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Diffusion of native defects such as vacancies and their interactions with impurities are fundamental to semiconductor crystal growth, device processing, and design. However, the transient equilibration of native defects is difficult to directly measure. We used (AlxGa1−x)2O3/Ga2O3 superlattices (SLs) to detect and analyze transient diffusion of cation vacancies during annealing in O2 at 1000–1100 °C. Using a novel finite difference scheme for diffusion with time- and space-varying diffusion constants, we determined diffusion constants for Al, Fe, and cation vacancies, including the vacancy concentration dependence for Al. In the case of SLs grown on Sn-doped β-Ga2O3 (010) substrates, gradients observed in the extent of Al diffusion indicate a supersaturation of vacancies in the substrates that transiently diffuse through the SLs coupled strongly to Sn and thus slowed compared to undoped cases. In the case of SLs grown on (010) Fe-doped substrates, the Al diffusion is uniform through the SLs, indicating a depth-uniform concentration of vacancies. We find no evidence for the introduction of VGa from the free surface at rates sufficient to affect Al diffusion at at. % concentrations, establishing an upper bound on surface injection. In addition, we show that unintentional impurities in Sn-doped Ga2O3 such as Fe, Ni, Mn, Cu, and Li also diffuse toward the surface and accumulate. Many of these likely have fast interstitial diffusion modes capable of destabilizing devices, thus suggesting that impurities may require further reduction. This work provides a method to measure transients in diffusion-mediating native defects otherwise hidden in common processes such as ion implantation, etching, and film growth. [ABSTRACT FROM AUTHOR]

This study sought to analyze the ablation rates of Holmium:YAG (Ho:YAG) and thulium fiber laser (TFL) under different settings combinations. Lasering was carried out by a computed spiral pattern through a stepper motor bearing a laser fiber. BegoStones were placed inside a water container and lasered therein and the ablation rate was calculated. Different combinations were tested for ~12 Watts (W) for Ho:YAG and TFL lasers. Further 25 W combination for TFL were conducted testing higher frequencies. One-hundred-one experiments were conducted. Under ~12 W, the highest ablation rate for Ho:YAG was obtained with 40 Hz/0.3 J, and Virtual Basket™ (VB) emission mode [114.35 (88.30 – 126.40) mg/min] whereas for TFL, using 40 Hz/0.3 J, and long pulse [143.40 (137.40 – 146) mg/min]. A matched-comparison for 12 Hz/1 J settings showed that TFL outperformed Ho:YAG using medium pulse [63.30 (55.30 – 81.30) vs 132.00 (115.70 – 228.60) mg/min, p=0.016] and long pulse [62.90 (51.60 – 78.90) vs 134.70 (110.60 – 149.30) mg/min, p=0.016]. In the 40 Hz/0.3 J settings, TFL outperformed Ho:YAG (p=0.034). Nonetheless, Ho:YAG with VB’s ablation rate increased [114.35 (88.30 – 126.40)], being comparable to that of TFL with medium pulse [127.5 (88.90 – 141.70)] (p=0.400). In TFL 25 W experiments, the ablation rate of 500 Hz / 0.05 J, was higher than those of 1000 Hz / 0.025 J (p=0.049). TFL ablation rate is higher than that of Ho:YAG. Moreover, the Virtual Basket™ emission mode, increased Ho:YAG ablation rates, resulting reaching similar to that of TFL in certain modalities. [ABSTRACT FROM AUTHOR]

Objective: To determine 30‐day inpatient mortality, intensive care unit (ICU) admissions, inpatient admissions/readmissions, and yearly trends in sepsis prevalence and inpatient mortality after ureteroscopy (URS) in employed adults. Materials and Methods: We performed a retrospective analysis of the IBM MarketScan Commercial Database to identify employed adults aged 18–64 years who underwent URS between 2015 and 2019. Patients were categorized as having no sepsis (controls), non‐severe sepsis, or severe sepsis within 30 days of URS. The main outcomes included inpatient mortality, ICU admissions, inpatient admissions, readmissions, and annual rates of sepsis and associated inpatient mortality. Results: Among 109 496 patients undergoing URS, 5.6% developed sepsis (4.1% non‐severe, 1.5% severe). The 30‐day inpatient mortality rates were 0.03%, 0.3% and 2.5% for controls, non‐severe sepsis and severe sepsis, respectively (P < 0.001). In a multivariable analysis, diagnosis of sepsis regardless of severity (hazard ratio [HR] 17.2, 95% confidence interval [CI] 10.5–28.1; P < 0.001) or severe sepsis (HR 49.5, 95% CI 28.9–84.7; P < 0.001) increased the risk of 30‐day inpatient mortality compared to no sepsis (controls). ICU admissions on the day of procedure (1.5%, 19.8% and 52.4%), inpatient admission rates (18.3%, 74.9% and 76.9%) and readmission rates (7.1%, 12.0% and 15.9%) were higher with severe sepsis and non‐severe sepsis vs controls (all P < 0.001). During the study period, the prevalence of sepsis after URS increased from 4.7% to 6.6% (P < 0.001), while the associated mortality rate decreased from 0.7% to 0.2% (P < 0.001). Conclusion: Among working adults aged 18–64 years, sepsis after URS increases the risk of 30‐day inpatient mortality, ICU and hospital admission, and hospital readmission. Although the prevalence of sepsis after URS is increasing over time, associated mortality rates are declining. Urologists should be aware of the potentially deadly consequences of sepsis after URS in younger patients. [ABSTRACT FROM AUTHOR]

Objective: To determine 30‐day inpatient mortality, intensive care unit (ICU) admissions, inpatient admissions/readmissions, and yearly trends in sepsis prevalence and inpatient mortality after ureteroscopy (URS) in employed adults. Materials and Methods: We performed a retrospective analysis of the IBM MarketScan Commercial Database to identify employed adults aged 18–64 years who underwent URS between 2015 and 2019. Patients were categorized as having no sepsis (controls), non‐severe sepsis, or severe sepsis within 30 days of URS. The main outcomes included inpatient mortality, ICU admissions, inpatient admissions, readmissions, and annual rates of sepsis and associated inpatient mortality. Results: Among 109 496 patients undergoing URS, 5.6% developed sepsis (4.1% non‐severe, 1.5% severe). The 30‐day inpatient mortality rates were 0.03%, 0.3% and 2.5% for controls, non‐severe sepsis and severe sepsis, respectively (P < 0.001). In a multivariable analysis, diagnosis of sepsis regardless of severity (hazard ratio [HR] 17.2, 95% confidence interval [CI] 10.5–28.1; P < 0.001) or severe sepsis (HR 49.5, 95% CI 28.9–84.7; P < 0.001) increased the risk of 30‐day inpatient mortality compared to no sepsis (controls). ICU admissions on the day of procedure (1.5%, 19.8% and 52.4%), inpatient admission rates (18.3%, 74.9% and 76.9%) and readmission rates (7.1%, 12.0% and 15.9%) were higher with severe sepsis and non‐severe sepsis vs controls (all P < 0.001). During the study period, the prevalence of sepsis after URS increased from 4.7% to 6.6% (P < 0.001), while the associated mortality rate decreased from 0.7% to 0.2% (P < 0.001). Conclusion: Among working adults aged 18–64 years, sepsis after URS increases the risk of 30‐day inpatient mortality, ICU and hospital admission, and hospital readmission. Although the prevalence of sepsis after URS is increasing over time, associated mortality rates are declining. Urologists should be aware of the potentially deadly consequences of sepsis after URS in younger patients. [ABSTRACT FROM AUTHOR]

