Break Wave Lithotripsy for Urolithiasis: Results of the First-in-Human International Multi-Institutional Clinical Trial.

PURPOSE: This study reports on a prospective, multicenter, single-arm, clinical trial utilizing the SonoMotion (San Mateo, California) Break Wave lithotripsy (BWL) device to fragment urinary stones. MATERIALS AND METHODS: Patients with a urinary stone underwent a single treatment of 30 minutes and peak negative pressure of 4.5 to 8 MPa. Subjects were contacted and outcomes assessed at 7, 14, and 35 days after treatment, with clinical follow-up and CT imaging 70 ± 14 days postprocedure. The primary objectives were to assess the safety (hematomas, complications, etc) and effectiveness of BWL (any fragmentation, residual fragments ≤4 mm or ≤2 mm, and completely stone-free rate) as assessed via noncontrast CT-kidneys, ureters, and bladder. RESULTS: Forty-four patients with a ureteral (43%) or renal (57%) stone were treated across 5 centers. Stone fragmentation occurred in 88% of cases; 70% had fragments ≤ 4 and 51% ≤ 2 mm, while 49% were completely stone free on CT; no serious adverse events were reported. Eighty-six percent of patients received either no analgesic medication at all (50%) or minor analgesia (36%). After determining optimal therapy settings, 36 patients were treated and the effectiveness improved exhibiting fragmentation in 92% (33/36), residual fragments ≤ 4 mm in 75% and 58% with fragments ≤ 2 mm with 58% completely stone free. Effectiveness was less in subjects with lower pole stones with 81% fragmentation, 71% having fragments ≤ 4 mm, 29% with fragments ≤ 2 mm, and 29% completely stone free; of distal ureteral stone patients, 89% were completely stone free. CONCLUSIONS: BWL offered safe and effective noninvasive stone therapy requiring little to no anesthesia and was carried out successfully in nonoperative environments. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03811171.

Clinical and postoperative characteristics of stentless ureteroscopy patients: a prospective analysis from ReSKU.

INTRODUCTION: To evaluate the clinical characteristics as well as the postoperative course of urolithiasis patients undergoing a ureteroscopy (URS) without stent placement. MATERIALS AND METHODS: This was a prospective case cohort study utilizing data collected in the Registry for Stones of the Kidney and Ureter (ReSKU) from a single institution between October 2015 and December 2020. We identified all consecutive patients undergoing URS for stone disease and analyzed data encompassing demographics, medical history, intra and postoperative characteristics, including complications and postoperative symptoms. Univariate and multivariate logistic regression analyses were performed based on the presence or absence of an indwelling ureteral stent. RESULTS: A total of 470 patients were included for analysis, 92 patients in the stentless group (19.5%). Factors associated with stentless ureteroscopy were a lower stone burden (p < 0.001), the pre-existence of a ureteral stent (37.4% vs. 27.9% p = 0.011), absence of an access sheath (14.6% vs. 69.5% p < 0.001), and a shorter operative time (31 vs. 58 min p < 0.001). Postoperative gross hematuria and lower urinary tract symptoms (LUTS) were reported less frequently in stentless patients (p = 0.02, p = 0.01, respectively). There was no difference in postoperative complications between both groups (15.2% vs. 12.0%, p = 0.385). On multivariate analysis, the risk of postoperative complications was associated with obesity, stone burden ≥ 1 cm, and positive preoperative urine culture. There was no patient who required emergent stent placement in the stentless group. CONCLUSION: Our data show that, in well selected patients, omitting ureteral stent placement after URS can decrease postoperative gross hematuria and LUTS without increasing postoperative complications.

Ultrasound guidance can be used safely for renal tract dilatation during percutaneous nephrolithotomy.

