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Introduction: Extracorporeal shock wave lithotripsy (SWL) can be used in conjunction with endoscopic retrograde cholangiopancreatography (ERCP) for the treatment of large (≥5 mm) or impacted pancreatolithiasis. We report our experience demonstrating the safety and effectiveness of urologist-directed SWL for pancreatolithiasis. Methods: We performed a retrospective review of all patients undergoing SWL for pancreatolithiasis at our institution between 2016 and 2020. We defined a treatment cycle as one in which the patient underwent a predefined number of SWL procedures prior to performance of a post-SWL ERCP. Stone-free status was defined as the absence of stone fragments at post-SWL ERCP. Multivariable logistic regression was performed to determine characteristics associated with stone persistence after a treatment cycle. Results: There were 44 patients who underwent 59 treatment cycles consisting of 118 pancreatic SWL procedures. Forty-two cycles (71.2%) were staged, and 17 (28.8%) were not staged. The median size of the largest pancreatic stone was 9 mm [IQR 6-11] and was impacted in 38 cases (64.4%). Patients reported pain in 51 cases (86.4%), of which 28 required the use of opioid analgesics. Patients were rendered stone free in 38 cycles (64.4%). Pain improvement was noted in 39 cases (66.1%), and the reduction in opioid use was statistically significant (28 cases vs. 10 cases, P = 0.004). Impacted stones were associated with an increased odds of stone persistence (OR 7.04, 95% CI 1.14-43.43, P = 0.04). Conclusions: In this joint venture with gastroenterology, we demonstrate that urologist-directed SWL for pancreatolithiasis is safe, effective, and in line with published rates.

Introduction: We sought to examine the practice patterns of pain management in the emergency room (ER) for renal colic and the impact of opioid prescriptions on return ER visits and persistent opioid use. Methods: TriNetX is a collaborative research enterprise that collects real-time data from multiple health care organizations within the United States. The Research Network obtains data from electronic medical records and the Diamond Network provides claims data. We queried the Research Network for adults who visited the ER for urolithiasis, stratified by receipt of oral opioid prescriptions, to calculate the risk ratio (RR) of patients returning to the ER within 14 days and persistent opioid use ≥6 months from the initial visit. Propensity score matching was performed to control for confounders. The analysis was repeated in the Diamond Network as a validation cohort. Results: There were 255,447 patients in the research network who visited the ER for urolithiasis, of whom 75,405 (29.5%) were prescribed oral opioids. Black patients were less likely to receive opioid prescriptions than other races ( p  < 0.001). After propensity score matching, patients who were prescribed opioids had an increased risk of a return ER visit (RR 1.25, confidence interval [95% CI] 1.22-1.29, p  < 0.001) and persistent opioid use (RR 1.12, 95% CI 1.11-1.14, p  < 0.001) compared with patients who were not prescribed opioids. These findings were confirmed in the validation cohort. Conclusions: A significant proportion of patients presenting to the ER for urolithiasis receive opioid prescriptions, which carries a markedly increased risk of return ER visits and long-term opioid use.

Introduction: Patients who form kidney stones are typically advised to limit intake of nondairy animal protein. Plant-based meat products may be a processed substitute protein source for these patients and have recently gained popularity because of health concerns, increased retail availability, decreased environmental impact, and meat supply shortages during the COVID-19 pandemic. Despite these perceived benefits and tangential association with whole food plant-based diets, the potential lithogenic risks associated with these products are not well characterized. Methods: The U.S. Department of Agriculture database was queried with a sample of plant-based meat products widely available to U.S. consumers. Nutrient profile data were compiled and compared with animal protein data using standardized serving sizes. Primary protein sources were identified using verified ingredient lists. Oxalate content was extrapolated based on dietary data sources. Results: A total 47 plant-based meat products (16 beef, 11 pork, 10 chicken, and 10 seafood) were analyzed. Compared with their respective animal protein, most products contained on average fewer calories (plant-based beef 77%, pork 94%, chicken 86%, and seafood 83%) and less protein (plant-based beef 68%, pork 96%, chicken 53%, and seafood 54%). Most products used soy protein as the primary protein source (55%). Soy-based beef contained the highest average oxalate content (18 mg per serving), whereas soy-based seafood contained the lowest (7 mg). The most common non-soy protein source was pea protein (30%), containing trace amounts of oxalate. Sodium content was higher in most plant-based products overall (72%) and in each category (plant-based beef 109%, pork 128%, chicken 100%, and seafood 148%). Calcium content was higher (plant-based beef 317%, pork 144%, chicken 291%, and seafood 295%) compared with animal protein. Conclusions: Most plant-based meat products consist of protein sources that are, relative to animal protein sources, higher in oxalate, sodium, and calcium. Stone-forming patients should be counseled about the potential lithogenic risk of these processed products.

Background: Higher temperatures have been associated with increased stone formation and subsequent utilization of hospital resources, including inpatient admission. However, these observations have been derived from the adult population. We sought to examine if this purported association extends to the pediatric population. Methods: We used the 2016 Kids' Inpatient Database to identify nationwide pediatric inpatient admissions related to nephrolithiasis. Temperature data from the National Oceanic and Atmospheric Administration was linked to each admission. Comparative statistics analyzed patient and admission characteristics. Multivariable logistic regression analyzed associations between stone-related admissions and temperature. As a frame of reference, this analysis was replicated using the National Inpatient Sample from 2016 to evaluate associations in the adult population. Results: Of the 2,496,257 pediatric admissions, 8453 (0.33%) were related to nephrolithiasis. Temperatures at the time of stone admission were higher than those during nonstone admission (55.9°F vs 54.8°F, p  < 0.001). The stone admission group had a higher proportion of females than the nonstone admission group (64.8% vs 55.4%, p  < 0.001). Stone admission was significantly associated with temperature (odds ratio [OR] 1.025 per 10°F, confidence interval [95% CI] 1.003-1.049, p  = 0.03) and female gender (OR 1.097, 95% CI 1.027-1.171, p  = 0.006). In the adult population, 380,520 out of 30,000,941 patients (1.3%) were admitted with a stone. The effect of temperature on stone admissions was similar to that in the pediatric population (OR 1.020, 95% CI 1.014-1.026, p  < 0.001), but women were >20% less likely to be admitted for stones than men (OR 0.770, 95% CI 0.757-0.784, p  < 0.001). Conclusions: Increased temperatures were associated with an increased risk of stone-related admission in both the pediatric and adult populations. Females were at increased risk for stone-related admissions during childhood, but this trend reverses in adulthood.

