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Introduction and Objective: In early 2020, as the SARS-Cov-2 (COVID-19) pandemic progressed, many institutions limited nonurgent surgical care. This coincided with a decade-long trend of increasing percutaneous nephrolithotomy (PCNL) and ureteroscopy (URS) and decreasing shock wave lithotripsy (SWL) for surgical management of urolithiasis. Herein, we evaluate temporal stone surgery rates and surgeon volumes in the Medicare population and suggest how COVID-19 contributed to them. Methods: Retrospective analysis was conducted using the "Medicare Physician & Other Practitioners" database containing data from January 2013 to December 2021. Adult patients who underwent stone surgery were included. We evaluated surgeon characteristics and changes in case volumes over time adjusted for population. Results: In 2013, urologists performed 68,910 stone surgeries: SWL 42,903 (62%); URS 25,321 (37%); PCNL 686 (1%). Over the next 8 years, there was an average annual increase in URS (+13%) and PCNL (+13%) and decrease in SWL (−2%). In 2020, there was a 14% reduction in all stone cases: SWL (−25%); URS (−6%); PCNL (−8%). By 2021, case volumes recovered to pre-2020 levels, though SWL remained low: SWL 33,974 (34%); URS 64,541 (64%); PCNL 1764 (2%). From 2013 to 2021, the number of urologists performing SWL decreased (1718 to 1361) while URS and PCNL providers doubled (1,347 to 2,914 and 28 to 76, respectively). Conclusions: From 2013 to 2021, there was an increase in URS and PCNL and a decrease in SWL in the US Medicare population. The COVID-19 pandemic was associated with a decline in stone surgeries, particularly SWL. By 2021, PCNL and URS case numbers increased significantly with a smaller increase in SWL. [ABSTRACT FROM AUTHOR]

Introduction: The use of a ureteral access sheath (UAS) during ureteroscopy (URS) has been associated with the risk for ureteral injuries. Preoperative administration of α1-blockers presents a potential mitigator of such lesions by inducing ureteral relaxation, which may also contribute to improving other surgical outcomes. Methods: A comprehensive literature search was conducted across MEDLINE, Embase, and Cochrane databases for studies comparing preoperative α1-blockers administration vs its non-use in adult patients without pre-stenting undergoing URS. Binary outcomes were evaluated using risk ratios (RRs) and odds ratios (ORs) with 95% confidence intervals (CIs). Heterogeneity was measured with the Cochran's Q test, I2 statistics, and prediction intervals (PIs). A DerSimonian and Laird random-effects model was utilized for all outcomes. Results: Eleven studies encompassing 1074 patients undergoing URS were included, of whom 522 (48.60%) received α1-blockers before the procedure. Preoperative α1-blockers were associated with a reduction in significant ureteral injuries (RR 0.30; 95% CI 0.17–0.53; I2 = 6%; PI 0.10–0.88) and an increase in mean successful UAS insertion (OR 2.14; 95% CI 1.08–4.23; I2 = 23%; PI 0.51–8.93). In patients undergoing exclusively ureteroscopy lithotripsy (URSL), the medications also reduced total complications (RR 0.62; 95% CI 0.46–0.84; I2 = 0%) and complications graded Clavien–Dindo III or higher (RR 0.16; 95% CI 0.04–0.69; I2 = 0%), but no significant difference between groups was found in the stone-free rate (RR 1.10; 95% CI 0.86–1.40; I2 = 91%; PI 0.47–2.59). Conclusion: Preoperative α1-blockers were linked to a decrease in significant ureteral injuries with UAS use and fewer complications during URSL procedures. However, their impact on the successful insertion of a UAS remains uncertain. Consideration of administering preoperative α1-blockers in non-stented adult patients undergoing URS with UAS is advisable. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study is to evaluate the possible benefits of using video consent in the preoperative ureteroscopy (URS) consent process. Material and Methods: Prospective randomized trials took place at two Italian tertiary-care centers from March 2022 to September 2022. Patients were randomly assigned to two groups: Group A (standard verbal/written informed consent) and Group B (informed consent supported by video). We investigated the impact of both types of informed consent on patient anxiety levels using the Spielberger State-Trait Anxiety Inventory (STAI) questionnaire both pre- and post-consent. In addition, using the Visual Analogue Scale, analysis of the effect of informed consent on postoperative pain and the number of calls for assistance during hospitalization as secondary outcomes was done. To assess the satisfaction level related to the whole process, patients were asked to rate their experience on a scale of 1–10, with 1 indicating "not satisfied" and 10 indicating "completely satisfied." Results: Overall, 166 patients were randomized 1:1 in each group. The multivariable regression model demonstrated that video-assisted informed consent significantly increased the difference between post- and pre-consent STAI with a reduced level of anxiety. The video-assisted informed consent significantly predicted the number of assistance calls during hospitalization. Conclusions: Video consent for ureteroscopies is a valid tool to improve procedure awareness and satisfaction. Video consent is able to reduce procedure-related patient anxiety and postoperative assistance calls, thus proving to be useful in obtaining better-informed consent for endourological procedures. [ABSTRACT FROM AUTHOR]

Introduction: Ureteral stents can cause significant patient discomfort, yet the temporal dynamics and impact on activities remain poorly characterized. We employed an automated tool to collect daily ecological momentary assessments (EMAs) regarding pain and the ability to work following ureteroscopy with stenting. Our aims were to assess feasibility and better characterize the postoperative patient experience. Materials and Methods: As an exploratory endpoint within an ongoing clinical trial, patients undergoing ureteroscopy with stenting were asked to complete daily EMAs for 10 days postoperatively or until the stent was removed. Questionnaires were distributed through text messages and included a pain scale (0–10) and a single item from the validated Patient-Reported Outcomes Measurement Information System Ability to Participate in Social Roles and Activities instrument, as well as days missed from work or school. Results: Among the first 65 trial participants, 59 completed at least 1 EMA (overall response rate 91%). Response rates were >85% for each time point through postoperative day (POD)10. Median respondent age was 58 years (interquartile range [IQR] 50–67), and 56% were female. Stones were 54% renal and 46% ureteral, with a median diameter of 9 mm (IQR 7–10). Median stent dwell time was 7 days (IQR 6–8). Pain scores were highest on POD1 (median score 4) and declined on each subsequent day, reaching a median score of 2 on POD5. Sixty-three percent of patients on POD1 reported that they had trouble performing their usual work at least sometimes, but by POD5, this was <50% of patients. Patients who work or attend school reported a median of 1 day missed (IQR 0–2). Conclusions: An automated daily EMA system for capturing patient-reported outcomes was demonstrated to be feasible with sustained excellent engagement. Patients with stents reported the worst pain and interference with work on POD1, with steady improvements thereafter, and by POD5, the majority of patients had minimal pain or trouble performing their usual work. This work is associated with a registered clinical trial [NCT05026710]. [ABSTRACT FROM AUTHOR]

Introduction: The wide use of high-power laser has changed the landscape of ureteroscopy and lasertripsy (URSL). We wanted to look at the role and outcomes of high-power holmium:yttrium–aluminum–garnet laser for URSL in pediatric stone disease. Methods: A prospective analysis of consecutive pediatric patients treated with "Dusting and Pop-dusting" using a high-power laser was done between January 2016 and March 2022. The project was registered with our audit committee. Data were analyzed for patient demographics, stone characteristics, operative details, procedural outcomes, and complications. Stone-free rate (SFR) was defined as fragments ≤2 mm on postoperative ultrasound imaging 2–3 months after the procedure. Results: A total of 35 patients underwent 43 procedures (1.2 procedure/patient) during the study period with a mean age of 9.4 years (range 1–16 years) and a male:female ratio of 13:22. The stone location was in the kidney in 32 (91.4%) patients of which 8 were in multiple renal locations. The mean stone size was 18 mm (range 10–39 mm), with the pre- and post-stent rates of 37% and 56%, respectively. An access sheath was used in 19 (44%) procedures. The overall SFR on ultrasound scan was 94% (n = 33) with no procedural complications noted in our series and a mean length of stay of 0.9 days. Conclusion: Pediatric URSL using a high-power laser achieves a high SFR even for large and multiple renal stones with no complications noted in our prospective series. Parents must, however, be counseled about the need for staged procedures, which might be needed for large stones. [ABSTRACT FROM AUTHOR]

Objective: The primary aim of the study was to explore intrarenal temperatures (IRTs) during flexible ureteroscopic laser lithotripsy (FURSL). The secondary aim was to investigate the correlation between temperatures and renal pelvis anteroposterior diameter (APD). Materials and Methods: From February 2023 to June 2023, 10 patients with an indwelling nephrostomy tube (NT) undergoing FURSL were enrolled in the study. Sheathless FURSL was performed using gravitational irrigation (23°C) at 60 cm. A sterile K-type thermocouple was inserted through the NT. Temperatures were recorded for 120 seconds with continuous laser activation and for another 60 seconds after deactivation. Thulium fiber laser delivered energy using a 150 μm fiber and incremental power settings of 5, 10, 20, and 30 W. The laser was deactivated whenever the IRT reached 43°C. Results: IRT correlated directly to power settings. Each time the power settings were increased, the temperature rose significantly. The increase in average peak temperature was 2.6°C between 5 and 10 W (p < 0.001), 3.4°C between 10 and 20 W (p < 0.001), and 2.5°C between 20 and 30 W (p < 0.001). Temperatures reached 43°C in three patients applying 20 W and in eight patients applying 30 W. The shortest activation-time until threshold was 12 and 28 seconds with 30 and 20 W settings, respectively. When reaching 43°C, temperatures remained above this threshold for an additional 29 seconds on average. There was a significant correlation between IRT and renal APD. For example, when 10 W was applied in the setting of APD ≤20 mm, the recorded temperature was on average 2.3°C higher compared with APD >20 mm, with the same power settings applied, p < 0.001. Conclusion: During FURSL, IRT correlates directly with power settings and is inversely correlated with renal pelvic APD. Using a sheathless approach, power settings ≥20 W should arguably be avoided, especially in the context of a nondilated renal pelvis. ClinicalTrials: The study was registered on ClinicalTrials.gov (NCT05677425). [ABSTRACT FROM AUTHOR]

