POCUS-first for nephrolithiasis: A Monte Carlo simulation illustrating cost savings, LOS reduction, and preventable radiation.

OBJECTIVES: Non-contrast computed tomography (NCCT) is the gold standard for nephrolithiasis evaluation in the emergency department (ED). However, Choosing Wisely guidelines recommend against ordering NCCT for patients with suspected nephrolithiasis who are <50 years old with a history of kidney stones. Our primary objective was to estimate the national annual cost savings from using a point-of-care ultrasound (POCUS)-first approach for patients with suspected nephrolithiasis meeting Choosing Wisely criteria. Our secondary objectives were to estimate reductions in ED length of stay (LOS) and preventable radiation exposure. METHODS: We created a Monte Carlo simulation using available estimates for the frequency of ED visits for nephrolithiasis and eligibility for a POCUS-first approach. The study population included all ED patients diagnosed with nephrolithiasis. Based on 1000 trials of our simulation, we estimated national cost savings in averted advanced imaging from this strategy. We applied the same model to estimate the reduction in ED LOS and preventable radiation exposure. RESULTS: Using this model, we estimate a POCUS-first approach for evaluating nephrolithiasis meeting Choosing Wisely guidelines to save a mean (±SD) of $16.5 million (±$2.1 million) by avoiding 159,000 (±18,000) NCCT scans annually. This resulted in a national cumulative decrease of 166,000 (±165,000) annual bed-hours in ED LOS. Additionally, this resulted in a national cumulative reduction in radiation exposure of 1.9 million person-mSv, which could potentially prevent 232 (±81) excess cancer cases and 118 (±43) excess cancer deaths annually. CONCLUSION: If adopted widely, a POCUS-first approach for suspected nephrolithiasis in patients meeting Choosing Wisely criteria could yield significant national cost savings and a reduction in ED LOS and preventable radiation exposure. Further research is needed to explore the barriers to widespread adoption of this clinical workflow as well as the benefits of a POCUS-first approach in other patient populations.

Initial Safety and Feasibility of Steerable Ureteroscopic Renal Evacuation: A Novel Approach for the Treatment of Urolithiasis.

Background: There is a need to reliably render urolithiasis patients completely stone free with minimal morbidity. We report on the initial safety and feasibility with steerable ureteroscopic renal evacuation (SURE) in a prospective study using basket extraction as a comparison. Materials and Methods: A pilot randomized controlled study was conducted comparing SURE with basket extraction postlaser lithotripsy. SURE is performed using the CVAC™ Aspiration System, a steerable catheter (with introducer). The safety and feasibility of steering CVAC throughout the collecting system under fluoroscopy and aspirating stone fragments as it was designed to do were evaluated. Fluoroscopy time, change in hemoglobin, adverse events through 30 days, total and proportion of stone volume removed at 1 day, intraoperative stone removal rate, and stone-free rate (SFR) at 30 days through CT were compared. Results: Seventeen patients were treated (n = 9 SURE, n = 8 Basket). Baseline demographics and stone parameters were not significantly different between groups. One adverse event occurred in each group (self-limiting ileus for SURE and urinary tract infection for Basket). No mucosal injury and no contrast extravasation were observed in either group. The CVAC catheter was steered throughout the collecting system and aspirated fragments. There was no significant difference in fluoroscopy time, procedure time, change in hemoglobin, or stone removal rate between groups. SURE removed more and a greater proportion of stone volume at day 1 vs baskets (202 mm3 vs 91 mm3, p < 0.01 and 84% vs 56%, p = 0.022). SURE achieved 100% SFR at 30 days vs 75% for baskets, although this difference was not statistically significant (p = 0.20). Conclusions: This initial study suggests SURE is safe, feasible, and may be more effective in stone removal postlaser lithotripsy compared to basketing. More development is needed, and larger clinical studies are underway.

Determining Variable Costs in the Acute Urolithiasis Cycle of Care Through Time-Driven Activity-Based Costing.