OBJECTIVES: To compare clinical outcomes in patients who underwent percutaneous nephrolithotomy (PCNL) with renal tract dilatation performed under fluoroscopic guidance vs renal tract dilatation with ultrasound guidance. PATIENTS AND METHODS: We conducted a prospective observational cohort study, enrolling successive patients undergoing PCNL between July 2015 and March 2018. Included in this retrospective analysis were cases where the renal puncture was successfully obtained with ultrasound guidance. Cases were then grouped according to whether fluoroscopy was used to guide renal tract dilatation or not. All statistical analyses were performed using Stata version 15.1 including univariate (Fisher's exact test, Welch's t-test) and multivariate analyses (binomial logistic regression, ordinal logistic regression, and linear regression). RESULTS: A total of 176 patients underwent PCNL with successful ultrasonography-guided renal puncture, of whom 38 and 138 underwent renal tract dilatation with fluoroscopic vs ultrasound guidance, respectively. There were no statistically significant differences in patient age, gender, body mass index (BMI), preoperative hydronephrosis, stone burden, procedure laterality, number of dilated tracts, and calyceal puncture location between the two groups. Among ultrasound tract dilatations, a higher proportion of patients were placed in the modified dorsal lithotomy position as opposed to prone, and a significantly shorter operating time was observed. Only modified dorsal lithotomy position remained statistically significant after multivariate regression. There were no statistically significant differences in postoperative stone clearance, complication rate, or intra-operative estimated blood loss. A 5-unit increase in a patient's BMI was associated with 30% greater odds of increasingly severe Clavien-Dindo complications. A 5-mm decrease in the preoperative stone burden was associated with 20% greater odds of stone-free status. No variables predicted estimated blood loss with statistical significance. CONCLUSIONS: Renal tract dilatation can be safely performed in the absence of fluoroscopic guidance. Compared to using fluoroscopy, the present study demonstrated that ultrasonography-guided dilatations can be safely performed without higher complication or bleeding rates. This can be done using a variety of surgical positions, and future studies centred on improving dilatation techniques could be of impactful clinical value.

Does routine repeat imaging change management in high-grade renal trauma? Results from three level 1 trauma centers.

PURPOSE: Guidelines call for routine reimaging of Grade 4-5 renal injuries at 48-72 h. The aim of the current study is to evaluate the clinical utility of computed tomography (CT) reimaging in high-grade renal injuries. MATERIALS AND METHODS: We assembled data on 216 trauma patients with high-grade renal trauma at three level 1 trauma centers over a 19-year span between 1999 and 2017 in retrospectively collected trauma database. Demographic, radiographic, and clinical characteristics of patients were retrospectively reviewed. RESULTS: In total, 151 cases were Grade 4 renal injuries, and 65 were Grade 5 renal injuries. 53.6% (81) Grade 4 and 15.4% (10) Grade 5 renal injuries were initially managed conservatively. Of the 6 asymptomatic cases where repeat imaging resulted in intervention, 100% had collecting system injuries at initial imaging. Collecting system injuries were only present in 42.9% of cases where routine repeat imaging did not trigger surgical intervention. Collecting system injury at the time of initial imaging was a statistically significant predictor of routine repeat imaging triggering surgical intervention (p = 0.022). Trauma grade and the presence of vascular injury were not significant predictors of intervention after repeat imaging in asymptomatic patients. CONCLUSION: In asymptomatic patients with high-grade renal trauma, the number needed to image is approximately one in eight (12.5%) to identify need for surgical intervention. There is potentially room to improve criteria for routine renal imaging in high-grade renal trauma based on the more predictive imaging finding of collecting system injury.

Effect of core preventative screening on kidney stone surgical patterns.