Purpose: Ureteral access sheaths (UAS) pose the risk of severe ureteral injury. Our prior studies revealed forces ≤6 Newtons (N) prevent ureteral injury. Accordingly, we sought to define the force urologists and residents in training typically use when placing a UAS. Materials and Methods: Among urologists and urology residents attending two annual urological conferences in 2022, 121 individuals were recruited for the study. Participants inserted 12F, 14F, and 16F UAS into a male genitourinary model containing a concealed force sensor; they also provided demographic information. Analysis was completed using t-tests and Chi-square tests to identify group differences when passing a 16F sheath UAS. Participant traits associated with surpassing or remaining below a minimal force threshold were also explored through polychotomous logistic regression. Results: Participant force distributions were as follows: ≤4N (29%), >6N (45%), and >8N (32%). More years of practice were significantly associated with exerting >6N relative to forces between 4N and 6N; results for >8N relative to 4N and 8N were similar. Compared to high-volume ureteroscopists (those performing >20 ureteroscopies/month), physicians performing ≤20 ureteroscopies/month were significantly less likely to exert forces ≤4N (p = 0.017 and p = 0.041). Of those surpassing 6N and 8N, 15% and 18%, respectively, were high-volume ureteroscopists. Conclusions: Despite years of practice or volume of monthly ureteroscopic cases performed, most urologists failed to pass 16F access sheaths within the ideal range of 4N to 6N (74% of participants) or within a predefined safe range of 4N to 8N (61% of participants). [ABSTRACT FROM AUTHOR]

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

Objectives: To introduce a novel hydrodynamic design for a flexible ureteroscope that can increase stone debris clearance. Methods: Based on hydrodynamics, the new design allowed the ureteroscope to have six water jets. Fluid gushed from the six jets and would ultimately converge into an eddy. The safety and stone debris clearance efficiency were tested in a 3D-printed kidney model. Stone fragments between 0.5 and 1 mm were used to mimic the debris. A ureteroscope already approved for marketing was used as a control. Results: The new design did not change the local renal pressure and did not raise the whole renal pressure under irrigation at 80 or 100 mL/min but slightly raised it under irrigation at 120 mL/min. The pressures in the 2 g stone clearance procedures were 26.0, 33.1, and 37.5 cmH2O for the new design and 25.1, 30.2, and 39.3 cmH2O for the current design; in the 4 g stone clearance procedures, the pressures were 30.1, 37.2, and 40.0 cmH2O for the new design and 26.9, 30.8, and 39.8 cmH2O for the current design, all under conditions of 80, 100, and 120 mL/min irrigation, respectively. The new design significantly improved the stone clearance rate by ∼10-fold. It effectively cleared 2 and 4 g stones within 900 seconds under the three irrigation rates. In contrast, the current design cleared <10% of the stone debris in all tests. Conclusion: The new hydrodynamic design significantly improved the stone debris clearance rate without causing obviously increased renal pressure, and the improvement was maintained under different irrigation pressures and stone burdens. [ABSTRACT FROM AUTHOR]

Background: Same-session bilateral ureteroscopy may reduce the number of surgeries for stone removal but can lead to higher overall complication rates. We aimed to compare same-session bilateral ureteroscopy with unilateral ureteroscopy in terms of perioperative outcomes. Methods: We used the GeRmAn Nationwide inpatient Data (GRAND), provided by the Research Data Center of the Federal Bureau of Statistics (2005–2021). We assessed, through multiple patient-level analyses, severe perioperative complications, mortality, length of hospital stay, hospital revenues, intensive care unit admission, and the evolution of ureteroscopy during the last years in Germany. Results: We included 833,609 patients undergoing either same-session bilateral (n = 6914, 0.8%) or unilateral (n = 826,695, 99.2%) ureteroscopy for stone management. Patients undergoing bilateral ureteroscopy presented worse baseline characteristics. After adjusting for these characteristics, same-session bilateral ureteroscopy, compared to unilateral ureteroscopy, was significantly associated with higher odds of postoperative sepsis (odds ratio [OR]: 2.4, 95% confidence interval [CI]: 2–2.8, p < 0.001), myocardial infarction (OR: 2, 95% CI: 1.03–3.5, p = 0.024), acute kidney disease (OR: 2.8, 95% CI: 2.5–3.2, p < 0.001), transfusion (OR: 4.2, 95% CI: 3.6–4.8, p < 0.001), urinary tract infection (OR: 1.6, 95% CI: 1.5–1.7, p < 0.001), intensive care unit admission (OR: 1.9, 95% CI: 1.6–2.3, p < 0.001), and mortality (OR: 3.1, 95% CI: 2.1–4.5, p < 0.001). Similarly, the length of hospital stay was longer, and the in-hospital costs were higher (p < 0.001) after same-session bilateral ureteroscopy. Interestingly, the annual cases of ureteroscopy have undergone about a threefold increase in the last 17 years. Conclusions: The present real-world data demonstrate that same-session bilateral ureteroscopy leads to higher rates of perioperative myocardial infarction, acute kidney disease, transfusion, urinary tract infections, sepsis, and intensive care unit admission, as well as to increased length of hospital stay, costs, and inpatient mortality compared to unilateral ureteroscopy. [ABSTRACT FROM AUTHOR]

Introduction: Ureteral stents are widely used throughout urologic surgery, most commonly following ureteroscope (URS) procedures. This systematic review aims to assess the current evidence concerning stent on string (SOS) placed after URS and compare it with stents without strings (SWOSs). Methods: A systematic review was conducted on several databases using the preferred reporting items for systematic review and meta-analysis (PRISMA) methodology for studies in English language, for patients of all age groups, who had an SOS after URS for stone disease. Results: Of 1210 records identified, a total of 22 studies (20 adult and 2 pediatric studies) were included, with a total of 8382 patients. Of these, 3427 (40.9%) had SOSs inserted and 434 (11%) were in the pediatric age group. Our results show that SOS provides several advantages, and compared with SWOS, they were in situ for less time, with no difference in complications such as urinary tract infection or urinary symptoms. Furthermore, significant cost savings, less pain on removal, and high rates of safe home removal were reported in SOS, with >90% patients reporting that they would be happy to remove their SOSs at home. However, a small risk of stent dislodgment must be considered when making decisions regarding SOS placement after URS. Conclusion: SOS provides an excellent option after URS, especially in those patients with no intraoperative complication, and their placement is done as a routine insertion based on surgeon preference. These stents reduce dwell time, pain, cost, risks, and suffering involved from prolonged stenting, and majority of patients are happy to remove it themselves at home. Although their use seems to be still restricted in the current endourology practices, they are likely to become the new gold standard for routine URS in future, with more shared decision making and patient-reported outcome measures coming into the mainstream. [ABSTRACT FROM AUTHOR]

Introduction: New opioid dependency after urologic surgery is a serious adverse outcome that is well-described in the literature. Patients with stone disease often require multiple procedures because of recurrence of disease and hence are at greater risk for repeat opioid exposures. Despite this, opioid prescribing after urologic surgery remains highly variable and in an emergency setting, opioids are still used commonly in management of acute renal colic. Methods: Two literature searches were performed using PubMed. First, we searched available literature concerning opioid-sparing pathways in acute renal colic. Second, we searched available literature for opioid-sparing pathways in ureteroscopy and percutaneous nephrolithotomy (PCNL). Abstracts were reviewed for inclusion in our narrative review. Results: In the setting of acute renal colic, multiple randomized control trials have shown that nonsteroidal anti-inflammatory drugs (NSAIDs) attain greater reduction in pain scores, decreased need for rescue medications, and decreased vomiting events in comparison with opioids. NSAIDs also form a core component in management of postureteroscopy pain and have been demonstrated in randomized trials to have equivalent to improved pain control outcomes compared with opioids. Multiple opioid-free pathways have been described for postureteroscopy analgesia with need for rescue narcotics falling under 20% in most studies, including in patients with ureteral stents. Enhanced Recovery After Surgery protocols after percutaneous nephrolithotomy are less well described but have yielded a reduction in postoperative opioid requirements. Conclusions: In select patients, both acute renal colic and after kidney stone surgery, adequate pain management can usually be obtained with minimal or no opioid medication. NSAIDs form the core of most described opioid-sparing pathways for both ureteroscopy and PCNL, with the contribution of other components to postoperative pain outcomes limited because of lack of head-to-head comparisons. However, medications aimed specifically at targeting stent-related discomfort form a key component of most multimodal postsurgical pain management pathways. Further investigation is needed to develop pathways in patients unable to tolerate NSAIDs. [ABSTRACT FROM AUTHOR]