OBJECTIVE: To characterize full cycle of care costs for managing an acute ureteral stone using time-driven activity-based costing. METHODS: We defined all phases of care for patients presenting with an acute ureteral stone and built an overarching process map. Maps for sub-processes were constructed through interviews with providers and direct observation of clinical spaces. This facilitated calculation of cost per minute for all aspects of care delivery, which were multiplied by associated process times. These were added to consumable costs to determine cost for each specific step and later aggregated to determine total cost for each sub-process. We compared costs of eight common clinical pathways for acute stone management, defining total cycle of care cost as the sum of all sub-processes that comprised each pathway. RESULTS: Cost per sub-process included $920 for emergency department (ED) care, $1665 for operative stent placement, $2368 for percutaneous nephrostomy tube placement, $106 for urology clinic consultation, $238 for preoperative center visit, $4057 for ureteroscopy with laser lithotripsy (URS), $2923 for extracorporeal shock wave lithotripsy, $169 for clinic stent removal, $197 for abdominal x-ray, and $166 for ultrasound. The lowest cost pathway ($1388) was for medical expulsive therapy, whereas the most expensive pathway ($8002) entailed a repeat ED visit prompting temporizing stent placement and interval URS. CONCLUSION: We found a high degree of cost variation between care pathways common to management of acute ureteral stone episodes. Reliable cost accounting data and an understanding of variability in clinical pathway costs can inform value-based care redesign as payors move away from pure fee-for-service reimbursement.

Care Setting as a Modifiable Predictor of Perioperative Cost and Outcomes following Elective Urinary Stone Surgery.

INTRODUCTION: We sought to identify predictors of index surgical care setting and to determine if care setting influences risk adjusted perioperative costs and/or 30-day revisits following elective surgery for urinary stones. METHODS: Using 2014 HCUP (Healthcare Cost and Utilization Project) all payer claims data from New York and Florida, we retrospectively identified 29,433 patients undergoing index ureteroscopy or shock wave lithotripsy. We used inverse probability of treatment weighting adjusted multivariable logistic and gamma regression to assess the association between index surgical care setting and 30-day revisits and total costs, respectively. RESULTS: Most urinary stone procedures (70.8%) were performed in the ambulatory setting. Underinsurance was associated with lower odds of undergoing surgery in the ambulatory setting (Medicaid vs private: OR 0.44, 95% CI 0.37-0.53; p <0.001; self-pay vs private: OR 0.21, 95% CI 0.17-0.26; p <0.001). Adjusted mean index surgical and 30-day acute care costs were significantly lower among ambulatory vs inpatient/emergency department cases ($4,746.10 vs $10,669.26 and $5,434.42 vs $11,729.39, both p <0.001), respectively. Ambulatory surgery was independently associated with lower odds of experiencing a 30-day revisit (OR 0.82, 95% CI 0.72-0.94; p=0.005). CONCLUSIONS: Urinary stone cases managed surgically in an ambulatory setting had lower risk adjusted costs and odds of a 30-day revisit compared to those managed in an inpatient setting. Our findings support use of ambulatory rather than inpatient based elective surgery for uncomplicated urinary stones. We invite clinicians and policymakers alike to reconsider clinical and nonclinical factors that influence pathways of care.

Testosterone replacement therapy is associated with an increased risk of urolithiasis.

PURPOSE: To determine whether TRT in men with hypogonadism is associated with an increased risk of urolithiasis. METHODS: We conducted a population-based matched cohort study utilizing data sourced from the Military Health System Data Repository (a large military-based database that includes beneficiaries of the TRICARE program). This included men aged 40-64 years with no prior history of urolithiasis who received continuous TRT for a diagnosis of hypogonadism between 2006 and 2014. Eligible individuals were matched using both demographics and comorbidities to TRICARE enrollees who did not receive TRT. The primary outcome was 2-year absolute risk of a stone-related event, comparing men on TRT to non-TRT controls. RESULTS: There were 26,586 pairs in our cohort. Four hundred and eighty-two stone-related events were observed at 2 years in the non-TRT group versus 659 in the TRT group. Log-rank comparisons showed this to be a statistically significant difference in events between the two groups (p < 0.0001). This difference was observed for topical (p < 0.0001) and injection (p = 0.004) therapy-type subgroups, though not for pellet (p = 0.27). There was no significant difference in stone episodes based on secondary polycythemia diagnosis, which was used as an indirect indicator of higher on-treatment testosterone levels (p = 0.14). CONCLUSION: We observed an increase in 2-year absolute risk of stone events among those on TRT compared to those who did not undergo this hormonal therapy. These findings merit further investigation into the pathophysiologic basis of our observation and consideration by clinicians when determining the risks and benefits of placing patients on TRT.

