Burden of Urolithiasis: Trends in Prevalence, Treatments, and Costs

Flexible ureteroscopy in Chinese air force pilots with renal calculi: a cohort study at a single medical centre

INTRODUCTION

Renal calculi are the predominant urological ailment in air force pilots. Flexible ureteroscopy (FURS) constitutes a valuable approach for renal calculi treatment. This study presents a decade-long exploration of using FURS for renal calculi treatment in air force pilots. Additionally, it investigates the safety and feasibility of granting waiver flights to pilots with renal parenchyma calcification.

METHODS

From December 2009 to December 2019, a retrospective review was conducted on Chinese air force pilots undergoing treatment for renal calculi. Among the pilots assessed, a total of 71 individuals underwent FURS. Endoscopic methodology involved the insertion of a flexible ureteroscope into the ureter and renal pelvis, guided by a safety wire. Stone fragmentation was achieved using a holmium laser fibre, followed by extraction using a soft stone basket. Postoperative non-enhanced CT (NECT) scans was used to confirm stone clearance. Furthermore, clinical diagnoses were classified based on endoscopic findings and postoperative NECT results. All data were presented as mean (SD) or median (minimum-maximum) for continuous variables and frequency counts and percentages for categorical variables.

RESULTS

FURS identified free kidney stones in 60 cases among all patients. The remaining 11 cases, without free stones detected during ureteroscopy, exhibited persistent high-density spots on postoperative NECT. Of the 60 cases with stones, renal calculi were successfully cleared in 30 pilots, while the remaining 30 exhibited persistent high-density spots on NECT postsurgery. Pilots with completely cleared free stones were deemed fit for flight. Pilots with diagnosed renal parenchyma calcification were granted permission to fly under waivers following a meticulous evaluation.

CONCLUSIONS

FURS could not only effectively eliminate renal calculi but also accurately diagnose renal parenchyma calcification, facilitating a prompt return to flight for pilots. A protocol for managing pilot renal calculi, informed by FURS and our experience, is proposed.

The reverse Trendelenburg position in proximal ureteral stone management: A systematic review and meta-analysis

INTRODUCTION

Ureteroscopy lithotripsy (URSL) presents a therapeutic option for patients with proximal ureteral calculi warranting active removal. This systematic review and meta-analysis aimed to assess the efficacy of the reverse Trendelenburg (RT) position during this procedure.

MATERIALS

A comprehensive literature search was conducted across PubMed, Embase, and Cochrane databases to identify randomized controlled trials and observational studies comparing RT versus standard positioning (STD) in patients undergoing URSL for proximal ureteral stones. Heterogeneity was measured with the Cochran's Q test, I2 statistics, and prediction intervals (PI). A DerSimonian and Laird random-effects model was utilized for all outcomes.

RESULTS

Four studies encompassing 505 patients undergoing URSL were analyzed. Among the studied participants, 293 (58%) underwent RT positioning. Overall, RT was associated with a lower average incidence of stone retropulsion (RR 0.42; 95% CI 0.27-0.65; I2=48%; PI 0.08-2.10) and a higher mean stone-free rate (RR 1.33; 95% CI 1.18-1.49; I2=0%). However, no significant difference between groups was found in the mean rate of overall complications (RR 0.76; 95% CI 0.40-1.43; I2=51%; PI 0.00-520.22) and operative time (MD -0.65; 95% CI -9.58-8.27; I2=94%; PI -111.95-110.65). In those with proximal ureteral stones undergoing RT positioning at only the 20° angle, there was a reduction in stone retropulsion without any measured heterogeneity (RR 0.35; 95% CI 0.23-0.52; I2=0%).

CONCLUSION

These findings suggest that RT positioning is effective in improving outcomes for patients with proximal ureteral stones undergoing URSL, and its use should be considered during the procedure.

Outcomes of retrograde ureteroscopy in Chinese infants and toddlers under 3 years old with ureteric stones from a single center

INTRODUCTION

Pediatric urolithiasis is a less common disease with a steadily increasing incidence of 10.6 % per year. The comprehensive management of pediatric urolithiasis is more challenging than in adults, and published studies of endourological treatment in children have small sample sizes and older mean ages, which may not be representative of the overall pediatric population, especially in infants and toddlers. This study aimed to report results of retrograde ureteroscopy for treating pediatric ureteral stones in infants and toddlers (<3 years) from a single center in China.

METHODS

Demographic and surgical data of infants and toddlers with ureteral stones who underwent retrograde URS were retrospectively analyzed from January 2015 to September 2022.

RESULTS

The mean age of 100 infants (73 boys and 27 girls) was 19.6 ± 7.6 months and stone burden was 0.27 (0.11-0.52) cm³. 111 procedures were performed for all children due to 11 patients with bilateral ureteric stones were simultaneously treated. Among them, 70.3 % were semi-rigid URS, 12.6 % were Micro-URS and 17.1 % were flexible URS. SFR was up to 96 %, the median operation time and hospitalization days were 35.0 (25.0-50.0) minutes and 6.0 (5.0-6.0) days, respectively. 15 (15.0 %) infants had postoperative fever (Grade I), and complications above grade I were not observed.

DISCUSSIONS

This research reported the largest sample size of infant and toddler ureteric stones (under 3 years old) and shared optimal management strategies for these special populations. Compared to other related studies, we had a higher SFR due to diverse management strategies and reasonable application of pre-operative ureteric stents. The most important potential reason why our complication rate was relatively higher might be the younger population under 3 years old. In additionally, the reason of long hospitalization was maybe some patients underwent staged surgeries during one hospitalization. Those results indicated the robust effectiveness of URS for infants. This study has limitations, including its retrospective single-center design, absence of long-term follow-up data, and potential variability in surgical outcomes due to differences in surgeons' experience.

CONCLUSIONS

The experience of endourologic procedures for 100 infant and toddler patients with ureteric stones from a Chinese single center was reported. And URS showed its effectiveness and safety for those special populations based on its high SFR and low complication rate.

The mayo adhesive probability score predicts postoperative fever and sepsis in retrograde intrarenal surgery

Infectious complications are among the most common and potentially life-threatening morbidities of retrograde intrarenal surgery (RIRS). Few predictive tools on these complications include radiological signs. The Mayo adhesive probability (MAP) score is an image-based scoring system that incorporates two radiological signs: perinephric fat stranding and perinephric fat thickness. Previous studies have suggested an association between these signs and febrile urinary tract infection (UTI) following lithotripsy. This study aimed to evaluate the predictive factors, including the MAP score, for post-RIRS fever and sepsis. A total of 260 patients who underwent 306 RIRS between October 2019 to December 2023 due to renal or upper ureteral stones were included in this retrospective study. Patient demographics, perioperative characteristics, stone factors, radiological signs, and MAP scores were recorded. Multivariate logistic regression analysis was used to evaluate the risk factors associated with postoperative fever and sepsis. Postoperative fever and sepsis occurred in 20.8% and 8.5% of the patients, respectively. On multivariate analysis, female gender, history of recurrent UTI, larger maximal stone diameter, and higher MAP score were independent risk factors for postoperative fever and sepsis. Identifying the risk factors for post-RIRS infectious complications is imperative to providing the proper perioperative management. The MAP score is a promising, easily calculated, image-based scoring system that predicts post-RIRS fever and sepsis.

Analysis of metabolic syndrome in bilateral upper urinary tract stones: A retrospective study of 3905 cases

Bilateral upper urinary tract stones are significantly related to renal function damage. However, few studies characterized the risk factors of bilateral upper urinary tract stones. We retrospectively enrolled 3905 patients with urinary tract stones from March 2019 to March 2022 at the Second Hospital of Tianjin Medical University. Patients were divided into two groups according to the location of the stones, and the related data were evaluated. In this study, 2485 unilateral and 1420 bilateral stone patients were included. Multivariate logistic regression analysis showed that BMI, gout, hyperparathyroidism, uric acid stone, urine PH, 24-h urinary calcium, blood uric acid, and metabolic syndrome (Mets) were independent risk factors for bilateral stone formation(P < 0.05). Based on these results, we construct a discrimination model. This model revealed good discrimination with an area under the receiver operating characteristic curves of 0.617, and the sensitivity and specificity were 0.592 and 0.586, respectively. Furthermore, the number of Mets components increased the risk of bilateral upper urinary tract stones. Hypertension, hyperglycemia, and low HDL level were strongly associated with bilateral upper urinary tract stones (P < 0.05). Patients with 5 components Mets had 1.89-fold higher risk of bilateral upper urinary tract stones than those with 1 component Mets (OR 3.381; 95 % CI 1.221-9.360; P = 0.013). Additionally, male patients with Mets had higher risk of bilateral upper urinary tract stones than female patients. Our analysis revealed that eight clinical factors were associated with the formation of bilateral upper urinary tract stones, namely BMI, gout, hyperparathyroidism, uric acid stone, urine PH, 24-h urinary calcium, blood uric acid, and Mets. This study could help clinicians adjust treatment strategies for high-risk patients with bilateral upper urinary tract stones.

Urinary Tract Infection Predictors in Patients Undergoing Retrograde IntraRenal Surgery for Renal Stones: Does the Instrument Make the Difference?

Background: Retrograde intrarenal surgery (RIRS) using flexible ureterorenoscopes is a cornerstone approach for renal stone removal, yet it carries a significant risk of postoperative urinary tract infection (UTI). With the emergence of single-use ureterorenoscopes, there is growing interest in their potential to mitigate this risk. This study aimed to compare the postoperative infection rates between single-use and multi-use ureterorenoscopes in RIRS procedures and to identify predictors of postoperative UTI. Methods: Data were collected from 112 consecutive patients who underwent RIRS for renal stones between March 2022 and September 2023. Peri-operative variables including age, gender, body mass index (BMI), stone size, stone location, type of ureterorenoscope, Hounsfield Units (HU), pre-operative hydronephrosis, laboratory analysis, and operative time were evaluated. Univariate and multivariate logistic regression analyses were performed to assess the predictors of postoperative UTI. Results: Of the cohort, 77 surgeries (68.7%) utilized multi-use ureterorenoscopes, while 35 (31.3%) utilized single-use devices. Stone diameter, number of stones, type of ureterorenoscope, and operative time were significant predictors of postoperative UTI in the univariate analysis. Multivariable logistic regression showed that operative time (OR, 1.3; 95% CI, 0.55-0.99; p = 0.03) and type of ureterorenoscope (multi-use vs. single-use) (OR, 1.14; 95% CI, 1.08-1.2; p < 0.001) were independent predictors of postoperative UTI. Conclusions: In conclusion, this study highlights that multi-use ureterorenoscopes and prolonged operative time are associated with an increased risk of postoperative UTI in RIRS procedures. Careful pre-operative evaluation and meticulous patient selection are essential to minimize the occurrence of postoperative UTIs and optimize patient outcomes in RIRS for renal stones.

