The impact of kidney stone disease on quality of life in high-risk stone formers

OBJECTIVE

To assess the impact of kidney stone disease (KSD) and its treatment on the health-related quality of life (HRQOL) of high-risk stone formers with hyperparathyroidism, renal tubular acidosis, malabsorptive disease, and medullary sponge kidney.

PATIENTS AND METHODS

The Wisconsin Stone Quality of Life questionnaire was used to evaluate HRQOL in 3301 patients with a history of KSD from 16 institutions in North America between 2014 and 2020. Baseline characteristics and medical history were collected from patients, while active KSD was confirmed through radiological imaging. The high-risk group was compared to the remaining patients (control group) using the Wilcoxon rank-sum test.

RESULTS

Of 1499 patients with active KSD included in the study, the high-risk group included 120 patients. The high-risk group had significantly lower HRQOL scores compared to the control group (P < 0.01). In the multivariable analyses, medullary sponge kidney disease and renal tubular acidosis were independent predictors of poorer HRQOL, while alkali therapy was an independent predictor of better HRQOL (all P < 0.01).

CONCLUSIONS

Among patients with active KSD, high-risk stone formers had impaired HRQOL with medullary sponge kidney disease and renal tubular acidosis being independent predictors of poorer HRQOL. Clinicians should seek to identify these patients earlier as they would benefit from prompt treatment and prevention.

Prevalence and determinants of shared decision-making for PSA testing in the United States

BACKGROUND

Shared decision-making (SDM) is recommended for prostate-specific antigen (PSA) testing but appears underutilized. This population-based study assessed the prevalence and determinants of SDM for PSA testing among US men.

METHODS

We assessed PSA testing rates and SDM engagement in men aged 40 and older without prostate cancer history using the 2019 National Health Interview Survey. SDM was defined as discussing the advantages and disadvantages of PSA testing with a physician. We used multivariable logistic regression with machine learning to identify factors associated with lack of SDM.

RESULTS

Among 9723 eligible participants (mean age 58 years), lifetime PSA testing prevalence was 45.9% and the 1-year testing incidence was 29.1%. Only 24.1% reported engaging in SDM with a physician, while 62.9% never discussed PSA testing. Younger age and lower education levels were the primary determinants of decreased SDM engagement. Men with less education engaged in SDM less than half as often as those with higher education levels across all age groups.

CONCLUSIONS

Societal guidelines recommend SDM for PSA testing. However, most men, regardless of age, have never engaged in SDM conversations with a healthcare provider about PSA testing, especially those with less education. More efforts are needed to improve patient-provider conversations about the potential benefits and harms of PSA testing.

Monogenic features of urolithiasis: A comprehensive review

Objective

Urolithiasis formation has been attributed to environmental and dietary factors. However, evidence is accumulating that genetic background can contribute to urolithiasis formation. Advancements in the identification of monogenic causes using high-throughput sequencing technologies have shown that urolithiasis has a strong heritable component.

Methods

This review describes monogenic factors implicated in a genetic predisposition to urolithiasis. Peer-reviewed journals were evaluated by a PubMed search until July 2023 to summarize disorders associated with monogenic traits, and discuss clinical implications of identification of patients genetically susceptible to urolithiasis formation.

Results

Given that more than 80% of urolithiases cases are associated with calcium accumulation, studies have focused mainly on monogenetic contributors to hypercalciuric urolithiases, leading to the identification of receptors, channels, and transporters involved in the regulation of calcium renal tubular reabsorption. Nevertheless, available candidate genes and linkage methods have a low resolution for evaluation of the effects of genetic components versus those of environmental, dietary, and hormonal factors, and genotypes remain undetermined in the majority of urolithiasis formers.

Conclusion

The pathophysiology underlying urolithiasis formation is complex and multifactorial, but evidence strongly suggests the existence of numerous monogenic causes of urolithiasis in humans.

Accuracy and Readability of Kidney Stone Patient Information Materials Generated by a Large Language Model Compared to Official Urologic Organizations

OBJECTIVE

To compare the readability and accuracy of large language model generated patient information materials (PIMs) to those supplied by the American Urological Association (AUA), Canadian Urological Association (CUA), and European Association of Urology (EAU) for kidney stones.

METHODS

PIMs from AUA, CUA, and EAU related to nephrolithiasis were obtained and categorized. The most frequent patient questions related to kidney stones were identified from an internet query and input into GPT-3.5 and GPT-4. PIMs and ChatGPT outputs were assessed for accuracy and readability using previously published indexes. We also assessed changes in ChatGPT outputs when a reading level was specified (grade 6).

RESULTS

Readability scores were better for PIMs from the CUA (grade level 10-12), AUA (8-10), or EAU (9-11) compared to the chatbot. GPT-3.5 had the worst readability scores at grade 13-14 and GPT-4 was likewise less readable than urologic organization PIMs with scores of 11-13. While organizational PIMs were deemed to be accurate, the chatbot had high accuracy with minor details omitted. GPT-4 was more accurate in general stone information, dietary and medical management of kidney stones topics in comparison to GPT-3.5, while both models had the same accuracy in the surgical management of nephrolithiasis topics.

CONCLUSION

Current PIMs from major urologic organizations for kidney stones remain more readable than publicly available GPT outputs, but they are still higher than the reading ability of the general population. Of the available PIMs for kidney stones, those from the AUA are the most readable. Although Chatbot outputs for common kidney stone patient queries have a high degree of accuracy with minor omitted details, it is important for clinicians to understand their strengths and limitations.

Deficient butyrate metabolism in the intestinal microbiome is a potential risk factor for recurrent kidney stone disease

Intestinal microbiome dysbiosis is a known risk factor for recurrent kidney stone disease (KSD) with prior data suggesting a role for dysfunctional metabolic pathways other than those directly utilizing oxalate. To identify alternative mechanisms, the current study analyzed differences in the metabolic potential of intestinal microbiomes of patients (n = 17) and live-in controls (n = 17) and determined their relevance to increased risk for KSD using shotgun metagenomic sequencing. We found no differences in the abundance of genes associated with known oxalate degradation pathways, supporting the notion that dysfunction in other metabolic pathways plays a role in KSD. Further analysis showed decreased abundance of key enzymes involved in butyrate biosynthesis in patient intestinal microbiomes. Furthermore, de novo construction of microbial genomes showed that the majority of genes significantly enriched in non-stone formers are affiliated with Faecalibacterium prausnitzii, a major butyrate producer. Specifically pertaining to butyrate metabolism, the majority of abundant genes mapped back to F. prausnitzii, Alistipes spp., and Akkermansia muciniphila. No differences were observed in ascorbate or glyoxylate metabolic pathways. Collectively, these data suggest that impaired bacterial-associated butyrate metabolism may be an oxalate-independent mechanism that contributes to an increased risk for recurrent KSD. This indicates that the role of the intestinal microbiome in recurrent KSD is multi-factorial, which is representative of the highly intertwined metabolic nature of this complex environment. Future bacteria-based treatments must not be restricted to targeting only oxalate metabolism.

Incidence and trends in the treatment of kidney stones in Canada: A population-based cohort study

INTRODUCTION

Our objective was to assess the incidence of kidney stones requiring acute care, trends in the surgical treatment of stones, and the demographics of stone formers in Canada.

METHODS

We conducted a population-based, retrospective cohort study using administrative data from the Canadian Institute for Health Information. We included Canadian residents age >18, outside of Quebec, who presented between January 1, 2013, and December 31, 2018, with a kidney stone episode. This was defined as a kidney stone resulting in hospital admission, emergency department visit, or stone intervention, specifically shockwave lithotripsy (SWL), ureteroscopy (URS), or percutaneous nephrolithotomy (PCNL).