Homoepitaxial growth of β -Ga 2 O 3 using metalorganic vapor-phase epitaxy (MOVPE) on several different crystal orientations has previously been studied, but growth on the (2 ¯ 01) plane has remained comparatively unexplored. To investigate this, we grew Si-doped and unintentionally doped (UID) homoepitaxial layers simultaneously on Sn-doped (2 ¯ 01) and (010) substrates under conditions optimized for (010) growth. We report herein on results from current–voltage and capacitance–voltage (IV and CV) and deep level transient spectroscopy (DLTS) characterization of Schottky diodes fabricated on these samples. Devices on (010) display nearly ideal Schottky diode JV and CV behaviors while for (2 ¯ 01) evidence of complete depletion of > --> 2 μ m thickness, UID epilayers are observed. The (2 ¯ 01) UID diodes exhibited Mott–Gurney space charge-limited transport and were completely depleted even at zero bias. Doping (2 ¯ 01) samples heavily with Si was sufficient to overcome background compensation and reproduce near-ideal diode behavior. DLTS data from these doped devices show, in addition to typical negative majority-carrier transients, positive transients with a broad energy distribution, possibly indicating traps on structural defects or surface states. An etch pit analysis under SEM revealed intricate structures of the grown layers. Cross-sectional TEM characterization of a (2 ¯ 01) sample revealed a high density of structural defects within the epitaxial layer, likely stacking faults. Hypotheses for the origins of the compensation in (2 ¯ 01) β -Ga 2 O 3 homoepitaxial MOVPE growth under (010) growth conditions are discussed; the most likely explanation is the presence of defect states introduced by the stacking faults visible under TEM. [ABSTRACT FROM AUTHOR]

Purpose: The relationship between ureteral stent duration before percutaneous nephrolithotomy (PCNL) and infectious complications, admissions, imaging, and medical costs was evaluated. Materials and Methods: Patients who underwent PCNL within 6 months of ureteral stent placement were identified from commercial claims, categorized by time to treatment (0–30, 31–60, and >60 days), and followed 1-month post-PCNL. The effect of delayed treatment on inpatient admissions, infectious complications (pyelonephritis/sepsis), and imaging utilization was evaluated with logistic regression. A generalized linear model evaluated the effect of delayed treatment on medical costs. Results: Among 564 patients with PCNL and meeting the inclusion criteria (mean age 50; 55% female; 45% from South), mean (standard deviation) time to surgery was 48.8 (41.8) days. Less than half (44.3%; n = 250) underwent PCNL within 30 days of ureteral stent placement, 27.0% (n = 152) between 31 and 60 days, and 28.7% (n = 162) >60 days. Time to PCNL was significantly associated with inpatient admissions (>60 vs ≤30 days odds ratio [OR] 1.97, 95% confidence interval [CI] 1.29–3.01, p = 0.0016), infectious complications (>60 vs ≤30 days OR 2.43, 95% CI 1.55–3.81, p = 0.0001), imaging utilization (31–60 vs ≤30 days OR 1.56, 95% CI 1.02–2.38, p = 0.0383; >60 vs ≤30 days OR 2.01, 95% CI 1.31–3.06, p = 0.0012), and medical costs (31–60 vs ≤30 days OR 1.27, 95% CI 1.08–1.49, p = 0.0048; >60 vs ≤30 days OR 1.46, 95% CI 1.24–1.71, p < 0.0001). Conclusions: Compared with PCNL within 30 days, patients undergoing PCNL >30 days after ureteral stent placement had increased likelihood of infectious complications, resource use, and medical costs. These results may inform health care resource utilization and PCNL prioritization. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effects of ureteral stent duration before ureteroscopy (URS) or extracorporeal shockwave lithotripsy (SWL) on infectious complications, health care resource utilization (HCRU), and costs. Materials and Methods: Patients who underwent URS/SWL within 6months of ureteral stent placement were identified from commercial claims, categorized by time from stent placement to URS (0–15, 16–30, 31–60, and >60 days) or SWL (0–15, 16–30, and >30 days), and followed 1-month postprocedure. The relationship between ureteral stent duration and emergency department (ED) visits, inpatient admissions, infectious complications (pyelonephritis/sepsis), imaging, and costs was evaluated. Results: Mean time to URS (n = 9276 patients) was 21.3 ± 24.4 days and SWL (n = 4689 patients) was 19.0 ± 24.8 days. Compared with patients who underwent URS within 15 days of ureteral stent placement, URS 31 to 60 days after ureteral stent placement was significantly associated with inpatient admissions (odds ratio [OR] 2.56, 95% confidence interval [CI] 2.03–3.22); infectious complications (OR 2.82, 95% CI 2.09–3.81); imaging (OR 2.12, 95% CI 1.82–2.46); and medical costs (OR 1.49, 95% CI 1.40–1.58). Compared with patients who underwent SWL within 15 days of ureteral stent placement, SWL more than 30 days after ureteral stent placement was significantly associated with ED visits (OR 1.79, 95% CI 1.37–2.34); inpatient admissions (OR 3.34, 95% CI 2.38–4.69); infectious complications (OR 3.54, 95% CI 2.20–5.70); imaging (OR 2.65, 95% CI 2.23–3.15); and medical costs (OR 1.45, 95% CI 1.36–1.54). Conclusions: URS or SWL >30 days after ureteral stent placement increased the likelihood of infectious complications, HCRU, and medical costs. [ABSTRACT FROM AUTHOR]

Computed tomography (CT) has witnessed tremendous growth in utilization. Despite its immense benefits, there is a growing concern from the general public and the medical community about the detrimental consequences of ionizing radiation from CT. Anxiety from the perceived risks associated with CT can deter referring physicians from ordering clinically indicated CT scans and patients from undergoing medically necessary exams. This article discusses various strategies for educating patients and healthcare providers on the benefits and risks of CT scanning and salient techniques for effective communication. [ABSTRACT FROM AUTHOR]

