Prospective, Randomized Comparison of Dual-Lumen vs Single-Lumen Flexible Ureteroscopes in Proximal Ureteral and Renal Stone Management.

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

First reported case of penile epithelial-myoepithelial carcinoma.

Epithelial-myoepithelial carcinoma (EMC) of the penis is a rare malignant tumor which has not previously been described in the literature. Genetic associations exist in EMC that could potentially help guide early diagnosis and treatment of this type of penile cancer. This serves as the first reported case of such cancer of the penis, and highlights the indolent course it takes to presentation, and the need for an appropriate histopathologic evaluation for the correct diagnosis.

Ureteral Access Sheath Deployment: How Much Force Is Too Much? Initial Studies with a Novel Ureteral Access Sheath Force Sensor in the Porcine Ureter.

Introduction and Objectives: Ureteral injuries can occur during ureteral access sheath (UAS) deployment. The force exerted during deployment and the amount of force that results in ureteral injury is yet to be accurately quantitated. In this feasibility study, we developed and then tested a novel force-sensing device in our animal laboratory to identify the threshold force that results in a porcine ureteral injury. Methods: With Institutional Animal Care and Use Committee approval, we measured ureteral dilator and UAS deployment force using our proprietary University of California, Irvine Ureteral Access Sheath Force Sensor (UAS-FS). The exerted force was measured during deployment from the moment that the tip of the UAS was passed into the urethral meatus until it reached the renal pelvis; progression of the UAS along the ureter was monitored with fluoroscopy. Ureteroscopic evaluation was performed after deployment of each catheter/sheath ≥8F to assess for ureteral injury using the Postureteroscopic Lesion Scale (PULS). Results: Six juvenile Yorkshire female pigs (12 ureters) were studied. No injuries were detected when the deployment force was <4 Newtons (N), which was the case when the catheter/access sheath was ≤13F. Increasing UAS size >13F resulted in greater peak forces. In five of the pigs, ureters selected for 14F UAS deployment without previous sequential dilation were injured (PULS ≥3) at a mean threshold force of 4.84 N. Serial dilation had a higher threshold for PULS ≥3 at 5.56 N. Overall, injury of PULS ≥3 was routinely noted when the force applied exceeded 8.1 N. Conclusions: The UAS-FS reliably measured forces while deploying a UAS. Significant ureteral injury can routinely be avoided if the applied force is <4.84 N; PULS ≥3 routinely occurred when forces exceeded 8.1 N. Serial dilation may allow safe passage at higher deployment forces, as much as 5.56 N.

Evaluation of Urology Residency Training and Perceived Resident Abilities in the United States.

OBJECTIVE: To identify differences and potential deficiencies in urology residency training programs in the United States as they are perceived by residents/recent graduates and program directors. MATERIALS AND METHODS: A 45-question and 38-question survey was sent to chief residents/recent graduates and program directors, respectively, at all 120 US urology programs regarding prior medical education, urologic training curricula, and perceived surgical proficiency, among other topics. RESULTS: Survey response rate was 58% and 52% for residents and program directors, respectively. Responses regarding program characteristics (e.g., salary, vacation) and research training were similar between program directors and residents. However, their responses regarding skills training and subspecialty training (e.g., robotics and pediatrics) differed substantially. Program directors reported the availability of advanced skills trainers (robot-88%, laparoscopic-86%), whereas fewer residents felt they were available (robot 54% and laparoscopic 72%). The same discrepancies persisted with questions about subspecialty exposure (e.g., program directors reported 48% renal transplant experience vs. 13% reported by residents). Most residents felt comfortable performing essential urology procedures (e.g., cystoscopy/ureteroscopy, open nephrectomy). In contrast, the majority expressed a lack of confidence in performing unsupervised advanced minimally invasive procedures (e.g., laparoscopic and robotic partial nephrectomy, endopyelotomy). Among the responding residents, 72% pursued fellowship training; nearly two-thirds of these residents chose to enter fellowship in order to overcome perceived training deficiencies. CONCLUSIONS: Program directors and residents have differing perceptions regarding the education and resources associated with US urology residency training programs. US graduates of urology residency programs express a perceived lack of confidence in several procedures that are commonly encountered in a general urologic practice.

Pilot Assessment of Immersive Virtual Reality Renal Models as an Educational and Preoperative Planning Tool for Percutaneous Nephrolithotomy.