Ureteral stone volume and female gender predicts perioperative complications after complete ipsilateral upper urinary tract stone removal using flexible ureterorenoscopy

PURPOSE

To identify the risk factors for perioperative complications to prevent perioperative complications after complete ipsilateral upper urinary stone removal using flexible ureterorenoscopy.

MATERIALS AND METHODS

We retrospectively examined 111 patients who underwent flexible ureterorenoscopy for ipsilateral renal stones with a diameter ≥ 5 mm at the same time as ureterorenoscopy for ureteric stones. The flexible ureterorenoscopy procedures were performed following the fragmentation technique. Patients who experienced (complication group) and did not experience (non-complication group) perioperative complications were compared. The complication group included 33 patients with Clavien-Dindo classification scores of I, II, III, or IV and/or those with a body temperature of > 37.5 ℃ during hospitalization.

RESULTS

The overall stone volume, stone-free rate and procedure duration were 1.71 mL, 96.4% and 77 min, respectively. The rate of perioperative complications was 29.7% (grade 1, 2 and 3 was 23.4%, 5.4% and 0.9%, respectively). Severe complications (Clavien-Dindo grade 4) were not observed. Multivariable analysis revealed that ureteral stone volume and female patients were independent predictors of perioperative complications after flexible ureterorenoscopy (p = 0.015 and 0.017, respectively).

CONCLUSIONS

This study showed that ureteral stone volume and female gender have the possibility to increase perioperative complications. These preliminary data help to select for patients who are at low risk of complications. Therefore, in these selected patients, complete ipsilateral upper urinary tract stone removal using flexible ureterorenoscopy may reduce the recurrence of urolithiasis without increasing perioperative complications.

Understanding formation processes of calcareous nephrolithiasis in renal interstitium and tubule lumen

Kidney stone, one of the oldest known diseases, has plagued humans for centuries, consistently imposing a heavy burden on patients and healthcare systems worldwide due to their high incidence and recurrence rates. Advancements in endoscopy, imaging, genetics, molecular biology and bioinformatics have led to a deeper and more comprehensive understanding of the mechanism behind nephrolithiasis. Kidney stone formation is a complex, multi-step and long-term process involving the transformation of stone-forming salts from free ions into asymptomatic or symptomatic stones influenced by physical, chemical and biological factors. Among the various types of kidney stones observed in clinical practice, calcareous nephrolithiasis is currently the most common and exhibits the most intricate formation mechanism. Extensive research suggests that calcareous nephrolithiasis primarily originates from interstitial subepithelial calcified plaques and/or calcified blockages in the openings of collecting ducts. These calcified plaques and blockages eventually come into contact with urine in the renal pelvis, serving as a nidus for crystal formation and subsequent stone growth. Both pathways of stone formation share similar mechanisms, such as the drive of abnormal urine composition, involvement of oxidative stress and inflammation, and an imbalance of stone inhibitors and promoters. However, they also possess unique characteristics. Hence, this review aims to provide detailed description and present recent discoveries regarding the formation processes of calcareous nephrolithiasis from two distinct birthplaces: renal interstitium and tubule lumen.

Extracorporeal shock wave lithotripsy: Prematurely falling out of favour? A 7 year retrospective study from an Australian high-volume centre

Objectives

The aim of this study is to audit 7 years of data with a 3 year follow up from a high-volume stone centre performing extracorporeal shock wave lithotripsy (ESWL) to evaluate efficacy in stone clearance compared to existing knowledge and understand reasons for this performance.

Methods

Patients who received ESWL treatment for renal or proximal ureteric stones at a single centre between January 2012 and January 2019 (to allow minimum 3 year follow up) were retrieved. A retrospective analysis was performed cross referencing for stone size, location, treatment and need for further procedures. Ethical approval was granted through Metro North HHS HREC, Queensland, Australia.

Results

A total of 1930 patients met inclusion criteria. Fifty-seven percent (n = 1100) underwent left-sided ESWL, compared to 43% (n = 830) on the right. Stone size and location were both statistically significant to treatment outcome. Small stones (<1 cm) had an overall clearance rate of 81.9%, medium stones (1-2 cm) had a clearance rate of 60.6% and stones (>2 cm) had a clearance rate of 31.3%. Small stones in an upper calyx had the highest clearance rate (87.5%, n = 120). Allowing for two procedures, 89% of stones were treated successfully.

Conclusion

ESWL remains a legitimate option for the treatment of small and medium sized renal calculi. ESWL stone clearance rates at our centre are higher than published elsewhere and serve as proof to its efficacy. X-ray imaging on the day of the procedure, heavy consultant input and frequent intra-operative imaging are cited as key reasons for success. Further research is warranted to elucidate factors affecting stone clearance rate and to enable more standardised outcomes. Further investment may be required into ESWL provisions in most Australian states and especially in Queensland to enable its continued use in contrast to developing endourological techniques.

Patient experiences and perceptions of kidney stone surgery: what lessons can be learned from TikTok?

Introduction

The aim of this study was to perform an evaluation of patient experiences and perceptions regarding kidney stone surgery on the social media platform TikTok. An increasing number of the public use social media (SoMe) as a platform to share their views regarding their experiences related to surgical treatment.

Methods

Using the hashtag #kidneystonesurgery, the 100 most recent video posts as of 01.01.2024 on TikTok were included. As well as demographic data such as gender and location, thematic content was also collected. To achieve this, a previously published framework was used and adapted for application in the setting of kidney stone surgery. This was piloted on 20 sample videos to assess its feasibility before revision and establishment of the final framework. This included the following key areas: Pain, Complications, Anxiety, Recovery, Return to work, Finances, Treatment delays, Diet and Prevention and stent complaints.

Results

The majority of posts (95%) were from North America, 80% by females and the mean number of video views was 92,826 (range: 261-2,000,000). 76% of the videos discussed ureteroscopy (URS). 49% were filmed at the hospital, which was named in 9% of the videos. Top three topics discussed were: Recovery (65%), pain (62%) and stents (55%). This was followed by anxiety (39%) and complications (24%). 12% of these videos uploaded by lay people included basic medical information that was wholly incorrect. More than half of the posts (51%) were negative in tone. Treatment delays (5%) and a lack of sufficient preoperative information (4%) were also raised, that appeared to contribute to the negative reports. However, the main cause for negative tone owed to the 80% of the patients (n = 44) who discussed stents that focused their video on the pain suffered from the post operative stent.

Conclusion

There is a high level of usership and engagement on TikTok on the subject of kidney stone surgery. The proportion of negative videos is high and much of this is related to the bothersome stent symptoms and complications. This could easily lead to misperceptions among potential patients about the true burden of such adverse events.

Cost-effectiveness of quality improvement intervention to reduce time between CT-detection and ureteroscopic laser fragmentation in acute symptomatic ureteric stones management

OBJECTIVE

To prospectively assess clinical and cost effectiveness of emergency ureteroscopic laser fragmentation of urinary stones causing symptoms or obstruction.

PATIENTS AND METHODS

100 consecutive patients with an average (median) age 55.6 (57.5) years and average (median) stone size of 8.2 mm (± 7 mm) between October 2018 and December 2021 who underwent emergency ureteroscopy and laser fragmentation formed the study cohort as part of a clinical service quality improvement. Primary outcome was single procedure stone-free rate and cost-effectiveness. The secondary outcomes were complications, re-admission and re-intervention. A decision analysis model was constructed to compare the cost-effectiveness of emergency ureteroscopy with laser fragmentation (EUL) and emergency temporary stenting followed by delayed ureteroscopy with laser fragmentation (DUL) using our results and success rates for modelling.

RESULTS

Single procedure stone-free rates (SFR) for EUL and DUL were 85%. The re-intervention rate, re-admission and complication rates of the study cohort (EUL) were 9%, 18%, and 4%, respectively, compared to 15%, 20%, and 5%, respectively for the control cohort (DUL). The decision analysis modelling demonstrated that the EUL treatment option was more cost-efficient, averting £2868 (€3260) per patient for the UK health sector. Total cost of delayed intervention was £7783 (€8847) for DUL in contrast to £4915 (€5580) for EUL.

CONCLUSIONS

Implementation of quality improvement project based on a reduction in CT detection-to-laser fragmentation time interval in acute ureteric obstruction or symptoms caused by stones had similar clinical effectiveness compared to delayed ureteroscopic management, but more cost-effective.

Comparison of ureteral stone measurements for predicting the efficacy of a single session of extracorporeal shockwave lithotripsy: one-, two-, and three-dimensional computed tomography measurements

The objective of this study was to compare the value of one-, two- and three-dimensional computed tomography (CT) measurements for predicting the efficacy of a single session of extracorporeal shock wave lithotripsy (ESWL) in patients with a single ureteral stone. A total of 165 patients were included based on the inclusion and exclusion criteria. Different models were constructed using a combination of patients' clinical data and measurements obtained by manual sketching and automated extraction software. Multivariate logistic regression was used to develop the models. Receiver operating characteristic curves were used to assess the performance of the models. There was good interobserver agreement for all measurements in different dimensions (P < 0.001). We also found that hydronephrosis, the largest diameter, the largest area, volume, and mean CT value were significantly greater in the failure group than in the success group (P < 0.01). Furthermore, all sizes and CT measurement values were found to be independent predictors for predicting efficacy after one session of ESWL (P < 0.05). In addition, the multivariate logistic analysis showed that the area under the curve (AUC) for two-dimensional and three-dimensional measurements was superior to that of one-dimensional measurement (P < 0.01). However, when size alone was included as a measurable predictor, there was no significant difference in the AUC among the one-, two-, and three-dimensional measurements (P > 0.05). In summary, after adjusting for clinical data, two- and three-dimensional measurements combining ureteral stone size and CT values were found to be the best predictors of ESWL efficacy, and software-based three-dimensional measurements should be considered to avoid interobserver variability in clinical practice.

