Prospective Multicenter Evaluation of Pain Before and After Removal of Nonobstructing Renal Calculi: A CoRE Initiative.

PURPOSE: Flank pain associated with stone disease is typically caused by a stone that obstructs urine flow. However, it is plausible that nonobstructing kidney stones may still cause pain. We performed a multicenter, observational trial to evaluate whether treatment of small nonobstructing calyceal stones improves pain and kidney stone-specific health-related quality of life. MATERIALS AND METHODS: Patients aged 18 years or older with nonobstructing renal stone(s) up to 10 mm in longest diameter and moderate to severe pain were recruited. All participants completed 3 questionnaires: the Brief Pain Inventory (BPI), the Patient-Reported Outcomes Measurement Information System pain interference form 6a, and the Wisconsin Stone Quality of Life questionnaire. Thereafter, all participants underwent ureteroscopy for renal stone treatment. All 3 questionnaires were repeated at 2, 6 to 8, and at 12 weeks postprocedure. The primary outcomes were change in preoperative to 12-week postoperative mean BPI score and worst BPI pain score. RESULTS: A total of 43 patients with nonobstructing kidney stones and associated flank pain were recruited. All stones were removed. Preoperatively, BPI scores for mean pain and worst pain were 5.5 and 7.2, respectively which decreased to 1.8 and 2.8 respectively at 12 weeks postoperatively. Wisconsin Stone Quality of Life questionnaire mean score increased from 70.4 to 115.3 at 12 weeks postoperatively. A total of 86% and 69% of patients had at least a 20% and 50% reduction in their mean pain scores, respectively. CONCLUSIONS: This study determined that patients benefit significantly from the removal of calyceal nonobstructing kidney stones for at least 12 weeks with a reduction in pain and an increase in quality of life. Therefore, surgical removal of these stones in this patient population should be offered as a treatment option.

Robotic Simulation in Urologic Surgery.

Robotic surgery continues to revolutionize the field of urologic surgery, and thus it is crucial that graduating urologic surgery residents demonstrate proficiency with this technology. The large learning curve of utilizing robotic technology limits resident immediate participation in real-life robotic surgery, and skill acquisition is further challenged by variable case volume. Robotic simulation offers an invaluable opportunity for urologic trainees to cultivate strong foundational skills in a non-clinical setting, ultimately leading to both competence and operative confidence. Several different simulation technologies and robotic assessment protocols have been developed and demonstrate validity in several domains. However, despite their demonstrable utility, there is no formal robotic curricula within US urologic surgery residencies. In this article, we will review the current state of robotic simulation training in urologic surgery and highlight the importance of its widespread utilization in urologic surgery residency training programs.

Development of an Automated Composite Ureteroscopic Efficiency Score Through Simulated Ureteroscopic Skills Assessment.

Introduction: Flexible ureteroscopy (fURS) is the most common procedure for treatment of urolithiasis. We previously utilized kinematic evaluations of simulated fURS to demonstrate that certain body movements are associated with efficient ureteroscopic manipulation for complex tasks. In this study, we incorporated computer vision to create an efficiency score using the ureteroscope travel distance (DIST), task time (TIME), spectral arc length (SPARC), and percentage of purposeful wall collisions (COLL). The goal is a simulation-based system that can abstract these automated performance metrics (APMs) to differentiate between novice and expert ureteroscope handling. Methods: A ureteroscopic simulation box was used. Body kinematics, task time, and ureteroscopic movements were analyzed using a motion capture system and video camera. Optical flow computer vision was used to track the ureteroscope. DIST, TIME, and SPARC were automatically calculated. Wall collisions were automatically captured and independently judged by two authors; an algorithm was developed to automatically determine the COLL variable. A mixed-effects model was used to aggregate these variables and distinguish between surgeons' first and final task attempts. Normalized values of these metrics were added to create a composite ureteroscopic efficiency score (CUES). Results: Twelve urologists completed the simulated tasks. The COLL assessment algorithm determined beneficial wall collisions with an accuracy of 77%. Normalized values of TIME, DIST, SPARC, and COLL were combined to create a composite ureteroscopic efficiency score (CUES). Compared with the first attempt, both the second and third attempts showed statistically significant improvements in CUES. The ROC-AUC score reached 0.86, suggesting excellent discrimination between attempts. There was also a statistically significant difference in CUES when comparing resident and attending performance. Conclusions: APMs can be abstracted using computer vision and artificial intelligence; an aggregate composite score (CUES) may be a promising method for evaluation of ureteroscopic efficiency.