BACKGROUND: Percutaneous nephrolithotomy (PCNL) requires the urologist to have detailed knowledge of the stone and its relationship with the renal anatomy. Immersive virtual reality (iVR) provides patient-specific three-dimensional models that might be beneficial in this regard. Our objective is to present the initial experience with iVR in surgeon planning and patient preoperative education for PCNL. MATERIALS AND METHODS: From 2017 to 2018 four surgeons, each of whom had varying expertise in PCNL, used iVR models to acquaint themselves with the renal anatomy before PCNL among 25 patients. iVR renderings were also viewed by patients using the same head-mounted Oculus rift display. Surgeons rated their understanding of the anatomy with CT alone and then after CT+iVR; patients also recorded their experience with iVR. To assess the impact on outcomes, the 25 iVR study patients were compared with 25 retrospective matched-paired non-iVR patients. Student's t-test was used to analyze collected data. RESULTS: iVR improved surgeons' understanding of the optimal calix of entry and the stone's location, size, and orientation (p < 0.01). iVR altered the surgical approach in 10 (40%) cases. Patients strongly agreed that iVR improved their understanding of their stone disease and reduced their preoperative anxiety. In the retrospective matched-paired analysis, the iVR group had a statistically significant decrease in fluoroscopy time and blood loss as well as a trend toward fewer nephrostomy tracts and a higher stone-free rate. CONCLUSIONS: iVR improved urologists' understanding of the renal anatomy and altered the operative approach in 40% of cases. In addition, iVR improved patient comprehension of their surgery. Clinically, iVR had benefits with regard to decreased fluoroscopy time and less blood loss along with a trend toward fewer access tracts and higher stone-free rates.

Pretreatment Diagnosis of the Small Renal Mass: Status of Renal Biopsy in the United States of America.

INTRODUCTION: We surveyed United States of America-based urologists to characterize practice patterns and indications to perform a renal mass biopsy for small renal masses. MATERIALS AND METHODS: Members of the American Urological Association who practice in the United States were invited to participate in a 11-question web-based survey that was distributed via SurveyMonkey® from December 2016 to January 2017. RESULTS: There were 1131 respondents. The respondents equally represented all regions of the United States; the majority were in private practice. Overall, 32% of American urologists would "never" perform a biopsy of a renal mass ≤4 cm. Those who saw fewer than five small renal masses per year were more likely to "never" perform a renal biopsy on either a renal mass ≤4 cm or a renal mass 2-3 cm compared with those who saw more than five small renal masses per year (p < 0.001). Urologists who practiced at an academic hospital were more likely to perform a renal biopsy on both a renal mass ≤4 cm and a renal mass 2-3 cm compared with private practice and government-based urologists (p < 0.001 and p = 0.008 respectively). The primary reason for not performing a biopsy, cited by 68% of responding urologists, was that the results of a biopsy "would not change their management of the renal mass." Respondents independently performed only 2% of biopsies; however, almost half stated that they would be interested in learning office-based ultrasound-guided biopsy of a small renal mass. CONCLUSIONS: Among members of the American Urological Association, biopsy of a small renal mass remains an underutilized diagnostic procedure, especially in light of 6000 unnecessary surgeries annually; nonuniversity-based urologists and those who see <5 renal mass cases each year infrequently perform a biopsy. Currently, interventional radiologists perform almost all small renal mass biopsies.

Procedural Module: Flexible Cystoscopy.

INTRODUCTION: Cystoscopy is a basic urologic skill necessary for the endoscopic evaluation of the urethra and bladder. Presented is a step-by-step guide for flexible cystoscopy of the male and female patient. MATERIALS/METHODS: Routine flexible cystoscopy was performed on a male patient with a history of upper tract urothelial carcinoma and a female patient as part of a hematuria evaluation. The male patient was positioned supine, and the female patient frog-leg supine. Preoperative equipment included a flexible cystoscope (Storz 11272 VP; Karl Storz, Inc., Germany), irrigant, lubricating gel, sterile gloves, and towels/drapes. A typical cystoscopy room layout is shown. RESULTS: This guide outlines the indications, preoperative preparation, and procedural steps for each gender, postoperative care, and troubleshooting recommendations. The video depicts the author's (R.V.C.) typical office cystoscopy procedure. In both cases, the cystoscopies were within normal limits. CONCLUSION: A simple, standardized manner for performing office-based flexible cystoscopy is essential to the practice of all urologists. By following the outlined steps, the urethra and the entire bladder, including the bladder neck area, can be thoroughly evaluated.

Medical impulsive therapy (MIT): the impact of 1 week of preoperative tamsulosin on deployment of 16-French ureteral access sheaths without preoperative ureteral stent placement.