Introduction: Holmium laser lithotripsy is a standard energy source used for treatment of kidney stones during flexible ureteroscopy. Efficiency of laser surgery may be affected by patient and operator characteristics or perioperative management. Here, we sought to examine intraoperative data from patients undergoing high frequency dusting with high-powered holmium laser lithotripsy to evaluate surgical and demographic factors associated with lasing efficiency (LE). Methods: A total of 82 intraoperative reports were analyzed from an ongoing laser lithotripsy clinical trial evaluating the Lumenis Pulse™ 120H holmium laser with renal stones up to 20 mm in diameter with and without Moses 2.0 technology. For each case, the total pause time between lasing activations was corrected to remove lengthy pauses and divided by the total lasing time to calculate an efficiency percentage. This was then compared with patient demographics, anesthesia administration, stone burden, postoperative complications, and stone-free rates using both univariate and multivariate analyses. Results: Of the 82 included patients, 36 received endotracheal tube (ETT) intubation and 46 had a laryngeal mask airway (LMA). Patients with ETT had significantly higher LE (78.7%) compared to those with an LMA (73.3%) in our univariate analysis (p < 0.01) as well as in the multivariate model that adjusted for maximum stone size, number of stones, stone density, and patient body mass index (p < 0.05). There was also significantly higher mean LE in patients with no postoperative complications (76.3%) compared to those with any grade (I–V) Clavien-Dindo complication within 30 days after surgery (70.0%) (p < 0.05). Conclusions: Flexible ureteroscopy and laser lithotripsy cases with higher LE are associated with lower rates of postoperative complications. The data also support the use of ETT over LMA to improve overall LE; however, this remains one consideration among many for choosing anesthesia administration. Clinical Trial Registration number: NCT04505956. [ABSTRACT FROM AUTHOR]

Objectives: To determine whether urinary symptoms are significantly improved with a shorter duration of stent placement without an increase in complications. Methods: A total of 100 patients were prospectively randomized to two groups, either a 3-day (n = 59, Group 1) or 7-day (n = 41, Group 2) stent placement group depending on date of operation. Patients submitted Ureteral Stent Symptom Questionnaires both while stents were in situ and 2 to 3 days after removal. Results: Group 2 reported greater urinary symptoms (p < 0.001) and pain (p < 0.001) with stents in situ compared with Group 1. Urinary symptoms (p < 0.001), pain (p = 0.003), and general health (p = 0.02) were more severe in Group 2 after stent removal as well. The analysis also revealed that urinary symptoms, pain, and general health improved after stent removal compared with stent in situ (p < 0.001). There were no significant differences in work-related functioning between two groups. There was one complication in Group 1 requiring bilateral stent replacement. There were no significant differences in emergency department visits, unplanned clinic visits, or hospitalizations between Groups 1 and 2. Conclusions: Patients with stent removal at 3-day group had better reported urinary, pain, and general health score compared with 7-day group. Patients after stent removal had improved urinary symptoms, pain symptom, and general health compared with ureteral stent in situ. There was no statistically significant difference in complications between the groups. [ABSTRACT FROM AUTHOR]

Objectives: To explore beliefs and practice patterns of urologists regarding intrarenal pressure (IRP) during ureteroscopy (URS). Methods: A customized questionnaire was designed in a 4-step iterative process incorporating a systematic review of the literature and critical analysis of topics/questions by six endourologists. The 19-item questionnaire interrogated perceptions, practice patterns, and key areas of uncertainty regarding ureteroscopic IRP, and was disseminated via urologic societies, networks, and social media to the international urologic community. Consultants/attendings and trainees currently practicing urology were eligible to respond. Quantitative responses were compiled and analyzed using descriptive statistics and chi-square test, with subgroup analysis by procedure volume. Results: Responses were received from 522 urologists, practicing in six continents. The individual question response rate was >97%. Most (83.9%, 437/515) respondents were practicing at a consultant/attending level. An endourology fellowship incorporating stone management had been completed by 59.2% (307/519). The vast majority of respondents (85.4%, 446/520) scored the perceived clinical significance of IRP during URS ≥7/10 on a Likert scale. Concern was uniformly reported, with no difference between respondents with and without a high annual case volume (p = 0.16). Potential adverse outcomes respondents associated with elevated ureteroscopic IRP were urosepsis (96.2%, 501/520), collecting system rupture (80.8%, 421/520), postoperative pain (67%, 349/520), bleeding (63.72%, 332/520), and long-term renal damage (26.1%, 136/520). Almost all participants (96.2%, 501/520) used measures aiming to reduce IRP during URS. Regarding the perceived maximum acceptable threshold for mean IRP during URS, 30 mm Hg (40 cm H2O) was most frequently selected [23.2% (119/463)], with most participants (78.2%, 341/463) choosing a value ≤40 mm Hg. Conclusions: This is the first large-scale analysis of urologists' perceptions of ureteroscopic IRP. It identifies high levels of concern among the global urologic community, with almost unanimous agreement that elevated IRP is associated with adverse clinical outcomes. Equipoise remains regarding appropriate IRP limits intraoperatively and the most appropriate technical strategies to ensure adherence to these. [ABSTRACT FROM AUTHOR]

Background: Recently a novel omnidirectional (OD) ureteral access sheath (UAS) has been developed. By retrospectively reviewing and comparing the flexible ureteroscopic lithotripsy (FURL) cases in our institution with either a conventional Cook UAS or an OD UAS in the past year, we shared our experience of the safety, efficacy, and relevant issues on the usage of OD UAS. Materials and Methods: The medical history and surgery details of 199 patients with kidney stones or ureterojunctional stones who underwent FURL in Xinhua Hospital, including 61 Cook UAS and 138 OD UAS, were reviewed and compared. The maximal deflection angle was measured by steering four different types of ureteroscopes to bend the OD UAS in different states. Result: The deflection angle of OD UAS was ∼110° to 130° free load, and 90° to 130° when loaded with different instruments. The stone burden and position were similar in two groups. Given a similar prestent ratio and operation time, the OD UAS group achieved a higher single-session stone-free rate (SFR) (63.9% vs 94.2%, p < 0.0001) at 1-month follow-up evaluated by a CT scan. Conclusion: OD UAS is a novel device with high safety and efficacy. The unique flexible design allows it to bend with the ureteroscope and enter renal calices and be set close to the stone. Combined with the suction port, OD UAS contributes greatly to dealing with large-burden kidney stones, shortens operation time, and improves single-session SFR. [ABSTRACT FROM AUTHOR]

Introduction: The American Urological Association guidelines state that continuing anticoagulant (AC) and antiplatelet (AP) agents during ureteroscopy (URS) is safe. Through a multi-institutional retrospective study, we sought to determine whether pre-stenting in patients on AP or AC was associated with fewer URS bleeding-related complications. Methods: A series of 8614 URS procedures performed across three institutions (April 2010 to September 2017) was electronically reviewed for AC/AP use at time of URS. Records indicating AC or AP use at time of URS were then manually reviewed to characterize intraoperative and 30-day postoperative (intraoperative bleeding, postoperative hematuria, emergency department visits, hospital readmission, unplanned reoperation, phone calls, and other minor 30-day complications). Results: A total of 293 identified URS procedures were completed on patients on AC/AP therapy—112 cases were on AC only (38 were pre-stented), 158 on AP only (51 pre-stented), and 23 on both AP and AC (8 pre-stented). Patient characteristics and comorbidities were similar between the pre-stented and non-pre-stented groups. For AC and AP subjects, pre-stenting did not decrease the composite risk of bleeding complications (10.3% pre-stent vs 12.2% non-prestent, p = 0.6). Pre-stented patients did have a significantly lower likelihood of requiring an unplanned reoperation (1.0% vs 5.6%, p = 0.04). In the subgroup of patients on AP alone, pre-stented patients had significantly fewer episodes of intraoperative bleeding (0% vs 9%, p = 0.04), unplanned reoperations (0% vs 6.5%, p = 0.02), and 30-day complications (14% vs 27%, p = 0.05). In the subgroup of patients on AC alone, there were no significant differences in outcomes based on stent status. Conclusions: In this multi-institutional study, we found that pre-stenting before URS was not associated with fewer bleeding complications. However, pre-stenting appeared to be associated with improved outcomes for those patients on AP therapy. These results suggest a need for prospective studies to clarify the role of pre-stenting for URS. [ABSTRACT FROM AUTHOR]

Introduction and Objective: The study's primary objective was to compare the laser efficiency and clinical outcomes of two widely used systems, the holmium MOSES laser and the thulium fiber laser (TFL), in managing kidney stones. The secondary outcomes were to evaluate the impact of stone composition on laser efficacy. Methods: We conducted a retrospective review of patients who underwent flexible ureteroscopy (f-URS) for solitary renal calculi between December 2020 and August 2022 at our institution and had a 3-month postoperative CT scan. Patient demographics and stone parameters were recorded, including stone site, size, volume, and density. Intraoperative data were collected and analyzed, including total operative time, ureteroscopy time, lasing time, technique, total energy delivered, and stone composition. All patients underwent a CT scan at 3 months follow-up. We recorded the presence of residual stones and the percentage of stone volume reduction. Ablation efficiency was calculated by dividing the energy utilized (J) by the stone volume (mm3). The ablation speed was calculated by dividing the stone volume (mm3) by the lasing time (seconds). Patients with a stone size <4 mm were deemed stone-free. Results: The MOSES and TFL groups comprised 62 and 49 patients, respectively. There were no significant differences between groups for baseline patient demographics or stone characteristics. The two modalities had comparable total energy, laser time, efficacy, and ablation speeds. No differences were detected in stone-free rates or complications between both groups. When dealing with calcium phosphate stones, we observed that the lasing time was significantly shorter with MOSES than TFL (7.95 vs 10.85 minutes, respectively [p = 0.01]). Conclusions: MOSES and TFL laser systems had comparable efficacy for lithotripsy of renal calculi during f-URS; however, calcium phosphate stones had a longer lasing time with TFL. REB Number: 100210. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the feasibility and efficacy of live renal ultrasonography to guide Double-J ureteral stent placement at the bedside. Patients and Methods: Between April 12 and June 5, 2020, patients presenting with acute ureteral obstruction requiring decompression were prospectively selected for ultrasound-guided bedside ureteral stent placement. During stent placement, upper tract access confirmed using ultrasound with or without retrograde injection of ultrasound contrast before Double-J stent insertion. A postprocedural abdominal X-ray was obtained for stent position confirmation. Results: Eight patients (four men and four women) were offered bedside ultrasound-guided ureteral stent placement, and all eight consented to proceed. Stents were placed in seven of eight patients. One patient had an impacted ureterovesical junction stone and stricture requiring ureteroscopy and laser lithotripsy in the operating room. All patients tolerated procedures without immediate complications. Conclusion: Live renal ultrasonography can facilitate a high success rate for bedside ureteral stent placement outside the operating room. This approach is an attractive alternative to fluoroscopy-guided stent placement in the operating room and is of particular value in the COVID-19 era when judicious use of these resources is salient.