Objective: To develop a standardised tool to evaluate flexible ureterorenoscopes (fURS). Materials and Methods: A three‐stage consensus building approach based on the modified Delphi technique was performed under guidance of a steering group. First, scope‐ and user‐related parameters used to evaluate fURS were identified through a systematic scoping review. Then, the main categories and subcategories were defined, and the expert panel was selected. Finally, a two‐step modified Delphi consensus project was conducted to firstly obtain consensus on the relevance and exact definition of each (sub)category necessary to evaluate fURS, and secondly on the evaluation method (setting, used tools and unit of outcome) of those (sub)categories. Consensus was reached at a predefined threshold of 80% high agreement. Results: The panel consisted of 30 experts in the field of endourology. The first step of the modified Delphi consensus project consisted of two questionnaires with a response rate of 97% (n = 29) for both. Consensus was reached for the relevance and definition of six main categories and 12 subcategories. The second step consisted of three questionnaires (response rate of 90%, 97% and 100%, respectively). Consensus was reached on the method of measurement for all (sub)categories. Conclusion: This modified Delphi consensus project reached consensus on a standardised grading tool for the evaluation of fURS – The Uniform grading tooL for flexIble ureterorenoscoPes (TULIP) tool. This is a first step in creating uniformity in this field of research to facilitate future comparison of outcomes of the functionality and handling of fURS. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the relationship between renal pelvis pressure and fluid absorption during ureteroscopy (URS) in a live porcine model. Materials and Methods: Flexible URS (fURS) was performed in anaesthetised female Yorkshire pigs. Prior to performing fURS, a 0.3556‐mm (0.014″) pressure‐sensing guidewire (Comet™, Boston Scientific) was placed to monitor renal pelvis pressure. A simulated fURS procedure was then performed for 1 h. Infusion of irrigation fluid (5% ethanol in saline) at target renal pelvis pressures (37–150 mmHg) was maintained for 1 h using a pressure bag and real‐time feedback from the pressure‐sensing guidewire. Venous blood was sampled every 10 min. The volume of irrigation fluid absorbed was estimated with established equations. Results: A URS procedure was performed in vivo in 18 porcine kidneys and the volume of irrigation fluid absorbed during the 1 h URS was calculated. The mean (SD) volume of irrigation fluid absorbed after 1 h of simulated URS was 7.6 (5.7), 10.8 (7.1), 26.0 (15.8), and 56.8 (22.3) mL at renal pelvis pressures of 37, 55, 75, and 150 mmHg, respectively. Compared with URS with renal pelvis pressure of 37 mmHg, the volume of fluid absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (P = 0.026 and P = 0.047, respectively). In addition, compared with URS with renal pelvis pressure of 37 mmHg, the rate of absorption was significantly greater at renal pelvis pressures of 75 and 150 mmHg (both P < 0.001). Conclusion: In this study of an in vivo porcine model of URS, increasing renal pelvis pressures during URS were associated with increases in irrigation fluid absorption and increases in the rate of fluid absorption. [ABSTRACT FROM AUTHOR]

Introduction: Systemic inflammatory response syndrome (SIRS) criteria have long been used to predict septic shock. The sequential organ failure assessment and quick sequential organ failure assessment (qSOFA) scores have been suggested to be more accurate predictors. This study aims to compare SIRS and qSOFA for predicting of septic shock in the setting of retrograde ureteral stenting for obstructing stones and concomitant urinary tract infection. Methods: A retrospective review of records at two centers of consecutive patients was performed. Patients with unilateral ureteral obstruction by a stone who underwent ureteral stent placement and suspicion of urinary tract infection were identified. Primary endpoints were SIRS and qSOFA positive scores, intensive care unit admission, and vasopressor requirements. Results: A total of 187 patients were included. SIRS criteria were met in 103 patients (55.1%) and in 30 patients who experienced septic shock. qSOFA criteria were met for 24 patients (12.8%) and in 18 patients who experienced septic shock. Specificity for postoperative septic shock was significantly higher for qSOFA than for SIRS criteria (75 vs 29.1%, McNemar test p < 0.001). Both SIRS and qSOFA had significant areas under the curve (AUC), qSOFA had a fair AUC of 0.750, p = 0.001, whereas SIRS had a poor AUC of 0.659, p = 0.008. Univariate logistic regression of SIRS and qSOFA for septic shock showed: qSOFA (odds ratio [OR] 46 [0.25–228], p = 0.001) and SIRS (OR 2.29 [0.716–7.37], p = 0.162). Conclusion: Although SIRS offers higher sensitivity, qSOFA score may offer advantages over SIRS criteria in evaluation of risk for septic shock for patients who present with obstructing ureteral stone and urinary tract infection. [ABSTRACT FROM AUTHOR]

Background: There is a need to reliably render urolithiasis patients completely stone free with minimal morbidity. We report on the initial safety and feasibility with steerable ureteroscopic renal evacuation (SURE) in a prospective study using basket extraction as a comparison. Materials and Methods: A pilot randomized controlled study was conducted comparing SURE with basket extraction postlaser lithotripsy. SURE is performed using the CVAC™ Aspiration System, a steerable catheter (with introducer). The safety and feasibility of steering CVAC throughout the collecting system under fluoroscopy and aspirating stone fragments as it was designed to do were evaluated. Fluoroscopy time, change in hemoglobin, adverse events through 30 days, total and proportion of stone volume removed at 1 day, intraoperative stone removal rate, and stone-free rate (SFR) at 30 days through CT were compared. Results: Seventeen patients were treated (n = 9 SURE, n = 8 Basket). Baseline demographics and stone parameters were not significantly different between groups. One adverse event occurred in each group (self-limiting ileus for SURE and urinary tract infection for Basket). No mucosal injury and no contrast extravasation were observed in either group. The CVAC catheter was steered throughout the collecting system and aspirated fragments. There was no significant difference in fluoroscopy time, procedure time, change in hemoglobin, or stone removal rate between groups. SURE removed more and a greater proportion of stone volume at day 1 vs baskets (202 mm3vs 91 mm3, p < 0.01 and 84% vs 56%, p = 0.022). SURE achieved 100% SFR at 30 days vs 75% for baskets, although this difference was not statistically significant (p = 0.20). Conclusions: This initial study suggests SURE is safe, feasible, and may be more effective in stone removal postlaser lithotripsy compared to basketing. More development is needed, and larger clinical studies are underway. [ABSTRACT FROM AUTHOR]