INTRODUCTION AND OBJECTIVES: Medical expulsive therapy is based on pharmacologic ureteral relaxation. We hypothesized this concept may facilitate the deployment of the large 16 French (F) ureteral access sheath (UAS) when patients are intentionally pre-treated with oral tamsulosin, i.e., medical impulsive therapy. METHODS: We retrospectively analyzed our experience with UAS deployment during endoscopic-guided percutaneous nephrolithotomy in prone position in patients pre-treated for 1 week with oral tamsulosin with a contemporary untreated cohort. Between January 2015 and September 2016, seventy-seven patients without a pre-existing ureteral stent met inclusion criteria. Demographic data, tamsulosin usage, UAS size, deployment failure, ureteral injuries, stone-free rates, and complications were recorded. Univariate and multivariate analysis was conducted to assess the impact of tamsulosin on deployment of the 16F UAS. RESULTS: There was no statistical difference between the tamsulosin (n = 40) group and non-tamsulosin (n = 37) group in regard to demographic data. The tamsulosin group had a significantly higher percentage of 16F UAS deployment, 87 vs. 43% (p < 0.001), and no significant difference in ureteral injuries (p = 0.228). Univariate and multivariate analysis revealed that tamsulosin significantly increased the odds ratio (9.3 and 19.4, respectively) for successful passage of a 16F UAS. Despite a larger stone volume, there was no significant difference in computed tomography scan complete stone-free rates (29 vs. 42%; p = 0.277) at median post-operative time of only 3 days. CONCLUSIONS: In this retrospective study, 1 week of preoperative tamsulosin was associated with an increase in the deployment of a 16F UAS in patients without preoperative ureteral stent placement.

Multi-institutional Evaluation of Upper Urinary Tract Biopsy Using Backloaded Cup Biopsy Forceps, a Nitinol Basket, and Standard Cup Biopsy Forceps.

OBJECTIVE: To compare the performance of 3 contemporary ureteroscopic biopsy devices for the histopathologic diagnosis of upper tract urothelial carcinoma (UTUC). METHODS: We retrospectively reviewed 145 patients who underwent 182 urothelial biopsies using 2.4F backloaded cup biopsy forceps, a nitinol basket, or 3F standard cup biopsy forceps at 3 tertiary academic centers between 2011 and 2016. Experienced genitourinary pathologists provided an assessment of each specimen without knowledge of the device used for biopsy. For patients who underwent nephroureterectomy without neoadjuvant chemotherapy within 3 months of biopsy-proven UTUC diagnosis, the biopsy grade was compared with both the grade and stage of the surgical specimen. RESULTS: Biopsy utilization varied among the 3 institutions (P <.0001). Significant variabilities in specimen size (P = .001), the presence of intact urothelium (P = .008), and crush artifact (P = .028) were found among the biopsy devices. The quality of specimens from backloaded cup forceps was rated similarly to the nitinol basket (P >.05) and was favored over standard cup forceps specimens. Grade concordance was not affected by specimen size (P >.05), morphology (P >.1), or location (P >.5). No difference existed among the devices in the rate of acquiring a grade concordant biopsy; however, the backloaded cup forceps provided concordant biopsies that could be distinguished as low- and high-grade (P = .02). CONCLUSION: The backloaded cup forceps and nitinol basket obtained a higher quality urothelial specimen compared with standard cup forceps. Ureteroscopic biopsy device selection did not significantly impact the accuracy of the histologic diagnosis of UTUC.

Three-dimensional evaluation of perirenal fat volume in patients with nephrolithiasis.

The concept of adipose tissue as an organ unto itself represents a new medical construct; already differences in the volume of perirenal fat around a tumor-bearing kidney have been described. We hypothesized that renal calculi may have similar impact on perirenal fat or alternatively abnormalities in urinary metabolites may be the result of perirenal fat affecting renal metabolism and subsequent stone formation. Accordingly, we conducted a study utilizing three-dimensional imaging software to evaluate perirenal fat volume (PFV) in patients with nephrolithiasis. Among 40 patients with a history of unilateral nephrolithiasis who underwent percutaneous nephrolithotomy between 2010 and 2016, the following data were acquired: body mass index, past medical history, stone characteristics and composition (i.e., calcium oxalate, calcium phosphate, uric acid, and struvite calculi). In addition, patients were stratified by dominant stone composition (≥ 50% fraction). Bilateral PFV measurements were obtained using the preoperative computed tomography scan and specialized three-dimensional imaging software. The PFV of stone-bearing kidneys was significantly greater than non-stone-bearing kidneys (397.3 and 323 cc, respectively; p = 0.004), with the PFV difference in patients with CO-dominant stone-bearing kidneys reaching statistical significance (p = 0.003). Subgroup analysis showed greater PFV surrounding the stone-bearing kidney irrespective of gender (p = 0.03), with male patients possessing significantly greater stone-bearing (p = 0.01) and bilateral PFV (p = 0.01) compared to females. No significant correlations were found between PFV and stone volume or stone density. The PFV of calcium oxalate stone-bearing kidneys is significantly greater than non-stone-bearing kidneys for both male and female patients with nephrolithiasis.