Purpose: Robot-assisted laparoscopy (RALP), conventional laparoscopy (LP), and balloon dilation (BD) have all been identified as common treatments for benign ureteral stricture (BUS). The purpose of the research would be to compare the safety and efficacy differences in the three groups. Patients and Methods: Patients who received RALP, LP, or BD for BUS were studied retrospectively from January 2016 through December 2020. Professional and experienced surgeons performed all operations. We collect and analyze baseline characteristics, stricture details, and perioperative and follow-up information. Results: The results showed no statistically significant difference between the three groups for baseline characteristics and stricture details. No statistical difference was also found between RALP and LP in specific surgical techniques. The average operative time was longer in the LP group than RALP and BD groups (178 minutes vs 150 minutes vs 67 minutes, respectively, p < 0.001). BD had lower estimated blood loss than RALP and LP (14 mL vs 40 mL vs 32 mL, p < 0.001) and similar between the RALP and LP groups (p = 0.238). The BD group had the shortest postoperative hospital stay compared with the RALP and LP groups (2.95 days vs 5.25 days vs 6.52 days, p < 0.001), and no statistically significant difference existed between the RALP and LP groups (p = 0.098). RALP had considerably greater hospitalization expenses than both LP (p < 0.001) and BD (p < 0.001). Complications and short-term success rates (6 months) were similar. The BD group had poorer long-term success (12 and 24 months) than the RALP and LP groups, whereas there was no statistically significant difference between the RALP and LP groups. Conclusions: For the management of BUS, RALP, LP, and BD are all safe and effective, with equivalent complication rates and short-term success. In long-term success rates, BD is low than RALP and LP. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction: Flexible ureteroscopy (fURS) is a one-person surgical technique, limiting trainees' ability to practice intraoperatively. Although well suited for simulation training, few existing fURS simulators can accurately reproduce complex renal collecting system anatomies. We developed an anatomically accurate fURS simulator using three-dimensional (3D) reconstruction of CT urograms and 3D printing technology to address this need. Materials and Methods: Patient-specific CT urograms were used to create 3D reconstruction of the renal collecting system using Slicer™. 3D models were modified using Blender™. Hollow, elastomer kidney models were created using an Objet 3D™ printer. To test and evaluate the new fURS simulator, 25 volunteers were recruited (5 novices, 13 residents, and 7 urologists). Participants were asked to explore the model with fURS and were evaluated on their ability to deduce its 3D anatomy, their ability to navigate to prespecified calices, and their time to task completion. Furthermore, participants were asked to compare the anatomical model with existing fURS benchtop models (Cook Medical™ and Limbs & Things™) on several criteria, including internal visualization, tactile feedback, and overall functional and teaching fidelity, in a survey. Results: We were able to create a fURS simulator that accurately replicates anatomically complex renal collecting systems. In exploring the model, we noted that unlike staff urologists, novices and residents often completely missed lower pole calices. A survey comparison between our simulator and comparable benchtop simulators revealed consistently better ratings of our simulator on all criteria (p < 0.05). Conclusions: We were able to create an anatomically accurate fURS simulator that provides a more realistic scoping experience. Preliminary testing revealed that trainees will benefit from this simulator, particularly with respect to learning how to navigate challenging collecting systems. [ABSTRACT FROM AUTHOR]

Objectives: To compare the effectiveness of antireflux ureteral stents on improving symptoms and quality of life of patients with ureteral stents. Materials and Methods: We randomized 120 patients with ureteral stone who required ureteral stent placement after ureteroscopic lithotripsy, of which 107 (56 in standard ureteral stent group and 51 in antireflux ureteral stent group) entered the final analysis. Severity of flank pain and suprapubic pain, visual analog scale (VAS), analgesic used after hospitalization, back soreness during micturition, gross hematuria, creatinine abnormality, hydronephrosis grade, symptomatic urinary tract infection (UTI), and quality of life were compared between the two groups. Results: There were no serious complications after operation in all 107 cases. The antireflux ureteral stent group had less flank pain and suprapubic pain (p < 0.05), analgesic used after hospitalization (p < 0.05), back soreness during micturition (p < 0.05), and lower VAS (p < 0.05). The health status index scores (p < 0.05), dimensions of usual activities, and pain/discomfort (p < 0.05) in the antireflux ureteral stent group were statistically better than those in the standard ureteral stent group. There were no significant differences between the groups in creatinine abnormality, hydronephrosis grade, gross hematuria, and symptomatic UTI. Conclusions: The antireflux ureteral stent has the same safety and efficacy as the standard ureteral stent, and is significantly better than the standard ureteral stent in flank pain and suprapubic pain, VAS, analgesic used after hospitalization, back soreness during micturition, and quality of life. [ABSTRACT FROM AUTHOR]

Introduction: Surgical experience is associated with superior outcomes in complex urologic cases, such as prostatectomy, nephrectomy, and cystectomy. The question remains whether experience is predictive of outcomes for less complex procedures, such as ureteroscopy (URS). Our study examined how case volume and endourology-fellowship training impacts URS outcomes. Methods: We retrospectively reviewed URS cases from 2017 to 2019 by high ureteroscopy volume urologists (HV), low ureteroscopy volume urologists (LV), endourology-fellowship trained (FT), and non-endourology FT (NFT) urologists. Surgical outcomes including stone-free rate (SFR), complication and reoperation rates, and postoperative imaging follow-up were analyzed between groups. Results: One thousand fifty-seven cases were reviewed across 23 urologists: 6 HV, 17 LV, 3 FT, and 20 NFT. Both FT and HV operated on more complex cases with lower rates of pre-stented patients. HV also operated on patients with higher rates of renal stones, lower pole involvement, and prior failed procedures. Despite this, FT and HV showed between 11.7% and 14.4% higher SFR, representing 2.7- to 3.6-fold greater odds of stone-free outcomes for primary and secondary stones. Additionally, HV and FT had a 4.9% to 7.8% lower rate of postoperative complications and a 3.3% to 4.3% lower rate of reoperations, representing 1.9- to 4.0-fold lower odds of complications. Finally, their patients had a 1.6- to 2.1-fold higher odds of postoperative imaging follow-up with a greater proportion receiving postoperative imaging within the recommended 3-month postoperative period. Conclusions: More experienced urologists, as defined by higher case volume and endourology-fellowship training, had higher SFR, lower complication and reoperation rates, and better postoperative imaging follow-up compared with less experienced urologists. Although less experienced urologists had outcomes in-line with clinical and literature standards, continued training and experience may be a predictor of better outcomes across multiple URS modalities. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study is to evaluate the current availability of technology for urolithiasis treatment and ureteroscopy (URS). Perioperative practice patterns, availability of ureteroscopic technologies, pre- and poststenting practices, and methods to alleviate stent-related symptoms (SRS) 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 URS (9), intraoperative URS (2), and postoperative URS (9). Results: A total of 191 urologists responded to the survey and 126 completed all questions of the survey (66%). Fifty-one percent (65/127) of urologists were fellowship trained and dedicated an average of 58% of their practice to stone management. In terms of procedures, most urologists performed URS most commonly (68%), followed by percutaneous nephrolithotomy (23%) and extracorporeal shockwave lithotripsy (11%). Ninety percent (120/133) of respondent urologists purchased a new ureteroscope within the last 5 years (16% single-use scopes, 53% reusable, and 31% purchased both). Fifty-three percent (70/132) of the respondents stated that they would be interested in a ureteroscope that can sense intrarenal pressure, with an additional 28% (37/132) stating they would be interested depending on the cost. Seventy-four percent (98/133) of responders purchased a new laser within the last 5 years, and 59% (57/97) changed their lasering technique due to the new laser. Urologists are performing primary ureteroscopy for obstructing stones in 70% of cases, and prefer prestenting patients for subsequent URS in 30% (on average after 21 days). Seventy-one percent (90/126) of responders insert a ureteral stent after uncomplicated URS, which is removed, on average, after 8 days in uncomplicated cases and 21 days after complicated URS. Most urologists give analgesics, alpha-blockers, and anticholinergics for SRS and <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. [ABSTRACT FROM AUTHOR]