Hand-assisted laparoscopic versus robot-assisted laparoscopic partial nephrectomy: comparison of short-term outcomes and cost.

INTRODUCTION: Robot-assisted laparoscopic partial nephrectomy (RALPN) and laparoscopic partial nephrectomy (LPN) have become standard for the surgical management of small renal masses (SRMs). However, no studies have evaluated the short-term outcomes or cost of RALPN as compared with hand-assisted laparoscopic partial nephrectomy (HALPN) in a standardized fashion. METHODS: A retrospective review of all patients who underwent HALPN or RALPN from 2006 to 2010 were assessed for patient age, body mass index (BMI), American Society of Anesthesiologists (ASA) score, radiographic tumor size, nephrometry (radius, endo/exophytic, nearness to collecting system, anterior/posterior, lines of polarity [RENAL]) scores, operative and room times, hospital length of stay (LOS), estimated blood loss (EBL), requirement of hilar vessel clamping, warm ischemia time (WIT), pre- and postprocedural creatinine and hemoglobin levels, and complications. Total costs of the procedures were estimated based on operating room component (operative staff time, anesthesia, and supply) and hospital stay cost (room and board, pharmacy). A robotic premium cost, estimated based on the yearly overall cost of the da Vinci S surgical system divided by the annual number of cases, was included in the RALPN cost. Cost figures were obtained from hospital administration and applied to the mean HALPN and RALPN patient. RESULTS: Forty-seven patients underwent HALPN since 2006 and 21 patients underwent RALPN since 2008. ASA, BMI, EBL, tumor size, nephrometry score, positive margin rate, change in creatinine, change in hemoglobin, morphine equivalents used, and complication rate were all similar in both groups (p>0.05). Room time and operative time were significantly shorter for the HALPN cohort (p=0.001) whereas LOS was significantly shorter in the RALPN cohort (p=0.019). Despite the shorter LOS, RALPN was associated with a $1165 increased cost, mainly due to increased operating room time and premium cost of the robot. CONCLUSIONS: While early in our experience, RALPN offered no significant advantage in short-term outcomes over HALPN and was associated with an increased cost of over $1150.

Dedicated robotics team reduces pre-surgical preparation time.

CONTEXT: Robot-Assisted Laparoscopic Radical Prostatectomy (RALRP) requires significant preoperative setup time for the room, staff, and surgical platform. The utilization of a dedicated robotics operating room (OR) staff may facilitate efficiency and decrease costs. AIMS: We sought to determine the degree to which preoperative time decreased as experience was gained. MATERIALS AND METHODS: A total of 476 patients with a mean age of 60.2 years were evaluated (11/2006 to 1/2010). Data was assimilated through an institutional review board approved blinded, prospective database. Utilizing time from patient arrival in the OR to robot docking as preoperative preparation, our experience was evaluated. Age, body mass index (BMI), and American Society of Anesthesiologists risk scores (ASA) were compared. STATISTICAL ANALYSIS USED: Analysis of variance; Two-sample t-test for unequal variances. RESULTS: The first and last 100 cases were found to have similar age (P=0.27), BMI (P=0.11), and ASA (P=0.09). The average preoperative times were 66. 4 and 53.4 min, respectively (P<0.05). The second 100 patients treated were found to have a significantly shorter preoperative time when compared to the first 100 patients (P<0.05). When the first 100 cases were divided into cohorts of 10 cases the mean preoperative time for the first through fourth cohorts were 80.5, 69.3, 78.8, and 64.7 min, respectively. After treatment of our first 30 patients we found a significant drop in preoperative time. This persisted throughout the remainder of our experience. CONCLUSIONS: From the time of patient arrival a number of tasks are accomplished by the non-physician operating room staff during RALRP. The use of a consistent staff can decrease preoperative setup times and, therefore, the overall length of surgery.

Stone forming risk factors in patients with type Ia glycogen storage disease.