Acoustic emission of kidney stones: a medical adaptation of statistical breakdown mechanisms

Kidney stones have a prevalence rate of > 10% in some countries. There has been a significant increase in surgery to treat kidney stones over the last 10 years, and it is crucial that such techniques are as effective as possible, while limiting complications. A selection of kidney stones with different chemical and structural properties were subjected to compression. Under compression, they emit acoustic signals called crackling noise. The variability of the crackling noise was surprisingly great comparing weddellite, cystine and uric acid stones. Two types of signals were found in all stones. At high energies of the emitted sound waves, we found avalanche behaviour, while all stones also showed signals of local, uncorrelated collapse. These two types of events are called 'wild' for avalanches and 'mild' for uncorrelated events. The key observation is that the crossover from mild to wild collapse events differs greatly between different stones. Weddellite showed brittle collapse, extremely low crossover energies (< 5 aJ) and wild avalanches over 6 orders of magnitude. In cystine and uric acid stones, the collapse was more complicated with a dominance of local "mild" breakings, although they all contained some stress-induced collective avalanches. Cystine stones had high crossover energies, typically [Formula: see text] 750 aJ, and a narrow window over which they showed wild avalanches. Uric acid stones gave moderate values of crossover energies, [Formula: see text] 200 aJ, and wild avalanche behaviour for [Formula: see text] 3 orders of magnitude. Further research extended to all stone types, and measurement of stone responses to different lithotripsy strategies, will assist in optimisation of settings of the laser and other lithotripsy devices to insight fragmentation by targeting the 'wild' avalanche regime.

Is ureteroscopy and active stone treatment safe and effective in octogenarians? A review of current literature

Background

With the aging of our patient population, and the increasing incidence of kidney stone disease in the elderly, active stone treatment is becoming more common. In this review of current literature, we aim to assess safety and efficacy of ureteroscopy (URS) as primary treatment for urolithiasis in the octogenarians.

Materials and methods

A scoping review of literature according to the PRISMA guidelines was performed, using the relevant search terms. Original articles were screened and included. A narrative review of the studies is provided, with emphasis on outcomes of URS in the elderly.

Results

10 studies were included in the analysis. URS performed in the elderly population showed a good safety and efficacy, with stone-free rates (SFR) comparable to the general population. URS specific complication rates seems to be comparable to the other age groups, with postoperative events mostly related to anaesthesia and pre-existing medical conditions. The overall complication rate was still low, with a slightly prolonged hospital stay. Predictors for SFR were age, severe comorbidities and stone burden.

Conclusion

URS for stone treatment in the elderly population is safe and effective, with comparable surgical outcomes to that of the general population. As comorbidities play an important role in the fitness for surgery and overall survival, risks and benefit of active stone treatment should be carefully balanced in this group.

Urological Guidelines for Kidney Stones: Overview and Comprehensive Update

BACKGROUND

Evidence-based guidelines are published by urological organisations for various conditions, including urolithiasis. In this paper, we provide guidance on the management of kidney stone disease (KSD) and compare the American Urological Association (AUA) and European Association of Urologists (EAU) guidelines.

METHODS

We evaluate and appraise the evidence and grade of recommendation provided by the AUA and EAU guidelines on urolithiasis (both surgical and medical management).

RESULTS

Both the AUA and EAU guidelines provide guidance on the type of imaging, treatment options, and medical therapies and advice on specific patient groups, such as in paediatrics and pregnancy. While the guidelines are generally aligned and based on evidence, some subtle differences exist in the recommendations, but both are generally unanimous for the majority of the principles of management.

CONCLUSIONS

We recommend that the guidelines should undergo regular updates based on recently published material, and while these guidelines provide a framework, treatment plans should still be personalised, respecting patient preferences, surgical expertise, and various other individual factors, to offer the best outcome for kidney stone patients.

Failed insertion of ureteral access sheath during flexible ureterorenoscopy: a randomized controlled trial comparing second session flexible ureterorenoscopy or same session mini percutaneous nephrolithotomy

PURPOSE

To compare different treatment approaches in patients with failed ureteral access sheath placement during first flexible ureterorenoscopy (f-URS) session.

METHODS

Patients with kidney stones measuring 1-2 cm, presented to our urology clinic between September 2020 and September 2021, were included in the study for evaluation. The study was designed prospectively (Clinical-Trials number NCT05911945). Patients were randomized into two groups, in case of a failed ureteral access sheath placement during the first f-URS session. In group 1, JJ stent was placed for dilation and second session of f-URS was planned. In group 2, mini percutaneous nephrolithotomy (mPNL) was performed in the same session.

RESULTS

Twenty-four patients were included in each group. Pre-operative demographic data and stone characteristics of the patients in each group were comparable. Operation time, fluoroscopy time, and hospital stay were significantly higher in the mini-PNL group. When SF-36 values were compared, physical function, pain, role limitation, and general health value scores were improved in both groups after treatment. The improvement in physical function and pain parameters was statistically significant in the mPNL group. In patients with failed ureteral access sheath placement, placing a JJ stent for dilation and postponing f-URS for 4-6 weeks provides the advantages of low hospitalization time for each admission, shorter fluoroscopy and operation time.

CONCLUSIONS

Performing mPNL in the same session, results in better improvements in SF-36 parameters such as pain and physical function compared to f-URS. The success and complication rates of the two procedures were comparable.

Exploring optimal settings for safe and effective thulium fibre laser lithotripsy in a kidney model

OBJECTIVES

To explore the optimal laser settings and treatment strategies for thulium fibre laser (TFL) lithotripsy, namely, those with the highest treatment efficiency, lowest thermal injury risk, and shortest procedure time.

MATERIALS AND METHODS

An in vitro kidney model was used to assess the efficacy of TFL lithotripsy in the upper calyx. Stone ablation experiments were performed on BegoStone phantoms at different combinations of pulse energy (EP ) and frequency (F) to determine the optimal settings. Temperature changes and thermal injury risks were monitored using embedded thermocouples. Experiments were also performed on calcium oxalate monohydrate (COM) stones to validate the optimal settings.

RESULTS

High EP /low F settings demonstrated superior treatment efficiency compared to low EP /high F settings using the same power. Specifically, 0.8 J/12 Hz was the optimal setting, resulting in a twofold increase in treatment efficiency, a 39% reduction in energy expenditure per unit of ablated stone mass, a 35% reduction in residual fragments, and a 36% reduction in total procedure time compared to the 0.2 J/50 Hz setting for COM stones. Thermal injury risk assessment indicated that 10 W power settings with high EP /low F combinations remained below the threshold for tissue injury, while higher power settings (>10 W) consistently exceeded the safety threshold.

CONCLUSIONS

Our findings suggest that high EP /low F settings, such as 0.8 J/12 Hz, are optimal for TFL lithotripsy in the treatment of COM stones. These settings demonstrated significantly improved treatment efficiency with reduced residual fragments compared to conventional settings while keeping the thermal dose below the injury threshold. This study highlights the importance of using the high EP /low F combination with low power settings, which maximizes treatment efficiency and minimizes potential thermal injury. Further studies are warranted to determine the optimal settings for TFL for treating kidney stones with different compositions.

Risk factors of stone residual after retrograde intrarenal surgery: A prospective cohort study

BACKGROUND

Complete removal of renal stones is crucial for optimal patient outcomes, but recent studies have reported residual stones after retrograde intrarenal surgery (RIRS). This study aimed to identify the associated risk factors to improve patient management and treatment selection.

METHODS

This cohort study was conducted over 18 months at two hospitals and recruited adult patients with renal stones less than 3 cm. Preoperative assessment included medical history, physical examination, laboratory tests, and radiological imaging. Intraoperative and postoperative data collection and follow-up were conducted to evaluate surgical success and potential complications.

RESULTS

A total of 100 patients were included, with a mean age of 45.3 ± 10.7 years and a mean BMI of 26.2 ± 1.4 kg/m2. Approximately 19% of the patients had residual stones after the RIRS procedure. The RUSS score showed good diagnostic performance with an AUC of 0.843, and the optimal cut point was ⩾2.0 with a sensitivity of 52.6% and specificity of 95.1%. Independent predictors of residual stones were multiple sites (OR = 24.98; p = 0.002), multiple stones (OR = 13.62, p = 0.002), stone size of 21-30 mm (OR = 4.91, p = 0.038), lower calyx site (OR = 4.85, p = 0.033), and surgeon experience of fewer than 50 cases (OR = 6.82, p = 0.020).

CONCLUSIONS

This study identifies several factors associated with residual stones after RIRS for renal stones, including stone size, location, number, and surgeon experience. The study suggests that the RUSS score can be used as a reliable tool for predicting the likelihood of residual stones, which can help clinicians in patient selection and treatment planning.

Mirabegron for medical expulsive therapy of ureteral stones: a systematic review and meta-analysis

Objective

To systematically review and quantitively evaluate the efficacy and safety of mirabegron as a medical expulsive therapy for ureteral stones.

Methods

We performed an extensive search of the EMBASE and PubMed databases for studies examining the use of mirabegron as a medical expulsive therapy for ureteral stones. The primary outcome measure assessed was the stone expulsion rate (SER), while the secondary outcomes evaluated were the stone expulsion interval (SEI) and the occurrence of pain episodes during follow-up. Risk ratios (RRs) and mean differences (MDs) with their respective 95% CIs were calculated.