RESULTS

There were 471 824 kidney stone episodes, including 184 373 interventions. The number of kidney stone episode increased from 277/100 000 in 2013 to 290/100 000 in 2018. The median age was 53 (interquartile range 41-65) and 59.9% were male. The crude rate for stone intervention was 877/100 000. The age- and gender-standardized rate for interventions was highest in Nova Scotia and Newfoundland and Labrador and lowest in Prince Edward Island. The most common intervention in Canada was URS (73.5%), followed by SWL (19.8%) and PCNL (6.7%). The percent utilization of SWL was highest in Manitoba, whereas for URS, it was highest in Prince Edward Island and Alberta.

CONCLUSIONS

Our study provides the first population-based data on the demographics of stone formers and treatment trends across Canada. There has been a 4.7% increase in kidney stone episodes over the study period. Those presenting to hospital or requiring intervention for a kidney stone are more likely to be male, age 41-65, and undergo URS.

Application of novel burst wave lithotripsy and ultrasonic propulsion technology for the treatment of ureteral calculi in a bottlenose dolphin (Tursiops truncatus) and renal calculi in a harbor seal (Phoca vitulina)

Marine mammals may develop kidney stones, which can be challenging to treat. We describe burst wave lithotripsy (BWL) and ultrasonic propulsion to treat ureteral calculi in a 48-year-old female bottlenose dolphin (Tursiops truncatus) and to reduce renal stone burden in a 23-year-old male harbor seal (Phoca vitulina). BWL and ultrasonic propulsion were delivered transcutaneously in sinusoidal ultrasound bursts to fragment and reposition stones. Targeting and monitoring were performed with real-time imaging integrated within the BWL system. Four dolphin stones were obtained and fragmented ex vivo. The dolphin case received a 10-min and a 20-min BWL treatment conducted approximately 24 h apart to treat two 8-10 mm partially obstructing right mid-ureteral stones, using oral sedation alone. For the harbor seal, while under general anesthesia, retrograde ureteroscopy attempts were unsuccessful because of ureteral tortuosity, and a 30-min BWL treatment was targeted on one 10-mm right kidney stone cluster. All 4 stones fragmented completely to < 2-mm fragments in < 20 min ex vivo. In the dolphin case, the ureteral stones appeared to fragment, spread apart, and move with ultrasonic propulsion. On post-treatment day 1, the ureteral calculi fragments shifted caudally reaching the ureteral orifice on day 9. On day 10, the calculi fragments passed, and the hydroureter resolved. In the harbor seal, the stone cluster was observed to fragment and was not visible on the post-operative computed tomography scan. The seal had gross hematuria and a day of behavior indicating stone passage but overall, an uneventful recovery. BWL and ultrasonic propulsion successfully relieved ureteral stone obstruction in a geriatric dolphin and reduced renal stone burden in a geriatric harbor seal.

Retrospective first-in-human use of the LithoVue™ Elite ureteroscope to measure intrarenal pressure

OBJECTIVE

To report on our first-in-human experience using the LithoVue Elite™ ureteroscope (Boston Scientific Corp., Marlborough, MA, USA) to measure intrarenal pressure (IRP) during flexible ureteroscopy.

PATIENTS AND METHODS

A single-arm retrospective observational analysis was performed in 50 consecutive patients undergoing ureteroscopic lithotripsy using the LithoVue Elite™ system with pressure sensing capability between April 2022 and February 2023 at two centres. A pressure bag set at 150 mmHg or hand irrigation with a 60-mL syringe was used for irrigation and a ureteric access sheath (UAS) was placed at the physician's discretion. Median and maximum IRPs, and relative cumulative time exceeding 20, 40, 60, 80, 100, 120, 140, 160, and 200 mmHg per total procedure time were analysed. The two-sample Mann-Whitney U-test was used, with statistical significance set at P < 0.05.

RESULTS

The median (interquartile range [IQR]) patient age and body mass index (BMI) was 62.5 (46.7-68.2) years and 27.6 (23.3-32.1) kg/m2 , respectively. During the median (IQR) total procedure time of 31.9 (17.4-44.9) min, the median and maximum IRPs were 28.5 (20.0-47.5) and 174.0 (133.5-266.0) mmHg, respectively. IRP remained at <60 mmHg during 92% of the procedure times. Patients with Asian ethnicity, and those without pre-stenting or UAS use exhibited longer cumulative/total durations exceeding pre-defined IRP cut-off values. The smaller 10/12-F UAS did not lower pressures as much as the 11/13-F or 12/14-F UAS (P < 0.001). Age, diabetes, hypertension, preoperative α-blockade, stone size, and BMI did not show any statistically significant associations with IRP.

CONCLUSIONS

The IRP can now be routinely measured during ureteroscopy. Patients had a median IRP of 28.5 mmHg and a maximum of 174 mmHg. Using a smaller UAS (10/12 F), Asian ethnicity, and tight ureters were found to have higher IRPs.

The Impact of Bilateral Stone Disease on Patients' Disease Progression and Health-Related Quality of Life

Purpose: Patients with recurring kidney stone events can expect significant morbidity and functional impairment. Few studies have evaluated the effect of bilateral kidney stones on disease progression and quality of life. We wanted to determine the association of bilateral stone disease on age of onset, and the impact on number of stone events and individual kidney stone disease-specific health-related quality of life (HRQOL) by analyzing the validated and prospectively collected Wisconsin Stone Quality of Life (WISQOL) database. Materials and Methods: We studied 2906 stone patients from 16 centers in North America after having completed the WISQOL questionnaire from 2014 to 2019. Kidney stone formers were assessed if kidney stones were bilateral or unilateral on imaging. Analysis with a chi-square test compared categorical variables. Bilateral kidney stone disease and its impact on HRQOL were evaluated through a multivariable linear regression model. Results: Of 2906 kidney stone formers, 1340 had unilateral kidney stones and 1566 had bilateral kidney stones. We observed more frequently that patients with bilateral stones had an increased number of depression/anxiety symptoms, renal tubular acidosis, and rheumatoid arthritis (all p < 0.05). Patients with bilateral stones had a younger mean (standard deviation [SD]) age of kidney stone disease onset (37.2 ± 15.8 vs 46.4 ± 15.9 years of age, p < 0.001). Bilateral kidney stone formers had a higher mean (SD) number of stone events (11.3 ± 21.8) than unilateral kidney stone formers (3.0 ± 5.1) (p < 0.001). Within our multivariable analysis, we found that HRQOL was negatively affected by the presence of bilateral stones for kidney stone patients (β = -11.2 [confidence interval: -19.5 to -3.0] points, p < 0.05). Conclusions: Bilateral kidney stone formers had a younger age of kidney stone disease onset and a higher number of stone events compared with unilateral kidney stone disease formers. The presence of bilateral kidney stone disease negatively impacted HRQOL.

Intrarenal Pressure Measured Using a Novel Flexible Ureteroscope with Pressure Sensing Capabilities: A Study of the Effects of Ureteral Access Sheath, Irrigation, and Working Channel Accessories

Introduction: Intrarenal pressure is emerging as an important monitoring parameter during flexible ureteroscopy (fURS). We measure how intraoperative conditions affect intrarenal pressure using a novel pressure sensing ureteroscope. Methods: The LithoVue Elite (LVE) single-use digital flexible ureteroscope (Boston Scientific) is the first commercial ureteroscope that senses pressure at its tip. LVE was used in a porcine model to measure intrarenal pressure with and without a ureteral access sheath (UAS) with various sizes and placement locations, irrigation methods, and working channel accessories. LVE pressure accuracy was measured in a bench model. This abstract shows the least-square means from multiway analysis of variances used for analysis. Results: Intrarenal pressures were the highest without a UAS (64 mm Hg), followed by the 11/13 UAS (51 mm Hg) and the 12/14 and 13/15, which were not statistically different (39-40 mm Hg). The pressures were highest with UASs placed at the ureteropelvic junction (61 mm Hg), and lowest if placed in the renal pelvis (24 mm Hg). Irrigation methods showed the highest pressures with syringe (57 mm Hg), while irrigation bags (pressurized at 150-300 mm Hg) produced 43 to 46 mm Hg and 25 mm Hg when applied with 80 cm of gravity. Placing a 200 μm laser fiber reduced pressures from 44 to 41 mm Hg. Finally, the bench model showed that LVE was 96% accurate up to 300 mm Hg. Conclusion: Intrarenal pressure significantly varied based on UAS sizes, placement, and irrigation methods. Accordingly, fURS with LVE is poised to be an invaluable tool for clinical decision-making and future studies of intrarenal pressure.