(1) Background: New pulse modulation (PM) technologies in Holmium:YAG lasers are available for urinary stone treatment, but little is known about them. We aim to systematically evaluate the published evidence in terms of their lithotripsy performance. (2) Methods: A systematic electronic search was performed (MEDLINE, Scopus, and Cochrane databases). We included all relevant publications, including randomized controlled trials, non-randomized comparative and non-comparative studies, and in-vitro studies investigating Holmium:YAG lithotripsy performance employing any new PM. (3) Results: Initial search yielded 203 studies; 24 studies were included after selection: 15 in-vitro, 9 in-vivo. 10 In-vitro compared Moses with regular PM, 1 compared Quanta's, 1 Dornier MedTech's, 2 Moses with super Thulium Fiber Laser, and 1 compared Moses with Quanta PMs. Six out of seven comparative studies found a statistically significant difference in favor of new-generation PM technologies in terms of operative time and five out of six in fragmentation time; two studies evaluated retropulsion, both in favor of new-generation PM. There were no statistically significant differences regarding stone-free rate, lasing and operative time, and complications between Moses and regular PM when data were meta-analyzed. (4) Conclusions: Moses PM seems to have better lithotripsy performance than regular modes in in-vitro studies, but there are still some doubts about its in-vivo results. Little is known about the other PMs. Although some results favor Quanta PMs, further studies are needed. [ABSTRACT FROM AUTHOR]

Introduction Percutaneous nephrolithotomy (PCNL) is the standard of care for the treatment of large renal stones. Bleeding-related complications remain a major concern when performing this procedure. Tranexamic acid (TXA) has recently been studied in both urologic and non-urologic procedures to reduce bleeding, transfusions and complications. Material and methods In June 2021 a systematic review was conducted following PRISMA guidelines on randomized prospective studies comparing the effects of TXA on bleeding complications during PCNL. Data was analyzed using Review Manager 5.3. Results Eight studies were included with a total 1,201 patients, of which 598 received TXA and 603 received placebo. TXA was associated with less bleeding (decreased change in hemoglobin) -0.79 Hb g/dl [-1.09, -0.65] p <.00001 and decreased transfusion rates (OR 0.31 [0.18, 0.52] p <0.0001). This was also associated with lower complication rates, both minor, major and overall, OR 0.59[0.41, .85] p = 0.005, OR 0.31 [0.17, 0.56] p = 0.0001 and OR 0.40 [0.29, 0.56] p <0.00001 respectively. TXA was also associated with improved stone-free rates as compared with placebo (OR 1.79 [1.23, 2.62] p = 0.003). TXA resulted in shorter operative times (11.51 minutes [-16.25, -6.77] p =.001) and length of stay (-0.74 days [-1.13 -0.34] p = 0.0006). Two pulmonary embolisms were registered in a single study in the TXA group. Conclusions In this meta-analysis, the use of TXA during PCNL was associated with a statistically significant reduction in the following parameters when compared with placebo: change in hemoglobin, transfusion rates, complication rates, operative time, and length of stay. It was also associated with improvement in stone-free rates. These data should be considered by surgeons performing PCNL. [ABSTRACT FROM AUTHOR]

Objective: To report the outcomes of percutaneous nephrolithotomy (PCNL) in horseshoe kidneys (HSK) in 12 institutions worldwide and evaluate the impact of patient position during operation. Methods: We carried out a retrospective analysis of PCNL procedures performed between 2008 and 2018 in patients with HSK. Pre-, peri-, and postoperative data were collected, and a subgroup analysis was performed according to patient position. Success was defined as an absence of >4-mm fragments. Values of p < 0.05 were considered significant. Results: We analyzed 106 procedures. The transfusion, complication, and immediate success rates (ISRs) were 3.8%, 17.5%, and 54.7%, respectively. The final success rate (FSR) increased to 72.4% after a mean of 0.24 secondary procedures. Logistic regression showed that higher body mass index (BMI) and stone size were significantly associated with residual fragments ≥4 mm. Sixty-seven patients (63.2%) were treated in prone and 39 (36.8%) in supine position. The prone group had a significantly higher BMI than the supine group (30.1 vs 27.7, p = 0.024). The transfusion, complication, and ISRs between the prone and supine groups were 4.5% vs 2.6% (p = 0.99), 16.9% vs 18.4% (p = 0.99), and 52.5% vs 69.2% (p = 0.151), respectively. Surgical time was significantly longer in the prone group (126.5 vs 100 minutes, p = 0.04). Upper pole was the preferred access in 80.3% of the prone group and 43.6% of the supine group (p < 0.001). The prone group had significantly more Clavien 2 complications than the supine (p = 0.013). The FSR in the prone and supine groups increased to 66.1% and 82.1% after 0.26 and 0.21 secondary procedures, respectively. No complications higher than Clavien 3 occurred. Conclusion: PCNL in patients with HSK is safe and effective with a low complication rate. Higher BMI and stone size negatively impacted outcomes. Supine PCNL may be an option for treating kidney stones in patients with HSK. [ABSTRACT FROM AUTHOR]

Introduction: There are limited data regarding the effect of thulium laser (Tm:YAG) and holmium laser (Ho:YAG) on upper urinary tract. The aim of this study was to compare soft tissue effects of these two lasers at various settings, with a focus on incision depth (ID) and coagulation area (CA). Materials and Methods: An ex vivo experimental study was performed in a porcine model. The kidneys were dissected to expose the upper urinary tract and the block samples containing urothelium and renal parenchyma were prepared. The laser fiber, fixed on a robotic arm, perpendicular to the target tissue was used with a 100 W Ho:YAG and a 200 W Tm:YAG. Incisions were made with the laser tip in contact with the urothelium and in continuous movement at a constant speed of 2 mm/s over a length of 1.5 cm. Total energy varied from 5 to 30 W. Incision shape was classified as follows: saccular, triangular, tubular, and irregular. ID, vaporization area (VA), CA, and total laser area (TLA = VA + CA) were evaluated. Statistical analysis was performed using the SPSS V23 package, p-values <0.05 were considered statistically significant. Results: A total of 216 experiments were performed. Incision shapes were saccular (46%), triangular (38%), and irregular (16%) with the Ho:YAG, while they were tubular (89%) and irregular (11%) with the Tm:YAG. ID was significantly deeper with the Ho:YAG (p = 0.024), while CA and TLA were larger with the Tm:YAG (p < 0.001 and p < 0.005). Conclusion: ID was deeper with Ho:YAG, whereas CA and TLA were larger with the Tm:YAG. Considering surgical principles for endoscopic ablation of upper tract urothelial carcinoma, these results suggest that Tm:YAG may have a lower risk profile (less depth of incision) while also being more efficient at tissue destruction. Future in vivo studies are necessary to corroborate these findings. [ABSTRACT FROM AUTHOR]