PURPOSE: In the surgical treatment of kidney stones, decreased access to healthcare has been shown to exacerbate stone burden, often requiring more invasive and extensive procedures. The objective of this study is to evaluate the effects of preventative health screening on kidney stone surgical treatment patterns. METHODS: We performed a retrospective analysis of data from the Healthcare Cost and Utilization Project (HCUP) Florida state-wide dataset and the PLACES Local Data for Better Health dataset from the Centers of Disease Control and Prevention (CDC). ZIP Code Tabulation Areas (ZCTAs) identified from the PLACES data were merged with the HCUP dataset to create a single dataset of community-level stone outcomes and community health measures. We included adult patients 18 years or older who underwent at least one urologic stone procedure from 2016 to 2020. RESULTS: 128,038 patients from 885 communities were included in the study. Patients underwent an average of 1.42 surgeries (Median = 1.39, SD = 0.16). Increased core preventative screening was associated with increased surgical frequency (Estimate: 0.51, P < 0.001). The low core preventative screening group had a higher prevalence of PNL than SWL while the high core preventative screening group had a low PNL prevalence compared to SWL. CONCLUSION: Increased core preventative screenings are associated with less invasive kidney stone surgeries, suggesting that preventative screenings detect stones at an earlier stage.

Single-Use Ureteroscopes Are Associated with Decreased Risk of Urinary Tract Infection After Ureteroscopy for Urolithiasis Compared to Reusable Ureteroscopes.

Objective: Urinary tract infection (UTI) is a common complication after ureteroscopy. Despite sterilization, there is evidence that reusable ureteroscopes can still harbor bacteria. Whether this property is associated with increased risk of UTI is unknown. The objective of this study was to compare rates of postoperative UTI after ureteroscopy for urolithiasis performed with single-use ureteroscopes vs reusable ureteroscopes. Materials and Methods: This was a single-center, retrospective cohort study of all patients who underwent ureteroscopy for urolithiasis between June 2012 and March 2021. Outcomes were compared between those who underwent stone removal with single-use and reusable ureteroscopes. The primary endpoint was postoperative UTI. The secondary endpoints were intra-operative and postoperative outcomes, and health service utilization after surgery. Results: Of 991 patients identified, 500 (50.4%) underwent ureteroscopy with a single-use ureteroscope. Rates of postoperative UTI were lower in those undergoing ureteroscopic stone removal with a single-use ureteroscope compared to a reusable ureteroscope (6.5% vs 11.9%, p = 0.018). In multivariable analysis, use of a single-use ureteroscope was associated with lower odds of postoperative UTI compared to a reusable ureteroscope when adjusting for risk (odds ratio 0.37, p = 0.015). Use of a single-use ureteroscope was associated with a higher stone clearance rate compared to a reusable ureteroscope (90.0% vs 83.9%, p = 0.005). There was no difference in operative time, overall complication rate, readmission, or emergency department visits between two groups. Conclusion: Single-use ureteroscopes are associated with a twofold decreased risk of UTI and increased stone clearance rate after ureteroscopy for urolithiasis compared to reusable ureteroscopes.

Ultrasound-Only Percutaneous Nephrolithotomy Is Safe and Effective Compared to Fluoroscopy-Directed Percutaneous Nephrolithotomy.

Introduction: Outcomes after ultrasound-only percutaneous nephrolithotomy (PCNL), in which no fluoroscopy is used, are not well known. The goal of this study was to compare outcomes of ultrasound-only and fluoroscopy-directed PCNL. Materials and Methods: Prospectively collected data from the Registry for Stones of the Kidney and Ureter database were reviewed for all patients who underwent PCNL at one academic center from 2015 to 2021. Primary outcomes were complications and stone-free rates (no residual fragments ≥3 mm). Results: Of the 141 patients who underwent ultrasound-only PCNL and 147 who underwent fluoroscopy-directed PCNL, there was no difference in complication rates (15% vs 16%, p = 0.87) or stone-free status (71% vs 65%, p = 0.72), respectively. After adjusting for body mass index, American Society of Anesthesiologists (ASA), stone size, and stone complexity by Guy score, ultrasound-only PCNL was not associated with any increased odds of complications (odds ratio [OR] 0.7, 95% confidence interval [CI] 0.3-1.6, p = 0.41) or residual stone fragments ≥3 mm (OR 1.0, 95% CI 0.5-1.9, p = 0.972) compared with fluoroscopy-directed PCNL. Ultrasound-only PCNL was associated with shorter operative time (median 99.5 vs 126 minutes, p < 0.001), and the use of ultrasound remained a significant predictor of short operative time (<100 minutes) after controlling for supine positioning, stone size, and stone complexity by Guy score (OR 2.31, 95% CI 1.01-5.29, p = 0.048). Patients in the ultrasound-only group were spared a mean radiation exposure dose of 10 mGy per procedure. Conclusions: Ultrasound-only PCNL is safe and achieves similar stone-free rates compared with fluoroscopy-directed PCNL with the added benefit of avoidance of radiation.