Development and external validation of a machine learning-based model to classify uric acid stones in patients with kidney stones of Hounsfield units < 800

The correct diagnosis of uric acid (UA) stones has important clinical implications since patients with a high risk of perioperative morbidity may be spared surgical intervention and be offered alkalization therapy. We developed and validated a machine learning (ML)-based model to identify stones on computed tomography (CT) images and simultaneously classify UA stones from non-UA stones. An international, multicenter study was performed on 202 patients who received percutaneous nephrolithotomy for kidney stones with HU < 800. Data from 156 (77.2%) patients were used for model development, while data from 46 (22.8%) patients from a multinational institution were used for external validation. A total of 21,074 kidney and stone contour-annotated CT images were trained with the ResNet-18 Mask R-convolutional neural network algorithm. Finally, this model was concatenated with demographic and clinical data as a fully connected layer for stone classification. Our model was 100% sensitive in detecting kidney stones in each patient, and the delineation of kidney and stone contours was precise within clinically acceptable ranges. The development model provided an accuracy of 99.9%, with 100.0% sensitivity and 98.9% specificity, in distinguishing UA from non-UA stones. On external validation, the model performed with an accuracy of 97.1%, with 89.4% sensitivity and 98.6% specificity. SHAP plots revealed stone density, diabetes mellitus, and urinary pH as the most important features for classification. Our ML-based model accurately identified and delineated kidney stones and classified UA stones from non-UA stones with the highest predictive accuracy reported to date. Our model can be reliably used to select candidates for an earlier-directed alkalization therapy.

Sepsis prevalence and associated hospital admission and mortality after ureteroscopy in employed adults

OBJECTIVE

To determine 30-day inpatient mortality, intensive care unit (ICU) admissions, inpatient admissions/readmissions, and yearly trends in sepsis prevalence and inpatient mortality after ureteroscopy (URS) in employed adults.

MATERIALS AND METHODS

We performed a retrospective analysis of the IBM MarketScan Commercial Database to identify employed adults aged 18-64 years who underwent URS between 2015 and 2019. Patients were categorized as having no sepsis (controls), non-severe sepsis, or severe sepsis within 30 days of URS. The main outcomes included inpatient mortality, ICU admissions, inpatient admissions, readmissions, and annual rates of sepsis and associated inpatient mortality.

RESULTS

Among 109 496 patients undergoing URS, 5.6% developed sepsis (4.1% non-severe, 1.5% severe). The 30-day inpatient mortality rates were 0.03%, 0.3% and 2.5% for controls, non-severe sepsis and severe sepsis, respectively (P < 0.001). In a multivariable analysis, diagnosis of sepsis regardless of severity (hazard ratio [HR] 17.2, 95% confidence interval [CI] 10.5-28.1; P < 0.001) or severe sepsis (HR 49.5, 95% CI 28.9-84.7; P < 0.001) increased the risk of 30-day inpatient mortality compared to no sepsis (controls). ICU admissions on the day of procedure (1.5%, 19.8% and 52.4%), inpatient admission rates (18.3%, 74.9% and 76.9%) and readmission rates (7.1%, 12.0% and 15.9%) were higher with severe sepsis and non-severe sepsis vs controls (all P < 0.001). During the study period, the prevalence of sepsis after URS increased from 4.7% to 6.6% (P < 0.001), while the associated mortality rate decreased from 0.7% to 0.2% (P < 0.001).

CONCLUSION

Among working adults aged 18-64 years, sepsis after URS increases the risk of 30-day inpatient mortality, ICU and hospital admission, and hospital readmission. Although the prevalence of sepsis after URS is increasing over time, associated mortality rates are declining. Urologists should be aware of the potentially deadly consequences of sepsis after URS in younger patients.

A Feasibility Study on Clinical Utility, Efficacy and Limitations of 2 Types of Flexible and Navigable Suction Ureteral Access Sheaths in Retrograde Intrarenal Surgery for Renal Stones

OBJECTIVE

To evaluate stone-free rate, device maneuverability, and complications after retrograde intrarenal surgery (RIRS) using 2 different sizes of flexible and navigable suction ureteral access sheaths (FANS).

METHODS

A retrospective analysis was performed for patients who underwent RIRS for renal stones of any size, number, and location between November 2021 and October 2022. Group 1 had FANS of 12 French. Group 2 had FANS of 10 French. Both sheaths have a Y-shaped suction channel. Tip of 10 French FANS has 20% more flexibility. Lithotripsy was achieved using either thulium fiber or high-power holmium lasers. A 5-point Likert scale was used to assess the performance of each sheath.

RESULTS

There were 16 patients in Group 1 and 15 patients in Group 2. Baseline demographics and stone parameters were similar. Four patients in Group 2 had the same session bilateral RIRS. Sheath insertion was successful in all renal units but one. Ten French FANS had a higher percentage of excellent scores for ease of use, manipulation, and visibility. Neither of the sheaths had an average or difficult rating for all evaluation scales. A fornix rupture requiring prolonged stenting occurred in group 2. All patients were discharged within 24 hours of surgery. One patient in each group visited the emergency department (analgesic treatment). There were no infectious complications. At 3 months, a computed tomography scan showed that the absence of residual fragments >2 mm was significantly higher in Group 2 (94.7% vs 68.8%, P = 0.01).

CONCLUSION

The 10 Fr FANS showed a higher stone-free rate. There was no infectious complication using both sheaths.

Quick Sequential Organ Failure Assessment (qSOFA) Score is a Better Predictor of Septic Shock after Percutaneous Nephrolithotomy: A secondary analysis of Two Multi-Center Prospective Trials

INTRODUCTION

Recent retrospective literature suggests that the quick sequential organ failure assessment scoring (qSOFA) tool is a potentially superior tool over use of the systemic inflammatory response syndrome criteria (SIRS) to predict septic shock after percutaneous nephrolithotomy (PCNL) surgery. Here we examine use of qSOFA and SIRS to predict septic shock within data series collected prospectively on PCNL patients as part of a greater study of infectious complications.

MATERIALS AND METHODS

We performed a secondary analysis of two prospective multicenter studies including PCNL patients across nine institutions. Clinical signs informing SIRS and qSOFA scores were collected no later than post-operative day one. The primary outcome was sensitivity and specificity of SIRS and qSOFA (high risk score of greater-or-equal to 2 points) in predicting admission to the intensive care unit (ICU) for vasopressor support.

RESULTS

A total of 218 cases at nine institutions were analyzed. One patient required vasopressor support in the ICU. The sensitivity/specificity was 100%/72.4% (McNemar's test p < 0.001) for SIRS and was 100%/90.8% (McNemar's test p < 0.001) for qSOFA.

CONCLUSION

Although PPV for both qSOFA and SIRS in prediction of post-PCNL septic shock is low, prospectively collected data demonstrates use of qSOFA may offer greater specificity than SIRS criteria when predicting post-PCNL septic shock.