Objectives: To determine whether obesity has an impact on the outcomes of supine percutaneous nephrolithotomy (PCNL). Patients and Methods: We retrospectively evaluated a prospectively created database of patients who underwent PCNL in the supine position from June 2009 to June 2014. The patients were divided into two groups according to their body mass index (BMI): <30 kg/m2 (group 1, nonobese) and ≥30 kg/m2 (group 2, obese). Pre, peri, and postoperative data were analyzed. Stone complexity was classified according to Guy's stone score. The primary endpoint was the absence of stone fragments of ≥4 mm on CT scans at postoperative day 1. Complications were graded according to the modified Clavien classification. Results: Of the 401 patients, 307 (76.6%) were nonobese and 94 (23.4%) were obese. Regarding demographic and stone characteristics, group 2 (BMI ≥30 kg/m2) had a higher percentage of female patients (67.3% vs 50.4%, p = 0.002) and a higher mean BMI (34.8 vs 24.5 kg/m2, p < 0.001) than group 1. Success rates were not statistically different between the groups (group 1 = 61.8%, group 2 = 51%, p = 0.08). There were no differences in the transfusion rate (group 1 = 2.9%, group 2 = 4.2%, p = NS) or total number of complications greater than Clavien grade 1 (group 1 = 13.6%, group 2 = 13.8%, p = NS). Conclusion: In a retrospective study of 400 patients undergoing PCNL, the outcomes were not different between nonobese and obese patients. To our knowledge, this is the first study evaluating these outcomes for PCNL performed in the supine position. Further multicenter and prospective studies are necessary to verify these findings. [ABSTRACT FROM AUTHOR]

Purpose: Cystinuria is a genetic disorder with both autosomal recessive and incompletely dominant inheritance. The disorder disrupts cystine and other dibasic amino acid transport in proximal tubules of the kidney, resulting in recurrent kidney stone formation. Currently, there are no consensus guidelines on evaluation and management of this disease. This article represents the consensus of the author panel and will provide clinicians with a stepwise framework for evaluation and clinical management of patients with cystinuria based on evidence in the existing literature. Materials and Methods: A search of MEDLINE®/PubMed® and Cochrane databases was performed using the following key words: "cystine nephrolithiasis," "cystinuria," "penicillamine, cystine," and "tiopronin, cystine." In total, as of May 2018, these searches yielded 2335 articles, which were then evaluated for their relevance to the topic of evaluation and management of cystinuria. Evidence was evaluated by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. Results: Twenty-five articles on the topic of cystinuria or cystine nephrolithiasis were deemed suitable for inclusion in this study. The literature supports a logical evaluation process and step-wise treatment approach beginning with conservative measures: fluid intake and dietary modification. If stone formation recurs, proceed to pharmacotherapeutic options by first alkalinizing the urine and then using cystine-binding thiol drugs. Conclusions: The proposed clinical pathways provide a framework for efficient evaluation and treatment of patients with cystinuria, which should improve overall outcomes of this rare, but highly recurrent, form of nephrolithiasis. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate the image quality (IQ) considerations of rapid kVp switching dual-energy CT (rsDECT) in the assessment of urolithiasis in patients with large body habitus and to evaluate whether it allows stone characterization.Materials and methods: In this IRB-approved, HIPAA compliant retrospective study, 93 consecutive patients (M/F = 72/21, mean age 56.9 years, range 23-83 years) with large body habitus (> 90 kg/198 lbs) who underwent dual-energy (DE) stone protocol CT on a rapid kVp switching DECT scanner between January 2013 and December 2016 were included. Scan acquisition protocol included an initial unenhanced single-energy CT (SECT) scan of KUB followed by targeted DECT in the region of stones. Two readers evaluated both CT data sets (axial 5 mm 120 kVp/140 kVp QC/70 keV monoenergetic, material density water/iodine images and coronal/sagittal 3 mm images) for the assessment of image quality (Scores: 1-4) and characterization of stone composition (reference standard: crystallography).Results: One hundred and five CT examinations were performed in 93 patients (mean body weight 105.12 ± 13.53 kg, range 91-154 kg), and a total of 321 urinary tract calculi (mean size-4.8 ± 3.2 mm, range 1.2-22 mm) were detected. Both SECT and targeted monoenergetic images were of acceptable image quality (mean IQ: 3.77 and 3.83, kappa 0.79 and 0.87 respectively). Material density water and iodine images had lower IQ scores (mean IQ: 2.97 and 3.09 respectively) with image quality deterioration due to severe photon starvation/streak artifacts in 20% (21/105) and 17% (18/105) scans, respectively. Characterization of stone composition into uric acid/non-uric acid stones was achieved in 93.14% (299/321) of calculi (mean size: 4.99 ± 3.3 mm, range 1.2-22 mm), while 7% (22/321) stones could not be characterized (mean size 3.03 ± 1.16 mm, range 1.6-6.4 mm) (p < 0.001). Most common reason for non-characterization was image quality deterioration of the material density iodine images due to severe photon starvation artifacts. On multivariate regression, stone size and patient weight were predictors of stone composition determination on DECT (p < 0.05). The transverse diameter had a weak negative correlation with stone composition determination, but it was not statistically significant. Stone characterization into uric acid vs. non-uric acid stones was accurate in 95% (n = 38/40) of stones in comparison with crystallography.Conclusion: In patients with large body habitus, rsDECT allowed characterization of most calculi (93%) despite image quality deterioration due to photon starvation/streak artifacts in up to 20% of material density images. Stone size and patient weight were predictors of stone composition determination on DECT, and small calculi in very large patients may not be characterized. [ABSTRACT FROM AUTHOR]

Ureteroscopy is an endoscopic kidney stone removal procedure which increases the internal pressure in the renal pelvis, the kidney’s urinary collecting system. Elevated renal pelvic pressure may result in systemic absorption of irrigation fluid and urine, which can increase the risk of postoperative fever and sepsis. Urologists have investigated the effects of various surgical parameters on the renal pelvic pressure. However, it still remains unknown which surgical parameter has the most dominant effect on the renal pelvic pressure over time. Here we develop a physical model that computes the renal pelvic pressure as a function of time based on parameters that can be varied during ureteroscopy. The model is developed by applying pipe network analysis to the regions of the urinary tract that are involved in a representative ureteroscopic procedure. Our model unifies the findings of the previously published studies on this topic; an ex-vivo porcine study and an in-vivo human study. Furthermore it allows simulation of surgical procedures based on various techniques. Our simulation demonstrates that the two strong regulators of renal pelvis pressure during ureteroscopy are the size of the gap between ureteroscope and ureteral access sheath and the frequency and duration of ureteroscope withdrawal. [ABSTRACT FROM AUTHOR]