Results

We included a total of seven studies involving 728 participants. Our analysis revealed a significant increase in the stone expulsion rate (SER) with mirabegron (RR = 1.40; 95% CI = 1.17-1.67; p < 0.001) and a reduction in the frequency of pain episodes (MD = -0.80; 95% CI = -0.39 to -0.21; p = 0.008) compared to the control group. No significant difference was found in SEI between the two groups (MD = -3.04; 95% CI = -6.33 to 0.25; p = 0.07). Subgroup analysis revealed that the increased SER was significant for distal ureteral stones, but not for proximal and middle ureter stones. Compared to tamsulosin or silodosin, mirabegron showed no significant difference in SER, SEI, or pain episode frequency. The adverse effects of mirabegron were relatively rare and mild.

Conclusion

Mirabegron appears to be a promising candidate for the MET of distal ureteral stones rather than proximal and middle ureteral stones, as it significantly increases SER and reduces pain episode frequency. Further well-designed randomised controlled trials are needed to validate and affirm these findings.

Systematic Review Registration

PROSPERO (CRD42022341603).

Genes polymorphism as risk factor of recurrent urolithiasis: a systematic review and meta-analysis

INTRODUCTION

Urolithiasis is one of the most prevalent diseases worldwide. Its prevalence is rising, both in developing and developed countries. It is known that genetic factors play big roles in the development of urolithiasis. One of the suspected factors is gene polymorphism. This study aims to find an accurate estimate of the association between genetic polymorphism and the risk of recurrent urolithiasis.

METHODS

A systematic review and meta-analysis were performed on 12 studies from 3 databases that investigated gene polymorphism as an risk factor of urolithiasis. The review was done using Review Manager® version 5.3.

RESULTS

Insignificant heterogenicity was found in this study. Populations from Asia and the Middle East are more likely to experience recurrent urolithiasis. Additionally, variation in the VDR and urokinase genes, particularly in the Asian population, increases the risk of developing recurrent urolithiasis.

CONCLUSIONS

Gene polymorphisms have significant roles in the development of urolithiasis, especially in the Middle Eastern region.

Effect of preoperative prophylactic antibiotic use on postoperative infection after percutaneous nephrolithotomy in patients with negative urine culture: a single-center randomized controlled trial

PURPOSE

To compare the effects of different preoperative antibiotic prophylaxis (ABP) regimens on the incidence of sepsis after percutaneous nephrolithotomy (PCNL) in patients with negative urine culture.

METHODS

A single-center, randomized controlled trial (June 2022-December 2023) included 120 patients with negative preoperative urine cultures for upper urinary tract stones who underwent PCNL (chictr.org.cn; ChiCTR2200059047). The experimental group and the control group were respectively given different levofloxacin-based preoperative ABP regimes, including 3 days before surgery and no ABP before surgery. Both groups were given a dose of antibiotics before the operation. The primary outcome was differences in the incidence of postoperative sepsis.

RESULTS

A total of 120 subjects were included, including 60 patients in the experimental group and 60 patients in the control group. The baseline characteristics of the two groups were comparable and intraoperative characteristics also did not differ. The sepsis rate was not statistically different between the experimental and control groups (13.3% vs.13.3%, P = 1.0). A multivariate logistic regression analysis revealed that body mass index (BMI) (OR = 1.3; 95% CI = 1.1-1.6; P = 0.003) and operating time (OR = 1.1; 95% CI = 1.0-1.1; P = 0.012) were independent risk factors of sepsis.

CONCLUSION

Our study showed that prophylactic antibiotic administration for 3 days before surgery did not reduce the incidence of postoperative sepsis in patients with negative urine cultures undergoing PCNL. For this subset of patients, we recommend that a single dose of antibiotics be given prior to the commencement of surgery seems adequate.

Is stone free status really necessary for metabolic evaluation following stone removal procedures?

OBJECTIVE

To evaluate the impact of stone free status on the outcomes of metabolic evaluation in recurrent stone formers after ureteroscopic stone removal.

PATIENTS AND METHODS

A total of 78 patients undergoing retrograde intrarenal surgery (RIRS) for renal stones were included and cases were divided into two groups after 4 weeks based on the NCCT findings. While cases in the Group 1 (n = 54) was completely stone free, cases in Group 2 (n = 24) had residual fragments in the kidney. A full 24-h urine analysis for relevant stone forming risk factors has been performed after 4 weeks following the fURS procedures in all patients of both groups. Outcomes of metabolic evaluation (24-h urine and serum) have been comparatively evaluated in both groups.

RESULTS

Evaluation of the preoperative serum and urine stone forming risk factors revelaed no statistical difference in both groups. Comparative evaluation of the 24-h urinary stone forming risk factors also revealed no statistically significant difference between preoperative and postoperative findings in cases of Group 2 with residual stones. Last but not least, no significant difference was observed between the mean preoperative and postoperative serum variables between two groups.

CONCLUSIONS

Our results show that in the light of the similar metabolic evaluation outcomes obtained in cases with and without residual fragments, 'stone free status' may not be an essential factor to perform a detailed metabolic evaluation (24-h urine analysis and serum parameters) after endourological stone removal procedures.

Comparison of immediate versus post-stenting ureteroscopy for ureteral stones treatment

Ureteroscopy is a highly effective treatment for ureteral stones, characterized by a high stone-free rate and a low need for re-treatment. Ureteral stent placement can improve the insertion of the ureteral access sheath and ureteroscope but may be associated with higher morbidity prior to and after ureteroscopy. The study aimed to compare immediate versus post-stenting ureteroscopy for ureteral stone treatment in terms of operative time, intra- and post-operative complications, length of hospital stay, and stone-free rate. This prospective study involved 126 patients with ureteral stones divided into two groups: the post-stenting ureteroscopy group (PS-URS), who underwent primary ureteral stenting by double J followed by delayed ureteroscopy, and the immediate ureteroscopy group (I-URS), who underwent immediate ureteroscopy without previous stenting. Sixty-six patients were included in the PS-URS group and 60 patients in the I-URS group. Results were comparable, with no significant differences between both groups. The mean operative time was 33.77±3.51 minutes for the PS-URS group and 34.60±2.01 minutes for the I-URS group. The average length of hospital stay was 0.84±2.55 days for PS-URS and 0.92±1.96 days for I-URS patients. The stone-free rate was 97% in the PS-URS group and 95% in the I-URS group. The overall complication rate was 4.5% versus 5% in the PS-URS and I-URS groups, respectively, with all complications being minor and managed effectively. Immediate ureteroscopy is a safe and relevant operative approach for ureteral stones, with comparative results for post-stenting delayed ureteroscopy.

Thulium:YAG laser: a good compromise between holmium:YAG and thulium fiber laser for endoscopic lithotripsy? A narrative review

PURPOSE

To provide a technological description of the new pulsed solid-state Thulium:YAG laser (Tm:YAG). In addition, current available literature on Tm:YAG lithotripsy is also reviewed.

MATERIALS AND METHODS

Medline, Scopus, Embase, and Web of Science databases were used to search for Tm:YAG operating mode articles.

RESULTS

Tm:YAG technology works with a laser cavity with thulium-doped YAG crystal, pumped by laser diodes. Laser beam operates at 2013 nm, with an adjustable peak power (≥ 1000 W) and the minimal fiber laser diameter is of 200 µm. It has an intermediate water absorption coefficient and peak power-pulse duration. Various pulse modulations are proposed, aiming to minimize stone retropulsion. Multiple comparative in vitro studies suggest that Tm:YAG's ability to fragment stones is similar to the one of the Ho:YAG laser; on the contrary, its ability to dust all stone types is similar to the one of the TFL, with a low retropulsion. A single in vivo study assessed Tm:YAG lithotripsy feasibility.

CONCLUSIONS

The new pulsed solid-state thulium:YAG laser could represent a safe and effective compromise between Ho:YAG laser and TFL for endoscopic lithotripsy, either in retrograde intra-renal surgeries or in percutaneous nephrolithotomy.

A population-based retrospective cohort study of surgical trends and outcomes of pediatric urolithiasis in Ontario, Canada (2002-2019)

INTRODUCTION

The worldwide incidence of pediatric urinary stone disease (PUSD) is increasing. However, there is no commensurate data on whether this translates to an increasing need for surgical intervention for PUSD, given the role of conservative management.

OBJECTIVE

We aimed to evaluate the trends and outcomes of clinically significant PUSD, using administrative databases to identify patients surgically treated for PUSD.

STUDY DESIGN

This retrospective population-based cohort study assessed the incidence and trends of surgically treated PUSD and outcomes in Ontario, Canada in patients <18 years of age who underwent their first PUSD procedure between 2002 and 2019 utilizing administrative databases held at the Institute of Clinical Evaluative Sciences (ICES). We assessed the incidence of surgically treated PUSD, demographics, initial surgical treatment and imaging modality, and risk factors for repeat intervention within 5 years. Statistical analyses summarized demographics, surgical trends, and logistic regression was used to identify risk factors for repeat surgical intervention.

RESULTS

We identified 1149 patients (mean age 11.3 years), with 59.6% older than 12 years. There was a decrease in the number of PUSD procedures performed per year that was close to statistical significance (p = 0.059) and a trend towards increased utilization of ureteroscopy (URS) compared with Shockwave Lithotripsy (SWL). In addition, there was a significant increase in the proportion of females surgically treated with PUSD (p = 0.001). In the 706 patients followed for 5 years, 17.7% underwent a repeat procedure within 6 months, while 20.4% underwent a repeat procedure from 6-months to 5 years. Renal stone location (OR 2.79, 95% confidence interval (CI) 1.62-4.80, p = 0.0002) and index SWL (OR 1.66, 95% CI 1.20-2.31, p = 0.0025) were risk factors for repeat surgical intervention within the first 6-months. There was an increasing utilization of ultrasound (US) compared to computerized tomography (CT) (p = 0.0008).

DISCUSSION

Despite the literature reporting increasing PUSD incidence, we observed a non-significant decrease in the number of surgical PUSD procedures performed. Exclusion of those treated conservatively may explain our results. The increase in the proportion of females treated reflects the narrowing gender gap in stone disease. A trend towards increased URS utilization was observed and re-intervention rates were similar to previous studies.

CONCLUSION

The overall rate of surgically treated PUSD did not show an increasing trend in Ontario, Canada from 2002 to 2019. URS was the most common surgical treatment modality, with a corresponding decline in SWL rates. PUSD was associated with a high surgical re-intervention rate within 6 months.