Electromechanically Functionalized Ureteral Stents for Wireless Obstruction Monitoring

While millions of ureteral stents are placed in patients with urinary tract issues around the world every year, hydronephrosis still poses great danger to these patients as a common complication. In the present work, an intelligent double-J ureteral stent equipped with a micro pressure sensor and antenna circuitry is investigated and prototyped toward enabling continuous wireless monitoring of kidney pressure to detect a ureteral obstruction and the resultant hydronephrosis via the indwelling stent. This electromechanically functionalized "intelligent" ureteral stent acts as a radiofrequency resonator with a pressure-sensitive resonant frequency that can be interrogated using an external antenna to track the local pressure. The prototype passes mechanical bending tests of up to 15 cm radius of curvature and shows wireless sensing with a sensitivity of 3.1 kHz/mmHg in artificial urine, which represents 25× enhancement over the preceding design, using an in vitro model with test tissue layers and a pressure range that functions within the conditions found in hydronephrotic conditions. These promising results are expected to propel intelligent ureteral stent technology into further clinical research.

The Fate of Residual Fragments After Percutaneous Nephrolithotomy: Results from the Endourologic Disease Group for Excellence Research Consortium

Background: Residual fragments (RFs) after percutaneous nephrolithotomy (PCNL) have a significant impact on patients' quality of life and clinical course. There is a paucity of studies that evaluate the natural history of RFs after PCNL. The objective of this study is to compare rates of reintervention, complications, stone growth, and passage in patients with RFs >4, ≤4, and ≤2 mm after PCNL. Methods: Sites from the Endourologic Disease Group for Excellence (EDGE) research consortium examined data of PCNL patients from 2015 to 2019 with at least 1-year follow-up. RF passage, regrowth, reintervention, and complications were recorded and RFs were stratified into >4 and ≤4 mm groups, as well as >2 and ≤2 mm groups. Potential predictors for stone-related events after PCNL were determined using multivariable logistic regression analysis. It was hypothesized that larger RF thresholds would result in lower passage rates, faster regrowth, and greater clinically significant events (complications and reinterventions) than smaller RF thresholds. Results: A total of 439 patients with RFs >1 mm on CT postoperative day 1 were included in this study. For RFs >4 mm, rates of reintervention were found to be significantly higher and Kaplan-Meier curve analysis showed significantly higher rates of stone-related events. Passage and RF regrowth were not found to be significantly different compared with RFs ≤4 mm. However, RFs ≤2 mm had significantly higher rates of passage, and significantly lower rates of fragment regrowth (>1 mm), complications, and reintervention compared with RFs >2 mm. On multivariable analysis, older age, body mass index, and RF size were found to be predictive of stone-related events. Conclusions: With the largest cohort to date, this study by the EDGE research consortium further confirms that clinically insignificant residual fragment is problematic for patients after PCNL, particularly in older more obese patients with larger RFs. Our study underscores the importance of complete stone clearance post-PCNL and challenges the use of Clinically insignificant residual fragment (CIFR).

Comparing dusting and fragmenting efficiency using the new SuperPulsed thulium fiber laser versus a 120 W Holmium:YAG laser

PURPOSE

Holmium:YAG laser lithotripsy requires high amperage power and has an upper limit of frequency and a minimal fiber size. The technology utilizing thulium-doped fiber offers low pulse energy settings and high pulse frequencies up to 2,400 Hz. We compared the novel SuperPulsed thulium fiber laser (SOLTIVE™; Olympus) to a commercially available 120 W Ho:YAG laser.

MATERIALS AND METHODS

Bench-top testing was conducted with 125 mm³ standardized BegoStones (Bego USA). Time to ablate the stone into particles <1 mm was recorded for efficiency calculations. Finite energy was delivered, and resulting particle sizes were measured to determine fragmentation (0.5 kJ) and dusting (2 kJ) efficiencies. Remaining mass or number of fragments were measured to compare efficacy.

RESULTS

SOLTIVE™ was faster at ablating stones to particles <1 mm (2.23±0.22 mg/s, 0.6 J 30 Hz short pulse) compared to Ho:YAG laser (1.78±0.44 mg/s, 0.8 J 10 Hz short pulse) (p<0.001). Following 0.5 kJ of energy in fragmentation testing, fewer particles >2 mm remained using SOLTIVE™ than Ho:YAG laser (2.10 vs. 7.20 fragments). After delivering 2 kJ, dusting (1.05±0.08 mg/s) was faster using SOLTIVE™ (0.1 J 200 Hz short pulse) than 120 W 0.46±0.09 mg/s (0.3 J 70 Hz Moses) (p=0.005). SOLTIVE™ (0.1 J 200 Hz) produced more dust particles <0.5 mm (40%) compared to 24% produced by the P120 W laser at 0.3 J 70 Hz Moses and 14% at 0.3 J 70 Hz long pulse (p=0.015).

CONCLUSIONS

The efficacy of SOLTIVE™ is superior to the 120 W Ho:YAG laser by producing smaller dust particles and fewer fragments. Further studies are warranted.

Innovations in endourologic stone surgery: contemporary practice patterns from a global survey

OBJECTIVE

The purpose of this study is to evaluate the current availability of technology for urolithiasis treatment and ureteroscopy. Perioperative practice patterns, availability of ureteroscopic technologies, pre- and post-stenting practices, and methods to alleviate stent-related symptoms were assessed via a survey of members of the Endourological Society. Methods We distributed a 43-question survey online via the Qualtrics platform to members of the Endourological Society. The survey consisted of questions pertaining to the following topics: general (6), equipment (17), preoperative ureteroscopy (URS; 9), intraoperative URS (2), and postoperative URS (9). Results A total of 191 urologists responded to the survey. 51% of urologists were fellowship trained and dedicated an average of 58% of their practice to stone management. In terms of procedures, most urologists performed ureteroscopy most commonly (68%), followed by percutaneous nephrolithotomy (23%) and shockwave lithotripsy (11%). 90% of respondent urologists purchased a new ureteroscope within the last five years (16% single-use scopes, 53% reusable, and 31% purchased both). 57% of the respondents stated that they would be interested in a ureteroscope that can sense intrarenal pressure, with an additional 30% stating they would be interested depending on the cost. 80% of responders purchased a new laser within the last five years, and 59% changed their lasering technique due to the new laser. 70% are performing primary ureteroscopy for obstructing stones, and 30% prefer pre-stenting patients for subsequent URS (on average after 21 days). 59% of responders insert a ureteral stent after URS, which is removed, on average, after eight days in uncomplicated cases and 21 days after complicated URS. Most urologists give analgesics, alpha-blockers, and anticholinergics for stent-related symptoms and less than 10% prescribe opioids. Conclusion Our survey revealed urologists' eagerness for the early adoption of novel technologies and adherence to conservative practice patterns focused on patient safety.

Long-term follow-up on dusting versus basketing during ureteroscopy: a prospective multicenter trial from the EDGE Research Consortium

In 2018, the Endourology Disease Group for Excellence (EDGE) published a prospective trial comparing dusting versus basketing during ureteroscopy. One hundred fifty-nine patients were included in the original analysis, which found no difference in stone-free rate at 3 months. We report the intermediate and long-term outcomes of patients included in the original trial. Two analyses were performed. At 1-year, a retrospective chart review was performed, and data collected on stone episodes, Emergency Department (ED) visits, hospital admissions and surgical interventions. To obtain long-term outcomes, the four sites with the largest initial accrual were included in a second phase of data collection with updated analyses. The patients from those sites were contacted, re-consented, and data were collected on stone surgical interventions, stone episodes, stone recurrences on imaging, emergency department (ED) visits, and hospital admissions for stone-related care since their original procedure. One-year follow-up data were collected in 111 of the original 159 (69.8%) patients from the nine sites. There were no statistically significant differences in the number of painful episodes, ED visits, hospital admissions, or surgical interventions. 94 patients from four sites were included in the long-term analysis. There were no statistically significant differences in surgical interventions, painful stone episodes, stone recurrence on imaging, ED visits or hospitalizations for stone-related events between the two groups. Long-term outcomes of dusting versus basketing during ureteroscopy indicate that there are no significant differences in clinical outcomes between the two surgical modalities.