Low Urologist Density Predicts High-Cost Surgical Treatment of Stone Disease.

Introduction and Objectives: Lack of access to urologic specialists is approaching crisis levels as the number of urologists is decreasing, while the demand for urologic care is increasing. The financial implications of this have not been explored. The objective of this study is to examine the impact of access and other patient factors on cost to treat urolithiasis. We hypothesized that markers of poor access would associate with higher costs of surgical encounters for patients presenting with urolithiasis. Methods: A retrospective review of prospectively collected data from the Registry for Stones of the Kidney and Ureter (ReSKU) from September 2015 to July 2018 was conducted to investigate characteristics of surgical patients treated for urinary stone disease. Univariate analysis was performed using the Welch two-sample t-test. Multivariate analysis was performed using logistic regression. Statistical analysis was performed in R version 3.5. Results: When taking into account age, delayed presentation, procedure type, stone size >20 mm, American Society of Anesthesiologists (ASA) code, gender, race, income, distance, urologist density, body mass index, diabetes, infection, education, language, insurance, and stone complexity, patients undergoing percutaneous nephrolithotomy procedure (p < 0.001; odds ratio [OR] 12.9, confidence interval [CI] 4.05-48.5), urologist density in the bottom quartile (p = 0.014; OR 4.66, CI 1.40-16.9), diabetes (p = 0.018; OR 4.38, CI 1.32-15.6), and infection (p = 0.007; OR 4.51, CI 1.55-14.0) were the only variables statistically significant for association with top quartile of total cost. Conclusions: Surgical encounter costs are largely dictated by patient clinical factors, but low regional urologist density appears to independently predicted for high-cost stone surgery. Increasing patients' access to a urologist may prove to be financially beneficial in the longitudinal reduction in health care costs for stone disease.

Techniques - Ultrasound-guided percutaneous nephrolithotomy: How we do it.

Ultrasonography has emerged as an alternative to fluoroscopy for image-guided percutaneous nephrolithotomy (PCNL) in many countries. Compared to fluoroscopy-guided PCNL (F-PCNL), ultrasound-guided PCNL (US-PCNL) is easier to learn and reduces radiation exposure to patients and providers. Despite these advantages, uptake of ultrasound-guided PCNL (US-PCNL) in Canada has been almost nonexistent, largely because it is not incorporated into urologists' training. In this article, we seek to familiarize Canadian urologists with this approach by describing our step-by-step technique for US-PCNL. Additionally, we provide keys to successful implementation of this technique.

Ultrasound-guided Morcellation During Difficult Holmium Laser Enucleation of the Prostate.

OBJECTIVE: To demonstrate how bladder ultrasound can be useful in completing morcellation during difficult Holmium Laser Enucleation of the Prostate (HoLEP). As HoLEP has emerged as a standard of care for the treatment of benign prostatic hyperplasia, multiple studies have reported the potentially catastrophic complication of bladder injury during morcellation. This video aims to assist any urologist performing HoLEP by providing step-by-step instruction for using ultrasound to complete morcellation safely. METHODS: Enucleation is performed using a 26-French continuous flow scope, off-set laser bridge with a laser stabilization catheter, and a 550 µm holmium laser fiber. Once the median and lateral lobes have been enucleated, the outer sheath is removed and the nephroscope is inserted to facilitate morcellation. Under dual inflow irrigation, the Piranha morcellator (Richard Wolf, Knittlingen, Germany) is introduced and set to the manufacturer's recommended settings of 1500 rpm. A 3.5-MHz convex abdominal ultrasound transducer (Hitachi Prosound Alpha 7; Hitachi Aloka Medical America, Wallingford, CT) under B-mode is used to visualize the bladder, predominantly in the sagittal orientation. Morcellation proceeds under simultaneous ultrasound and direct cystoscopic guidance. RESULTS: The distended bladder is visualized concurrently with the ultrasound and via the nephroscope as the Piranha engages the adenoma and begins morcellation. Once the adenoma is engaged, the operator then drops their hands to place the morcellator in the center of the bladder. Ultrasound provides real-time feedback as to the location of the morcellator in relation to the adenoma and bladder. CONCLUSION: This video highlights the use of intraoperative bladder ultrasound as a visual aid to assist during the morcellation portion of HoLEP. This proof of concept demonstrates that ultrasound can be an additional tool to utilize during difficult cases when cystoscopic visualization during morcellation is limited.