Purpose: Retrograde intrarenal surgery (RIRS) requires urologists to adopt an awkward body posture for long durations. Few urologists receive training in ergonomics despite the availability of ergonomic best practices utilized by other surgical specialties. We characterize ergonomic practice patterns and rates of musculoskeletal (MSK) pain among urologists performing RIRS. Methods: A web-based survey was distributed through the Endourological Society, the European Association of Urology, and social media. Surgeon anthropometrics and ergonomic factors were compared with ergonomic best practices. Pain was assessed with the Nordic Musculoskeletal Questionnaire (NMQ). Results: Overall, 519 of 526 participants completed the survey (99% completion rate). Ninety-three percent of urologists consider ergonomic factors when performing RIRS to reduce fatigue (68%), increase performance (64%), improve efficiency (59%), and reduce pain (49%). Only 16% received training in ergonomics. Residents/fellows had significantly lower confidence in ergonomic techniques compared with attending surgeons with any career length. Adherence to proper ergonomic positioning for modifiable factors was highly variable. On the NMQ, 12-month rates of RIRS-associated pain in ≥1 body part, pain limiting activities of daily living (ADLs), and pain requiring medical evaluation were 81%, 51%, and 29%, respectively. Annual case volume >150 cases (odds ratio [OR] 0.55 [0.35-0.87]) and higher adherence to proper ergonomic techniques (OR 0.67 [0.46-0.97]) were independently associated with lower odds of pain. Limitations include a predominantly male cohort, which hindered the ability to assess gender disparities in pain and ergonomic preferences. Conclusions: Adherence to ergonomic best practices during RIRS is variable and may explain high rates of MSK pain among urologists. These results underscore the importance of utilizing proper ergonomic techniques and may serve as a framework for establishing ergonomic guidelines for RIRS.

Introduction: Multimodal analgesic regimens incorporating peripheral nerve blocks (PNBs) have demonstrated reduced postoperative pain, opioid use, and recovery time in various disease states. However, this remains a subject of limited investigation in the percutaneous nephrolithotomy (PCNL) domain. In the face of an ongoing opioid epidemic and collective push to enhance prescribing stewardship, we sought to examine the potential opioid-sparing effect of PNBs in PCNL. Methods: A systematic review of Embase and PubMed was performed to identify all randomized controlled trials evaluating the use of a PNB with general anesthesia (GA) vs GA alone for pain control following PCNL. Studies evaluating neuraxial (epidural and spinal) anesthesia and those without GA as the control arm were excluded. Results: Seventeen trials evaluating 1,012 procedures were included. Five different blocks were identified and evaluated: paravertebral ( n  = 8), intercostal nerve ( n  = 3), quadratus lumborum ( n  = 2), transversus abdominis plane ( n  = 1), and erector spinae ( n  = 3). Nine of 16 (56%) studies observed lower pain scores with PNB use throughout the 24-hour postop period. By comparison, improved pain scores with PNBs were limited to the early (<6 hours) recovery period in five studies and two found no difference. Total analgesic and opioid requirements were significantly higher in the GA control arm in nearly all studies (12/14, 86%). Operative times were similar and there were no differences in rates of intercostal access or nephrostomy tube insertion between study arms in any trial. Conclusions: While greater analgesic use with GA alone likely minimizes or obscures differences in patient-reported pain scores, PNBs may offer a significant opioid-sparing analgesic effect during postoperative recovery after PCNL.

Introduction: Procedure-specific guidelines for postsurgical opioid use can decrease overprescribing and facilitate opioid stewardship. Initial recommendations were based on feasibility data from limited pilot studies. This study aims to refine opioid prescribing recommendations for endourological and minimally invasive urological procedures by integrating emerging clinical evidence with a panel consensus. Materials and Methods: A multistakeholder panel was convened with broad subspecialty expertise. Primary literature on opioid prescribing after 16 urological procedures was systematically assessed. Using a modified Delphi technique, the panel reviewed and revised procedure-specific recommendations and opioid stewardship strategies based on additional evidence. All recommendations were developed for opioid-naive adult patients after uncomplicated procedures. Results: Seven relevant studies on postsurgical opioid prescribing were identified: four studies on ureteroscopy, two studies on robotic prostatectomy including a combined study on robotic nephrectomy, and one study on transurethral prostate surgery. The panel affirmed prescribing ranges to allow tailoring quantities to anticipated need. The panel noted that zero opioid tablets would be potentially appropriate for all procedures. Following evidence review, the panel reduced the maximum recommended quantities for 11 of the 16 procedures; the other 5 procedures were unchanged. Opioids were no longer recommended following diagnostic endoscopy and transurethral resection procedures. Finally, data on prescribing decisions supported expanded stewardship strategies for first-time prescribing and ongoing quality improvement. Conclusion: Reductions in initial opioid prescribing recommendations are supported by evidence for most endourological and minimally invasive urological procedures. Shared decision-making before prescribing and periodic reevaluation of individual prescribing patterns are strongly recommended to strengthen opioid stewardship.

Objective: The aim of this study was to comprehensively evaluate the quality of patient-oriented, mobile health applications (apps) available for medical management of kidney stone disease (KSD). Materials and Methods: A systematic search was performed to identify apps from the Apple and Google Play app stores. Eligible apps were divided into two categories: (1) fluid apps and (2) dietary apps. Descriptive characteristics were summarized and app quality was independently evaluated on the basis of technical quality, usability, clinical value, and privacy/security. The validated Mobile App Rating Scale (MARS) was the backbone for the evaluation framework. Results: In total, 31 apps (18 fluid apps and 13 dietary apps) were included. Fluid apps outscore dietary apps in all dimensions of MARS quality. All but one fluid app exceeded the minimum acceptable MARS score of 3.0 vs 46% of dietary management apps. Dietary apps feature less functionality and most are limited to noninteractive informational content. While most data-capturing apps provide a privacy policy and ensure that security measures are taken to protect user identity, only 36% offer users choice or consent for secondary use of their data after data have already been collected. Overall, only one app has undergone any form of real-world clinical investigation. Conclusions: Fluid management apps outperform dietary apps in technical quality, usability, and clinical value at the cost of greater privacy/security risks. Despite not being targeted to patients with KSD, they are higher in most quality measures and offer greater functionality to support long-term disease management compared with dietary apps.