Feasibility of multi-section continuum robotic ureteroscope in the kidney.

Our objective was to evaluate the feasibility of a multi-section continuum robotic ureteroscope to address the difficulties with access into certain renal calyces during flexible ureteroscopy. First, the robotic ureteroscope developed in previous research, which utilizes three actuated bendable sections controlled by wires, was modified for use in this project. Second, using phantom models created from five randomly selected computer tomography urograms, the flexible ureteroscope and robotic ureteroscope were evaluated, focusing on several factors: time taken to access each renal calyx, time taken to aim at three targets on each renal calyx, the force generated in the renal pelvic wall associated with ureteroscope manipulation, and the distance and standard deviation between the ureteroscope and the target. As a result, the robotic ureteroscope utilized significantly less force during lower pole calyx access (flexible ureteroscope vs. robotic ureteroscope; 2.0 vs. 0.98 N, p = 0.03). When aiming at targets, the standard deviation of proper target access was smaller for each renal calyx (upper pole: 0.49 vs. 0.11 mm, middle: 0.84 vs. 0.12 mm, lower pole: 3.4 vs. 0.19 mm) in the robotic ureteroscope group, and the distance between the center point of the ureteroscope image and the target was significantly smaller in the robotic ureteroscope group (upper: 0.49 vs. 0.19 mm, p < 0.001, middle: 0.77 vs. 0.17 mm, p < 0.001, lower: 0.77 vs. 0.22 mm, p < 0.001). In conclusion, our robotic ureteroscope demonstrated improved maneuverability and facilitated accuracy and precision while reducing the force on the renal pelvic wall during access into each renal calyx.

Promoting the use of the PI-QUAL score for prostate MRI quality: results from the ESOR Nicholas Gourtsoyiannis teaching fellowship.

OBJECTIVES: The Prostate Imaging Quality (PI-QUAL) score is a new metric to evaluate the diagnostic quality of multiparametric magnetic resonance imaging (MRI) of the prostate. This study assesses the impact of an intervention, namely a prostate MRI quality training lecture, on the participant's ability to apply PI-QUAL. METHODS: Sixteen participants (radiologists, urologists, physicists, and computer scientists) of varying experience in reviewing diagnostic prostate MRI all assessed the image quality of ten examinations from different vendors and machines. Then, they attended a dedicated lecture followed by a hands-on workshop on MRI quality assessment using the PI-QUAL score. Five scans assessed by the participants were evaluated in the workshop using the PI-QUAL score for teaching purposes. After the course, the same participants evaluated the image quality of a new set of ten scans applying the PI-QUAL score. Results were assessed using receiver operating characteristic analysis. The reference standard was the PI-QUAL score assessed by one of the developers of PI-QUAL. RESULTS: There was a significant improvement in average area under the curve for the evaluation of image quality from baseline (0.59 [95 % confidence intervals: 0.50-0.66]) to post-teaching (0.96 [0.92-0.98]), an improvement of 0.37 [0.21-0.41] (p < 0.001). CONCLUSIONS: A teaching course (dedicated lecture + hands-on workshop) on PI-QUAL significantly improved the application of this scoring system to assess the quality of prostate MRI examinations. KEY POINTS: • A significant improvement in the application of PI-QUAL for the assessment of prostate MR image quality was observed after an educational intervention. • Appropriate training on image quality can be delivered to those involved in the acquisition and interpretation of prostate MRI. • Further investigation will be needed to understand the impact on improving the acquisition of high-quality diagnostic prostate MR examinations.

The Uniform grading tooL for flexIble ureterorenoscoPes (TULIP-tool): a Delphi consensus project on standardised evaluation of flexible ureterorenoscopes.

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

Biodegradable ring-shaped implantable device for intravesical therapy of bladder disorders.