Objectives: To complement our previous findings regarding effect of ureteral access sheath (UAS) use, we checked RIRSearch database for patients who operated without using UAS. The aim of the study was to understand these new data better by comparing outcomes of retrograde intrarenal surgery (RIRS) that continued sheathless after a failed UAS insertion vs those planned and completed sheathless. Materials and Methods: Data of 195 patients who underwent sheathless RIRS for kidney and/or ureteral stones between 2011 and 2021 were retrieved from the database. Patients divided into two groups: cases who were planned and completed sheathless (n = 110, Group 1) and those who proceeded without UAS after insertion failure (n = 85, Group 2). After propensity score matching (PSM), each group consisted of 76 patients. Results: After PSM, stone-free rate for Group 1 (90.8%) was significantly higher than stone-free rate of Group 2 (76.3%) in sheathless RIRS (p = 0.02). Also postoperative complication rate was significantly lower in Group 1 (10.5%) than in Group 2 (27.6%) (p = 0.007). In Group 2, median operating time was longer (60 minutes, interquartile range [IQR]: 40–80) and more unplanned auxilliary procedure (22.4%) was needed than Group 1 (45 minutes, IQR: 40–50 and 3.9%) (both p = 0.001). Stone burden (odds ratio [OR]: 1.002, p = 0.019) and stone density (OR: 1.002, p = 0.003) were associated with high risk of residual stones after RIRS. Higher hydronephrosis grades were associated with increased stone-free rates (OR: 0.588 for residual stone risk, p = 0.024). Cases who completed sheathless by dusting all available stones, as planned preoperatively, were more likely to have stone-free status after RIRS than those who proceeded sheathless after UAS insertion failure (OR: 2.645, p = 0.024). Conclusions: Operation course after UAS insertion failure may be more challenging. In cases who performed without using UAS, surgeons who proceed with procedure sheathless after UAS insertion failure may more frequently run into complications and may fail achieving stone-free status compared with sheathless-planned cases. [ABSTRACT FROM AUTHOR]

Purpose: Ureteral stents are commonly used after ureteroscopy and cause significant discomfort, yet qualitative perspectives on patients' stent experiences remain unknown. We describe psychological, functional, and interpersonal effects of post-ureteroscopy stents and whether additional patient-reported assessments may be needed. Materials and Methods: Using a qualitative descriptive study design, we conducted in-depth interviews with a nested cohort of participants in the STudy to Enhance uNderstanding of sTent-associated Symptoms (STENTS). Participants shared their symptoms with a post-ureteroscopy stent and described symptom bother and impact on daily activities. All interviews were audio-recorded, transcribed, and analyzed using applied thematic analysis. During analysis, participants' experiences with interference in daily activities were categorized into three groups based on their impact: minimal, moderate, and substantial. Results: All 39 participants experienced pain, although descriptions varied and differentiated between feelings of pain vs discomfort. Almost all experienced urinary symptoms. Only a few reported other physical symptoms, although several psychological aspects were identified. In the areas of sleep, mood, life enjoyment, work, exercise, activities of daily living, driving, childcare, and leisure/social activities, the stent had little impact on daily living among participants placed in the minimal group (n = 12) and far greater impact for participants in the substantial group (n = 8). For patients in the moderate group (n = 19), some daily activities were moderately or substantially affected, whereas other activities were minimally affected. Conclusions: Counseling to better prepare patients for the impact of stent-associated symptoms may help mitigate symptom burden. While existing instruments adequately cover most symptoms, additional assessments for other domains, particularly psychological factors, may be needed. [ABSTRACT FROM AUTHOR]

Purpose: Retropulsion of stone fragments during ureteroscopic laser lithotripsy (URSLL) remains a challenge for urologists and is associated with increased operative time and reduced stone-free rate (SFR). In this study, we compared the rate of retropulsion of ureteral stones during URSLL between the standard dorsal lithotomy (SDL) position and dorsal lithotomy position with reverse Trendelenburg (RT). Materials and Methods: Patients with ureteral stones requiring surgical intervention between May 2019 and January 2022 were randomized to undergo URSLL in either SDL or RT positions. The primary outcome of this study was stone retropulsion. Secondary outcomes included retropulsion to the kidney, SFR, operative time, 30-day emergency department visits and complications, and the need for conversion from semirigid to flexible ureteroscope. Differences between groups were evaluated using the chi-square test, Fisher exact test, Kruskal–Wallis test, or t-test. Results: A total of 114 patients were included in the study, with 57 patients in each group. There were no differences between groups in terms of baseline demographics or stone characteristics. Retropulsion was significantly less frequent in the RT group (68.4% vs 10.5%, p < 0.01). Similarly, the RT group was favored for lower risk of retropulsion into the kidney (40.4% vs 5.3%, p < 0.01), operative time (43.5 vs 33.0 minutes, p = 0.02), and need for ureteroscope conversion (16.7% vs 2.2%, p = 0.04). There was no difference in the SFR (100% vs 95%, p = 0.49). Conclusions: RT positioning during URSLL for ureteral stones significantly decreases the rate of stone retropulsion, operative time, and the need for conversion from semirigid to flexible ureteroscope. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effects of ureteral stent duration before ureteroscopy (URS) or extracorporeal shockwave lithotripsy (SWL) on infectious complications, health care resource utilization (HCRU), and costs. Materials and Methods: Patients who underwent URS/SWL within 6months of ureteral stent placement were identified from commercial claims, categorized by time from stent placement to URS (0–15, 16–30, 31–60, and >60 days) or SWL (0–15, 16–30, and >30 days), and followed 1-month postprocedure. The relationship between ureteral stent duration and emergency department (ED) visits, inpatient admissions, infectious complications (pyelonephritis/sepsis), imaging, and costs was evaluated. Results: Mean time to URS (n = 9276 patients) was 21.3 ± 24.4 days and SWL (n = 4689 patients) was 19.0 ± 24.8 days. Compared with patients who underwent URS within 15 days of ureteral stent placement, URS 31 to 60 days after ureteral stent placement was significantly associated with inpatient admissions (odds ratio [OR] 2.56, 95% confidence interval [CI] 2.03–3.22); infectious complications (OR 2.82, 95% CI 2.09–3.81); imaging (OR 2.12, 95% CI 1.82–2.46); and medical costs (OR 1.49, 95% CI 1.40–1.58). Compared with patients who underwent SWL within 15 days of ureteral stent placement, SWL more than 30 days after ureteral stent placement was significantly associated with ED visits (OR 1.79, 95% CI 1.37–2.34); inpatient admissions (OR 3.34, 95% CI 2.38–4.69); infectious complications (OR 3.54, 95% CI 2.20–5.70); imaging (OR 2.65, 95% CI 2.23–3.15); and medical costs (OR 1.45, 95% CI 1.36–1.54). Conclusions: URS or SWL >30 days after ureteral stent placement increased the likelihood of infectious complications, HCRU, and medical costs. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the performance of computer vision models for automated kidney stone segmentation during flexible ureteroscopy and laser lithotripsy. Materials and Methods: We collected 20 ureteroscopy videos of intrarenal kidney stone treatment and extracted frames (N = 578) from these videos. We manually annotated kidney stones on each frame. Eighty percent of the data were used to train three standard computer vision models (U-Net, U-Net++, and DenseNet) for automatic stone segmentation during flexible ureteroscopy. The remaining data (20%) were used to compare performance of the three models after optimization through Dice coefficients and binary cross entropy. We identified the highest performing model and evaluated automatic segmentation performance during ureteroscopy for both stone localization and treatment using a separate set of endoscopic videos. We evaluated performance of the pixel-based analysis using area under the receiver operating characteristic curve (AUC-ROC), accuracy, sensitivity, and positive predictive value both in previously recorded videos and in real time. Results: A computer vision model (U-Net++) was evaluated, trained, and optimized for kidney stone segmentation during ureteroscopy using 20 surgical videos (mean video duration of 22 seconds, standard deviation ±13 seconds). The model showed good performance for stone localization with both digital ureteroscopes (AUC-ROC: 0.98) and fiberoptic ureteroscopes (AUC-ROC: 0.93). Furthermore, the model was able to accurately segment stones and stone fragments <270 μm in diameter during laser fragmentation (AUC-ROC: 0.87) and dusting (AUC-ROC: 0.77). The model automatically annotated videos intraoperatively in three cases and could do so in real time at 30 frames per second (FPS). Conclusion: Computer vision models demonstrate strong performance for automatic stone segmentation during ureteroscopy. Automatically annotating new videos at 30 FPS demonstrate the feasibility of real-time application during surgery, which could facilitate tracking tools for stone treatment. [ABSTRACT FROM AUTHOR]

Objectives: To improve care in patients with large kidney stones using advanced intraoperative imaging techniques to reduce perioperative radiation exposure, improve stone-free rates (SFRs), and reduce the number of surgical interventions in a quality improvement project. Patients and Methods: Patients with kidney stones appropriate for percutaneous nephrolithotomy (PCNL) treatment were scheduled into a hybrid operating room for endoscopic surgery (PCNL and/or ureteroscopy) with intent to perform intraoperative CT (ICT). Imaging was performed using an Artis Zeego Care+Clear™ (Siemens) robotic-armed multiplanar fluoroscopy system with collimation to the level of the affected kidney(s). After the initial case, the proprietary CARE™ (combined applications to reduce exposure) protocol was used. When the hybrid room was unavailable, a mobile CT scanner (O-Arm; Medtronics) was used in the traditional room (n = 2). Results: Thirty-one ICTs were performed in 23 consecutive patients during endoscopic stone procedures with a median effective radiation dose of 1.39 mSv per scan, significantly less than the preoperative noncontrast CT (12.02 mSv) in the same patients (p < 0.001). Longitudinal radiation exposure associated with stone treatment significantly decreased by 83% (15.80 to 2.68 mSv, p < 0.001) compared with a similar historical PCNL cohort. Clinically significant residual stones (≥3 mm) were identified at initial ICT in eight patients (35%) and further treated in six patients. One patient had missed residual stone diagnosed 34 days after surgery, which was apparent on re-review of the ICT. Thus, final verified SFR was 87% for all stages. Mean number of procedures improved from 1.77 to 1.30 (p = 0.05) and rate of postoperative CT scans improved from 82% to 26% (p < 0.001). Conclusion: Ultralow-dose ICT was demonstrated to simultaneously improve SFR and number of staged treatments, and greatly reduce the perioperative radiation dose for our patients. The findings support the continued use of this modality to benefit all patients with large stones. [ABSTRACT FROM AUTHOR]