Development of a High-Throughput Urosepsis Mouse Model

Murine sepsis models are typically polymicrobial, and are associated with high mortality. We aimed to develop a high-throughput murine model that mimics a slow-paced, monomicrobial sepsis originating from the urinary tract. A total of 23 male C57Bl/6 mice underwent percutaneous insertion of a 4 mm catheter into the bladder using an ultrasound-guided method, previously developed by our group. The following day, Proteus mirabilis (PM) was introduced percutaneously in the bladder in three groups: g1-50 µL 1 × 10⁸ CFU/mL solution (n = 10); g2-50 µL 1 × 10⁷ CFU/mL solution (n = 10); and g3 (sham mice)-50 µL sterile saline (n = 3). On day 4, mice were sacrificed. The number of planktonic bacteria in urine, adherent to catheters, and adherent to/invaded into the bladder and spleen was assessed. Cell-free DNA, D-dimer, thrombin-antithrombin complex (TAT), and 32 pro-/anti-inflammatory cytokines/chemokines were quantified in the blood. All mice survived the 4 day postinterventional period. Mean weight loss was 11% in g1, 9% in g2, and 3% in the control mice. Mean urine CFU counts were highest in group 1. All catheters showed high catheter-adhered bacterial counts. Of the infected mice, 17/20 had CFU counts in the splenic tissue, indicating septicemia. Plasma levels of cell-free DNA, D-dimer, and the proinflammatory cytokines IFN-γ, IL-6, IP-10, MIG, and G-CSF were significantly elevated in infected mice versus controls. We present a reproducible, monomicrobial murine model of urosepsis that does not lead to rapid deterioration and death, and is useful for studying prolonged urosepsis.

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.

Role of Bacterial Surface Components in the Pathogenicity of Proteus mirabilis in a Murine Model of Catheter-Associated Urinary Tract Infection

Proteus mirabilis (PM) is a Gram-negative, rod-shaped bacterium that causes catheter-associated urinary tract infections (CAUTIs). The specific roles of bacterial surface components (BSCs) in PM pathogenicity and CAUTIs remain unknown. To address this knowledge gap, we utilized relevant in vitro adhesion/invasion models and a well-established murine model of CAUTI to assess the ability of wildtype (WT) and seven mutant strains (MSs) of PM with deficiencies in various genes encoding BSCs to undergo the infectious process (including adhesion to catheters) in both model systems. Overall, MSs adhesion to catheters and the different cell types tested was significantly reduced compared to WT, while no invasion of cells was evident at 24 h. In vivo, WT showed a greater number of planktonic (urine) bacteria, bacteria adherent to catheters, and bacteria adherent to/invading bladder tissue when compared to the MSs. Bacterial counts in urine for PMI3191 and waaE mutants were lower than that for WT and other MSs. The complementation of mutated BSC genes resulting in the biggest defects restored the invasion phenotype both in vitro and in vivo. BSCs play a critical role at various steps in the pathogenicity of PM including adhesion to indwelling medical devices and adhesion/invasion of urinary tissue in vivo.

Preoperative patient optimization for endourological procedures: the current best clinical practice

PURPOSE OF REVIEW

Despite technological advancements in endourological surgery, there is room for improvement in preoperative patient optimization strategies. This review updates recent best clinical practices that can be implemented for optimal surgical outcomes.

RECENT FINDINGS

Outcome and complication predictions using novel scoring systems and techniques have shown to assist clinical decision-making and patient counseling. Innovative preoperative simulation and localization methods for percutaneous nephrolithotomy have been evaluated to minimize puncture-associated adverse events. Novel antibiotic prophylaxis strategies and further recognition of risk factors that attribute to postoperative infections have shown the potential to minimize perioperative morbidity. Accumulating data on the roles of preoperative stenting and selective oral alpha-blockers adds evidence to the current paradigm of preventive measures for ureteral injury.

SUMMARY

Ample tools and technologies exist that can be utilized preoperatively to improve surgical outcomes. The combination of these innovations, along with validation in larger-scale studies, presents the cornerstone of future urolithiasis management.

Indwelling stents cause obstruction and induce ureteral injury and fibrosis in a porcine model

OBJECTIVES

To investigate global changes in ureters at the transcriptional, translational and functional levels, both while stents are indwelling and after removal and recovery, and to study the effects of targeting pathways that play a potential role.

METHODS

Pig ureters were stented for varying amounts of time (48 h, 72 h, 14 days) and the impact on peristalsis, dilatation and hydronephrosis were assessed. RNAseq, proteomic, histological and smooth muscle (SM) function analyses were performed on ureteric and kidney tissues to assess changes induced by stenting and recovery. Pathway analysis was performed using Ingenuity Pathway Analysis software. To study the impact of possible interventions, the effects of erythropoeitin (EPO) and a Gli1 inhibitor were assessed.

RESULTS

Stenting triggers massive ureteric dilatation, aperistalsis and moderate hydronephrosis within 48 h. Pathways associated with obstruction, fibrosis and kidney injury were upregulated by stenting. Increased expression of GLI1, clusterin-α (a kidney injury marker) and collagen 4A2 (a fibrosis marker) was found in stented vs contralateral unstented ureters. EPO did not improve peristalsis or contraction force but did decrease non-purposeful spasming seen exclusively in stented ureters. Tamsulosin administration increased contractility but not rate of peristalsis in stented ureters.

CONCLUSIONS

Ureters respond to stents similarly to how they respond to an obstruction, that is, with activation of pathways associated with hydronephrosis, fibrosis and kidney injury. This is driven by significant dilatation and associated ureteric SM dysfunction. EPO and tamsulosin induced mild favourable changes in SM physiology, suggesting that targeting specific pathways has potential to address stent-induced complications.

International Alliance of Urolithiasis guideline on retrograde intrarenal surgery

OBJECTIVES

To set out the second in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis that concerns retrograde intrarenal surgery (RIRS), with the aim of providing a clinical framework for urologists performing RIRS.

MATERIALS AND METHODS

After a comprehensive search of RIRS-related literature published between 1 January 1964 and 1 October 2021 from the PubMed database, systematic review and assessment were performed to inform a series of recommendations, which were graded using modified GRADE methodology. Additionally, quality of evidence was classified using a modification of the Oxford Centre for Evidence-Based Medicine Levels of Evidence system. Finally, related comments were provided.

RESULTS

A total of 36 recommendations were developed and graded that covered the following topics: indications and contraindications; preoperative imaging; preoperative ureteric stenting; preoperative medications; peri-operative antibiotics; management of antithrombotic therapy; anaesthesia; patient positioning; equipment; lithotripsy; exit strategy; and complications.

CONCLUSION

The series of recommendations regarding RIRS, along with the related commentary and supporting documentation, offered here should help provide safe and effective performance of RIRS.

RIRS with disposable or reusable scopes: does it make a difference? Results from the multicenter FLEXOR study

Introduction

With several single-use ureteroscopes now available, our aim was to analyze and compare data obtained globally from high-volume centers using both disposable and reusable flexible ureteroscopes and see if indeed in real-world practice either scope has a distinct advantage.

Methods

Retrospective analysis was performed on the FLEXOR registry, which was created as a TOWER group (Team of Worldwide Endourological Researchers, research wing of the Endourological Society) endeavor. Patients who underwent retrograde intrarenal surgery (RIRS) for renal stones from January 2018 to August 2021 were enrolled from 20 centers globally. A total of 6663 patients whose data were available for analysis were divided into Group 1 (Reusable scopes, 4808 patients) versus Group 2 (Disposable scopes, 1855 patients).