PURPOSE: Patients with type Ia glycogen storage disease have an increased recurrent nephrolithiasis rate. We identified stone forming risk factors in patients with type Ia glycogen storage disease vs those in stone formers without the disease. MATERIALS AND METHODS: Patients with type Ia glycogen storage disease were prospectively enrolled from our metabolic clinic. Patient 24-hour urine parameters were compared to those in age and gender matched stone forming controls. RESULTS: We collected 24-hour urine samples from 13 patients with type Ia glycogen storage disease. Average +/- SD age was 27.0 +/- 13.0 years and 6 patients (46%) were male. Compared to age and gender matched hypocitraturic, stone forming controls patients had profound hypocitraturia (urinary citrate 70 vs 344 mg daily, p = 0.009). When comparing creatinine adjusted urinary values, patients had profound hypocitraturia (0.119 vs 0.291 mg/mg creatinine, p = 0.005) and higher oxalate (0.026 vs 0.021 mg/mg creatinine, p = 0.038) vs other stone formers. CONCLUSIONS: Patients with type Ia glycogen storage disease have profound hypocitraturia, as evidenced by 24-hour urine collections, even compared to other stone formers. This may be related to a recurrent nephrolithiasis rate greater than in the overall population. These findings may be used to support different treatment modalities, timing and/or doses to prevent urinary lithiasis in patients with type Ia glycogen storage disease.

Percutaneous nephrolithotomy can be safely performed in the high-risk patient.

OBJECTIVES: To determine whether percutaneous nephrolithotomy (PCNL) can be safely performed in the high-risk patient. METHODS: The records of 84 patients undergoing 98 consecutive PCNL procedures from January 2005 to January 2007 at a single institution were examined. Patients were divided into a high-risk preoperative group, which comprised patients having American Society of Anesthesiologist scores of III or IV (n = 25) and a low-risk preoperative group of patients with an American Society of Anesthesiologist score of II or less (n = 59). RESULTS: A total of 33 and 65 procedures were performed in the high- and low-risk groups, respectively. The high-risk group had significantly more comorbidities than the low-risk group (5.4 vs 1.5) (P <.001). No significant difference was noted in the mean cumulative stone size for single or multiple stones in either group. A significant difference was observed between the average anesthesia time (45 vs 25 minutes) and average length of hospital stay (4.0 +/- 3.5 vs 2.7 +/- 1.2 days) but no significant difference in estimated blood loss (132 vs 150 mL) or mean operative time (118 vs 100 minutes) between the high- and low-risk groups, respectively. The overall complication rate was similar between the high-risk (12.1%) and low-risk (12.3%) groups (P = .41). The stone-free rate for the high-risk group was 61% compared with 92% for the low-risk group (P = .028). CONCLUSIONS: PCNL can be safely performed in the high-risk preoperative patient population.

Renal parenchyma thickness: a rapid estimation of renal function on computed tomography.

PURPOSE: To define the relationship between renal parenchyma thickness (RPT) on computed tomography and renal function on nuclear renography in chronically obstructed renal units (ORUs) and to define a minimal thickness ratio associated with adequate function. MATERIALS AND METHODS: Twenty-eight consecutive patients undergoing both nuclear renography and CT during a six-month period between 2004 and 2006 were included. All patients that had a diagnosis of unilateral obstruction were included for analysis. RPT was measured in the following manner: The parenchyma thickness at three discrete levels of each kidney was measured using calipers on a CT workstation. The mean of these three measurements was defined as RPT. The renal parenchyma thickness ratio of the ORUs and non-obstructed renal unit (NORUs) was calculated and this was compared to the observed function on Mag-3 lasix Renogram. RESULTS: A total of 28 patients were evaluated. Mean parenchyma thickness was 1.82 cm and 2.25 cm in the ORUs and NORUs, respectively. The mean relative renal function of ORUs was 39%. Linear regression analysis comparing renogram function to RPT ratio revealed a correlation coefficient of 0.48 (p < 0.001). The linear regression equation was computed as Renal Function = 0.48 + 0.80 * RPT ratio. A thickness ratio of 0.68 correlated with 20% renal function. CONCLUSION: RPT on computed tomography appears to be a powerful predictor of relative renal function in ORUs. Assessment of RPT is a useful and readily available clinical tool for surgical decision making (renal salvage therapy versus nephrectomy) in patients with ORUs.