Introduction: Accurate estimation of stone fragment size during ureteroscopic lithotripsy procedures facilitates operative efficiency and predicts the safety of fragment extraction or spontaneous passage. Using a novel stone measurement software application, this study assesses the feasibility of performing integrated real-time digital stone measurement during ureteroscopy. Methods: This workflow feasibility study was conducted in two phases. First, in the ex vivo simulation, mock stone fragments were placed in a renal collecting system training model. A basket extraction task was performed using a digital ureteroscope, with and without digital stone measurement. The time required to perform the tasks was recorded and compared. Second, in the in vivo workflow trial, adult patients undergoing ureteroscopic stone procedures were prospectively enrolled. Intraoperative measurements of stone fragments were performed to determine the time required to complete the measurements. Technical failures and perioperative complications were recorded. Results: In the ex vivo simulation, 20 mock stones mimicking varied fragmentation conditions were tested in the training model. The mean completion time of the basketing task without vs with digital stone measurement was 16.5 seconds (range 10.2-33.7) vs 38.9 seconds (range 27.2-60.0). Mean additional time required to measure stones was 22.3 seconds (range 8.4-42.7). In the in vivo workflow trial, nine patients undergoing ureteroscopy were enrolled. A median of five fragments (range 3-10) were measured in each patient. Mean completion time for each measurement was 10.1 seconds (range 8.2-12.8). Mean total time required to perform digital measurement per procedure was 50.8 seconds (range 25.9-99.0). No technical failures or clinical complications were observed. Conclusions: Integrating real-time digital stone measurement during ureteroscopy is safe and feasible. The findings support clinical trials of digital stone measurement to enhance intraoperative decision-making during ureteroscopy.

Introduction: Numerous dietary supplements claiming to treat or prevent kidney stones have recently been brought to the market. However, the evidence for these claims is not clear. This study assesses the scientific evidence supporting dietary supplements for the treatment and prevention of urinary stone disease. Materials and Methods: Two online marketplaces (Amazon and Google) were queried for dietary supplements available without a prescription to treat, alleviate, or prevent stone disease. Product labels were reviewed to compile stone-related claims and active ingredients. The 30-day cost of treatment and consumer star rating were assessed. MEDLINE, Web of Science, and Google Scholar were queried with labeled ingredients to assess the scientific evidence from published and lay sources. Results: A total of 27 dietary supplements containing 56 ingredients were analyzed. Supplements made a variety of claims, including dissolving stones (12 products, 44%), preventing stone formation (7 products, 26%), and reducing stone symptoms (6 products, 22%). Mean 30-day cost was $32 (range $4-$189). All products were rated highly by consumers (mean 4.2 of 5 stars). Of the 56 ingredients, 9 (16%) had any published studies for use in stone disease, and 5 (9%) had exclusively studies supporting their use. Eighteen scientific publications about the ingredients were identified, of which six showed mixed or no benefit in stone disease. Overall, 18 (67%) supplements contained ingredients with conflicting or absent evidence of benefit. No association was found between product cost or rating and products containing ingredients supported by human or animal studies ( p  > 0.05). Conclusions: Two-thirds of dietary supplements claiming to treat or prevent kidney stones contain ingredients with conflicting or no scientific evidence to support their claims. Clinicians should counsel stone formers that the effects of most supplements are unknown or unstudied in humans, and that the absence of evidence does not imply absence of potential harm.

Objective: In recent years, there has been increasing interest in the use of ultrasound guidance for endoscopic and percutaneous procedures. Kidney mockups could be used for training, however, available mockups are normally incompatible with ultrasound imaging. We developed a reproducible method to manufacture an ultrasound-compatible collecting system mockup that can be made at urology laboratories. Methods: Positive and negative molding methods were used. A three-dimensional (3D) digital model of a urinary collecting system and the overlying skin surface were segmented from computed tomography. A containment mold (negative) was made following the shape of the skin surface using 3D printing. A collecting system mold (positive) was also 3D printed, but made of a dissolvable material. The containment mold was filled with a gelatin formula with the collecting system mold submersed in situ within. After the gelatin solidified, a solution was used to dissolve the collecting system mold, but not the gelatin, leaving a cavity with the shape of the collecting system. The gelatin was extracted from the container mockup and the collecting system cavity was filled with water. The mockup was imaged with ultrasound to assess echogenicity and suitability for simulating ultrasound-guided procedures. Results: A clear shape corresponding to the collecting system was observed inside the gel structure. Structural integrity was maintained with no observable manufacturing marks or separation seams. Ultrasound images of the mockup demonstrated clear differentiation at the gelatin/water interface. A mock stone was placed in the collecting system and needle targeted to simulate percutaneous needle access. Conclusion: We developed a simple method to manufacture a personalized mockup of the renal collecting system of a patient that can be used for ultrasound-guided percutaneous needle access. Generic collecting system mockups can be used for training, and patient-specific models can be used to simulate and decide the best access path before a clinical case.

Introduction: The surgical management of nephrolithiasis can be challenging due to multiple appropriate and feasible approaches. One advantage of urologists' increasing social media use is the opportunity for crowdsourcing or aggregating feedback from remote participants. This study assesses the purposes and extent of online crowdsourcing by urologists for surgical stone disease. Methods: Twitter was queried with 22 stone-related keywords during a 60-day study period. All public posts were reviewed to identify crowdsourcing requests by urologists seeking clinical advice or feedback about surgical stone management. Content analysis of the crowdsourcing posts was performed by two reviewers to assess the purposes of and responses to the requests. Results: A total of 399 posts linked to 29 crowdsourcing requests were analyzed. Crowdsourcing requests were answered rapidly; the median time from initial post to final reply by participants was 2 days. In the majority of requests, the author of the initial request posted a follow-up question or clarification, underscoring a bidirectional exchange of ideas. Most crowdsourcing engaged an international audience; requests originated from 27 urologists in 12 countries, and all but one of the 29 requests (97%) received replies from users outside the origin country. Four purposes for crowdsourcing were observed: patient-specific surgical planning (206 posts, 52%); colleagues' experiences with a device or technique (86 posts, 22%); general advice about stone-related concerns (57 posts, 14%); and solutions to complications or quality improvement challenges (50 posts, 12%). Finally, protection of patient privacy appeared to be a concern; among the 17 (59%) crowdsourcing requests that were about individual patients or cases, all included patient-specific images or radiography, but none noted whether patient permission had been obtained. Conclusions: Social media crowdsourcing facilitates a range of general, patient-specific, and quality improvement challenges in surgical stone management. Participants should consider privacy concerns when publicly sharing imaging or patient data.