Introduction: The objective of this study was to determine if use of an automated irrigation pump (AIP) during ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL) affects circulating nurse labor, irrigation-related issues, and surgeon and nurse satisfaction when compared to manual hand pump (HP) irrigation. Methods: Eighty consecutive adult patients undergoing unilateral URS or PCNL were prospectively randomized to irrigation with the HP or AIP. Preoperative pump setup time, intraoperative pump maintenance time, total pump time (setup+maintenance), and the number of irrigation-related concerns verbalized by the surgeon intraoperatively were recorded; postoperatively, surgeons and nurses rated their satisfaction with the irrigation system (1 = highly dissatisfied to 10 = highly satisfied). Results: Eighty patients were enrolled (39 AIP and 41 HP); 51 patients underwent URS and 29 patients underwent PCNL. On univariate analysis, the AIP resulted in a significantly reduced total pump time for URS (2.9 vs 5.9 minutes) and PCNL (4.6 vs 33.9 minutes; p

Introduction: Vacuum-assisted ureteral access sheaths (V-UASs) are a new tool designed to evacuate dust or small fragments during retrograde intrarenal surgery (RIRS). There are reports of increased stone-free rates, decreased infections, and decreased operative time with V-UAS usage. The optimal technique and setting for V-UAS has yet to be described. Herein, we investigate real-time intrarenal pressure (IRP) throughout a range of settings using V-UAS in a porcine RIRS model. Materials and Methods: Ureteroscopy was performed in three female porcine cadaver kidneys through a ClearPetra V-UAS. IRP was recorded through a percutaneous catheter at different inflow pressures, sheath sizes, sheath distance from the ureteropelvic junction, and suction settings. Magnitude of change in delta IRP (dIRP) was compared at various settings. Results: There was no statistical difference in IRP when comparing no suction with vent inactivated. As expected, IRP decreased with larger sheath size and lower irrigation pressures. Average IRP dropped ∼18 mm Hg with suction activation (42.30 mm Hg, vent inactivated; 24.45 mm Hg IRP, suction activated; p < 0.0001). Irrigation pressure and sheath size did not make a difference in the dIRP. dIRP was significantly greater at lower suction settings compared with max suction (25.44 dIRP at 200 mm Hg suction, 10.26 mm Hg dIRP at max suction, p = 0.04). In a subset of observations, IRP paradoxically increased to higher than IRP with no suction at all after >5 seconds of activated suction. Conclusion: Use of V-UAS during RIRS can lower mean IRP; however, this effect could reverse with extended suctioning especially under conditions of high vacuum (>200 mm Hg) owing to outflow tract collapse. Our results suggest urologists should use lower suction settings and short, <5-second bursts to maximize therapeutic benefit, and minimize potential shortcomings of V-UAS during RIRS. [ABSTRACT FROM AUTHOR]

Introduction: The volume of surgeries including ureteroscopy (URS) performed for urolithiasis is increasing. This includes for the elderly population. The aim of this study was to evaluate the outcomes of URS in extremely elderly patients and identify any lessons that could be learned for clinical practice and treatment planning. Materials and Methods: Retrospective analysis was performed of consecutive patients aged 85 years and older undergoing URS between 2010 and 2022 at our tertiary center. Uni- and multivariable logistic regression analyses were performed to identify possible risk factors for complications. Survival analysis, stratified by age-adjusted Charlson Comorbidity index (ACCI), was performed using the Kaplan–Meier method as well as the log-rank test. Results: Sixty-four URS procedures were performed on 51 patients (mean age 88 years, range 85–97). Mean ACCI score was 7 (range 4–13) and most patients were American Society Anesthesiologists 3 (78%). Mean operative time and hospital stay were 60 minutes (range 15–120) and 2 days (range 0–6), respectively. At 3-month follow-up imaging, 92% were stone free (zero fragments). Intraoperative complication rate was 14% and in three cases (5%), early termination of the procedure was necessary. Eight patients (13%) suffered a complication before discharge. Eighteen patients (28%) had documented late complications after their surgery. The complication rate when combining early and late adverse events was 41%. One year mortality rate was 23%. Multivariable regression analysis revealed that operation time and ACCI >7 were significant predictors of complications after surgery. Survival probability was significantly worse in those patients with ACCI >7 (p = 0.0083). Conclusion: The morbidity burden of URS in the extremely elderly is higher than for other population groups. Risk should be considered carefully and implementation of ACCI can aid this process. High scores should prompt strong consideration of a conservative approach. Operation time should be kept to a minimum wherever possible. [ABSTRACT FROM AUTHOR]

Purpose: Ureteral stenting following uncomplicated ureteroscopy (URS) is common practice. Several studies have proven the safety of omitting routine stent placement following distal ureteral stone treatment. However, there is a paucity of data regarding the utility of stent placement for proximal URS. We designed a prospective, randomized controlled trial to evaluate the role of ureteral stent placement following URS for proximal ureteral and renal stones. Methods: Seventy-two patients with proximal ureteral or renal stones measuring as much as 1.5 cm were prospectively randomized into stented (37) or unstented (35) groups. The surgeon was blinded to the treatment group until after stone treatment. Patients tracked postoperative pain medications and completed validated pain questionnaires on postoperative days 0, 3, 7, and 28. Stents were removed on postoperative day 7. Postoperative follow-up imaging was obtained at 4 weeks. Results: No statistical differences were observed between the two groups in terms of demographics or stone characteristics. The operative time was longer in the stented group (p < 0.03). Patients in the stented group had more irritative urinary symptoms (p < 0.0001) and pain (p < 0.0001), missed more days of work (p < 0.01), and used more narcotics (p < 0.0005) during the first week, but no differences were observed at 30 days. Emergency room visits and overall complication rates were similar between the two groups. Three nonstented patients required stent placement. Two stented patients required early stent removal. Urinary tract infections developed in three stented patients, but not in unstented patients. Postoperative imaging did not reveal any hydronephrosis in either group, and the total stone-free rate was 94%. Conclusions: For most patients undergoing uncomplicated ureteroscopic treatment for proximal ureteral and kidney stones, it may be safe to omit ureteral stents to potentially decrease urinary symptoms and pain while improving short-term quality of life. Further studies with larger patient cohorts may be warranted to confirm our results. [ABSTRACT FROM AUTHOR]

Aim: To conduct a comparative, nonrandomized study to assess the feasibility of mini-Endoscopic Combined Intrarenal Surgery (ECIRS) using supine Mini-percutaneous nephrolithotomy (PCNL) access (16F) in Galdakao-Modified Supine Valdivia position for managing proximal large-volume impacted ureteral calculi as ambulatory day-care surgery vis-a-vis standalone ureteroscopy (URS) with push-back PCNL, if needed. The primary aim was to study the outcomes and stone-free rates (SFRs). Secondary aim was to compare the intraoperative and short-term postoperative complications. Materials and Methods: Data of 60 patients undergoing ECIRS (Group 1) from January 2016 to December 2019 were collected prospectively in a nonrandomized fashion from a single center after Ethics Committee approval. A matched-paired analysis was performed with retrospectively collated data of 60 patients undergoing standard URS/pushback PCNL (Group 2) using analysis of variance, Fisher's exact test, and Chi-square test. p < 0.05 was considered statistically significant. Outcomes and Results: Group 1 patients had a significantly shorter procedure time vs Group 2 (42.1 ± 11.2 minutes vs 52.1 ± 13.7 minutes; p < 0.001). Group 1 (59/60) patients had an overall single stage SFR of 98.3%, which was significantly higher than single-stage SFR of 83% in Group 2 (50/60) (p < 0.002). Group 2 patients had a higher incidence of fever (10 vs 4, p = 0.01). However, there were no cases of sepsis in either group. Rest of the complications were comparable for both, as the need for ancillary procedures was significantly higher in Group 2 (10% vs 1.7%, p < 0.001). Patients were discharged on the same day in both groups. Conclusions: The findings of our study suggest that, in large and impacted proximal ureteric stones, combined minimally invasive endoscopic approach offers the best option to render the patient stone free by a single intervention. With better intra- and postoperative outcomes and safety profile, Mini-ECIRS may be considered as an ambulatory procedure in this setting. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to evaluate changes in irrigation fluid temperatures during laser activation by using thermography, with comparison between Moses mode (MM) and virtual basket mode (VBM). Materials and Methods: Experiments were performed using an unroofed pyelocaliceal model. The laser was fired for 60 seconds at 0.4 J/60 Hz. Three runs were tested per setting using short pulse mode, long pulse mode, MM contact, and VBM. The time to reach threshold of thermal injury (43°C) was evaluated using thermometer and thermography, both with and without saline irrigation (25 mL/min). These outcomes were compared between laser pulse modes. Results: In measurement of time to reach the threshold, thermography-based time was significantly shorter than thermometer-based time in all laser modes under the condition of no irrigation. Thermography measurement results indicate that the speed of temperature rise depends on laser pulse modes, and the time to reach the threshold in MM was significantly shorter than that in VBM (9.0 seconds vs 14.3 seconds, p = 0.03). When 25 mL/min saline irrigation was used, the peak temperatures by both thermometer and thermography measurements did not exceed the threshold during laser activation. Conclusions: Thermography-based evaluation suggests that irrigation temperatures near mucosa around stones can rapidly elevate during laser lithotripsy when the irrigation condition is poor. Temperature rise speed in MM may be more rapid than that in VBM. To prevent thermal injury, laser pulse modes must be used selectively according to the condition of irrigation. [ABSTRACT FROM AUTHOR]