Results

The age and gender distribution were similar in both groups. The mean stone size was 11.8 mm and 9.6 mm in Groups 2 and 1, respectively (p < 0.001). Group 2 had more patients with >2 cm stones, lower pole stones and of higher Hounsfield unit. Thulium fiber laser (TFL) was used more in Group 2 (p < 0.001). Patients in Group 2 had a slightly higher stone-free rate (SFR) (78.22%) and a lower number of residual fragments (RFs) compared with Group 1 (p < 0.001). The need for further treatments for RF and overall complications was comparable between groups. On multivariate analysis, overall complications were more likely to occur in elderly patients, larger stone size, lower pole stones, and were also more when using disposable scopes with longer operative time. RFs were significantly higher (p < 0.001) for lower pole, larger, harder, multiple stones and in elderly.

Conclusion

Our real-world practice observations suggest that urologists choose disposable scopes for bigger, lower pole, and harder stones, and it does indeed help in improving the single-stage SFR if used correctly, with the appropriate lasers and lasing techniques in expert hands.

Prospective randomized trial of 2 versus 12-weeks of postoperative antibiotics after percutaneous nephrolithotomy in complex patients with infection-related kidney stones

PURPOSE

Treatment of struvite kidney stones requires complete surgical stone removal combined with antibiotic therapy to eliminate urinary tract infections and preventive measures to reduce stone recurrence. The optimal duration of antibiotic therapy is unknown. We sought to determine if 2- or 12-weeks of antibiotics post percutaneous nephrolithotomy (PNL) for infection stones resulted in better outcomes for stone recurrence and positive urine cultures.

MATERIAL AND METHODS

This multi-center, prospective randomized trial evaluated patients with the clinical diagnosis of infection stones. Patients were randomized to 2- or 12-weeks of postoperative oral antibiotics (nitrofurantoin or culture-specific antibiotic) and included if residual fragments were ≤4 mm on computed tomography imaging after PNL. Imaging and urine analyses were performed at 3-, 6-, and 12-months post-procedure.

RESULTS

Thirty-eight patients were enrolled and randomized to either 2-weeks (n = 20) or 12-weeks (n = 18) of antibiotic therapy post-PNL. Eleven patients were excluded due to residual fragments >4 mm, and 3 patients were lost to follow-up. The primary outcome was the stone-free rate (SFR) at 6 months post-PNL. At 3-, 6-, and 12-months follow-up, SFRs were 72.7% versus 80.0%, 70.0% versus 57.1%, 80.0% versus 57.1% (p = ns), between 2- and 12-week-groups, respectively. At 3-, 6-, and 12-months follow-up, positive urine cultures were 50.0% versus 37.5%, 50.0% versus 83.3%, and 37.5% versus 100% between 2- and 12-week groups, respectively (p = ns).

CONCLUSIONS

For patients with stone removal following PNL, neither 2-weeks nor 12-weeks of postoperative oral antibiotics is superior to prevent stones and recurrent positive urine cultures.

Predictors and Healthcare Utilization of Sepsis Post-Ureteroscopy in a US-Based Population : Results from the Endourological Society TOWER Collaborative

Purpose To investigate the incidence, predictive factors, and healthcare utilization of sepsis post-ureteroscopy (URS) in patients enrolled in commercial insurance plans. Materials and Methods A retrospective claims analysis was conducted using the IBM® MarketScan® commercial database. Patients ≥18 years were included if they had URS between January 2015-October 2019 and developed sepsis within 30 days of URS. Multivariate logistic regression was used to identify various clinical and demographic predictors of sepsis post-URS. All-cause healthcare utilization (i.e., inpatient admissions and intensive care unit stays) and all-cause healthcare costs up to 1 month post-septic event were measured. Results Among the 104,100 URS patients meeting the inclusion criteria, 5.5% developed sepsis. Patients with diabetes (OR=1.52; p<0.0001), older age (age 55-64 versus 18-34; OR=1.35; p<0.0001), baseline sepsis (OR=3.51; p<0.0001), baseline inpatient visits (OR=1.17; p=0.0012), and higher Elixhauser comorbidity scores (OR=1.09; p<0.0001) had a significantly higher likelihood of developing sepsis post-URS. In septic patients, 94.8% required inpatient care and 35% were admitted to the ICU. Mean hospital stay for septic patients was 6.86 days. Average all-cause healthcare cost per patient at 1 month in the septic cohort was $49,625 versus $17,782 in the non-septic cohort indicating an incremental all-cause cost of $31,843 (p<0.0001). Conclusions A total of 5.5% of commercially insured patients undergoing URS developed sepsis post-URS. Diabetes, older age, baseline sepsis, baseline inpatient visit, and higher comorbidity score were all found to be independent predictors of post-URS sepsis. Patients with sepsis post-URS had higher healthcare utilization and costs indicating that sepsis is both a significant clinical and economic event.

The duration of stone disease and the impact of a stone event on patients' quality of life

INTRODUCTION

With a 5-year stone recurrence rate of 30-50%, kidney stone formers are subject to significant morbidity which negatively impacts their Health Related Quality of Life (HRQOL). We sought to determine the impact of age of kidney stone onset, duration of stone disease, and kidney stone event (surgery or stone passage) on patients' individual HRQOL by querying the validated and prospectively collected Wisconsin Stone Quality of Life (WISQOL) database.

MATERIALS AND METHODS

Cross-sectional data were obtained from a total of 2,438 kidney stone formers from 14 institutions in North America who completed the WISQOL questionnaire from 2014 to 2019. The 28-question survey has a 1-5 point scale for each item (total score range 0-140). Multivariable linear regression models assessed the impact of age of kidney stone onset, duration of stone disease and time since most recent surgery or stone passage on HRQOL.

RESULTS

Of 2,438 patients, older age at kidney stone onset and longer duration of disease were both independent predictors of better WISQOL (β=0.33 points/year; CI 0.17-0.49; p<0.001 and β=0.50 points/year; CI 0.32-0.68; p<0.001, respectively). Of 1,376 patients with surgery between 2010-2019, increased time since most recent surgery was an independent predictor of better WISQOL scores (β = 2.28 points/year; CI: 1.47-3.10; p=<0.001). Of 1,027 patients with spontaneous stone passage between 2010-2019, increased time since most recent stone passage was an independent predictor of better WISQOL scores (β = 1.59 points/year; CI: 0.59-2.59; p=<0.05).

CONCLUSION

Our study demonstrates that older age of onset, longer duration of disease, increase time from most recent surgery or stone passage were independent predictors of better HRQOL in kidney stone formers. Results of future studies that focus on optimizing stone related modifiable risk factors to decrease the amount of recurrent stone episodes and thus the need for recurrent surgeries will be essential.

A Global Survey of Ergonomics Practice Patterns and Rates of Musculoskeletal Pain Among Urologists Performing Retrograde Intrarenal Surgery

PURPOSE

Retrograde intrarenal surgery (RIRS) requires awkward body posture for long durations. Few urologists receive ergonomics training despite the availability of ergonomics best practices utilized by other surgical specialties. We characterize ergonomics practice patterns and rates of musculoskeletal (MSK) pain among urologists performing RIRS.

METHODS

A web-based survey was distributed via the Endourological Society, the EAU, and social media. Surgeon anthropometrics and ergonomic factors were compared to ergonomics 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 ergonomics training. Residents/fellows had significantly lower confidence in ergonomic technique compared to attending surgeons of any career length. Adherence to proper ergonomic positioning for modifiable factors were highly variable. On NMQ, 12-month rates of RIRS-associated pain in ≥1 body part, pain limiting activities of daily living, and pain requiring medical evaluation were 81%, 51%, and 29%, respectively. Annual case volume >150 cases (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.