Introduction: CT is the gold standard for visualizing renal and ureteral calculi. CT three-dimensional reformatting allows for automatic, accurate, and reliable measurement of stone size, volume, density, and location. In this study, we aimed to develop and test a software platform capable of calculating a battery of clinically important urinary stone parameters at the point-of-care (POC)., Methods: The syngo Calcium Scoring (Siemens Corporation) algorithm was modified to identify calcium-based stones using an attenuation threshold (250 HU) within a region of interest. Information automatically obtained after reconstruction included voxel sum and calculated volume, maximum diameter, largest diameter in the x, y, and z planes, cumulative diameter, distribution of attenuation in HU, and position relative to the skin for calculation of the skin-to-stone distance (SSD). This algorithm was packaged into a stand-alone application (MATLAB 9.1). From April 2017 to May 2017, all patients undergoing a noncontrast CT of the abdomen or the abdomen and pelvis at the Johns Hopkins Hospital were eligible for inclusion in this validation cohort., Results: A total of 55 index renal stones were included. The mean volume calculated by voxel sum was 216.53 mm 3 (standard deviation [SD] ±616.19, range 1.50-4060.13). The mean volume calculated using the Ackermann's formula and for a sphere was 232.96 mm 3 (SD ± 702.65, range 1.24-4074.04) and 1214.63 mm 3 (SD ± 4233.41, range 1.77-25,246.40), respectively. The mean largest diameter in any one direction was 6.95 mm (SD ± 7.31, range 1.50-36.40). The maximum density of the stones ranged from 164 to 1725 HU. The mean SSD at the shortest possible point was 14.19 cm (SD ± 6.13, range 6.67-31.28)., Conclusions: We developed a stand-alone platform with a simple easy-to-use interface, which will allow any user the ability to calculate a battery of clinically important urinary stone parameters from CT imaging at the POC. This program is now freely available online.

Introduction: Currently, stone size cannot be accurately measured while performing flexible ureteroscopy (URS). We developed novel software for ureteroscopic, stone size measurement, and then evaluated its performance., Methods: A novel application capable of measuring stone fragment size, based on the known distance of the basket tip in the ureteroscope's visual field, was designed and calibrated in a laboratory setting. Complete URS procedures were recorded and 30 stone fragments were extracted and measured using digital calipers. The novel software program was applied to the recorded URS footage to obtain ureteroscope-derived stone size measurements. These ureteroscope-derived measurements were then compared with the actual-measured fragment size., Results: The median longitudinal and transversal errors were 0.14 mm (95% confidence interval [CI] 0.1, 0.18) and 0.09 mm (95% CI 0.02, 0.15), respectively. The overall software accuracy and precision were 0.17 and 0.15 mm, respectively. The longitudinal and transversal measurements obtained by the software and digital calipers were highly correlated (r = 0.97 and 0.93). Neither stone size nor stone type was correlated with error measurements., Conclusions: This novel method and software reliably measured stone fragment size during URS. The software ultimately has the potential to make URS safer and more efficient.

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.

Introduction: To date, the ergonomics of flexible ureteroscopy (URS) have not been well described. We performed a study to assess the biomechanical stresses on urologists performing URS and to investigate the effect of ureteroscope type on these parameters., Methods: Electromyography (EMG) was used to quantify the activation level of muscle groups involved in URS. Surface EMG electrodes (Delsys, Boston, MA) were placed on the right and left thenar, flexor carpi ulnaris (FCU), extensor carpi ulnaris (ECU), biceps, triceps, and deltoid. Three endoscopes were studied: single-use digital (Boston Scientific LithoVue), reusable digital (Karl Storz Flex-X c ), and reusable fiber-optic (Karl Storz Flex-X 2 ). Each ureteroscope was used to perform a set sequence of navigation and procedural tasks in a training model. EMG data were processed and normalized to compare the maximum voluntary contractions between muscle groups. Cumulative muscular workload (CMW) and average muscular work per second (AWS) were used for comparative analysis., Results: For navigational tasks, CMW and AWS were greatest for the ECU, followed in descending order by right and left thenar, FCU, biceps, deltoid, and triceps. For procedural tasks, CMW and AWS were greatest for the right thenar, followed in descending order by the left thenar, ECU, FCU, triceps, biceps, and deltoid. During navigational tasks, both LithoVue and Flex-X c had lower CMWs for every muscle group than Flex-X 2 (p < 0.05). LithoVue and Flex-X c had similar AWS and both were lower than Flex-X 2 for the right thenar, ECU, biceps, and deltoid activation (p < 0.05). During procedural tasks, both LithoVue and Flex-X c had lower CMWs and AWS for right and left thenar, ECU, and biceps than Flex-X 2 (p < 0.05)., Conclusions: This study provides the first description of EMG-measured ergonomics of URS. Both the single-use and reusable digital ureteroscopes have similar profiles, and both have significantly better ergonomic metrics than the reusable fiber-optic ureteroscope.

Introduction: The forgotten ureteral stent (FUS) can lead to patient morbidity. To date, tracking ureteral stents is a cumbersome task, given their high frequency of insertion and variable indwelling times. To simplify this process, an application was developed to track patients with indwelling ureteral stents. We report our initial user experience and clinical outcomes with this application., Methods: Ureteral Stent Tracker™ (UST) is a secure, Health Insurance Portability and Accountability Act (HIPPA)-compliant, cloud-based point-of-care application. It is designed for logging stent insertion, scheduling the date of anticipated stent extraction, and confirming stent removal. It is accessible via a mobile phone application or web browser interface. We consecutively enrolled all patients who underwent ureteral stent insertion for any indication by two urologists from January 10, 2015, to October 10, 2016. A retrospective chart review was performed of all patients included in the UST database. Data extracted included patient demographics, diagnosis, procedure, and stent characteristics., Results: A total of 115 patients were included with a mean age of 52.4 years; 54% (62/115) were male and 58% (67/115) were Caucasian. This cohort represented 146 ureteral stent care plans with 23 patients (23/115; 20%) having more than one care plan during the study period. The most common procedure performed was ureteroscopy (70/146; 48%) for a diagnosis of nephrolithiasis (108/146; 74%). The median indwelling ureteral stent time was 14 days (interquartile range: 7-45 days). A total of three patients (3/115; 3%) did not return for their scheduled extraction, but were identified only through the application. Each patient was contacted, resulting in effective removal of all three stents in the office., Conclusions: Tracking of ureteral stents is critical to prevent the patient safety issue of the FUS. The UST is a secure, HIPPA-compliant, cloud-based application, which once incorporated into the workflow of a urologic practice can prevent the FUS.