Introduction and Objective: Shared decision making is recommended to guide medical/surgical treatment strategies. We aimed at developing a surgical decision aid (SDA) facilitating decision making between ureteroscopy (URS) or shockwave lithotripsy (SWL) in patients with symptomatic nephrolithiasis. Methods: The SDA scope was identified through discussions with patients and urologists in the Michigan Urological Surgery Improvement Collaborative (MUSIC). A steering committee of patient advocates, MUSIC coordinating center, content experts, biostatisticians, and urologists was formed. Content domains were assessed through best available evidence and content experts. For content validation we anonymously surveyed 35 MUSIC urologists. Content validity ratios (CVR), numeric value indicating degree of expert validity, were calculated. Face validation interviews were conducted with patient advocates. Results: The SDA prototype using descriptive plain language and pictorial information was designed for nephrolithiasis patients, candidates for SWL or URS. It first provides patients procedural education whereas the second section informs urologists of patient goals. Six content domains were chosen: anesthesia type, effectiveness, number of procedures, risk, pain, and recovery. Overall, 91.4% and 85.7% of MUSIC urologists indicated that each section accomplished their goals, respectively. Anesthesia received an unacceptable CVR. High levels of face validation overall were reported with unacceptable scoring for anesthesia and recovery. Conclusions: We developed an SDA facilitating treatment choice between SWL and URS with promising content and face validity. Agreement and contradiction between anesthesia type and recovery validation results indicate the importance of shared decision making and the need for a validated SDA. Future work should focus on the SDAs value and opportunities for refinement in practice. [ABSTRACT FROM AUTHOR]

Introduction: Triple D score was developed using skin-to-stone distance (SSD), stone density (SD), and stone volume (SV) for prediction of extracorporeal shockwave lithotripsy (SWL) outcomes in adults. SWL is the first-line treatment method for kidney stones <2 cm in children, however, it was not validated in the pediatric population. This article aims to validate Triple D score in pediatric patients. Materials and Methods: Of the 269 children treated with SWL between 2007 and 2021, a total of 147 children who had adequate follow-up data and evaluated with noncontrast CT before SWL were included in the study. Parameters were calculated for each of the SV, SSD, and SD variables. Receiver operator characteristic analysis was used to set cutoff values. Triple D scores were calculated, and success rates were determined for each score. Stone-free status was determined as complete clearance after 3 months of final SWL. Results: The median age of the study group was 7 years (range 1–16). Ninety-three of the 147 (63%) children had stone-free status. Mean SV, SSD, and SD values were significantly higher in the SWL-failed group than in the stone-free group after detecting cutoff values of 155 mm3, 6.5 cm, and 550 HU, respectively. Stone-free rates were detected as 23.8%, 35.1%, 74.0%, and 92.0% with the Triple D scores of 0, 1, 2, and 3 points. Conclusions: Our study confirms that Triple D scores support the SWL outcomes in the pediatric population. We believe that our research on Triple D score validation in children is of great clinical importance although various factors may affect to predict the success of SWL. IRB Approval: 2021/514/194/14. [ABSTRACT FROM AUTHOR]

Introduction and Objective: Both ureteroscopy (URS) and shock wave lithotripsy (SWL) are cornerstones in the surgical management of urolithiasis in the United States. We hypothesized that URS utilization outpaced SWL utilization in recent years and quantified the magnitude of change over time for caseloads of URS and SWL among urologists from a national Medicare database. Methods: Using the public "Medicare Physician & Other Practitioners" database (https://data.cms.gov), we determined case numbers of SWL (current procedural terminology [CPT] 50590) and URS (CPT 52356 or 52353) from 2012 to 2019. In a subanalysis, we identified "high-volume stone urologists" as those in the upper quartile of case numbers for both SWL and URS in baseline years of either 2012 or 2013 and trended their caseload from 2012 to 2019. Linear estimation models assessed annual rates of change and their statistical significance. Results: In 2012, urologists performed 41,135 SWL procedures vs 21,184 URS. URS overtook SWL in 2017 and by 2019 was the dominant modality (60,063 URS vs 43,635 SWL). Between 2012 and 2019, total URS cases annually increased by 5700 (15%/year, p < 0.001), while the number of SWL cases peaked in 2015 and has since declined on average −1.6%/year (p = 0.020). The number of urologists performing URS steadily rose from 1147 in 2012 to 2809 in 2019, reflecting an additional 246 urologists (21%/year) performing URS annually. The caseload of high-volume stone urologists showed similar trends with average URS cases increasing by 2.9/year/urologist (9.8%/year, p < 0.001) and average SWL cases declining by 0.9/year/urologist (−1.7%/year, p = 0.023). Conclusions: URS utilization has increased dramatically and outpaced SWL utilization from 2012 to 2019 within the Medicare population. URS was increasingly used by both the general urologist population and high-volume stone urologists while SWL utilization has begun to decline. [ABSTRACT FROM AUTHOR]

Introduction: Systemic inflammatory response syndrome (SIRS) criteria have long been used to predict septic shock. The sequential organ failure assessment and quick sequential organ failure assessment (qSOFA) scores have been suggested to be more accurate predictors. This study aims to compare SIRS and qSOFA for predicting of septic shock in the setting of retrograde ureteral stenting for obstructing stones and concomitant urinary tract infection. Methods: A retrospective review of records at two centers of consecutive patients was performed. Patients with unilateral ureteral obstruction by a stone who underwent ureteral stent placement and suspicion of urinary tract infection were identified. Primary endpoints were SIRS and qSOFA positive scores, intensive care unit admission, and vasopressor requirements. Results: A total of 187 patients were included. SIRS criteria were met in 103 patients (55.1%) and in 30 patients who experienced septic shock. qSOFA criteria were met for 24 patients (12.8%) and in 18 patients who experienced septic shock. Specificity for postoperative septic shock was significantly higher for qSOFA than for SIRS criteria (75 vs 29.1%, McNemar test p < 0.001). Both SIRS and qSOFA had significant areas under the curve (AUC), qSOFA had a fair AUC of 0.750, p = 0.001, whereas SIRS had a poor AUC of 0.659, p = 0.008. Univariate logistic regression of SIRS and qSOFA for septic shock showed: qSOFA (odds ratio [OR] 46 [0.25–228], p = 0.001) and SIRS (OR 2.29 [0.716–7.37], p = 0.162). Conclusion: Although SIRS offers higher sensitivity, qSOFA score may offer advantages over SIRS criteria in evaluation of risk for septic shock for patients who present with obstructing ureteral stone and urinary tract infection. [ABSTRACT FROM AUTHOR]

Introduction: Radical nephroureterectomy with bladder cuff excision (BCE) is the standard of care all high-risk upper tract urothelial carcinomas. With continued advancements, robot-assisted segmental ureteral resection can be employed for ureteral tumors for ipsilateral renal preservation. Herein, we are presenting our experience of different techniques classified by the affected ureteral segment, along with perioperative and intermediate to long-term functional and oncologic outcomes. Methods: From January 2008 to June 2021, a total of 17 patients underwent robot-assisted renal preserving excisional procedures for ureteral tumors. We collected and analyzed baseline, perioperative and follow-up outcomes parameters from our prospectively maintained institutional database. Eleven patients underwent segmental ureterectomy (SU) with BCE and ureteroneocystostomy with psoas hitch, five patients underwent SU with ureteroureteral anastomosis with/without psoas hitch, and one patient underwent ileal patch interposition after segmental ureteral excision. Results: Although majority of the patients had inconclusive or low-grade pathology on initial ureteroscopic biopsies, 73.33% of the patients were found to have high-grade tumors on final pathology report. Median tumor size was 2.7 cm (1–5.5 cm), and the median operative duration was 193 minutes (142–400 minutes). None of the procedures required conversion to open. Overall, only one patient (5.9%) had Clavien–Dindo grade ≥ III complication (pelvic abscess). At median follow-up of 41 months (7–156 months), four patients (26.67%) developed urothelial recurrences out of which only one patient required nephroureterectomy. Overall survival and nephroureterectomy-free survival were 86.67% and 92.31%, respectively. Conclusions: Our study provides a comprehensive review of various surgical approaches of robot-assisted renal sparing management for ureteral tumors. These procedures are surgically safe, feasible, and effective with satisfactory oncologic outcomes at intermediate to long-term follow-up. These procedures may be safely employed in select patients with a localized ureteral tumor to salvage the ipsilateral kidney and estimated glomerular filtration rate. [ABSTRACT FROM AUTHOR]

Purpose: Digital ureteroscopes employ "chip-on-the-tip" technology that allows for significant improvement in image resolution. However, image distortion often occurs during laser lithotripsy owing to acoustic wave production. We sought to compare image distortion using different laser power settings and distances from the laser fiber tip to the scope for the Super Pulsed Thulium Fiber (SPTF) laser and high-power Holmium:YAG (Ho:YAG) laser. Materials and Methods: Ureteroscopy was simulated using a silicon kidney-ureter-bladder model fitted with a 12F/14F access sheath and the Lithovue™ (Boston Scientific), disposable digital flexible ureteroscope. At defined laser parameters (10, 20, 30 and 40 W, short pulse), a 200-μm laser fiber was slowly retracted toward the tip of the ureteroscope during laser activation. Image distortion was identified, and distance from the laser tip to the scope tip was determined. Data from the two lasers were compared utilizing t-tests. Results: After controlling for frequency, power, and laser mode, utilizing 1.0 J of energy was significantly associated with less feedback than 0.5 J (−0.091 mm, p ≤ 0.05). Increased power was associated with larger feedback distance (0.016 mm, p ≤ 0.05); however, increase in frequency did not have a significant effect (−0.001 mm, p = 0.39). The SPFT laser had significantly less feedback when compared with all Holmium laser modes. Conclusions: Increased total power results in image distortion occurring at greater distances from the tip of the ureteroscope during laser activation. Image distortion occurs further from the ureteroscope with Ho:YAG laser than with SPTF fibers at the same laser settings. In clinical practice, the tip of the laser fiber should be kept further away from the tip of the scope during ureteroscopy as the power increases as well as when utilizing the Ho:YAG system compared with the SPTF laser platform. The SPTF laser may have a better safety profile in terms of potential scope damage. [ABSTRACT FROM AUTHOR]