A new position utilizing the effect of gravity in proximal ureteral stones, ureteroscopic lithotripsy in the reverse Trendelenburg position: a prospective, randomized, comparative study

PURPOSE

To evaluate the effect of the reverse Trendelenburg position in patients undergoing ureteroscopic lithotripsy for proximal ureteral stones.

METHODS

The study included 167 patients who underwent ureteroscopic lithotripsy for proximal ureter stones between December 2020 and September 2022. The patients were randomly assigned to one of three groups: standard lithotomy (n:55), 10° reverse Trendelenburg (n:55), and 20° reverse Trendelenburg (n:57). Preoperative information, including age, sex, body mass index (BMI), previous shock wave lithotripsy (SWL), stone side, volume, and density, distance to the ureteropelvic junction (UPJ) of the stone, and hydronephrosis degree. Stone-free status was evaluated with computed tomography (CT) at 4 weeks postoperatively. The groups were compared in respect of stone migration, stone-free rate, use of flexible ureterorenoscope, operating time, postoperative length of stay in the hospital, and complications.

RESULTS

No statistically significant difference was determined between the groups with respect to age, sex, BMI, previous SWL, stone side, volume and density, distance to the UPJ of the stone, and hydronephrosis degree (p > 0.05 for all). Statistically significant differences were determined between the groups with respect to stone migration (p = 0.001), stone-free rate (p < 0.001), use of flexible ureterorenoscope (p = 0.01), operating time (p < 0.001), hospital length of stay (p < 0.001), postoperative fever (p = 0.002), and total complications (p = 0.01).

CONCLUSION

A new patient position is presented in this study, which can be used in ureteroscopic lithotripsy performed for proximal ureteral stones. The reverse Trendelenburg position constitutes a surgical method that can be used safely and successfully in the treatment of proximal ureteral stones.

TRIAL REGISTRATION NUMBER

NCT04894058, 05/21/2021, Prospectively registered.

Evaluating the Performance of Different Large Language Models on Health Consultation and Patient Education in Urolithiasis

OBJECTIVES

To evaluate the effectiveness of four large language models (LLMs) (Claude, Bard, ChatGPT4, and New Bing) that have large user bases and significant social attention, in the context of medical consultation and patient education in urolithiasis.

MATERIALS AND METHODS

In this study, we developed a questionnaire consisting of 21 questions and 2 clinical scenarios related to urolithiasis. Subsequently, clinical consultations were simulated for each of the four models to assess their responses to the questions. Urolithiasis experts then evaluated the model responses in terms of accuracy, comprehensiveness, ease of understanding, human care, and clinical case analysis ability based on a predesigned 5-point Likert scale. Visualization and statistical analyses were then employed to compare the four models and evaluate their performance.

RESULTS

All models yielded satisfying performance, except for Bard, who failed to provide a valid response to Question 13. Claude consistently scored the highest in all dimensions compared with the other three models. ChatGPT4 ranked second in accuracy, with a relatively stable output across multiple tests, but shortcomings were observed in empathy and human caring. Bard exhibited the lowest accuracy and overall performance. Claude and ChatGPT4 both had a high capacity to analyze clinical cases of urolithiasis. Overall, Claude emerged as the best performer in urolithiasis consultations and education.

CONCLUSION

Claude demonstrated superior performance compared with the other three in urolithiasis consultation and education. This study highlights the remarkable potential of LLMs in medical health consultations and patient education, although professional review, further evaluation, and modifications are still required.

Single use flexible ureteroscopes: Current status and future directions

Introduction

Single use ureteroscopes are a technological innovation that have become available in the past decade and gained increased popularity. To this end, there are now an increasing number of both benchside and clinical studies reporting outcomes associated with their use. Our aim was to deliver a narrative review in order to provide an overview of this new technology.

Methods

A narrative review was performed to gain overview of the history of the technology's development, equipment specifications and to highlight potential advantages and disadvantages.

Results

Findings from preclinical studies highlight potenial advantages in terms of the design of single use ureteroscopes such as the lower weight and more recent modifications such as pressure control. However, concerns regarding plastic waste and environmental impact still remain unanswered. Clinical studies reveal them to have a non inferior status for outcomes such as stone free rate. However, the volume of evidence, especially in terms of randomised trials remains limited. From a cost perspective, study conclusions are still conflicting and centres are recommended to perform their own micro cost analyses.

Conclusions

Most clinical outcomes for single use ureteroscopes currently match those achieved by reusable ureteroscopes but the data pool is still limited. Areas of continued debate include their environmental impact and cost efficiency.

Nur MA, Mohamed FY, Mohamud AK, Hassan J. The prevalence of urolithiasis in subjects undergoing computer tomography in selected referral diagnostic centers in Mogadishu, Somalia

Introduction and objectives

Somalia was predicted to be in the global stone belt with high urolithiasis prevalence. We aimed to determine the prevalence of urolithiasis and their demographic and computer tomography (CT) characteristics among subjects under CT scans in Mogadishu, Somalia. Materials and Methods: From March 2014 to November 2022, a total of 7,276 patients who underwent an abdominopelvic non-contrast CT scan for various indications were retrospectively reviewed. The mean age was 45.6 years with a standard deviation of 21.1 (range, 0.2-110 years). Patients were subdivided into two categories: adults (≥18 years) and pediatric (≤17 years).

Results

Of the 7,276 patients, 1,075 (14.8%) were diagnosed with urolithiasis. Among those with urolithiasis, 702 (65.3%) were male patients, and 373 (34.7%) were female patients. Among them, adults accounted for 92.7%, while children were 7.3%. Renal stones (nephrolithiasis) were the most common, representing 57% followed by ureteric stones at 35.5%, making upper urinary stones 92.5%. Approximately 70 patients (6.5%) had bladder stones; of these, 26 of them (37%) were accompanied by benign prostatic hyperplasia (BPH). There were 10 urethral stones (0.9%) recorded in the study, all were found in male patients, 8 localized in prostatic urethra, and 2 in the bulbar urethra. The overall mean stone size was 13.2 mm, and 60% of them ranged from 5 to 22 mm. Only 24% of the patients were asymptomatic. Single stones were almost 70%, while staghorn calculi were 8.2%. More than 60% of the patients with urolithiasis showed some degree of hydronephrosis ranging between mild to severe.

Conclusion

A CT scan-based urolithiasis prevalence indicates 14.8% in Mogadishu, Somalia, and these results are consistent with the probability calculation of the weights-of-evidence (WofE) methodology based on several risk factors including temperature, climate change, mineral deposit, drinking water quality, and distribution of carbonated rocks. Considering the high prevalence of the disease, Somalia needs to invest more in prevention and treatment facilities while also training urologists that are capable of utilizing minimally invasive techniques in the country.

Dynamic change and preventive role of stress response via Keap1-Nrf2 during renal crystal formation

Oxidative stress is a major risk factor for calcium oxalate nephrolithiasis. Reports suggest that oxidative stress response is induced in animals and humans with kidney stones. Keap1, Nrf2, and HO-1 are known as oxidative stress mediators. However, the association between oxidative stress response and stone formation is unclear. In this study, we analyzed oxidative stress response from the acute to the crystal formation phase when crystal formation was applied to renal crystal mice model and bioimaging mice and investigated the effect on crystal formation. In renal tissues, after glyoxylate administration, HO-1 increased for up to 6 h and returned to baseline at 24 h. This was observed following each daily dose until five days after the crystallization phase; however, the range of increase was attenuated. The possibility that Nrf2 activity influenced the number of crystals was considered in the experiment. Crystal formation increased in Nrf2-deficient mice and could be reduced by Nrf2 activators. In conclusion, the oxidative stress response via the Keap1-Nrf2 pathway may contribute to crystal formation. Particularly, this pathway may be a prospective target for drug development to prevent and cure nephrolithiasis.

Real-world Practice Stone-free Rates After Ureteroscopy: Variation and Outcomes in a Surgical Collaborative

BACKGROUND

Studies assessing the stone-free rate (SFR) after ureteroscopy are limited to expert centers with varied definitions of stone free. Real-world data including community practices related to surgeon characteristics and outcomes are lacking.

OBJECTIVE

To evaluate the SFR for ureteroscopy and its predictors across diverse surgeons in Michigan.

DESIGN, SETTING, AND PARTICIPANTS

We assessed the Michigan Urological Surgery Improvement Collaborative (MUSIC) clinical registry for patients with renal or ureteral stones treated with ureteroscopy between 2016 and 2021 who had postoperative imaging.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Stone free was defined as no fragments on imaging reports within 60 d entered by independent data abstractors. Factors associated with being stone free were examined using logistic regression, including annual surgeon volume. We then assessed variation in surgeon-level SFRs adjusted for risk factors.

RESULTS AND LIMITATIONS

We identified 6487 ureteroscopies from 164 surgeons who treated 2091 (32.2%) renal and 4396 (67.8%) ureteral stones. The overall SFRs were 49.6% (renal) and 72.7% (ureteral). Increasing stone size, lower pole, proximal ureteral location, and multiplicity were associated with not being stone free. Female gender, positive urine culture, use of ureteral access sheath, and postoperative stenting were associated with residual fragments when treating ureteral stones. Adjusted surgeon-level SFRs varied for renal (26.1-72.4%; p < 0.001) and ureteral stones (52.2-90.2%; p < 0.001). Surgeon volume was not a predictor of being stone free for renal stones. Limitations include the lack of imaging in all patients and use of different imaging modalities.

CONCLUSIONS

The real-world complete SFR after ureteroscopy is suboptimal with substantial surgeon-level variation. Interventions focused on surgical technique refinement are needed to improve outcomes for patients undergoing ureteroscopy and stone intervention.

PATIENT SUMMARY

Results from a diverse group of community practicing and academic center urologists show that for a large number of patients, it is not possible to be completely stone free after ureteroscopy. There is substantial variation in surgeon outcomes. Quality improvement efforts are needed to address this.