Intravesical instillation is an efficient drug delivery route for the local treatment of various urological conditions. Nevertheless, intravesical instillation is associated with several challenges, including pain, urological infection, and frequent clinic visits for catheterization; these difficulties support the need for a simple and easy intravesical drug delivery platform. Here, we propose a novel biodegradable intravesical device capable of long-term, local drug delivery without a retrieval procedure. The intravesical device is composed of drug encapsulating biodegradable polycaprolactone (PCL) microcapsules and connected by a bioabsorbable Polydioxanone (PDS) suture with NdFeB magnets in the end. The device is easily inserted into the bladder and forms a 'ring' shape optimized for maximal mechanical stability as informed by finite element analysis. In this study, inserted devices were retained in a swine model for 4 weeks. Using this device, we evaluated the system's capacity for delivery of lidocaine and resiquimod and demonstrated prolonged drug release. Moreover, a cost-effectiveness analysis supports device implementation compared to the standard of care. Our data support that this device can be a versatile drug delivery platform for urologic medications.

Over-the-Counter Alkali Agents to Raise Urine pH and Citrate Excretion: A Prospective Crossover Study in Healthy Adults.

OBJECTIVE: To assess the effect of 2 over-the-counter alkalizing agents on 24 hour urinary parameters. MATERIALS AND METHODS: Ten healthy volunteers without a history of kidney stones were recruited to complete a baseline 24 hour urinalysis with a 4 day diet inventory. Participants then maintained the same diet on either LithoLyte (20 mEq 2 times per day) or KSPtabs (1 tablet 2 times per day) and submitted another 24 hour urinalysis. The process was repeated with the other supplement. Urinary alkali parameters were compared to baseline, and side effects were elicited with a questionnaire. RESULTS: LithoLyte intake resulted in a non-significant increase in citrate (597-758 mg/day, P =.058, an increase in urine pH (6.46-6.66, P =.028), and a decrease in urine ammonium (41-36 mmol/day, P =.005) compared to baseline. KSPtabs resulted in an increase in citrate (597-797 mg/day, P =.037) and urine pH (6.46-6.86, P =.037), with a non-significant decrease in ammonium (41-34 mmol/day, P =.059). No significant differences were seen comparing urinary analytes between LithoLyte and KSPtabs. With Litholyte, no side effects, mild, moderate, and severe side effects were seen in 50%, 40%, 10%, and 0%, respectively. With KSPtabs, rates were 60%, 20%, 10%, and 10%, respectively. CONCLUSION: In healthy participants without a history of kidney stones, LithoLyte and KSPtabs are effective over-the-counter alkali supplements, with a similar side effect profile to prescription potassium citrate.

Analysis of Flexible Ureteroscopic Motion and Kinematic Efficiency: A Simulation-Based Pilot Study.

Introduction: Flexible ureteroscopy (fURS) is the most common surgical procedure for treatment of urolithiasis. Various surgical disciplines and subspecialties have examined surgeon kinematics to improve assessment and generate measures of skill. Despite frequency of utilization, there is no undisputed method for evaluating fURS skills. Our pilot study utilized kinematic evaluations of fURS simulation to determine whether specific surgeon movements, techniques, and strategies correlate with measures of ureteroscopic (URS) efficiency. Methods: A motion capture system and standard video camera were employed to characterize surgeon movement variables. A URS simulation box was used by practicing urologists at various skill levels to perform a series of simple and complex URS movement tasks. Two tasks were chosen for this initial pilot analysis. Body kinematics, time to task completion, and URS movements were analyzed. Task efficiency was defined as quicker time to task completion and smaller ureteroscope end effector travel distance. A combined performance efficiency score (PES) was calculated using the root sum square of these two measures. Results: Twelve practicing urologists were enlisted. Average urologist age was 37 years with an average of 10.1 years of training; 50% were women, 50% were residents; and 33% had completed an Endourology fellowship. For the simple task, no kinematic data correlated with PES; for the complex task, participant head and torso movement correlated with PES (r = 0.60, p = 0.04 for head; r = 0.65, p = 0.02 for torso), with decreased body movement associated with higher efficiency. Conclusion: Our findings suggest that movement economy measures are associated with efficient URS manipulation for complex tasks. Decreased head and torso movement were associated with higher efficiency, suggesting that excess body movement may signal extraneous or improper URS movements. Additional assessment of these variables, including analysis in a clinical setting, is warranted as this may serve as a basis for improvement in endoscopic training and evaluation.

Assessment of conservative dietary management as a method for normalization of 24-h urine pH in stone formers.