Introduction: Ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL) are common procedures performed to treat kidney stones. Despite advances in technology/technique, serious infectious complications can occur. To better understand the preoperative antibiotic administration patterns and adherence to guidelines from the American Urological Association (AUA) and the European Association of Urology (EAU), members of the Endourological Society were sent a clinical vignette-based survey to assess the antibiotic use in a variety of pre-URS and pre-PCNL scenarios. Methods: Endourological Society members were e-mailed a survey that queried antibiotic therapy duration before uncomplicated URS and PCNL with negative and asymptomatic positive preoperative urine cultures (PUCs). For negative PUC questions, selecting more perioperative antibiotics was considered a "prolonged" course as it extends past the maximum of 24-hour perioperative prophylaxis recommended by both the AUA and EAU. Results: The response rate was 16.3% for a total of 326 responders. Twenty-one percent to 39% of respondents reported giving prolonged courses of preoperative antibiotics before a URS or PCNL with a negative PUC (p < 0.0001). When presented with a negative PUC, more prolonged antibiotic courses were reported with the following hierarchy: PCNL for 2 cm intrarenal stones (39%) > URS for 12 mm renal pelvis stone (28%) > URS for 7 mm distal ureteral stones (21%) (p < 0.0001). In both negative and positive PUC questions, differences were noted in preoperative antibiotic prescribing patterns among site of practice (United States, Canada, Europe, Asia, South America, and Others), type of practice (academic vs all others), years in practice (<10 or ≥10 years), and surgical volume (URS and PCNL >100 or ≤100 annual cases). Conclusions: Adherence to guidelines on antibiotic administration before PCNL and URS with a negative PUC varies by scenario and provider. In 21% to 39% of negative PUC cases, reported antibiotic use before a URS or PCNL is not consistent with recommendations from the AUA and EAU. Before a positive PUC URS or PCNL, nearly all surveyed provide preoperative antibiotics; however, the regimen length is variable. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the quality and readability of online information on ureteral stents.Methods: Google.com was queried using the search terms “ureteric stent”, “ureteral stent”, “double J stent” and, “Kidney stent” derived from Google AdWords. Website popularity was determined using Google Rank and the Alexa tool. Website quality assessment was performed using the following criteria: Journal of the American Medical Association (JAMA) benchmarks, Health on the Net (HON) criteria, and a customized DISCERN questionnaire. The customized DISCERN questionnaire was developed by combining the short validated DISCERN questionnaire with additional stent-specific items including definition, placement, complications, limitations, removal and “when to seek help”. Scores related to stent items were considered as the “stent score” (SS). Readability was evaluated using five readability tests.Results: Thirty-two websites were included. The mean customized DISCERN score and “stent score” were 27.1 ± 7.1 (maximum possible score = 59) and 14.6 ± 3.8 (maximum possible score = 24), respectively. A minority of websites adequately addressed “stent removal” and “when to seek medical attention”. Only two websites (6.3%) had HON certification (drugs.com, radiologyinfo.org) and only one website (3.3%) met all JAMA criteria (bradyurology.blogspot.com). Readability level was higher than the American Medical Association recommendation of sixth-grade level for more than 75% of the websites. There was no correlation between Google rank, Alexa rank, and the quality scores (P > 0.05).Discussion: Among the 32 most popular websites on the topic of ureteral stents, online information was highly variable. The readability of many of the websites was far higher than standard recommendations and the online information was questionable in many cases. These findings suggest a need for improved online resources in order to better educate patients about ureteral stents and also should inform physicians that popular websites may have incomplete information. [ABSTRACT FROM AUTHOR]

Introduction: Ureteroscopic laser lithotripsy is becoming the most commonly utilized treatment for patients with urinary calculi. The Holmium:YAG (yttrium aluminum garnet) laser is integral to the operation and is the preferred flexible intracorporeal lithotrite. In recent years, there has been increasing interest in examining the effect of varying the laser settings on the effectiveness of stone treatment. Herein, we review the two primary laser treatment approaches: dusting and fragmentation with extraction. Methods: We reviewed PubMed and MEDLINE databases from January 1976 through January 2017. All authors participated in the development of consensus definitions of dusting and fragmentation with extraction. The review protocol adhered to preferred reporting items for systematic reviews and meta-analyses (PRISMA) methodology. Results: When the Holmium:YAG laser is used to treat stones, there are two parameters that can be adjusted: power (J) and frequency (Hz). In one treatment paradigm, which became termed 'fragmentation with extraction,' laser settings that relied on high energy and low frequency were used. Another paradigm, which became termed 'dusting,' utilized low energy and high frequency settings, which had the effect of breaking off exceedingly small fragments from the stone. Conclusions: Both dusting and fragmentation with extraction approaches to ureteroscopic stone treatment are effective. In fact, there is little evidence that one approach is better than the other. However, each does have relative advantages and disadvantages, which should be considered. Although dusting tends to be associated with shorter procedure times and a lower risk of ureteral damage, this approach may place the patient at increased risk for future stone events should all of the resultant debris not be expelled from the collecting system. The active removal associated with fragmentation with extraction, in contrast, may provide for a more complete initial stone clearance. [ABSTRACT FROM AUTHOR]

Introduction: Immediate ureteroscopic treatment for patients presenting to the emergency room with symptomatic ureterolithiasis is more commonly being utilized. Recent reports demonstrate good efficacy for emergency ureteroscopy (URS); however, preoperative predictors of treatment success have not been described. In this study, we report our multicenter experience with emergency URS and identify predictors of successful treatment. We also describe the Emergency Ureteral Stone Treatment (EUST) score, which integrates these predictors and stratifies patients into those that are likely and unlikely to have successful treatment. Materials and Methods: Laboratory and radiographic data for all patients who underwent emergency URS for acute symptomatic ureterolithiasis from 2010 to 2015 were reviewed. Statistical difference among parameters for patients who were stone free (SF) and not SF was assessed with the Student’s t-test. Cutoff values for significant predictors were determined using sensitivity and specificity analysis. The EUST score was determined based on the number of cutoffs a patient was below. Results: Two hundred two of 247 patients (81.8%) were SF. Two complications (ureteral perforation) occurred. Stone size, duration of symptoms before presentation, and serum white blood count at presentation did not affect SF rates. 95.5% of the treatment failures were attributed to a tight ureter preventing stone access. Patients who received alpha blockers before treatment were more likely to be SF (98.0% vs 55.5%, p < 0.01). Periureteral density (PUD) was lower in SF patients (2.8 HU vs 19.6 HU, p < 0.01), whereas the increase in serum creatinine from baseline (ΔCr) was greater in non-SF patients (0.44 mg/dL vs 0.20 mg/dL, p < 0.01). EUST score of 0, 1, and 2 correlated with SF rates of 20.6%, 81.9%, and 99.2%, respectively. Conclusions: Combined consideration of PUD and ΔCr with the EUST score can assist in selecting optimal candidates for immediate ureteroscopic management. Administration of alpha blockers before surgery may improve success rates by providing preoperative ureteral dilation. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the cost-effectiveness of shockwave lithotripsy (SWL) versus ureteroscopic lithotripsy (URS) for patients with ureteral stones less than 1.5 cm in diameter. Methods: Patient age, stone diameter, stone location, and stone-free status were recorded for patients treated with SWL or URS for ureteral stones under 1.5 cm over a 1 year period. Institutional charges were obtained from in-house billing. A decision analysis model was constructed to compare the cost-effectiveness of SWL and URS using our results and success rates for modeling. Three separate models were created to reflect differing practice patterns. Results: A total of 113 patients were included-51 underwent SWL and 62 underwent URS as primary treatment. Single procedure stone-free rates for SWL and URS were 47.1 and 88.7 %, respectively ( p < 0.002). Decision analysis modeling demonstrated cost-effectiveness of SWL when SWL single procedure stone-free rates (SFR) were greater than or equal to 60-64 % or when URS single procedure SFRs were less than or equal to 57-76 %, depending on practice patterns. Conclusions: This retrospective study revealed superior SFR for ureteral stones less than 1.5 cm treated with URS compared to SWL. Our decision analysis model demonstrated that when SFR for SWL is less than 60-64 % or is greater than 57-76 % for URS, SWL is not a cost-effective treatment option. Based on these findings, careful stratification and selection of stone patients may enable surgeons to increase the cost-effectiveness of SWL. [ABSTRACT FROM AUTHOR]