Assessing Cost-Effectiveness of New Technologies in Stone Management.

Diagnosis, treatment, and follow-up are all influential in determining the overall cost to the health care system for kidney stones. New innovations in the field of nephrolithiasis have been abundant, including disposable ureteroscopes, ultrasound-guided approaches to percutaneous nephrolithotomy, and advanced laser lithotripters. Identifying cost-effective treatment strategies encourages practitioners to be thoughtful about providing value-based high-quality care and remains on important principle in the treatment of urinary stone disease.

The Impact of Stone Multiplicity on Surgical Decisions for Patients with Large Stone Burden: Results from ReSKU.

Introduction: American Urological Association (AUA) guidelines recommend percutaneous nephrolithotomy (PCNL) for total stone burden greater than 20 mm, yet it is unclear if the number of stones affects adherence to this guideline. We aim to assess the impact of stone multiplicity on the choice of ureteroscopy (URS) vs PCNL as a first-line therapy for patients with high burden (>20 mm), and examine whether the AUA guideline-discordant care impacts patient outcomes. Materials and Methods: Data were collected from the Registry for Stones of the Kidney and Ureter (ReSKU) database, a prospectively collected registry of patients with stone disease. Multivariate logistic regression (MLR) was used to estimate the association between stone multiplicity and the decision to perform URS for high stone burden (>20 mm) patients. MLR was further used to estimate the association between performing URS and the following outcomes: stone-free rate, need for a second operation, and complications. Postoperative hospital stay was compared between patients receiving URS vs PCNL using Student's t-test. Results: One hundred twenty-five patients were included in this analysis. For patients with total stone burden exceeding 20 mm, those with more than three stones had roughly nine times the likelihood of undergoing URS over PCNL compared with patients with a single stone (adjusted odds ratio 9.21, confidence interval [95% CI] 2.55-40.58, p = 0.001). Stone-free rates, Clavien-Dindo scores, and frequency of second-look operations did not differ significantly between URS and PCNL patients. URS patients were discharged an average of 1.26 days earlier than patients who received PCNL (95% CI 0.72-1.81, p < 0.001). Discussion: Stone multiplicity strongly predicts which patients with stone burden >20 mm will undergo URS and who will undergo PCNL. These deviations from AUA guidelines do not appear to worsen patient outcomes. These results suggest that careful consideration of each patient may warrant deviation from guidelines.

Influence of Socioeconomic Factors on Stone Burden at Presentation to Tertiary Referral Center: Data From the Registry for Stones of the Kidney and Ureter.