Low urine pH is a metabolic risk factor for stone formation. While medical therapy is typically prescribed (as urinary alkalinization), patients typically prefer dietary modifications. We aimed to assess capacity to alter urine pH with dietary management alone. We analyzed a retrospective cohort of stone formers seen between 2000 and 2015 with multiple 24-h urine collections (24hUC). Patients ≥ 18 years old with low urine pH (< 6.0) were included; those prescribed alkalinizing agents or thiazides were excluded. Demographic data, 24hUC parameters, and medications were abstracted. 24hUC was utilized to calculate gastrointestinal alkali absorption (GIAA). The primary outcome was urine pH ≥ 6.0 on second 24hUC. Predictors were selected utilizing multivariable logistic regression. The database consisted of 2197 stone formers; 224 of these met inclusion criteria. On second 24hUC, 124 (55.4%) achieved a favorable pH ≥ 6.0. On univariable analysis, a second pH ≥ 6.0 was associated with high initial pH, low initial sulfate, younger age, increase in citrate/GIAA/urine volume, and decrease in ammonium (P < 0.02). On multivariable analysis, high initial pH (OR = 23.64, P < 0.001), high initial GIAA (OR = 1.03, P = 0.001), lower initial sulfate (OR = 0.95, P < 0.001), increase in urine volume (OR = 2.19, P = 0.001), increase in GIAA (OR = 8.6, P < 0.001), increase in citrate (OR = 2.7, P = 0.014), decrease in ammonium (OR = 0.18, P < 0.001), and younger age (OR = 0.97, P = 0.025) were associated with a second pH ≥ 6.0. The analysis demonstrated a corrected AUC of 0.853. These data suggest that certain dietary recommendations (increases in urine volume, citrate, GIAA, and decreased acid load) may normalize urine pH in a select group of patients. This may allow urologists to counsel patients with low urine pH on possibility of success with dietary modification alone.

Holmium:Yttrium-Aluminum-Garnet Laser Pulse Type Affects Irrigation Temperatures in a Benchtop Ureteral Model.

Introduction: MOSES™ technology is a holmium:yttrium-aluminum-garnet laser pulse mode shown to minimize stone retropulsion. This may facilitate lithotripsy at higher power settings. However, power and heat production are proportional, and temperatures capable of tissue injury may occur during ureteroscopic lithotripsy. Although previous in vitro studies demonstrate the importance of irrigation and activation time on heat production, the impact of pulse type has not been evaluated. Methods: A flexible ureteroscope with a 365 µm laser fiber was placed in an 11/13 F access sheath inserted into a 50 mL saline bag to simulate a ureter, renal pelvis, and antegrade irrigant flow. A thermocouple was placed adjacent to the laser tip, and the laser fired for 30 seconds at 0.6 J/6 Hz, 0.8 J/8 Hz, 1 J/10 Hz, 1 J/20 Hz, and 0.2 J/70 Hz at irrigation pressure of 100 mmHg. Four runs were tested per setting using short pulse, long pulse (LP), MOSES-contact (MC), and MOSES-distance (MD) modes. The mean temperature changes (dT) were compared and thermal dose was calculated in cumulative equivalent minutes at 43°C (CEM43) using an adjusted baseline of 37°C. CEM43 ≥ 120 minutes was considered the tissue injury threshold. Results: At 0.8 J/8 Hz, LP produced the greatest dT, significantly higher than MC (p = 0.041). CEM43 did not exceed the injury threshold. At 1 J/10 Hz, dT was significantly higher for LP versus MC and MD (p = 0.024 and 0.045, respectively). Thermal dose remained below the injury threshold. No differences in dT were seen between pulse types at 0.6 J/6 Hz, 0.2 J/70 Hz, or 1 J/20 Hz. At 1 J/20 Hz, thermal dose exceeded the injury threshold for all pulse types within 3 seconds. Conclusions: Laser pulse type and length seemed to impact heat production in our ureteral model. LP produced significantly greater temperatures at 0.8 J/8 Hz and 1 J/10 Hz relative to MOSES settings. Fortunately, thermal dose remained safe at these settings. Both LP and MOSES technology have been shown to reduce stone retropulsion. At power ≤10 W, the latter may confer this advantage with decreased heat production.