Purpose: The ability to objectively predict which emergency department patients are likely to have a ureteral stone may aid in cost-effectiveness and patient-centered diagnostic imaging decisions. We performed an external validation of the STONE score, a clinical prediction rule for the presence of uncomplicated ureteral stones in emergency department patients developed at Yale University School of Medicine. Methods: Five hundred thirty-six (536) consecutive patients evaluated in an urban tertiary care emergency department for the possible diagnosis of ureteral stone were retrospectively reviewed. The STONE score uses five factors (gender, duration of pain, race, nausea/vomiting, erythrocytes on urine dipstick) to categorize patients into low, medium, and high probability of having a ureteral stone. The total STONE score risk is 0-13 and divided into three groups: low risk = 0-5, moderate risk = 6-9, and high risk = 10-13. Results: Of the 536 patients evaluated for suspected ureteral stone, 257 (47.8 %) had a ureteral stone. Mean patient age was 45.9 years (SD 16.3), and gender distribution was 43.9 % female and 56.1 % male. Distribution of STONE score risk was 24.1 % low, 48.1 % moderate, and 27.7 % high. Diagnosis of ureteral stone by STONE score risk was 14 % for low-risk group, 48.3 % for moderate-risk group, and 75.8 % for high-risk group. This distribution is consistent with internal validation at Yale University School of Medicine, where values were 8.3-9.2 % for low risk, 51.3-51.6 % for moderate risk, and 88.6-89.6 % for high risk. Conclusions: Our study validates the use of the STONE clinical score to categorize patients as low, moderate, and high risk for ureteral stone. This could help guide development of clinical decision rules for diagnostic studies and imaging in the future. [ABSTRACT FROM AUTHOR]

Introduction: While computerized tomography (CT) is the gold standard for diagnosis of ureterolithiasis, ultrasound is a less costly and radiation-free alternative which is commonly used to evaluate patients with ureteral colic. The purpose of this study was to evaluate the frequency with which patients with ureteral stones and renal colic demonstrate hydronephrosis in order to better understand the evaluation of these patients. Methods: Two hundred and forty-eight consecutive patients presenting with ureteral colic and diagnosed with a single unilateral ureteral stone on CT scan in an urban tertiary care emergency department were retrospectively reviewed. Radiology reports were reviewed for stone size, diagnosis, and degree of hydronephrosis. Results: Of the 248 patients evaluated for suspected ureteral stone, 221 (89.1 %) demonstrated any hydronephrosis, while 27 (10.9 %) did not. Hydronephrosis grade, available in 194 patients, was as follows: mild-70.6 %, moderate-27.8 %, and severe-1.5 %. Mean patient age was 47.0 years (SD 15.5), gender distribution was 35.9 % female and 64.1 % male, and mean stone axial diameter was 4.1 mm (SD 2.4). Stone location was as follows: ureteropelvic junction-4.1 %, proximal ureter-21 %, distal ureter-24.9 %, and ureterovesical junction-47.1 %. Axial stone diameter and coronal length (craniocaudal) were both significant predictors of degree of hydronephrosis (ANOVA, p < 0.001 for both). Age (ANOVA, p = NS), stone location (Chi square, p = NS), and gender (Chi square, p = NS) were not associated with degree of hydronephrosis. Conclusions: In patients with ureteral stones and colic, nearly 11 % do not demonstrate any hydronephrosis and a majority (nearly 71 %) will demonstrate only mild hydronephrosis. Stone diameter appears to be related to degree of hydronephrosis, whereas age, gender, and stone location are not. The lower incidence of hydronephrosis for small stones causing renal colic may explain the lower diagnostic accuracy of ultrasound when compared to CT for detecting ureteral stones. [ABSTRACT FROM AUTHOR]

The article discusses the author's views on the rights of transgender people to use bathrooms of their choice based on their gender identity and also discusses topics including the history of transgender rights, the bathroom bill in California and the need for gender neutral toilets.

Two previous studies (<10 patients each) have demonstrated that alkali therapy may reduce urine calcium excretion in patients with calcium oxalate nephrolithiasis. The hypothesized mechanisms are (1) a decrease in bone turnover due to systemic alkalinization by the medications; (2) binding of calcium by citrate in the gastrointestinal tract; (3) direct effects on TRPV5 activity in the distal tubule. We performed a retrospective review of patients on potassium citrate therapy to evaluate the effects of this medication on urinary calcium excretion. A retrospective review was performed of a metabolic stone database at a tertiary care academic hospital. Patients were identified with a history of calcium oxalate nephrolithiasis and hypocitraturia who were on potassium citrate therapy for a minimum of 3 months. 24-h urine composition was assessed prior to the initiation of potassium citrate therapy and after 3 months of therapy. Patients received 30-60 mEq potassium citrate by mouth daily. Inclusion criterion was a change in urine potassium of 20 mEq/day or greater, which suggests compliance with potassium citrate therapy. Paired t test was used to compare therapeutic effect. Twenty-two patients were evaluated. Mean age was 58.8 years (SD 14.0), mean BMI was 29.6 kg/m (SD 5.9), and gender prevalence was 36.4 % female:63.6 % male. Mean pre-treatment 24-h urine values were as follows: citrate 280.0 mg/day, potassium 58.7 mEq/day, calcium 216.0 mg/day, pH 5.87. Potassium citrate therapy was associated with statistically significant changes in each of these parameters-citrate increased to 548.4 mg/day ( p < 0.0001), potassium increased to 94.1 mEq/day ( p < 0.0001), calcium decreased to 156.5 mg/day ( p = 0.04), pH increased to 6.47 ( p = 0.001). Urine sodium excretion was not different pre- and post-therapy (175 mEq/day pre-therapy versus 201 mEq/day post-therapy, p = NS). Urinary calcium excretion decreased by a mean of 60 mg/day on potassium citrate therapy-a nearly 30 % decrease in urine calcium excretion. These data lend support to the hypothesis that alkali therapy reduces urine calcium excretion. [ABSTRACT FROM AUTHOR]