Crowdsourcing Evaluation of Ureteroscopic Videos Using the Post-Ureteroscopic Lesion Scale to Assess Ureteral Injury.

INTRODUCTION AND OBJECTIVES: We hypothesized that crowdsourcing assessments could be applied to the Postureteroscopic Lesion Scale (PULS) for ureteral injury. METHODS: At a single institution, we prospectively digitally recorded 14 ureters at the terminal portion of standard ureteroscopic procedures. Each recording was reviewed by 10 global experts to determine a mean PULS score. Following training, the Crowd-Sourced Assessment of Technical Skills, C-SATS® (C-SATS, Inc., Seattle, WA) platform was used to obtain crowd-based reviews. The mean crowd PULS scores was determined using the linear mixed-effects (LME) model. The intraclass correlation coefficient (ICC) was calculated to measure the agreement among experts. Spearman's rank correlation (rho) was used to quantify the strength of the relationship between the crowd LME mean and the experts. RESULTS: Ten expert's reviews and 2100 layman reviews were obtained in 21 days and 49 hours, respectively. The ICC for the 10 experts was 0.68 (95% confidence interval 0.49, 0.86). When the expert mean PULS was <1, the crowd scored those recordings at 1 or greater. The highest scored recording by the experts was a 3.2, which the crowd scored at 2.25. The correlation between the crowd LME means and expert means across all videos was 0.70 (p = 0.0056) indicative of moderately strong agreement. CONCLUSION: In this initial application of crowd-sourced evaluation of ureteral injury, there was a moderately strong correlation between crowd and expert ratings. Refinement of the training, through exposure to the nuances of ureteral injuries, in particular for PULS <1 or ≥3, may lead to better crowd/expert correlation. Compared to expert review, crowd data can be collected with much greater efficiency.

Acute Appendicitis: An Extracolonic Manifestation of Clostridium difficile Colitis.

The current report is the case of a 30-year-old male patient who presented with symptomatology suggestive of appendicitis. However, careful history-taking and laboratory tests led to the diagnosis of Clostridium difficile colitis, resulting in successful nonsurgical management of this patient. Although both appendicitis and C. difficile colitis are common conditions, they are rarely diagnosed concurrently. This is reflected by paucity of literature describing this manifestation. Given this current presentation, the authors contend that the manifestation of extracolonic colitis within the appendix is possibly underdiagnosed or misdiagnosed as an acute appendicitis and thus potentially results in unnecessary surgical intervention. This report reminds physicians to consider the medical approach to managing acute appendicitis given the possibility of underlying C. difficile colitis as the causative factor.

Prevalence of Protective Shielding Utilization for Radiation Dose Reduction in Adult Patients Undergoing Body Scanning Using Computed Tomography.

PURPOSE: Ionizing radiation is implicated in nearly 2% of malignancies in the United States; radiation shields prevent unnecessary radiation exposure during medical imaging. Contemporary radiation shield utilization for adult patients in the United States is poorly defined. Therefore, we evaluated the prevalence of protective shielding utilization in adult patients undergoing CT scans in United States' hospitals. MATERIALS AND METHODS: An online survey was sent to established radiology departments randomly selected from the 2015 American Hospital Association Guide. Radiology departments conducting adult CT imaging were eligible; among 370 eligible departments, 215 departments accepted the study participation request. Questions focused on shielding practices during CT imaging of the eyes, thyroid, breasts, and gonads. Prevalence data were stratified per hospital location, size, and type. Main outcomes included overall protective shielding utilization, respondents' belief and knowledge regarding radiation safety, and organ-specific shielding prevalence. RESULTS: Sixty-seven of 215 (31%) hospitals completed the survey; 66 (99%) reported familiarity with the ALARA (as low as reasonably achievable) principle and 56 (84%) affirmed their belief that shielding is beneficial. Only 60% of hospitals employed shielding during CT imaging; among these institutions, shielding varied based on CT study: abdominopelvic CT (13, 33%), head CT (33, 83%), or chest CT (30, 75%). CONCLUSIONS: Among surveyed hospitals, 40% do not utilize CT shielding despite the majority acknowledging the ALARA principle and agreeing that shielding is a beneficial practice. Failure to address the low prevalence of protective shielding may lead to poor community health due to increased risk of radiation-related cancers.