Extracorporeal shock wave lithotripsy (ESWL) versus percutaneous nephrolithotomy (PCNL) or retrograde intrarenal surgery (RIRS) for kidney stones

BACKGROUND

Nephrolithiasis is a common urological disease worldwide. Extracorporeal shock wave lithotripsy (ESWL) has been used for the treatment of renal stones since the 1980s, while retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) are newer, more invasive treatment modalities that may have higher stone-free rates. The complications of RIRS and PCNL have decreased owing to improvement in surgical techniques and instruments. We re-evaluated the best evidence on this topic in an update of a Cochrane Review first published in 2014.

OBJECTIVES

To assess the effects of extracorporeal shock wave lithotripsy compared with percutaneous nephrolithotomy or retrograde intrarenal surgery for treating kidney stones.

SEARCH METHODS

We performed a comprehensive search in CENTRAL, MEDLINE, Embase, and ClinicalTrials.gov with no restrictions on language or publication status. The latest search date was 6 December 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs that compared ESWL with PCNL or RIRS for kidney stone treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies, extracted data, and assessed risk of bias. Our primary outcomes were treatment success rate at three months (defined as residual fragments smaller than 4 mm, or as defined by the study authors), quality of life (QoL), and complications. Our secondary outcomes were retreatment rate, auxiliary procedures rate, and duration of hospital stay. We performed statistical analyses using a random-effects model and independently rated the certainty of evidence using the GRADE approach.

MAIN RESULTS

We included 31 trials involving 3361 participants (3060 participants completed follow-up). Four trials were only available as an abstract. Overall mean age was 46.6 years and overall mean stone size was 13.4 mm. Most participants (93.8%) had kidney stones measuring 20 mm or less, and 68.9% had lower pole stones. ESWL versus PCNL ESWL may have a lower three-month treatment success rate than PCNL (risk ratio [RR] 0.67, 95% confidence interval [CI] 0.57 to 0.79; I2 = 87%; 12 studies, 1303 participants; low-certainty evidence). This corresponds to 304 fewer participants per 1000 (397 fewer to 194 fewer) reporting treatment success with ESWL. ESWL may have little or no effect on QoL after treatment compared with PCNL (1 study, 78 participants; low-certainty evidence). ESWL probably leads to fewer complications than PCNL (RR 0.62, 95% CI 0.47 to 0.82; I2 = 18%; 13 studies, 1385 participants; moderate-certainty evidence). This corresponds to 82 fewer participants per 1000 (115 fewer to 39 fewer) having complications after ESWL. ESWL versus RIRS ESWL may have a lower three-month treatment success rate than RIRS (RR 0.85, 95% CI 0.78 to 0.93; I2 = 63%; 13 studies, 1349 participants; low-certainty evidence). This corresponds to 127 fewer participants per 1000 (186 fewer to 59 fewer) reporting treatment success with ESWL. We are very uncertain about QoL after treatment; the evidence is based on three studies (214 participants) that we were unable to pool. We are very uncertain about the difference in complication rates between ESWL and RIRS (RR 0.93, 95% CI 0.63 to 1.36; I2 = 32%; 13 studies, 1305 participants; very low-certainty evidence). This corresponds to nine fewer participants per 1000 (49 fewer to 48 more) having complications after ESWL.

AUTHORS' CONCLUSIONS

ESWL compared with PCNL may have lower three-month success rates, may have a similar effect on QoL, and probably leads to fewer complications. ESWL compared with RIRS may have lower three-month success rates, but the evidence on QoL outcomes and complication rates is very uncertain. These findings should provide valuable information to aid shared decision-making between clinicians and people with kidney stones who are undecided about these three options.

The predictive factors that total laser energy consumed during retrograde intrarenal surgery (RIRS): stone area and density

Holmium: YAG (Ho: YAG) laser lithotripsy with flexible ureterorenoscopy can be used with high stone-free and low complication rates for renal stones. This study aimed to determine the factors affecting the total laser energy in cases with provided stone-free status after a single session of retrograde intrarenal surgery (RIRS). Data of 222 patients who underwent RIRS between October 2017 and March 2020 were evaluated retrospectively. After exclusion criteria, the study was carried out with 184 stone-free cases. All cases were performed without using a ureteral access sheath (UAS), and dusting was preferred as the lithotripsy method. The effects of age, gender, body mass index (BMI), previous RIRS history, previous shock wave lithotripsy (SWL) history, stone localization, number of stones, stone surface area, and stone density on total laser energy were analyzed. There was no significant correlation between total laser energy with gender, BMI, previous RIRS history, previous SWL history, stone localization, and the number of stones (p:0.347, p:0.482, p:0.119, p:0.167, p:0.907, p:0.933 respectively). There was a significant correlation between age and total laser energy (p = 0.032), but it was not observed when the effect of the stone surface area was removed (p = 0.354). There were significant correlations between total laser energy and stone surface area, stone density, and total laser time (p<0.001, p<0.001, and p <0.001, respectively). Stone area and stone density affect the total energy consumed during laser lithotripsy. Urologists should consider the stone area, stone density, and the power of the laser device to determine which surgical technic to prefer.

The initial experience of 4.5/6.5 Fr ureteroscopic laser lithotripsy under topical intraurethral anesthesia supplemented by preoperative and intraoperative medications

PURPOSE

To assess the safety and effectiveness of the 4.5/6.5 Fr ureteroscopic laser lithotripsy (URSL) under topical intraurethral anesthesia (TIUA) compared to spinal anesthesia (SA).

METHODS

A retrospective study was conducted on 47 (TIUA: SA = 23:24) patients receiving 4.5/6.5 Fr URSL from July 2022 to September 2022. For the TIUA group, atropine, pethidine, and phloroglucinol were used apart from lidocaine. In the SA group, patients received lidocaine and bupivacaine. We compare the two groups including stone-free rate (SFR), procedure time, anesthesia time, overall operative time, hospital stay, anesthesia failure, intraoperative pain, need for additional analgesia, cost, and complications.

RESULTS

The conversion rate in the TIUA group was 4.35% (1/23). SFR was 100% in both groups. Surgical waiting time and anesthesia time were longer in the SA group (P < 0.001). There were no statistical differences in operational time and intraoperative pain. Patients developed grade 0-1 ureteral injuries. Post-surgical time out of bed was noticeably faster in the TIUA group (P < 0.001). The post-operative complication rate including vomiting and back pain was lower in the TIUA group (P = 0.005).

CONCLUSION

TIUA had an equal surgical success rate and controlled patients' intraoperative pain as SA. It was superior in terms of TIUA's patient admission, waiting time for surgery, anesthesia time, post-operative time out of bed, low complications, and costs, especially for females.

Ureteric stent associated spondylodiscitis

This case report describes a clinical presentation of spondylodiscitis, following an emergency ureteric stent placement for an infected and obstructed kidney in a woman in her late 70s who presented with right flank pain, raised inflammatory markers and an acute kidney injury. Non-contrast CT kidney, ureters and bladder (KUB) revealed a 9 mm obstructing stone and prompt decompression with a JJ stent was performed. Although the urine culture showed no growth at first, an extended spectrum beta-lactamase Escherichia coli was found in a subsequent urine culture after discharge. Postoperatively, the patient described a novel, worsening lower back pain and had persistently elevated inflammatory markers. An MRI revealed spondylodiscitis of L5/S1, for which she was treated with a 6-week course of antibiotics, and she has made a good but slow recovery. This case shows the unusual finding of spondylodiscitis postureteric stent placement and clinicians should be aware of this rare complication.

Personalized Prediction of Patient Radiation Exposure for Therapy of Urolithiasis: An Application and Comparison of Six Machine Learning Algorithms

The prediction of radiation exposure is an important tool for the choice of therapy modality and becomes, as a component of patient-informed consent, increasingly important for both surgeon and patient. The final goal is the implementation of a trained and tested machine learning model in a real-time computer system allowing the surgeon and patient to better assess patient's personal radiation risk. In summary, 995 patients with ureterorenoscopy over a period from May 2016 to December 2019 were included. According to the suggestions based on actual literature evidence, dose area product (DAP) was categorized into 'low doses' ≤ 2.8 Gy·cm² and 'high doses' > 2.8 Gy·cm² for ureterorenoscopy (URS). To forecast the level of radiation exposure during treatment, six different machine learning models were trained, and 10-fold crossvalidated and their model performances evaluated in training and independent test samples. The negative predictive value for low DAP during ureterorenoscopy was 94% (95% CI: 92-96%). Factors influencing the radiation exposure were: age (p = 0.0002), gender (p = 0.011), weight (p < 0.0001), stone size (p < 0.000001), surgeon experience (p = 0.039), number of stones (p = 0.0007), stone density (p = 0.023), use of flexible endoscope (p < 0.0001) and preoperative stone position (p < 0.00001). The machine learning algorithm identified a subgroup of patients of 81% of the total sample, for which highly accurate predictions (94%) were possible allowing the surgeon to assess patient's personal radiation risk. Patients without prediction (19%), the medical expert can make decisions as usual. Next step will be the implementation of the trained model in real-time computer systems for clinical decision processes in daily practice.

Anti-urolithiatic effect of Cucumis melo L. var inodorous in male rats with kidney stones

Melon seed extracts have high antioxidant activities and are effective against a variety of diseases, including kidney stones. In kidney stone model rats, the anti-urolithiatic effects of the hydro-ethanolic extract of melon seed and potassium citrate were studied and compared. After urolithiasis induction by ethylene glycol, the extract and potassium citrate were treated orally for 38 days concurrent with ethylene glycol. Then, urine and kidney sampling were done, and the urinary parameter levels were measured. The melon and potassium citrate treatments reduced the kidney index, the levels of urinary calcium and oxalate, calcium oxalate deposit numbers, the score of crystal deposits, histo-pathological damages, and the score of inflammation in the kidney sections, while elevating the urinary pH, magnesium, and citrate levels, and also the expression of the UMOD, spp1, and reg1 genes in the kidney of treated animals. The effect of potassium citrate is the same as the effect of melon in treated animals. So, their effects could be by normalizing urinary parameters, reducing crystal deposits, excreting small deposits from the kidney, reducing the chance of them being retained in the urinary tract, and elevating the expression of the UMOD, spp1, and reg1 genes, which are involved in kidney stone formation.