Background: American Urology Association (AUA) Best Practice Guidelines for ureteroscopic stone treatment recommend antibiotic coverage for <24 hours following the procedure. The purpose of this study was to evaluate if the addition of postoperative antibiotics reduces urinary tract infections (UTIs) following ureteroscopic stone treatment beyond the recommended preoperative dose. Methods: A retrospective review was performed of consecutive patients at two institutions, University of British Columbia and Massachusetts General Hospital, Harvard. All patients received a single dose of antibiotics before ureteroscopic stone treatment. A subset of patients was also given postoperative antibiotics. The rate of UTI was compared in patients receiving only preoperative antibiotics (group 1) vs those who received pre- and postoperative antibiotics (group 2). Results: Eighty-one patients underwent ureteroscopy for renal calculi. Mean time to follow up was 42 ± 88 days. Eight (9.9%) patients in total (two from group 1 and six from group 2, p = 0.1457) developed UTIs postoperatively. In group 1, both patients presented with pyelonephritis ( n = 2); those patients with infections in group 2 presented with urosepsis ( n = 2) and cystitis ( n = 2) and two patients had asymptomatic bacteriuria. Risk factors such as preoperative stenting, nephrostomy tubes, and foley catheters neither differed between groups nor did they predispose patients to postoperative infections. Conclusions: The postoperative UTI rate in this study (9.9%) is consistent with previous reports. Our data suggest that a single preoperative dose of antibiotics is sufficient, and additional postoperative antibiotics do not decrease infection rates after ureteroscopic stone treatment. Risk for selection bias is a potential limitation. [ABSTRACT FROM AUTHOR]

Background: Renal papillary calcification is a compelling candidate risk factor for chronic kidney disease (CKD) and nephrolithiasis. Renal papillary density (RPD), as assessed by computed tomography (CT), is a potential marker for calcification that has not been well studied. We developed a protocol to measure RPD using CT scans and assessed its reproducibility in participants from the Framingham Heart Study. Methods: We assessed RPD of right kidneys from a single abdominal CT slice in 100 representative participants from the Framingham Heart Study (47 % female, mean age 59.9 years) using a novel protocol. We selected the kidney slice with the most open sinus space and assessed RPD using the average of three 20 mm2 ellipses from upper, middle and lower papillary regions. Two different readers performed RPD measurements and the first reader repeated all measurements to determine both intra- and inter-reader reproducibility, respectively. Results: Of 100 total individuals included in the replication dataset, six were excluded for poor scan quality. Average RPD across all individuals was 48.7 ± 4.7 (range 38.7-61.7) Hounsfield Units (HU). The intra- and inter-reader correlation coefficients were 0.86 and 0.79, respectively. Bland-Altman analysis suggested no systematic bias between the different reads. Conclusion: Measuring RPD is practical and reproducible using MDCT scans from a small sample of a community-based cohort. [ABSTRACT FROM AUTHOR]

Purpose: To examine the association between statin medication use and sepsis risk after percutaneous nephrolithotomy (PCNL). Materials and Methods: Using medical claims data, we identified working-age adults with urinary stone disease who were treated with PCNL. Among this cohort, we determined which patients had a prescription fill for a statin agent that encompassed their surgery date. We then fitted logistic regression models to examine for differences in rates of postoperative sepsis between statin users and nonusers. In addition, we evaluated the frequency of nonfebrile urinary tract infections (UTIs) and intensive care unit (ICU) services utilization and hospital length of stay (LOS) as a function of statin use. Results: During the study period, at total of 2046 patients underwent PCNL, 382 (18.7%) of whom had a prescription fill for a statin agent preceding their surgery. The overall rate of sepsis in this population was 3.8%. After adjusting for patient health status and sociodemographic factors, the rate of postoperative sepsis was comparable between statin users and nonusers (5.3% vs 3.5%, respectively; P=0.105). In addition, UTI and ICU utilization rates did not relate to statin use ( P>0.05 for all associations). Adjusted hospital LOS was shorter among statin users, but the difference was clinically trivial (3.6 vs 4.1 days; P=0.007). Conclusions: Statin use is not associated with reductions in postoperative sepsis, nonfebrile UTIs, ICU utilization, or hospital LOS after PCNL. To increase the safety of PCNL, urologists will have to consider other processes of care (e.g., clinical care pathways). [ABSTRACT FROM AUTHOR]

Urolithiasis is a common disease with increasing prevalence worldwide and a lifetime‑estimated recurrence risk of over 50%. Imaging plays a critical role in the initial diagnosis, follow‑up and urological management of urinary tract stone disease. Unenhanced helical computed tomography (CT) is highly sensitive (>95%) and specific (>96%) in the diagnosis of urolithiasis and is the imaging investigation of choice for the initial assessment of patients with suspected urolithiasis. The emergence of multi‑detector CT (MDCT) and technological innovations in CT such as dual‑energy CT (DECT) has widened the scope of MDCT in the stone disease management from initial diagnosis to encompass treatment planning and monitoring of treatment success. DECT has been shown to enhance pre‑treatment characterization of stone composition in comparison with conventional MDCT and is being increasingly used. Although CT‑related radiation dose exposure remains a valid concern, the use of low‑dose MDCT protocols and integration of newer iterative reconstruction algorithms into routine CT practice has resulted in a substantial decrease in ionizing radiation exposure. In this review article, our intent is to discuss the role of MDCT in the diagnosis and post‑treatment evaluation of urolithiasis and review the impact of emerging CT technologies such as dual energy in clinical practice. [ABSTRACT FROM AUTHOR]

To examine the changes in stone composition from 1990 to 2010. A retrospective review was performed of all renal and ureteral stones submitted from the state of Massachusetts to a single laboratory (Laboratory for Stone Research, Newton, MA) for the years 1990 and 2010. Stone composition was determined by infrared spectroscopy and/or polarizing microscopy. A total of 11,099 stones were evaluated (56.7 % from 1990, 43.3 % from 2010). From 1990 to 2010, the percentage of stones from females (i.e., female/male ratio) increased significantly (29.8 % in 1990 to 39.1 % in 2010, p < 0.001). Among women, from 1990 to 2010, there was a significant increase in stones which were >50 % uric acid (7.6-10.2 %, p < 0.005) and a significant decrease in struvite stones (7.8-3.0 %, p < 0.001). Among women with calcium stones, the % apatite per stone decreased significantly (20.0 vs. 11.7 %, p < 0.001). Among men, there were no changes in stones which were majority uric acid (11.7-10.8 %, p = 0.2). Among men with calcium stones, the % apatite per stone increased significantly (9.8 vs. 12.5 %, p < 0.001). Males also demonstrated a significant increase in both cystine (0.1-0.6 %, p < 0.001) and struvite stones (2.8-3.7 %, p = 0.02). The epidemiology of stone disease continues to evolve and appears to vary according to gender. While some of these findings may be related to population changes in body mass index and obesity, the etiology of others remains unclear. [ABSTRACT FROM AUTHOR]