Renal parenchyma thickness: a rapid estimation of renal function on computed tomography

Purpose: To define the relationship between renal parenchyma thickness (RPT) on computed tomography and renal function on nuclear renography in chronically obstructed renal units (ORUs) and to define a minimal thickness ratio associated with adequate function. Materials and Methods: Twenty-eight consecutive patients undergoing both nuclear renography and CT during a six-month period between 2004 and 2006 were included. All patients that had a diagnosis of unilateral obstruction were included for analysis. RPT was measured in the following manner: The parenchyma thickness at three discrete levels of each kidney was measured using calipers on a CT workstation. The mean of these three measurements was defined as RPT. The renal parenchyma thickness ratio of the ORUs and non-obstructed renal unit (NORUs) was calculated and this was compared to the observed function on Mag-3 lasix Renogram. Results: A total of 28 patients were evaluated. Mean parenchyma thickness was 1.82 cm and 2.25 cm in the ORUs and NORUs, respectively. The mean relative renal function of ORUs was 39 percent. Linear regression analysis comparing renogram function to RPT ratio revealed a correlation coefficient of 0.48 (p < 0.001). The linear regression equation was computed as Renal Function = 0.48 + 0.80 * RPT ratio. A thickness ratio of 0.68 correlated with 20 percent renal function. Conclusion: RPT on computed tomography appears to be a powerful predictor of relative renal function in ORUs. Assessment of RPT is a useful and readily available clinical tool for surgical decision making (renal salvage therapy versus nephrectomy) in patients with ORUs.

Impact of long-term potassium citrate therapy on urinary profiles and recurrent stone formation.

PURPOSE: Potassium citrate therapy has become one of the cornerstones of medical stone management. We elucidated the long-term effects of potassium citrate on urinary metabolic profiles and its impact on stone formation rates. MATERIALS AND METHODS: We performed a retrospective cohort study in patients treated at the Comprehensive Kidney Stone Center at our institution between 2000 and 2006. Patients with pre-therapy and post-therapy 24-hour urinary profiles available who remained on potassium citrate for at least 6 months were included in the analysis. RESULTS: Of the 1,480 patients with 24-hour urinary profiles 503 met study inclusion criteria. Mean therapy duration was 41 months (range 6 to 168). Overall a significant and durable change in urinary metabolic profiles was noted as soon as 6 months after the onset of therapy. These changes included increased urinary pH (5.90 to 6.46, p <0.0001) and increased urinary citrate (470 to 700 mg a day, p <0.0001). The stone formation rate also significantly decreased after the initiation of potassium citrate from 1.89 to 0.46 stones per year (p <0.0001). There was a 68% remission rate and a 93% decrease in the stone formation rate. CONCLUSIONS: Potassium citrate provides a significant alkali and citraturic response during short-term and long-term therapy with the change in urinary metabolic profiles sustained as long as 14 years of treatment. Moreover, long-term potassium citrate significantly decreases the stone formation rate, confirming its usefulness in patients with recurrent nephrolithiasis.

Assessment of citrate concentrations in citrus fruit-based juices and beverages: implications for management of hypocitraturic nephrolithiasis.

BACKGROUND AND PURPOSE: Dietary intake of citrate in the form of citrus juices (eg, lemonade, orange juice) will enhance urinary citrate excretion, a valuable benefit for patients with hypocitraturic calcium oxalate nephrolithiasis. While information on citrate concentrations in select citrus juices is available, data on citrate concentrations of commercially available beverages (juice and otherwise) are limited. Using nuclear magnetic resonance spectroscopy (1H NMR), we report citrate concentrations of several beverages to help guide dietary recommendations aimed at increasing urinary citrate excretion and correcting hypocitraturia. METHODS: Citrate concentrations of a squeezed lemon, several fruit juices, and common beverages were measured using 1H NMR. Spectra for each sample were obtained in duplicate; citrate peak was identified, measured, and quantified and compared with the citrate concentration in the juice of 1 medium lemon. RESULTS: Quantitative analysis revealed the highest concentration of citrate was in grapefruit juice (64.7 mmol/L), followed in decreasing concentrations by lemon juice (47.66 mmol/L), orange juice (47.36 mmol/L), pineapple juice (41.57 mmol/L), reconstituted lemonade (38.65 mmol/L), lemonade flavored Crystal Light (38.39 mmol/L), ready to consume not from concentrate lemonade (38.24 mmol/L), cranberry juice (19.87 mmol/L), lemon-flavored Gatorade (19.82 mmol/L), homemade lemonade (17.42 mmol/L), Mountain Dew (8.84 mmol/L), and Diet 7Up (7.98 mmol/L), respectively. CONCLUSIONS: According to 1H NMR, all of the tested "natural" citrus juices have high concentrations of citrate (38.3-67.4 mmol/L), with grapefruit juice having the highest concentration of the beverages chosen. Lemonade flavored Crystal Light had the highest concentration of citrate in the nonjuice category of tested beverages. In patients with mild to moderate hypocitraturia, dietary supplementation with citrus-based juices may be an effective alternative to medical management while not requiring large serving sizes. Further prospective studies are warranted to evaluate the clinical significance of these findings.