Background and Purpose: Ureteroscopy (URS) is a common treatment for patients with stone disease. One of the disadvantages of this approach is the great capital expense associated with the purchase and repair of endoscopic equipment. In some cases, these costs can outpace revenues and lead to an unprofitable and unsustainable enterprise. We sought to characterize the profitability of our URS program when accounting for endoscope maintenance and repair costs., Materials and Methods: We identified all URS cases performed at a single hospital during fiscal year 2013 (FY2013). Charges, collection rates, and fixed and variable costs including annual equipment repair costs were obtained. The net margin and break-even point of URS were derived on a per-case basis., Results: For 190 cases performed in FY2013, total endoscope repair costs totaled $115,000, resulting in an average repair cost of $605 per case. The vast majority of cases (94.2%) were conducted in the outpatient setting, which generated a net margin of $659 per case, while inpatient cases yielded a net loss of $455. URS was ultimately associated with a net positive margin approaching $600 per case. On break-even analysis, URS remained profitable until repair costs reached $1200 per case., Conclusions: Based on these findings, an established URS program can sustain profitability even with large equipment repair costs. Nonetheless, our findings serve to emphasize the importance of controlling costs, particularly in the current setting of decreasing reimbursement. A multifaceted approach, based on improving endoscope durability and exploring digital and disposable platforms, will be critical in maintaining the sustainability of URS.

Background and Purpose: Percutaneous nephrolithotomy (PCNL) is the treatment of choice for patients with complex stone burdens. We performed a study to assess the effect of urologist-specific parameters on the use of PCNL-both the access component of the procedure as well as the stone removal. We also examined trends in PCNL utilization over time., Methods: We analyzed self-reported 6-month case logs submitted to The American Board of Urology (ABU) for urologists who certified or recertified between 2004 and 2013. Surgeons performing PCNL were identified by Current Procedural Terminology coding. Urologist-specific data, including fellowship training, practice type, and practice population, were used to further stratify this cohort. Trends were examined over the study period., Results: A total of 7278 urologists submitted case logs to the ABU between 2004 and 2013. The median ages of the initial certification group, first recertification group, and second recertification group were 36.0, 43.7, and 53 years, respectively. A greater proportion of newly certified urologists performed PCNL (53%) compared with urologists in the first (41%) and second (29%) recertification groups; initially certified urologists were also more likely to be high volume (>10) PCNL surgeons. Urologists with fellowship training were more likely to use PCNL (66%) and be high-volume surgeons (26.4%). PCNL utilization increased significantly during the study period, with 1330 procedures performed in 2004 and 2888 procedures performed in 2012 (117% increase)., Conclusions: Younger and fellowship-trained urologists are the primary users of PCNL; the majority of senior urologists do not perform this operation. Overall, the use of PCNL and urologist-directed access has increased in the previous decade.

Purpose: Encrusted ureteral stents are a challenging endourologic problem. We performed a multi-institutional review of percutaneous nephrolithotomy (PCNL) as primary treatment for encrusted stents., Materials and Methods: We identified 36 patients who underwent PCNL for treatment of an encrusted stent. A retrospective review was performed to compile details of procedures and outcomes for these patients., Results: In 36 patients, 38 renal units underwent PCNL for encrusted ureteral stents. The mean patient age was 47.1 years (±16.7), and the female:male ratio was 15:21. Mean stent indwelling time before removal was 28.2 months (±27.8). The reason for long indwelling time was reported in 25 cases; these reasons included "patient unaware stent needed to be removed" (17 cases), pregnancy (2 cases), other comorbidities (3 cases), and patient incarceration (3 cases). In 3 cases, the stent had become encrusted within 3 months of placement. Mean operative time was 162 minutes (±71). There were no major intraoperative complications, and no patients required blood transfusion. Litholapaxy was required for bladder coil encrustations in 22 cases (58%), and ureteroscopy with lithotripsy was required for encrustation of the ureteral portion of the stent in 13 cases (34.2%). Second look percutaneous procedures were required in 13 cases (34.2%). The stent was removed at the time of PCNL without need for concomitant or delayed ureteroscopy and/or cystolitholapaxy in 8 cases (21%). Ultimately, all stents were removed successfully. Patients were rendered stone free according to radiographs in 24 cases (63%)., Conclusions: In this multicenter review, PCNL is confirmed to be a safe and effective means of addressing the retained and encrusted ureteral stent. PCNL without ureteroscopy or litholapaxy was sufficient in a minority of cases (21%). Adjunctive endourologic modalities are often required, and the surgeon should anticipate the need for concomitant antegrade ureteroscopic laser lithotripsy and/or cystolitholapaxy. Although complete stent removal can be anticipated, residual fragments are not uncommon.

Purpose: We conducted this study to identify differences in the re-treatment rates and ancillary procedures for the two most commonly utilized stone treatment procedures in the Medicare population: ureteroscopy (URS) and shock wave lithotripsy (SWL)., Materials and Methods: A retrospective claims analysis of the Medicare standard analytical file 5% sample was conducted to identify patients with a new diagnosis of urolithiasis undergoing treatment with URS or SWL from 2009-2010. Outcomes evaluated: (1) repeat stone removal procedures within 120 days post index procedure, (2) stent placement procedures on the index date, 30 days prior to and 120 days post index date, and (3) use of general anesthesia., Results: We identified 3885 eligible patients, of which 2165 (56%) underwent SWL and 1720 (44%) underwent URS. Overall, SWL patients were 1.73 times more likely to undergo at least one repeat procedure than URS patients, and twice as likely to require multiple re-treatments compared to URS. Among those with ureteral stones, SWL patients were 2.27 times more likely to undergo repeat procedures. The difference was not statistically significant in renal stone patients. Overall, SWL patients were 1.41 times more likely than URS patients to have a stent placed prior to index procedure, and 1.33 times more likely to have a stent placed subsequent to the index procedure. The majority of URS patients (77.8%) had a stent placed at the time of index procedure. There was no significant difference in anesthetic approaches between SWL and URS., Conclusions: Patients undergoing SWL are significantly more likely to require re-treatments than URS patients. SWL patients are also significantly more likely to require ureteral stent placement as a separate event. SWL and URS patients have similar rates of general anesthesia.