OBJECTIVE: To determine social factors associated with advanced stone disease (defined as unilateral stone burden >2 cm) at time of presentation to a regional stone referral center. Little is known about social determinants of urolithiasis. We hypothesize that socioeconomic factors impact kidney stone severity at intake to referral centers. METHODS: A retrospective review of the prospectively collected data from the Registry for Stones of the Kidney and Ureter from 2015 to 2018 was conducted to evaluate patient characteristics predictive of having a large (>2 cm) unilateral kidney stone. Data on patient age, gender, body mass index, diabetes, race, language, education level, infection, distance, income, referring regional urologist density, American Society of Anesthesiologists score, and stone analysis were evaluated. RESULTS: Complete imaging and patient variable data was present in 650 of 1142 patients including 197 patients with unilateral stone burden >2 cm. On multivariate analysis, obesity, lower education level, increased distance from the referral center, and symptoms of infection predicted for unilateral stone burden greater than 2 cm. Among 191 patients with stone analysis data present, stone type, income, and urologist density predicted for unilateral stone burden greater than 2 cm. CONCLUSION: In addition to known biological risk factors, patients with lower education levels and from regions of lower mean income were found to be more likely to present to our tertiary care center with stone burden greater than 2 cm. More research is needed to elucidate the social and societal determinants of advanced stone disease and the impact this has on population costs for stone treatment.

Computed Tomography Radiation Exposure Among Referred Kidney Stone Patients: Results from the Registry for Stones of the Kidney and Ureter.

Purpose: Kidney stone patients routinely have CT scans during diagnostic work-up before being referred to a tertiary center. How often these patients exceed the recommended dose limits for occupational radiation exposure of >100 mSv for 5 years and >50 mSv in a single year from CT alone remains unknown. This study aimed to quantify radiation doses from CTs received by stone patients before their evaluation at a tertiary care stone clinic. Methods: From November 2015 to March 2017, consecutive new patients enrolled into the Registry for Stones of the Kidney and Ureter (ReSKU™) had the dose-length product of every available CT abdomen/pelvis within 5 years of their initial visit recorded, allowing for an effective dose (EDose) calculation. Multivariate logistic regression analysis identified factors associated with exceeding recommended dose limits. Models were created to test radiation reducing effects of low-dose and phase-reduction CT protocols. Results: Of 343 noncontrast CTs performed, only 29 (8%) were low-dose CTs (calculated EDose <4 mSv). Among 389 total patients, 101 (26%) and 25 (6%) had an EDose >20 mSv and >50 mSv/year, respectively. Increased body mass index, number of scans, and multiphase scans were associated with exceeding exposure thresholds (p < 0.01). The implementation of a low-dose CT protocol decreased the estimated number of scans contributing to overexposure by >50%. Conclusions: Stone patients referred to a tertiary stone center may receive excessive radiation from CT scans alone. Unnecessary phases and underutilization of low-dose CT protocols continue to take place. Enacting new approaches to CT protocols may spare stone patients from exceeding recommended dose limits.

Ultrasound for Intraoperative Confirmation of Antegrade Ureteral Stent Placement During Laparoscopic Pyeloplasty.

OBJECTIVE: To describe our ultrasound technique for confirming intraoperative, antegrade-placed ureteral stent position during laparoscopic pyeloplasty. BACKGROUND: Disadvantages of retrograde stent placement include the need to reposition the patient into and out of the lithotomy position. Antegrade stent placement can reduce procedure time but requires confirming appropriate distal placement into the bladder with cystoscopy, percutaneous drain placement, or instillation of methylthioninium chloride or indigo carmine. MATERIALS AND METHODS: A 3-way 20-French Foley catheter is placed after induction with general anesthesia. Laparoscopic transperitoneal dismembered pyeloplasty is performed. Intraoperatively, the bladder is filled retrograde with 300ccs normal saline. After completing the posterior suture line of the ureteral anastomosis, a 4.8-French, 26-cm ureteral stent is placed antegrade down the ureter using a 5-French exchange catheter and guidewire. The stent is passed over the guidewire into the bladder. The proximal curl is then placed into the renal pelvis and the anastomosis is completed. Without patient repositioning, an intraoperative bladder ultrasound is performed to identify the distal stent curl within the bladder lumen. RESULTS: This technique demonstrated that ultrasound can guide antegrade stent placement in adult, laparoscopic ureteral surgery. It eliminated the need for intraoperative repositioning of the patient for intraoperative cystoscopy to confirm stent placement and was performed successfully during 8 laparoscopic pyeloplasty cases without failure. Ultrasound is likely more sensitive compared with looking for the presence of vesicoureteral reflux after stent placement, prevents stent malposition, and avoids the use of intravesical dyes that upon reflux can stain tissues and obscure surgical planes. CONCLUSION: Here we demonstrate successful use of intraoperative ultrasound to confirm appropriate distal stent positioning in the bladder of an adult patient following antegrade stent placement for laparoscopic dismembered pyeloplasty. To our knowledge, this has been described in pediatrics, but never in adult patients.