Clinical characteristics of surgically managed patients with asymptomatic renal stones: Comparison of patients with symptomatic renal stones

PURPOSE

This study aimed to compare the characteristics of asymptomatic and symptomatic nephrolithiasis in patients who underwent surgical treatment for kidney stones.

MATERIALS AND METHODS

Between 2015 and 2019, 245 patients who underwent percutaneous nephrolithotomy or retrograde intrarenal surgery for kidney stones were included. The patients were divided into asymptomatic (n=124) and symptomatic (n=121) groups. All patients underwent blood and urine tests, preoperative non-contrast computed tomography, and postoperative stone composition analysis. We retrospectively analyzed and compared the characteristics of the patients and stones, operation time, stone-free rate, and postoperative complications between the two groups.

RESULTS

In the asymptomatic group, mean body mass index (BMI) was significantly higher (25.7±3.8 kg/m² vs. 24.3±2.8 kg/m², p=0.002) and urine pH was significantly lower (5.6±0.9 vs. 5.9±0.9, p=0.013). The ratio of calcium oxalate dihydrate stones was significantly higher in the symptomatic group (5.3% vs. 15.5%, p=0.023). No significant differences were observed in stone characteristics, postoperative outcomes, or complications. In the multivariate logistic regression analysis for predicting variables for asymptomatic renal stones, BMI (odds ratio [OR], 1.144; 95% confidence interval [CI], 1.038-1.260; p=0.007), and urine pH (OR, 0.608; 95% CI, 0.407-0.910; p=0.016) were independent predictive variables for asymptomatic renal stones.

CONCLUSIONS

This study demonstrated that thorough medical check-ups are needed for the early detection of renal stones in individuals with a high BMI or low urine pH.

A comparison between asymptomatic and symptomatic ureteral stones

To investigate the characteristics and impact of asymptomatic (silent) ureteral stones on renal function and compare them with those of symptomatic stones. We retrospectively reviewed the medical records of 677 patients who underwent ureteroscopic lithotripsy or laparoscopic ureterolithotomy for ureteral stones between 2016 and 2020. Patients were divided into two groups according to the presence of recognizable symptoms. We investigated the characteristics and impact of silent stones on post-treatment renal function recovery and compared them with those of symptomatic stones. Among the 677 patients, 43 (6.4%) had asymptomatic ureteral stones, and 634 (93.6%) had symptomatic ureteral stones. Compared to symptomatic stones, asymptomatic stones were larger (11.4 mm vs. 9.6 mm, p = 0.003), more commonly present in the upper ureter (62.7% vs. 48.0%, p = 0.04), and more commonly associated with high-grade hydronephrosis (32.8% vs. 12.3%, p < 0.001); however, no difference in metabolite composition was observed between the two group of stone. In the asymptomatic stone group, the mean preoperative estimated glomerular filtration rate (eGFR) was 77.37 ± 23.54 mL/min/1.73 m², and the mean postoperative eGFR indicated no significant improvement at 1 day, 7 days, 3 months, and 12 months (76.66 ± 21.45, 77.89 ± 20.87, 77.29 ± 22.22, and 76.71 ± 24.21 mL/min/1.73 m², respectively; p = 0.567, p = 0.613, p = 0.924, and p = 0.202, respectively). In the symptomatic stone group, the mean preoperative eGFR was 78.17 ± 28.25 mL/min/1.73 m²; the mean postoperative eGFRs at 1 day, 7 days, 3 months, and 12 months were 81.24 ± 26.38, 86.16 ± 25.61, 89.11 ± 25.43, and 89.50 ± 26.01 mL/min/1.73 m², respectively and demonstrated significant improvement (p = 0.002, p < 0.001, p < 0.001, and p < 0.001, respectively). Silent stones irreversibly impaired renal function, even after proper management. Therefore, active treatment strategies are required for all patients who are hesitant to receive treatment for silent stones because of their asymptomatic status to prevent permanent renal impairment.

High ASA Physical Status and Low Serum Uric Acid to Creatinine Ratio are Independent Risk Factors for Postoperative Delirium Among Older Adults Undergoing Urinary Calculi Surgery

Purpose

This study was to investigate the incidence and potential predictive factors for postoperative delirium (POD) in older people following urinary calculi surgery, and to establish the corresponding risk stratification score by the significant factors to predict the risk of POD.

Patients and Methods

We retrospectively analyzed the perioperative data of 195 patients aged 65 or older who underwent elective urinary calculi surgery between September 2020 and September 2022. POD was defined by chart-based method, and the serum uric acid to creatinine (SUA/Cr) ratio as well as neutrophil-to-lymphocyte ratio (NLR) were calculated, respectively. Identification of the risk factors for POD was performed by univariate and multivariate logistic regression analysis. Moreover, the risk stratification score was developed based on the regression coefficients of the associated variables.

Results

In 195 eligible patients following urinary calculi surgery, the median age was 69 (66-72) and 19 patients ultimately developed POD (9.7%). The results by univariate analysis showed that patients with advanced age, high American Society of Anesthesiologists (ASA) physical status (≥3) and low SUA/Cr ratio (≤3.3) were more likely to develop POD, but dexmedetomidine can significantly decrease the risk of the occurrence of POD. The multivariate analysis further indicated that high ASA physical status (≥3) and low SUA/Cr ratio (≤3.3) were independently associated with POD, and the POD incidence could obviously be elevated with the increase of risk stratification score. Moreover, patients with delirium had longer hospital stays.

Conclusion

POD is frequent in geriatric patients following urinary calculi surgery (9.7%). The high ASA physical status (≥3) and low SUA/Cr ratio (≤3.3) were effective predictors of POD. The corresponding risk stratification based on these factors could be beneficial to determining patients who are susceptible to POD, and thus better preventing and reducing the occurrence of POD. However, large prospective studies are needed to confirm this finding.

National Utilization, Reimbursement, and Urban Versus Rural Trends of Extracorporeal Shockwave Lithotripsy and Ureteroscopic Laser Lithotripsy

OBJECTIVE

To describe temporal utilization and reimbursement trends of extracorporeal shockwave lithotripsy (ESWL) and ureteroscopy (URS) with laser lithotripsy.

METHODS

The Medicare Provider Utilization and Payment Database was queried for all ESWL and URS performed between 2013 and 2020 using Current Procedural Terminology codes: ESWL - 50590; URS - 52352, 52353, 52356. Cases that lacked rural or urban identification codes were excluded. A total of 347,174 ESWL and 401,899 URS cases were identified. Linear regression was performed with statistical significance set to 95% confidence intervals.

RESULTS

There was a significant upward trend for URS utilization over the study period (R² = 0.91, P <.001), but there was not a significant trend for ESWL utilization. In 2013, ESWL was used more frequently than URS, but by 2016, URS was used more frequently than ESWL. From 2013 to 2019, URS utilization increased by 241% and 168% by urban and rural urologists, respectively. URS was also associated with a slight increase in physician reimbursement over time (R² = 0.87, P <.001), whereas there was no association between ESWL and physician reimbursement. For URS, rural and urban urologists were reimbursed an average of $312.07 (standard deviation [SD] $14.03) and $404.86 (SD $21.96), respectively. For ESWL, rural and urban urologists were reimbursed an average of $456.22 (SD $5.74) and $562.66 (SD $16.68), respectively.

CONCLUSION

According to the Medicare database, URS has surpassed ESWL in utilization, especially by urban urologists. Physician reimbursement for ESWL remained higher than URS reimbursement, though URS reimbursement increased slightly in recent years.

The role of breastfeeding as a protective factor against the development of the immune-mediated diseases: A systematic review

INTRODUCTION

Breast milk is rich in nutrients and immunological factors capable of protecting infants against various immunological diseases and disorders. The current systematic review has been framed with the objective of studying the role of breastfeeding as a protective factor against the development of immune-mediated diseases.

METHODS

The database and website searches were performed using PubMed, PubMed Central, Nature, Springer, Nature, Web of Science, and Elsevier. The studies were scrutinized based on the nature of participants and the nature of disease considered. The search was restricted to infants with immune-mediated diseases such as diabetes mellitus, allergic conditions, diarrhoea, and rheumatoid arthritis.

RESULTS

We have included 28 studies, out of which seven deal with diabetes mellitus, two rheumatoid arthritis, five studies about Celiac Disease, twelve studies about allergic/ asthma/wheezing conditions and one study on each of the following diseases: neonatal lupus erythematosus and colitis.

DISCUSSION

Based on our analysis, breastfeeding in association with the considered diseases was found to be positive. Breastfeeding is involved as protective factor against various diseases. The role of breastfeeding in the prevention of diabetes mellitus has been found to be significantly higher than for other diseases.

Physiologically based pharmacokinetic modelling and simulation to predict the plasma concentration profile of schaftoside after oral administration of total flavonoids of Desmodium styracifolium

Introduction: The total flavonoids of Desmodium styracifolium (TFDS) are the flavonoid extracts purified from Desmodii Styracifolii Herba. The capsule of TFDS was approved for the treatment of urolithiasis by NMPA in 2022. Schaftoside is the representative compound of TFDS that possesses antilithic and antioxidant effects. The aim of this study was to develop a physiologically based pharmacokinetic (PBPK) model of schaftoside to simulate its plasma concentration profile in rat and human after oral administration of the total flavonoids of Desmodium styracifolium. Methods: The physiologically based pharmacokinetic model of schaftoside was firstly developed and verified by the pharmacokinetic data in rats following intravenous injection and oral administration of the total flavonoids of Desmodium styracifolium. Then the PBPK model was extrapolated to human with PK-Sim^® software. In order to assess the accuracy of the extrapolation, a preliminary multiple-dose clinical study was performed in four healthy volunteers aged 18-45 years old. The predictive performance of PBPK model was mainly evaluated by visual predictive checks and fold error of C_max and AUC_0-t of schaftoside (the ratio of predicted to observed). Finally, the adult PBPK model was scaled to several subpopulations including elderly and renally impaired patients. Results: Schaftoside underwent poor metabolism in rat and human liver microsomes in vitro, and in vivo it was extensively excreted into urine and bile as an unchanged form. By utilizing literature and experimental data, the PBPK model of schaftoside was well established in rat and human. The predicted plasma concentration profiles of schaftoside were consistent with the corresponding observed data, and the fold error values were within the 2-fold acceptance criterion. No significant pharmacokinetic differences were observed after extrapolation from adult (18-40 years old) to elderly populations (71-80 years) in PK-Sim^®. However, the plasma concentration of schaftoside was predicted to be much higher in renally impaired patients. The maximum steady-state plasma concentrations in patients with chronic kidney disease stage 3, 4 and 5 were 3.41, 12.32 and 23.77 times higher, respectively, than those in healthy people. Conclusion: The established PBPK model of schaftoside provided useful insight for dose selection of the total flavonoids of Desmodium styracifolium in different populations. This study provided a feasible way for the assessment of efficacy and safety of herbal medicines.