Objective: Surgical treatment of kidney stones in an obese patient (body mass index [BMI] >30 kg/m(2)) remains challenging as shockwave lithotripsy may not be an option due to weight limitations. We sought to determine the effectiveness of ureteroscopic laser lithotripsy in obese patients compared to nonobese controls., Materials and Methods: Patients from 2004 to 2007 were retrospectively analyzed providing a group of 292 patients (163 obese, 76 overweight, 53 normal) who underwent ureteroscopic procedures for urolithiasis at four centers in the United States and Canada., Results: The percentage of obese patients requiring flexible ureteroscopy (URS) (79%) was higher than in the other groups (P<0.0001). Flexible URS was associated with a lower stone-free rate (SFR) on multivariate analysis (P=0.034). There was no difference in SFRs of patients who required a ureteral access sheath, basket extraction, or received a postoperative stent. Complication rates did not differ between groups., Conclusion: SFRs using ureteroscopic lithotripsy in obese and overweight populations are the same as in the normal weight patients. A flexible ureteroscope was associated with a decreased SFR, but this likely due to a more proximal stone location in these patients. Ureteroscopic laser lithotripsy is an effective and safe technique to treat urolithiasis in the overweight/obese patient.

Background and Purpose: Our present understanding of the effect of robotic surgery and surgical volume on the cost of radical prostatectomy (RP) is limited. Given the increasing pressures placed on healthcare resource utilization, such determinations of healthcare value are becoming increasingly important. Therefore, we performed a study to define the effect of robotic technology and surgical volume on the cost of RP., Methods: The state of Maryland mandates that all acute-care hospitals report encounter-level and hospital discharge data to the Health Service Cost Review Commission (HSCRC). The HSCRC was queried for men undergoing RP between 2008 and 2011 (the period during which robot-assisted laparoscopic radical prostatectomy [RALRP] was coded separately). High-volume hospitals were defined as >60 cases per year, and high-volume surgeons were defined as >40 cases per year. Multivariate regression analysis was performed to evaluate whether robotic technique and high surgical volume impacted the cost of RP., Results: There were 1499 patients who underwent RALRP and 2565 who underwent radical retropubic prostatectomy (RRP) during the study period. The total cost for RALRP was higher than for RRP ($14,000 vs 10,100; P<0.001) based primarily on operating room charges and supply charges. Multivariate regression demonstrated that RALRP was associated with a significantly higher cost (β coeff 4.1; P<0.001), even within high-volume hospitals (β coeff 3.3; P<0.001). High-volume surgeons and high-volume hospitals, however, were associated with a significantly lower cost for RP overall. High surgeon volume was associated with lower cost for RALRP and RRP, while high institutional volume was associated with lower cost for RALRP only., Conclusions: High surgical volume was associated with lower cost of RP. Even at high surgical volume, however, the cost of RALRP still exceeded that of RRP. As robotic surgery has come to dominate the healthcare marketplace, strategies to increase the role of high-volume providers may be needed to improve the cost-effectiveness of prostate cancer surgical therapy.

Background and Purpose: The optimal management of renal and ureteral calculi in transplanted kidneys is not well defined. Although larger (>1.5 cm) stone burdens are generally treated with percutaneous nephrolithotomy (PCNL), smaller stones may be reasonably approached with retrograde or antegrade ureteroscopy (URS). We report our multicenter experience with URS for transplant lithiasis., Patients and Methods: URS performed for stone disease within a transplanted kidney were retrospectively identified at three stone-referral centers between 2006 and 2011. Demographic and disease parameters were recorded, as were perioperative and postoperative details., Results: Twelve patients underwent URS for a calculus in a transplant renal unit and/or ureter. For retrograde procedures (7), access to the ureteral orifice was facilitated by the use of a Kumpe catheter; a two-wire (safety and working guidewire) technique was used. For antegrade procedures (5), the ureteroscope was passed into the kidney using a two-wire technique without tract dilation. All stones but one necessitated holmium:yttrium-aluminum-garnet laser lithotripsy with extraction of stone fragments. All patients were stone free on postoperative imaging except for one patient with a 2-mm fragment that was observed. Stone analysis included calcium oxalate (6), calcium phosphate (4), and struvite (1)., Conclusion: Antegrade and retrograde URS are safe and effective treatments for patients with simple stone burdens in a transplanted kidney. Although retrograde access to the ureter can be challenging, specialized techniques and modern endoscope technology facilitate this process. Antegrade URS for small stone burdens can be performed safely and effectively without tract dilation.

Background and Purpose: As surgical technology continues to advance, stone baskets are becoming increasingly miniaturized. We performed a study to define the effect of miniaturized stone baskets on ureteroscope irrigation flow and deflection., Materials and Methods: We compared the three smallest available stone baskets: Boston Scientific 1.3F OptiFlex, Cook 1.5F N-Circle, and Sacred Heart 1.5F Halo, measuring their effect on irrigant flow and deflection of three flexible ureteroscopes., Results: All devices adversely affected irrigation flow and active deflection of all of the ureteroscopes (P<0.05). The 1.3F device, however, exhibited significantly less of an effect on both parameters. Irrigation flow was 28% greater with the 1.3F device than it was for the 1.5F devices. The device's effect on active deflection was 43% less with the 1.3F device than it was for the 1.5F devices., Conclusion: Any device placed through the working channel of a ureteroscope will have a deleterious effect on the ureteroscope's irrigant flow and active deflection. As the caliber of the device decreases, however, its effect on these parameters appears to be reduced. Our present data suggest that the 1.3F basket has significantly less of an effect on both the irrigant flow and deflection of a flexible ureteroscope than do the 1.5F devices.

Aim: Precise targeting is essential for adequate treatment of lesions during image-guided therapy. The aim of this study was to compare the performance of two emerging image-guided targeting technologies in a phantom model., Materials and Methods: A computer-assisted navigation system and AcuBot were tested using three operators: an interventional radiologist and two endourologists. Fiducials were placed in an anatomic gelatin phantom and targeted by both systems. The images were reconstructed and analyzed using a specialized software package (Amira; Visage Imaging, Carlsbad, CA). Accuracy was assessed by measuring proximity of the tip of the needle to the fiducial on computed-tomography-guided imaging. Accuracy and time to target were quantified and compared., Results: The mean distance from the desired target for AcuBot was 1.2 mm (range: 0.39-2.82). The mean distance from the desired target for the navigation system was 5.8 mm (range: 1.8-11.9). The AcuBot was significantly more accurate than the navigation system (p < 0.0001). The mean time from target acquisition to needle placement was 37 seconds (range: 15-75) for the AcuBot and 108 seconds (range: 45-315) for the navigation system (p = 0.001)., Conclusion: Emerging technologies hold promise for increased accuracy during percutaneous targeted procedures. Both the AcuBot and the computer-assisted navigation system were accurate and efficient in a phantom targeting model. AcuBot was significantly more accurate, faster, and less user dependent than the navigation system. Further studies in animal and clinical studies are warranted to further advance this promising technology.