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

PurposeTo explore regional adoption of ureteroscopy (URS) over extracorporeal shockwave lithotripsy (SWL) in the state of California (CA) and to identify factors associated with this adoption over time.Materials and methodsWe used the California Office of Statewide Health Planning and Development (OSHPD) public data to identify URS and SWL procedures performed for renal and ureteral stones from 2005 to 2016. The level of analysis was the region wherein each procedure was performed, defined by the 19 CA labor market regions. OSHPD data were supplemented with the Area Health Resource File to provide information on regional characteristics. Generalized linear regression was used to determine procedural rates adjusted for age, gender and race. Choropleth time series maps were used to illustrate adoption of URS by region over time.ResultsA total of 328,795 URS and SWL procedures were identified from 2005 to 2016. The number of URS procedures surpassed the number of SWL procedures in 2011. Fourteen regions became URS predominant by 2016 and were characterized as having a higher per capita income, higher percentages with a college education and lower percentage of female heads-of-household (all p-values

Introduction: Ureteral thermal injury has been reported in patients following ureteroscopy with laser lithotripsy due to overheating of fluid within the ureter. Proper understanding of this risk necessitates knowing the volume of fluid available to absorb laser energy. This can be approximated as the volume of fluid that mixes during laser activation, since energy transfer through fluid is dominated by convection. Objectives of this study were to determine the volume of fluid that mixes during laser activation at different irrigation rates and to characterize the temporal/spatial temperature distribution in a model ureter. Methods: The model ureter consisted of a plastic tube—160 mm length and 5.3 mm inner diameter. Irrigation was first applied with clear, then dyed, deionized water at rates from 8 to 40 mL/min. The laser was activated at 20 W (0.5 J/40 Hz). The distances the dyed fluid propagated were measured and volumes calculated. Temperatures were recorded from six thermocouples—five embedded within the tube and one affixed to the ureteroscope. Thermal dose was calculated using the Dewey and Sapareto methodology. Results: The volume of total fluid mixing in the model ureter was ≤1.26 ± 0.10 cm3, consistent with a sharp temperature increase after laser activation from −5 to 25 mm from the ureteroscope tip. With irrigation rates ≤12 mL/min, calculated thermal dose within the model ureter exceeded the threshold of tissue injury and extended greater distances along the ureter with lower irrigation rates. Conclusion: The volume of total fluid mixing within the model ureter was found to be small thus conferring a greater risk of ureteral thermal injury. A thermocouple positioned near the tip of the ureteroscope reasonably approximates temperature in front of the ureteroscope. Until temperature sensors are incorporated into ureteroscopic systems, laser power settings should be carefully selected to minimize risk of ureteral thermal injury. [ABSTRACT FROM AUTHOR]

Introduction: Laser lithotripsy can cause excessive heating of fluid within the collecting system and lead to tissue damage. To better understand this effect, it is important to determine the percentage of applied laser energy that is converted to heat and the percentage used for stone ablation. Our objective was to calculate the percentage of laser energy used for stone ablation based on the difference in fluid temperature measured in an in vitro model when the laser was activated without and with stone ablation. Methods: Flat BegoStone disks (15:5) were submerged in 10 mL of deionized water at the bottom of a vacuum evacuated double-walled glass Dewar. A Moses 200 D/F/L laser fiber was positioned above the surface of the stone at a distance of 3.5 mm for control (no stone ablation) or 0.5 mm for experimental (ablation) trials. The laser was activated and scanned at 3 mm/second across the stone in a preprogrammed pattern for 30 seconds at 2.5 W (0.5 J × 5 Hz) for both short-pulse (SP) and Moses distance (MD) modes. Temperature of the fluid was recorded using two thermocouples once per second. Results: Control trials produced no stone ablation, while experimental trials produced a staccato groove in the stone surface, simulating efficient lithotripsy. The mean temperature increase for SP was 1.08°C ± 0.04°C for control trials and 0.98°C ± 0.03°C for experimental trials, yielding a mean temperature difference of 0.10°C ± 0.06°C (p = 0.0005). With MD, the mean temperature increase for control trials was 1.03°C ± 0.01°C and for experimental trials 0.99°C ± 0.06°C, yielding a smaller mean temperature difference of 0.04°C ± 0.06°C (p = 0.09). Conclusions: Even under conditions of energy-efficient stone ablation, the majority of applied laser energy (91%–96%) was converted to heat. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate learning curves in pediatric flexible ureteroscopy (FURS) and pediatric prone percutaneous nephrolithotomy (PCNL) by a single surgeon with experience in adult endourologic procedures. Materials and Methods: Children who were found to have nephrolithiasis and treated with PCNL or FURS from June 2014 to April 2019 were analyzed. Patient demographics, stone characteristics, stone-free rate (SFR), and complication rate (CR) were reported. Learning curves were generated to estimate the effect of a surgeon's experience on outcomes. Results: Seventy-three children underwent PCNL on 86 sides in 77 operations and 275 children underwent FURS on 320 sides in 288 operations. The SFRs were 88.1% (282/320) for FURS procedures and 89.5% (77/86) for PCNL procedures. CRs were 19.8% (57/288) and 35.1% (27/77), respectively. Learning curves showed that the SFRs of the two procedures increased with the accumulation of cases. There was an apparent improvement of SFR for PCNL procedures after ∼60 surgeries. A favorable SFR of FURS could be achieved at the start of learning. No apparently decreased CRs were observed for either PCNL or FURS. Conclusions: Both PCNL and FURS could achieve satisfactory SFRs and accepted CRs in pediatric stones. Increased surgical experience was associated with improved SFRs of both PCNL and FURS procedures, and the surgeon's experience of adult FURS translating to that of pediatric FURS was better than adult PCNL translating to pediatric PCNL. A surgeon needs ∼60 cases of PCNL to achieve competence. For FURS, a favorable SFR could be achieved at the start of learning. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study is to perform a literature review of stiff guidewires used in urology and to investigate if there is an official definition for stiffness (shaft rigidity) of wires. Materials and Methods: A literature search was performed for all English language articles in MEDLINE and Scopus databases, Google Scholar, and the official websites of international companies. Guidewires from different companies were included. Results: We analyzed 14 different stiff guidewires from the companies, Boston Scientific, Coloplast, Cook Medical, Olympus, Terumo, Rocamed, and Bard Urological, according to their characteristics. We found no concrete data regarding their stiffness on the official websites. In addition, there were a few published studies about the Amplatz Super Stiff guidewire (Boston Scientific), ZIPwire™ Stiff Nitinol Hydrophilic guidewire (Boston Scientific), HiWire Stiff Nitinol Core Wire Guide (Cook Medical), Amplatz Fixed Core Wire Guide (Cook Medical), and NiCore™ Nitinol Guidewire–Stiff (Bard Urological), whereas there were no available data for the majority of stiff guidewires. Conclusions: Stiff guidewires are listed in catalogs of companies without any information regarding their classification. They are only divided into stiff and standard versions without knowing the differences between them. The companies and their manufacturers should adopt a common method to calculate and define the stiffness of each guidewire. [ABSTRACT FROM AUTHOR]

Background: Proper control of irrigation flowrate during ureteroscopy is important to manage thermal and pressure risks. This task is challenging because flowrate is not directly measured by commercially available ureteroscopic or fluid management systems. However, flowrate can be calculated using a hydrodynamic relationship based on measurable values during ureteroscopy. Objectives of this in vitro study were to (1) calculate inflow resistance for different working channel conditions and then using these values and (2) calculate irrigation flowrate and determine its accuracy across a range of renal pelvis pressures. Materials and Methods: A 16 L container was filled with deionized water and connected by irrigation tubing to a 9.6F single-use ureteroscope. Inflow resistance was determined by plotting flowrate (mass of fluid collected from ureteroscope tip in 60 seconds) vs irrigation pressure (range 0–200 cmH2O). Next, the tip of the ureteroscope was inserted into the renal pelvis of a silicone kidney–ureter model and renal pelvis pressure was measured. In conjunction with the previously determined inflow resistance and known irrigation pressure values, flowrate was calculated and compared with experimentally measured values. All trials were performed in triplicate for working channel conditions: empty, 200 μm laser fiber, 365 μm laser fiber, and 1.9F stone basket. Results: Flowrate was linearly dependent on irrigation pressure for each working channel condition. Inflow resistance was determined to be 5.0 cmH2O/(mL/min) with the 200 μm laser fiber in the working channel and calculated flowrates were within 1 mL/min of measured flowrates. Similar results were seen with a 365 μm laser fiber, and 1.9F basket. Conclusions: Utilizing renal pelvis pressure measurements, flowrate was accurately calculated across a range of working channel conditions and irrigation pressures. Incorporation of this methodology into future ureteroscopic systems that measure intrarenal pressure could provide a real-time readout of flowrate for the urologist and thereby enhance safety and efficiency of laser lithotripsy. [ABSTRACT FROM AUTHOR]