CONCLUSION

Adherence to ergonomics 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 ergonomics guidelines for RIRS.

Role of pre-operative ureteral stent on outcomes of retrograde intra-renal surgery (RIRS): systematic review and meta-analysis of 3831 patients and comparison of Asian and non-Asian cohorts

PURPOSE

To evaluate the outcomes of pre-stented (PS) versus non-pre-stented (NPS) patients who have undergone retrograde intrarenal surgery (RIRS) for renal calculi with subgroup analysis of Asian and non-Asian cohorts.

METHODS

Protocol is registered in PROSPERO, CRD42021261123. Eligible studies identified from four electronic databases. Meta-analysis was done to enumerate the outcomes of RIRS in between PS and NPS. Secondary sub-analysis was done to look for differences in outcomes in Asian and non-Asian cohorts.

RESULTS

Fourteen studies involving 3831 patients (4 prospective, 10 retrospective studies) were included. PS patients experienced higher success rates of ureteral access sheath (UAS) insertion than NPS (RR 1.09, 95% CI 1.05-1.13, p < 0.00001). PS patients had lower risk of ureteral injuries from UAS placement (RR 0.69, 95% CI 0.50-0.96, p = 0.03). No significant differences in intra- and postoperative complications between two groups were found. Stone-free rate (SFR) outcomes for residual fragment (RF) cut-off of < 1 mm and < 4 mm favoured the PS patients (RR 1.10, 95% CI 1.04-1.17, p = 0.002 for < 4 mm, RR1.10, 95% CI 1.02-1.19, p = 0.02 for < 1 mm). In the subgroup analysis, PS Asian patients had similar SFR as NPS patients for SFR(< 4 mm) but non-Asian population showed better outcomes in the PS patients for SFR(< 4 mm) (RR 1.31, 95% CI 1.13-1.52, p = 0.0005).

CONCLUSIONS

This meta-analysis suggests that pre-stenting results in a higher success for UAS placement, minimising intraoperative ureteric injury, with higher overall SFR for any RF cut-off in PS cohorts. In non-Asian cohort, significant differences occurred at SFR < 4 mm but not for SFR < 1 mm. No difference was seen in our Asian cohort for any SFR cut-off in both PS and NPS patients.

Consensus Statement on Urinary Stone Treatment During A Pandemic: A Delphi Process from the Endourological Society TOWER Research Initiative

INTRODUCTION

The COVID-19 pandemic has had a significant impact on the care of patients with urolithiasis. Recommendations and prioritization of endourologic surgical procedures vary among regions and a comprehensive overall international directive is needed. We used the Delphi method to obtain international consensus on managing urolithiasis patients during the pandemic.

METHODS

A three-round Delphi process was used to elicit expert consensus (53 global key opinion leaders within the Endourological Society from 36 countries) on an extensive survey on management of endourologic patients in a pandemic. Questions addressed general management, inpatient and outpatient procedures, clinic visits, follow-up care and best practices for suspension and resumption of routine care.

RESULTS

Consensus was achieved in 64/84 (76%) questions. Key consensus findings included: consultations should be delivered remotely when possible. Invasive surgical procedures for urolithiasis patients should be reserved for high-risk situations (infection, renal failure, etc.). To prevent aerosolization, spinal anesthesia is preferred over general, whenever feasible. Treatment of asymptomatic renal stones should be deferred. Primary definitive treatment of obstructing or symptomatic stones (both renal and ureteral) is preferred over temporizing drainage. Extracorporeal shock wave lithotripsy should be continued for obstructive ureteral stones. There was consensus on treatment modalities and drainage strategies depending on location and size of the stone.

CONCLUSION

International endourologist members of the Endourological Society participated in this Delphi initiative to provide expert consensus on management of urolithiasis during a pandemic. These results can be applied currently and during a future pandemic.

Effect of Simulation-based Training on Surgical Proficiency and Patient Outcomes: A Randomised Controlled Clinical and Educational Trial

BACKGROUND

It is hypothesised that simulation enhances progression along the initial phase of the surgical learning curve.

OBJECTIVE

To evaluate whether residents undergoing additional simulation, compared to conventional training, are able to achieve proficiency sooner with better patient outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This international, multicentre, randomised controlled trial recruited 94 urology residents with experience of zero to ten procedures and no prior exposure to simulation in ureterorenoscopy, selected as an index procedure.

INTERVENTION

Participants were randomised to simulation or conventional operating room training, as is the current standard globally, and followed for 25 procedures or over 18 mo.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The number of procedures required to achieve proficiency, defined as achieving a score of ≥28 on the Objective Structured Assessment of Technical Skill (OSATS) scale over three consecutive operations, was measured. Surgical complications were evaluated as a key secondary outcome. This trial is registered at www.isrctn.com as ISCRTN 12260261.

RESULTS AND LIMITATIONS

A total of 1140 cases were performed by 65 participants, with proficiency achieved by 21 simulation and 18 conventional participants over a median of eight and nine procedures, respectively (hazard ratio [HR] 1.41, 95% confidence interval [CI] 0.72-2.75). More participants reached proficiency in the simulation arm in flexible ureterorenoscopy, requiring a lower number of procedures (HR 0.89, 95% CI 0.39-2.02). Significant differences were observed in overall comparison of OSATS scores between the groups (mean difference 1.42, 95% CI 0.91-1.92; p < 0.001), with fewer total complications (15 vs 37; p = 0.003) and ureteric injuries (3 vs 9; p < 0.001) in the simulation group.

CONCLUSIONS

Although the number of procedures required to reach proficiency was similar, simulation-based training led to higher overall proficiency scores than for conventional training. Fewer procedures were required to achieve proficiency in the complex form of the index procedure, with fewer serious complications overall.

PATIENT SUMMARY

This study investigated the effect of simulation training in junior surgeons and found that it may improve performance in real operating settings and reduce surgical complications for complex procedures.

Influence of webinar based learning on practice of percutaneous nephrolithotomy: Outcomes of a global survey

Background With webinars looking to be the mainstay post-pandemic, it is important to demonstrate if webinars are indeed effective educational tools for professional training and skill acquisition. We aim to demonstrate, via a global survey, the efficacy of webinars on PCNL and how this knowledge transforms clinical practice. Methods A structured online survey covering the following sections: (1) Demographics, (2) PCNL techniques, (3) PCNL equipment, was circulated. The target study population were practicing urologists and residents. Categorical data were presented with counts and percentages, and compared using Chi-square test. Continuous data was analysed with non-parametric methods. Respondents were dichotomised according to attendance of webinars type, attendees of dedicated PCNL webinars (Group A) or attendees of endourological webinars that discussed some aspects of PCNL (Group B). Results A total of 303 respondents participated from 38 countries. 91.7% (n=278) were in Group A with 8.3% (n=25) in Group B. 77.9% were under the age of fifty years while 51.8% had more than 10 years of urology experience. In group A, urologists of all ages, in academic institutions and private practitioners, significantly benefitted in gaining knowledge about the merits of newer devices and the role of suction assisted devices in modern PCNL; Majority of group A also reflected that by attending a dedicated PCNL based webinar they benefited in learning newer positions for PCNL access, especially supine, and how to effectively use laser as energy devices for lithotripsy. In Group B, the only area of benefit was in lasing techniques and the use of newer lasers like the TFL. Conclusion Our survey positively validates the two proposed hypothesis i.e. webinars as a medium of education do benefit practicing urologists in knowledge and the clinical practice domains. Age, experience or place of practice is no barrier to adopting newer mediums of education like webinars.