Introduction: Percutaneous nephrolithotomy (PCNL) can involve establishing more than one access into the urinary collecting system. The present study examined whether multiple percutaneous accesses results in a more severe reduction in renal function than that after single-percutaneous access., Methods: Adult female pigs were anesthetized, and percutaneous access to the left urinary collecting system was achieved by puncturing the lower pole calyx (single-tract access, n = 16) or serially puncturing the lower pole, interpolar region, and upper pole calyces [multiple (three)-tract access, n = 11]. Renal function measurements included glomerular filtration rate and effective renal plasma flow, and were taken immediately before and 1.5 and 4.5 hours after percutaneous access. We also examined glomerular function in a group of adult patients with normal preoperative serum creatinine (Cr) levels (

Percutaneous renal surgery is dependent upon appropriate access to the targeted portion of the collecting system. Obtaining a well-positioned nephrostomy tract improves the urologist's ability to both obtain the desired surgical outcome and minimize attendant morbidities. The two primary methods of obtaining fluoroscopic-guided percutaneous renal access-"bull's eye" targeting and triangulation-are reviewed. The authors' preferred techniques are outlined, technical refinements are noted, and recent modifications and future directions are reviewed.

Background and Purpose: Flexible ureteroscopes are fragile devices, and the costs associated with their repair and replacement can be considerable. Although surgical use can degrade ureteroscope function, the cleaning and sterilization process can also cause great damage. We performed a study to define the effect of having the urology nursing staff process and sterilize all ureteroscopes, rather than the central processing core; the total repair cost and cost per use were analyzed., Materials and Methods: From April 2007 to March 2008, all ureteroscopes were processed by the urology nursing staff. We analyzed the average cost per use as a measure of the effectiveness of this strategy. For all endoscopic stone removal cases, a flexible ureteroscope is opened onto the operative field; therefore, after every endoscopic procedure, the flexible ureteroscope needs processing and sterilizing. The number of times each ureteroscope was processed and the type and cost of repairs were recorded., Results: From April 2007 to March 2008, 11 ureteroscopes were processed 478 times; average uses before repair was 28.1. Seven ureteroscopes were returned for repair because of: loss of deflection (2); loss of fiberoptic bundles (2); failed leak test (3). No ureteroscope damage was because of processing. The total repair cost in this 12-month period was $57,664.50. Amortizing repair costs over use gives a value of $120.63 cost per use., Conclusions: Training the urology nursing staff to clean and sterilize ureteroscopes is a reasonable means to reduce processing-related damages.

Background and Purpose: Postoperative hemorrhage is a significant risk after laparoscopic partial nephrectomy (LPN). Hemostatic agents have become increasingly popular as adjuncts to renorrhaphy because of their potential to minimize intracorporeal suturing and lessen warm ischemia time. The objective of our study was to compare the safety and efficacy of an inexpensive, surgeon-prepared hemostatic agent with that of a more expensive, commercially prepared one., Materials and Methods: Between August 2006 and July 2008, 40 LPNs were performed by a single surgeon at two separate institutions. A commercially available gelatin matrix thrombin, FloSeal, was used at one institution (cohort 1, n=19), while a less expensive, surgeon-prepared gelatin hemostatic agent, Gelfoam, was used at a separate institution (cohort 2, n=21) over the same period. Outcomes, including estimated blood loss (EBL), operative time, transfusion rates, and complications, were compared between the two groups., Results: The median operative and warm ischemia times in cohorts 1 and 2 were 150 (range 132-192) and 16 (range 12-29) minutes and 150 (range 120-300) and 20 (range 14-37) minutes, respectively (P = 0.16, 0.07). The median EBL was 150 mL (range 50-250) and 100 mL (range 50-1000) (P = 0.09), and the postoperative transfusion rate was 0% and 4.8% (P = 0.33). Median LOS was 2 (range 2-7) and 3 (range 2-7) days (P = 0.62). Potential cost saved per case was $200 to $450., Conclusion: As health care costs continue to rise, delivering high-quality care in a cost-effective manner is paramount. Our study demonstrates similar safety and efficacy of a surgeon-prepared, cheaper gelatin matrix compared with FloSeal. Generic hemostatic agents are a viable alternative to more expensive agents in institutions in which commercially available agents are not available or cost prohibitive.

Background and Purpose: Percutaneous nephrolithotomy (PNL) is the treatment of choice for patients with large or complex renal calculi. Although injuries to intra-abdominal organs are rare during PNL, splenic injuries have been reported. The management of a splenic injury after PNL is not well defined; therefore, we performed a study to define a management strategy for such an event., Patients and Methods: A retrospective, multi-institutional study was performed to identify all cases of splenic injury that occurred during PNL. All procedures were performed as a single-stage operation, with percutaneous access obtained in the operating room by the urologist. A review of patient records and imaging was conducted to identify treatment strategies and outcomes., Results: Three patients were identified as having undergone a transsplenic PNL. All puncture sites were upper pole, supracostal access of the left kidney. All cases of injury were identified after the procedure, with two stable patients' injuries identified on postoperative CT scan, and a third patient presenting with significant bleeding at removal of the nephrostomy tube. The spleen-preserving, conservative management strategy was successful, because no patients needed exploratory surgery., Conclusion: Splenic injury is a rare complication sustained most commonly during supracostal, upper-pole access to the left renal unit. When patients are hemodynamically stable, this complication can be conservatively managed, with prolonged nephrostomy drainage and observation in a monitored setting before and after nephrostomy tube removal.

Background and Purpose: Large or complex calculi within a horseshoe kidney can present a challenge because many cases are associated with other aberrant anatomy. We performed a study to define the outcome of patients with a horseshoe kidney who were treated with percutaneous nephrolithotomy (PNL)., Patients and Methods: From August 1999 to February 2007, 44 PNLs were performed in 35 patients for calculi within a horseshoe kidney. Mean age was 55.4 years. Parameters evaluated to assess the outcomes of PNL included presenting symptoms, stone burden, location of access, stone-free rate, need for secondary intervention, length of stay (LOS), complication rate, stone analysis, and metabolic data., Results: The average stone burden per kidney was 2.59 cm (range 1-6.2 cm). Single percutaneous access was used in 97.7%. Location of the access tract was upper pole (82.2%), interpolar (13.4%), and lower pole (4.4 %). Flexible nephroscopy was performed in all patients. The stone-free rate after primary PNL was 84.1%. Second-look nephroscopy was performed in five kidneys. Overall stone-free rate was 93.2%. Average LOS was 1.92 days (range 1-4 d). Overall complication rate was 14.3%. Stone analysis revealed predominantly calcium stones, and metabolic abnormalities were demonstrated in all patients with 24-hour urine studies., Conclusions: PNL is the treatment of choice for large and/or complex stones. The presence of a horseshoe kidney does not affect the outcome of PNL. Upper pole access is usually preferred, and flexible nephroscopy is essential to maximize stone-free rates. SA and metabolic data support the premise that calculus formation is a metabolic event.

