecutive adult patients undergoing unilateral URS or PCNL were prospectively randomized to irrigation with the HP or AIP. Preoperative pump setup time, intraoperative pump maintenance time, total pump time (setup+maintenance), and the number of irrigation-related concerns verbalized by the surgeon intraoperatively were recorded; postoperatively, surgeons and nurses rated their satisfaction with the irrigation system (1 = highly dissatisfied to 10 = highly satisfied). Results: Eighty patients were enrolled (39 AIP and 41 HP); 51 patients underwent URS and 29 patients underwent PCNL. On univariate analysis, the AIP resulted in a significantly reduced total pump time for URS (2.9 vs 5.9 minutes) and PCNL (4.6 vs 33.9 minutes; p < 0.001). The number of irrigation-related concerns was significantly lower in the AIP group during URS (1.2 vs 2.8, p < 0.001), but not during PCNL (1.9 vs 4.0, p = 0.07). The AIP was associated with significantly higher nurse satisfaction during URS (9.2/10 vs 6.5/10, p < 0.001) and PCNL (9.4/10 vs 4.4/10, p = 0.001). There was no significant association between pump type and surgeon satisfaction. On multivariate analysis of URS cases controlling for body mass index and number of stones, use of the AIP was a predictor of total pump time <5 minutes (odds ratio 25.8, 95% confidence interval [CI] 4.0–165.4; p < 0.001) and favorable (8–10/10) nurse satisfaction rating (odds ratio 25.4, 95% CI 4.1–164.0; p < 0.001). Operative time, stone-free rate, and liters of irrigant used with the HP and AIP were similar. Conclusions: During URS and PCNL, the AIP was associated with a significant reduction in irrigation pump time and higher nurse satisfaction. [ABSTRACT FROM AUTHOR]