Quality of Life of Urolithiasis Patients During the COVID-19 Pandemic: A Multi-Institutional Cross-Sectional Study

Purpose The COVID-19 pandemic is an unprecedented global event that has caused significant fear and anxiety across all populations. To date, there have been no studies on how major health crises have affected the stone-related quality-of-life (QOL) of urolithiasis patients. In this multi-institutional study, we investigated whether the fear of COVID-19 affects the QOL of urolithiasis patients during the COVID-19 pandemic using the Fear of COVID-19 Scale (FCV-19S) and the Wisconsin Stone Quality of Life (WISQOL) questionnaires. Materials and Methods Patient-reported data collection occurred between April-October 2020 during the COVID-19 pandemic where many procedures (radiological or surgical) and visits were either delayed or cancelled. The scores generated from patient-reported responses to questionnaires were correlated and then further sub-analyzed dependent on categorical responses related to procedural delays or care and were analyzed via the Student's T-test. A single factor analysis of variance (ANOVA) was performed to analyze varying QOL scores across the FCV-19S quartiles. Results 400 respondents participated in this study. Overall mean total standardized FCV-19S and WISQOL scores (both transformed to min-max 0-100) were 34.3 and 70.3 respectively. A significant inverse correlation (r=-0.265, p<0.0001) was demonstrated suggesting greater COVID-19 fear may result in lower stone-related quality-of-life. A significant difference in fear and QOL scores was observed between the sexes, with women having more COVID-19 fear (35.8 vs. 28.6, p<0.01) and lower stone-related QOL (64.2 vs. 75.2, p<0.01). Quartile ANOVA analysis revealed significant mean difference in WISQOL scores across all FCV-19S score quartiles (p<0.05). Conclusions Using two validated questionnaires (FCV-19S and WISQOL) and correlating patient-reported responses, we found that greater fear for COVID-19 was associated lower stone-related QOL in urolithiasis patients.

Mediators of human ureteral smooth muscle contraction-a role for erythropoietin, tamsulosin and Gli effectors

Background

Ureteral contractility is a poorly understood process. Contractions have been demonstrated to occur in the smooth muscle layers of the ureter. Previous work suggests the involvement of Gli family proteins and erythropoietin (EPO) in regulating mammalian ureteral smooth muscle contraction. We sought to devise a method by which the effects of these proteins and tamsulosin on distal human ureteral tissue contractility could be investigated to better understand mechanisms regulating human ureteral function.

Methods

IRB approval was obtained to procure portions of extraneous distal ureteral tissue from living donor renal transplants. Contractility was measured by placing the tissue in Krebs buffer and stimulating via a uniform electric current. Contractile force was recorded with each stimulation with and without the presence of a Gli inhibitor (GANT61) or EPO. Each ureteral specimen was subsequently fixed and tested by immunohistochemistry to determine Gli, EPO and alpha-adrenergic receptor activity.

Results

Electrical field stimulation successfully elicited contractions in the ureteral tissue. Administering tamsulosin decreased force and duration of ureteral contractions. Inhibiting Gli signaling decreased contractility and EPO decreased ureteral contractile forces within 5 minutes of administration versus untreated controls. Staining confirmed Gli1 protein and α-adrenergic receptor expression in ureteral smooth muscle and epithelial tissue with EPO receptor expression confined to the epithelial layer.

Conclusions

Distal ureteral contractile forces are decreased by inhibition of Gli family proteins and the α-adrenergic receptor. EPO acts within five minutes, suggesting ion channel involvement instead of changes in gene expression. Continuing work will elucidate the role of these proteins in coordinating ureteral contractions. This has implications for the use of pharmacologic methods to address ureteral contractility and dysfunctional peristalsis during stone passage, ureteroscopy, in transplant patients and potentially to reduce symptoms from ureteral stents.

A Novel Visual Grading for Ureteral Encrusted Stent Classification to Help Decide the Endourologic Treatment

Objective: The aim of the study is to propose a visual classification for encrusted stents (ESs) to help choose the appropriate endourologic treatment. Materials and Methods: A multicenter, retrospective, and descriptive study was performed. A total of 140 patients with encrusted Double-J stents were enrolled from 5 different institutions. The novel visual grading for ureteral encrusted stent (V-GUES) classification system ranges from A to D, increasing with severity of encrustation. Results: ESs could be removed with a single intervention in 112 patients (86.8%). Type A and B ESs could be removed in all patients (100% success). Type D stents had minor retrieval and stone-free rates (p = 0.006 and p < 0.0001, respectively). Flexible ureteroscopy had a low success rate (77.7%) for type C stents (odds ratio [OR]: 0.21). Combined access had a 100% success rate for retrieval of type C ESs and a 92.9% success rate for type D ESs (OR: 9.18). Type D stents were associated with patients requiring more than one session to retrieve the stent (OR: 0.11) and stones (OR: 0.21). Conclusions: The V-GUES system is associated with treatment success rates of ES retrieval and stone-free status. It is also associated with the complication rate and the number of sessions needed for patients to be stent and stone free. The V-GUES classification could help counsel patients about the best treatment options and their outcomes. Further prospective studies will be needed to provide external validation.

Ureteroscopic Performance of High Power Super Pulse Thulium Fiber Laser for the Treatment of Urolithiasis: Results of the First Case Series in North America

OBJECTIVE

To report the first case series of ureterorenoscopy in North America using the High Power Super Pulse Thulium Fiber Laser for the treatment of upper urinary tract stones.

METHODS

After Institutional Review Board approval, a multicentric retrospective chart review of patients treated with the High Power Super Pulse Thulium Fiber Laser from October 2019 to March 2020 was conducted. Basic demographic information, pre-operative, and peri-operative data were recorded.

RESULTS

Seventy-six patients were included with a mean age of 60.9 ± 13.3 years. 118 stones were treated including 32 within the ureter, 49 in the lower pole, 37 in mid or upper poles. Dusting technique was commonly used (67.1%) with pulse frequencies up to 2400 Hz. Mean operative time was 59.4 ± 31.5 minutes. Mean laser time and total laser energy were 10.8 ± 14.1 minutes and 12.5 ± 19.1 KJ, respectively. Intraoperative complications were limited to 7 grade 1, 3 grade 2, and 1 grade 3 ureteral injuries and one case of renal collecting system bleeding that was adequately managed with laser coagulation settings (1J-20Hz).

CONCLUSION

This initial case series in North America of the High Power Super Pulse Thulium Fiber Laser is promising for the treatment of urolithiasis. Sub-200 μm fibers and dusting settings up to 2400 Hz were utilized successfully. No specific complications related to use of the laser were seen.

Validation of The Japanese Version of The Wisconsin Stone Quality of Life Questionnaire (WISQOL): Results from SMART Study Group

BACKGROUND

The Wisconsin Stone Quality of Life questionnaire (WISQOL) is a health-related quality of life measure designed for patients with urinary stones. It has been translated and used in several languages. This study aimed to validate the Japanese version of the WISQOL (J-WISQOL).

MATERIALS AND METHODS

The J-WISQOL was translated and validated using a multistep process proposed by the World Health Organization that involved forward translation, back-translation, and pilot testing with a group of patients. This study enrolled 150 patients with urinary stones who visited three academic hospitals for stone treatment. We assessed convergent validity of correlation patterns and internal consistency of the J-WISQOL and Short-Form 36-item survey version 2 (SF-36v2).

RESULTS

Overall, 150 patients were enrolled. The mean total score of the J-WISQOL was 108.18 ± 20.26 (raw score min-max, 28-140), suggesting that the onset and symptoms of urinary stones reduced the health-related quality of life in the patients. The J-WISQOL showed good internal consistency (Cronbach's α = 0.96) and inter-domain associations (Spearman's correlation coefficient r = 0.67-0.94). The J-WISQOL was correlated with the SF-36v2 in all domains: social, emotional, health, and vitality impact (r = 0.47-0.66).

CONCLUSION

The J-WISQOL is a reliable instrument for evaluating health-related quality of life measures in patients with urinary stones. It could be a useful quality of life questionnaire for urinary stones in Japan.