Comparación de la costo-efectividad de la nefrolitotomía percutánea y de la nefrolitotomía retrógrada flexible con láser de holmio en pacientes con litiasis renal de 20 a 30 mm en Colombia

Introducción y Objetivo Con el advenimiento de nuevas tecnologías, vienen controversias respecto al espectro de sus aplicaciones. El costo derivado de estas tecnologías juega un papel muy importante en el momento de la toma de decisiones terapéuticas. Es por esto que consideramos relevante estimar la costo-efectividad de la nefrolitotomía percutánea comparada con la nefrolitotomía retrógrada flexible con láser de holmio en pacientes con litiasis renal de 20 mm a 30 mm en Colombia.

Materiales y Métodos Por medio de la construcción de un modelo de árbol de decisión usando el programa Treeage (TreeAge Software, LLC, Williamstown, MA, EE.UU.), se realizó una comparación entre la nefrolitotomía percutánea y la nefrolitotomía retrógrada flexible con láser de holmio en pacientes con litiasis renal de 20 mm a 30 mm. La perspectiva fue la del tercer pagador, y se incluyeron los costos directos. Las cifras fueron expresadas en pesos colombianos de 2018. La mejoría clínica, definida como el paciente libre de cálculos, fue la unidad de resultado. Se hizo una extracción de datos de efectividad y seguridad por medio de una revisión sistemática de la literatura. La razón de costo-efectividad incremental fue calculada.

Resultados El modelo final indica que la nefrolitotomía percutánea puede ser considerada como la alternativa más costo-efectiva. Los hallazgos fueron sensibles a la probabilidad de mejoría clínica de la nefrolitotomía percutánea.

Conclusión Teniendo en cuenta las variables económicas, los supuestos del modelo y desde la perspectiva del tercer pagador, la nefrolitotomía percutánea para el tratamiento de pacientes con cálculos renales de 20 mm a 30 mm es costo-efectiva en nuestro país. Estos hallazgos fueron sensibles a los costos y a la efectividad de los procedimientos quirúrgicos.

Emergency Primary Ureteroscopy for Acute Ureteric Colic-From Guidelines to Practice

OBJECTIVE

To review the factors that may influence the ability to achieve the present guidelines' recommendations in a well-resourced tertiary centre. According to current National Institute for Health and Care Excellence (NICE) guidelines, definitive treatment (primary ureteroscopy (URS) or shock wave lithotripsy (ESWL)) should be offered to patients with symptomatic renal colic that are unlikely to pass the stone within 48 h of diagnosis.

METHODS

Retrospective review of all patients presenting to the emergency department between January and December 2019 with a ureteric or renal stone diagnosis. The rate of emergency intervention, risk factors for intervention and outcomes were compared between patients who were treated by primary definitive surgery vs. primary symptom relief by urethral stenting alone.

RESULTS

A total of 244 patients required surgical management for symptomatic ureteric colic without symptoms of urinary infection. Of those, 92 patients (37.7%) underwent definitive treatment by either primary URS (82 patients) or ESWL (9 patients). The mean time for the procedure was 25.5 h (range: 1-118). Patients who underwent primary definitive treatment were likelier to have smaller and distally located stones than the primary stenting group. Primary ureteroscopy was more likely to be performed in a supervised setting than emergency stenting.

CONCLUSIONS

Although definitive treatment carries high success rates, in a high-volume tertiary referral centre, it may not be feasible to offer it to all patients, with emergency stenting providing a safe and quick interim measure. Factors determining the ability to provide definitive treatment are stone location, stone size and resident supervision in theatre.

Flexible Ureterorenoscopy Versus Shockwave Lithotripsy for Kidney Stones ≤2 cm: A Randomized Controlled Trial

BACKGROUND

No clear recommendations are available on whether retrograde intrarenal surgery (RIRS) via flexible ureterorenoscopy or shockwave lithotripsy (SWL) should be preferred for kidney stones ≤2 cm, except for lower-pole stones.

OBJECTIVE

To compare outcomes between RIRS and SWL.

DESIGN, SETTING, AND PARTICIPANTS

This was a single-center randomized controlled trial from March 2015 to May 2018. Patients with a single 6-20-mm kidney stone were enrolled (NCT02645058).

INTERVENTION

Patients were randomized to RIRS or SWL.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was the single-procedure stone-free rate (SFR) at 1 mo. Two levels of success were set: fragments ≤4 mm (SFR-4) and no residual fragments (SFR-0). Secondary endpoints were the SFR at 6 mo and 1 yr and rates of complications and further treatments.

RESULTS AND LIMITATIONS

A total of 138 patients underwent treatment (70 RIRS vs 68 SWL). In comparison to SWL, RIRS SFR results were higher at 1 mo (SFR-4 70.0% vs 45.6%; p = 0.004; SFR-0 50.0% vs 26.5%; p = 0.004) and 6 mo (SFR-4 79.7% vs 63.6%; p = 0.038; SFR-0 59.4% vs 40.9%; p = 0.032). There was no difference in SFR measures between the groups at 1 yr (SFR-4 p = 0.322; SFR-0 p = 0.392). Overall complications were comparable (p = 0.207), but the complication rate for stones >10 mm was higher for the SWL group (p = 0.021). The need for further treatment was comparable (p = 0.368). In terms of patient satisfaction, 86.8% and 77.1% of patients would choose SWL and RIRS again, respectively (p = 0.24).

CONCLUSIONS

RIRS achieved better SFRs in comparison to SWL at 1 and 6 mo, but not at 1 yr. The RIRS complication rate was lower for stones >10 mm. SWL remains a viable alternative, especially for 6-10-mm stones, providing comparable results to RIRS in the long term.

PATIENT SUMMARY

We compared outcomes for the treatment of kidney stones ≤2 cm with two techniques: flexible ureteroscopy, in which a flexible telescope is passed through the urethra and bladder to reach the ureter between the bladder and kidney; and shockwave lithotripsy, in which shockwaves are applied to the skin over the location of the kidney stone. Ureteroscopy achieved better stone-free results at 1 and 6 months, but not at 1 year.

Opioid Analgesic Use After an Acute Pain Visit: Evidence from a Urolithiasis Patient Cohort

Introduction: Urolithiasis causes severe acute pain and is commonly treated with opioid analgesics in the emergency department (ED). We examined opioid analgesic use after episodes of acute pain. Methods: Using data from a longitudinal trial of ED patients with urolithiasis, we constructed multivariable models to estimate the adjusted probability of opioid analgesic use 3, 7, 30, and 90 days after ED discharge. We used multiple imputation to account for missing data and weighting to account for the propensity to be prescribed an opioid analgesic at ED discharge. We used weighted multivariable regression to compare longitudinal opioid analgesic use for those prescribed vs not prescribed an opioid analgesic at discharge, stratified by reported pain at ED discharge. Results: Among 892 adult ED patients with urolithiasis, 79% were prescribed an opioid analgesic at ED discharge. Regardless of reporting pain at ED discharge, those who were prescribed an opioid analgesic were significantly more likely to report using it one, three, and seven days after the visit in weighted multivariable analysis. Among those who were not prescribed an opioid analgesic, an estimated 21% (not reporting pain at ED discharge) and 30% (reporting pain at discharge) reported opioid analgesic use at day three. Among those prescribed an opioid analgesic, 49% (no pain at discharge) and 52% (with pain at discharge) reported using an opioid analgesic at day three. Conclusion: Urolithiasis patients who received an opioid analgesic at ED discharge were more likely to continue using an opioid analgesic than those who did not receive a prescription at the initial visit, despite the time-limited nature of urolithiasis.

Comparison of Surgical Outcomes between Single-Use and Reusable Flexible Ureteroscopes for Renal Stone Management: A Systematic Review and Meta-Analysis

Background and Objectives: Disposable flexible ureteroscopes have been widely used because of their cost-effectiveness and higher sterility potential compared with reusable flexible ureteroscopes. This study aimed to compare the surgical outcomes and complication rates in patients who undergo reusable or disposable flexible ureteroscopic stone surgeries (fURS) for urinary stone disease. Materials and Methods: A systematic review and meta-analysis were conducted under the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. This systematic review was registered with PROSPERO (CRD42022331291). Clinical trials comparing reusable and disposable fURS for stone disease were found from PubMed, EMBASE, Cochrane Library, and the Web of Science up to March 2022. Participants were patients with upper urinary tract stones; the interventions were reusable or disposable fURS. Outcomes, including stone-free rate, operation time, length of hospital stay, and complication rate, were compared for analysis. Results: Overall, 111 studies were identified, but after removing duplicate studies, 75 studies remained. Thirty-two of these studies were excluded. Of the 43 screened studies, 11 met the eligibility criteria. There was no difference in the stone-free rate (SFR) between disposable and reusable fURS (p = 0.14; OR = 1.36; 95% CI, 0.9 to 2.04). For operation time, no difference was identified between reusable and disposable fURS groups (p = 0.12; MD = -5.31; 95% CI, -12.08 to 1.46). For hospital stay, there was also no difference between the two groups (p = 0.61; MD = -0.03; 95% CI, -0.17 to 0.10). There was no significant difference in complication rate between the two groups (p = 0.85; OR = 0.95; 95% CI, 0.56 to 1.61). Conclusions: There were no differences in the SFR, operation time, length of hospital stay, and complication rate between reusable and disposable fURS. Disposable fURS may be a comparable alternative to reusable fURS.