Increasing Body Mass Index Steepens the Learning Curve for Ultrasound-guided Percutaneous Nephrolithotomy.

OBJECTIVE: To define how the learning curve for success in ultrasound-guided percutaneous nephrolithotomy (PCNL) is impacted by body mass index (BMI). Previous research has shown ultrasound-guided PCNL to be an effective method of nephrolithiasis treatment comparable to fluoroscopy-guided PCNL. A common concern for the ultrasound-guided approach is potential imaging difficulty in the obese patient population. METHODS: A prospective cohort study of consecutive patients undergoing PCNL with ultrasound guidance for renal tract access was performed. Clinical data collected included success in gaining renal access with ultrasound guidance, patient BMI, and clinical outcomes over time. Nonparametric LOWESS regression modeling was performed in R using locally weighted scatterplot smoother (R version 3.3.3) for gradations of patients by BMI group (<30, 30-40, and >40). RESULTS: A total of 150 cases were examined. Case number and BMI were evaluated as continuous variables. Multivariate logistic regression revealed that BMI (P = .010; OR 0.93) and case number (P<.001; OR 1.03) were significantly correlated with ultrasound success. Sex, age, hydronephrosis, stone type, puncture location, and stone size did not influence success at obtaining ultrasound-only access in a statistically significant fashion. LOWESS regression modeling of the relationship between case number and renal access success depicts that the curve representative of the BMI >40 group is downward and right-shifted relative to the other two groups. CONCLUSION: The learning curve for successful ultrasound-guided PCNL is impacted by patient's BMI as well as case number. Increasing BMI makes access more challenging when performing ultrasound-guided PCNL.

Guidelines of guidelines: a review of urethral stricture evaluation, management, and follow-up.

BACKGROUND: Our objective is to report a comparative review of recently released guidelines for the evaluation, management, and follow-up of urethral stricture disease. METHODS: This is an analysis of the American Urologic Association (AUA) and Société Internationale d'Urologie (SIU) guidelines on urethral stricture. Strength of recommendations is stratified according to letter grade that corresponds to the level of evidence provided by the literature. RESULTS: Although few, the discrepancies between the recommendations offered by the two guidelines can be best explained by varying interpretations of the literature and available evidence on urethral strictures. When comparing the AUA guidelines and the SIU guidelines on urethral stricture, there are very few discrepancies. Perhaps the most notable difference is in the use of repeat DVIU or urethral dilation after an initial failed attempt. SIU guidelines state that there are instances where repeat DVIU or urethral dilation can be indicated, and they give a range of time at which stricture recurrence post procedure mandates an urethroplasty (less than 3 to 6 months). The AUA guidelines definitively state that repeat endoscopic procedures should not be offered as an alternative to urethroplasty, and they do not mention time of stricture recurrence as a factor. SIU guidelines allow for management of urethral stricture with indwelling urethral stenting. CONCLUSIONS: Overall there is a need for more high quality research in the work up, management, and follow up care of urethral stricture.

Penetrating Trauma to the Ureter, Bladder, and Urethra.

We describe the epidemiology, diagnosis, and management of adult civilian penetrating trauma to the ureter, bladder, and urethra. Trauma is a significant source of death and morbidity. Genitourinary injuries are present in 10% of penetrating trauma cases. Prompt recognition and appropriate management of genitourinary injuries, which are often masked or overlooked due to concomitant injuries, is essential to minimize morbidity. Penetrating trauma most commonly results from gunshot wounds or stab wounds. Compared to blunt trauma, these typically require surgical exploration. An understanding of anatomy and a high index of suspicion are necessary for prompt recognition of genitourinary injuries.