Trainees do not negatively impact the institutional learning curve for robotic prostatectomy as characterized by operative time, estimated blood loss, and positive surgical margin rate.

OBJECTIVES: We evaluated the learning curves and perioperative outcomes of an experienced laparoscopic surgeon and his trainees to assess our structured teaching program. METHODS: We retrieved 383 patients undergoing robot-assisted laparoscopic prostatectomy (RALP) from our database. Trainees completed a structured teaching program and were categorized as early (days 0 to 232), mid (days 566 to 797), and late (days 825 to 1218) according to the time period in which they were working with the mentor. We compared operative times, estimated blood loss (EBL), and positive surgical margin (PSM) rates between the trainees and the mentor (Mann-Whitney and Chi-square test). Association of EBL, body mass index (BMI), and prostate weight with operative time was evaluated in multivariate linear regression analysis. RESULTS: Median operative times of the early, mid, and late trainees (258, 220, and 200 minutes) significantly decreased and were similar to the corresponding senior surgeon's (254, 242, and 180 minutes). Operative times decreased with lower BMI, EBL, and prostate weight (P = 0.006, P <0.001, and P <0.001, respectively). Overall, EBL (150 mL vs. 150 mL, P = 0.215) and PSM rates (20% vs. 18.6%, P = 0.741) did not differ between the mentor and the trainees. CONCLUSIONS: A structured teaching program for RALP is effective and trainees are able to adopt the increased efficiency and skills of their mentor. Lower BMI, EBL, and prostate weight were associated with shorter operative times. Trainees performing the procedure did not negatively affect EBL and positive surgical margin rate.

Efficacy of intravesical ropivacaine injection on urinary symptoms following ureteral stenting: a randomized, controlled study.

PURPOSE: Previous studies suggest that intravesical administration of nonsteroidal anti-inflammatory drugs may reduce the troublesome voiding symptoms and pain related to ureteral stenting. The objective of this study was to investigate the effectiveness of a long-acting local anesthetic, ropivacaine, injected submucosally into the bladder to control ureteral stent-associated symptoms. MATERIALS AND METHODS: A randomized, single-blinded, study approved by our Institutional Review Board of adult patients scheduled for ureteroscopic stone surgery and possible stent placement was conducted. Patients were randomized to either the treatment cohort, who received five injections of 2 mL 0.5% ropivacaine around the ureteral orifice or to the control cohort, who received five injections of 2 mL of 0.9% normal saline in identical locations. Pain scale questionnaires were provided to each subject preoperatively and at postoperative hours 2, 4, 8, 24, and 48 as well as on the day of stent removal. Student's t test and Wilcoxon signed rank sum tests were used for Gaussian and nonparametric data, respectively. RESULTS: Twenty-two patients were randomized evenly into the two cohorts. The ropivacaine group consisted of 11 patients (eight men and three women) with a mean age of 56.2 years (standard deviation [SD] = 12, range 27-69), and the saline group consisted of eleven patients (six men and five women) with a mean age of 47.8 years (SD = 6.6, range 37-58). Intraoperative parameters appeared similar between the two cohorts. Intraoperative and postoperative narcotic usage was not different between the two groups, except at postoperative hour 2 when it favored the ropivacaine cohort (P = 0.05). Trends favoring ropivacaine in flank pain, bladder pain, genitalia pain, and hematuria domains were seen as long as 8 hours and up to the day of stent removal. Trends of less magnitude and duration were seen in the dysuria domain. No differences were seen in the frequency and urgency domains. CONCLUSIONS: Our preliminary investigation with intravesical injection of ropivacaine before ureteroscopic surgery demonstrated trends toward decreased pain and voiding symptoms in this small-sample study. Inclusion of a larger sample should definitively address the effectiveness of intravesical ropivacaine and its impact on stent-related symptoms.