Purpose: Shockwave lithotripsy (SWL) injures renal tissue, and cavitation has been reported to mediate some of these effects. Much of the work characterizing the cavitation injury of SWL has been performed in small animals or in vitro. We describe experiments that promote cavitation during SWL and estimate the spatial distribution of the resulting hemorrhagic lesion in a large-animal (porcine) model of clinical lithotripsy., Materials and Methods: The lower pole calix of the left kidney in female farm pigs was targeted for SWL with a Dornier HM3 lithotripter. Intraventricular injections of polystyrene microspheres were made before and at intervals during lithotripsy to blanket systemic circulation with cavitation nuclei. Following SWL, the abdominal viscera were inspected and the kidneys were processed for morphologic analysis., Results: Extensive surface hemorrhage occurred over both the targeted and contralateral kidneys, along with widespread petechial hemorrhage over the spleen, intestines, and peritoneum. The targeted kidneys developed subcapsular hematomas. Histology revealed focal and diffuse damage to the targeted kidneys and vascular rupture in both kidneys with complete necrosis of the walls of intralobular arteries and veins., Conclusions: These results demonstrate the potential for unfocused shockwaves to damage blood vessels outside the focal zone of the lithotripter when the vasculature is seeded with cavitation nuclei. The wide distribution of damage suggests that the acoustic field of a lithotripter delivers negative pressures that exceed the cavitation threshold far off the acoustic axis. The findings underscore that conditions permissive for cavitation can lead to dramatic sequelae during SWL.

Background: Percutaneous nephrolithotomy (PCNL) is performed on a routine basis for the rapid and efficient removal of large caliceal stones. After percutaneous puncture, rigid dilators or an inflatable balloon are used to dilate the nephrostomy tract to allow access to the collecting system for stone removal. Little is known of the acute impact of tract dilation procedures on renal function., Materials and Methods: We compared renal hemodynamic and excretory function in female pigs immediately before and up to 5 hours after percutaneous nephrostomy (PCN) using sequential Amplatz dilators (N = 8) or Nephromax balloon inflation (N = 7) and control pigs with no PCN access (N = 8). We also examined renal function in patients undergoing PCNL., Results: The two PCN procedures produced a renal lesion of comparable size and morphology, as well as similar changes in renal function. Glomerular filtration rate (GFR), renal plasma flow (RPF), and urinary sodium excretion (U(Na)V) were significantly reduced in Amplatz- and Nephromax-treated kidneys throughout the 5-hour observation period, by about 50%, 60%, and 80%, respectively. In control pigs, GFR and RPF remained stable and U(Na)V declined progressively to about 50% of baseline over the course of the experiment. The contralateral kidney showed changes in renal function similar to those in the PCN-treated or control kidney in all three groups. A retrospective analysis of 196 adults with normal renal function who underwent unilateral PCNL using the Nephromax balloon dilator revealed a significant increase in serum creatinine of 0.14 mg/dL at 1 day., Conclusion: Both animal and human studies show that PCN is associated with an acute decline in renal function.

Background: Calculi are commonly found attached to the renal papilla in calcium oxalate (CaOx) stone formers, but the mechanisms by which stones form in this manner are not well established., Materials and Methods: Data are presented from three attached stones collected from different patients. Stone morphology and composition were determined using micro computed tomography (CT) and infrared microspectrometry., Results: One of the stones was composed of CaOx with a peripheral region of apatite, such as might have come from a Randall's plaque. Another stone was covered with large CaOx crystals but contained at least two layers of apatite, with no apatite regions exposed at the surface. The third stone contained CaOx with inclusions of apatite and more apatite on its surface, along with a substantial volume of poorly mineralized material that could not be identified., Conclusions: The complexity of these stones and their differing morphologies do not by themselves allow inference of the mechanism of stone formation. Future work will require the careful documentation of attached stones on the papilla, as well as study of the papilla after the stone has been removed, before it can be determined whether such diverse CaOx stones originate from the same or different underlying etiologies.

Caliceal diverticula harbor calculi in as many as 50% of cases. Such stones rarely pass spontaneously. Various stone-removal techniques have been used, with percutaneous techniques generally having the best results. In patients with nonradiopaque stones or in whom the diverticulum does not opacify when contrast is instilled retrograde or by intravenous urogram, contrast can be instilled directly into the cavity with CT or ultrasound guidance. Three such cases are described, with good results.

Background and Purpose: Holmium laser enucleation of the prostate (HoLEP) is perceived to be technically difficult, time consuming, and inefficient. We assessed the efficiency of HoLEP by documenting the technical features of the procedure at two hospitals located on different continents., Patients and Methods: A retrospective analysis of all patients who underwent HoLEP at the Methodist Hospital of Indiana and Tauranga Hospital in New Zealand was performed. A series of 40 patients from the Indiana cohort were pair-matched, by the weight of prostate tissue retrieved, with 40 patients from the New Zealand cohort. Enucleation time and morcellation time were compared in the two groups., Results: The mean weight of the tissue retrieved from the Indiana cohort was 27.1 g and that from the New Zealand cohort was 22.9 g (P = 0.41). The mean enucleation times were 47.6 minutes and 29.2 minutes, respectively (P < 0.001). The mean morcellation times were 9.9 minutes and 7.7 minutes (P = 0.201). The mean rates of enucleation were 0.58 g/min and 0.71 g/min (P = 0.17). The mean rates of morcellation were 3.4 g/min and 4.3 g/min (P = 0.20). The HoLEP efficiency increased as a function of gland size (R(2) = 0.56)., Conclusions: Holmium laser enucleation of the prostate is a reproducible technique, as there is little variation in efficiency from one surgeon to another. Furthermore, the efficiency of HoLEP increases as prostate size increases, which suggests that HoLEP may be an ideal treatment for men with large prostates.