Preoperative JJ stent placement in ureteric and renal stone treatment: results from the Clinical Research Office of Endourological Society (CROES) ureteroscopy (URS) Global Study

An analysis of the predictive factors for stone clearance at primary ureteroscopy

BACKGROUND

Ureteric colic is a common emergency urological presentation [1]. When operative intervention is required, retrograde ureteroscopy is the most common approach. There are multiple treatment strategies including primary ureteroscopy (URS), staged ureteroscopy, and deferred ureteroscopy following ureteric stent placement. The approach is based on a number of clinical and stone factors. This study assesses the factors which predict stone clearance at the initial procedure.

AIMS

All patients diagnosed with an obstructing ureteric stone who were managed operatively in a consecutive 12-month period were included. Patients were evaluated for stone clearance following a single or multiple procedures. A number of factors including stone size, location, gender, age and pre-operative laboratory results were evaluated for association with stone clearance at index procedure. Multivariate logistic regression analyses were performed to produce odds ratios (OR) with confidence interval (CI) at 95% and significance values P < 0.05.

RESULTS

One hundred and seventy patients were included in the final analysis. Stone clearance following the index procedure was achieved in 57% (n = 100) of patients. Predictors of successful stone clearance at index procedure were stone size < 6 mm, male gender and distal stone location (p < 0.05). Proximal stone location, stone size > 10 mm and elevated c-reactive protein (CRP) were associated respectively with multiple procedures to achieve stone clearance (p < 0.05).

CONCLUSIONS

Acute ureteric stones can be managed with a number of treatment strategies. This study identifies factors which predict stone clearance at index procedure. These results will help urologists accurately counsel patients when undertaking operative management for ureteric colic.

Actively extracting kidney stones combined dusting technique can improve SFR of moderate-complexity kidney stones in fURL

PURPOSE

To evaluate the necessity and effectiveness of actively extracting kidney stones with different complexity that have been visually dusted in flexible ureteroscopic lithotripsy (fURL).

METHODS

We retrospectively reviewed the medical records of patients who underwent fURL with dusting technique in established hospitals. A total of 535 cases were divided into the dusting group or the dusting plus basketing group according to the use of stone basket. Their characteristics and operative parameters were collected and analyzed. We used the R.I.R.S. scoring system to classify the complexity of kidney stones and divided these kidney stones into three subgroups, namely, mild-, moderate-, and severe-complexity group. And then, the effectiveness of stone basket in these subgroups was analyzed.

RESULTS

Although using a stone basket significantly reduced re-operation rate (17.8% in dusting group versus 10.2% in dusting plus basketing group, p = 0.013), no significant difference on stone-free rate (SFR) and overall incidence of complications were noticed between groups. After we classified the complexity of kidney stones using the R.I.R.S. scoring system, we found a stone basket was helpful to improve SFR in kidney stones with moderate-complexity that had been visually dusted in fURL (73.5% in dusting group versus 87.3% in dusting plus basketing group, p = 0.002) but had limited influence on SFR in mild (93.8% in dusting group versus 92.6% in dusting plus basketing group, p = 0.783) or severe (28.5% in dusting group versus 34.0% in dusting plus basketing group, p = 0.598)-complexity kidney stones.

CONCLUSION

The use of stone basket should be encouraged in moderate-complexity kidney stones which can be visually dusted in fURL.

A Machine Learning (ML) Predictive Model for Ureteroscopy lasertripsy (URSL) Outcomes in a Paediatric Population - Results from a large Endourology Tertiary Centre

INTRODUCTION

We aimed to develop machine learning (ML) algorithms for the automated prediction of post operative ureteroscopy outcomes for paediatric kidney stones based on pre-operative characteristics.

MATERIAL AND METHODS

Data from paediatric patients who underwent ureteroscopy for stone treatment by a single experienced surgeon, between 2010 and 2023 in Southampton General Hospital, were retrospectively collected. 15 ML classification algorithms were used to investigate correlations between preoperative characteristics and postoperative outcomes: primary stone free status (SFS, defined as stone fragments <2mm at the end of the procedure confirmed endoscopically and no evidence of stone fragments >2mm at XR KUB or US KUB at 3 months follow up) and complications. For the task of complication and stone status, ensemble model was made out of bagging classifier, extra trees classifier and LDA. Also, a multi-task neural network was constructed for the simultaneous prediction of all post-operative characteristics. Finally, Explainable AI techniques were used to explain the prediction made by the best models.

RESULTS

The ensemble model produced the highest accuracy (90%) in predicting SFS, finding correlation with overall stone size (-0.205), presence of multiple stones (-0.127) and preoperative stenting (-0.102). Complications were predicted by SMOTE oversampled dataset (93.3% accuracy) with relation to preoperative positive urine culture (-0.060) and SFS (0.003). Training the ML for the multi task model, accuracies of 83.3% and 80% were respectively reached.

CONCLUSION

ML has a great potential of assisting healthcare research, with possibilities to investigate dataset at a higher level. With the aid of this intelligent tool, urologists can implement their practice and develop new strategies for outcome prediction and patient counselling and informed shared decision making. Our model reached an excellent accuracy in predicting SFS and complications in the paediatric population, leading the way to the validation of patient-specific predictive tools.

Can Machine Learning Correctly Predict Outcomes of Flexible Ureteroscopy with Laser Lithotripsy for Kidney Stone Disease? Results from a Large Endourology University Centre

Background and objective

The integration of machine learning (ML) in health care has garnered significant attention because of its unprecedented opportunities to enhance patient care and outcomes. In this study, we trained ML algorithms for automated prediction of outcomes of ureteroscopic laser lithotripsy (URSL) on the basis of preoperative characteristics.

Methods

Data were retrieved for patients treated with ureteroscopy for urolithiasis by a single experienced surgeon over a 7-yr period. Sixteen ML classification algorithms were trained to investigate correlation between preoperative characteristics and postoperative outcomes. The outcomes assessed were primary stone-free status (SFS, defined as the presence of only stone fragments <2 mm on endoscopic visualisation and at 3-mo imaging) and postoperative complications. An ensemble model was constructed from the best-performing algorithms for prediction of complications and for prediction of SFS. Simultaneous prediction of postoperative characteristics was then investigated using a multitask neural network, and explainable artificial intelligence (AI) was used to demonstrate the predictive power of the best models.

Key findings and limitations

An ensemble ML model achieved accuracy of 93% and precision of 87% for prediction of SFS. Complications were mainly associated with a preoperative positive urine culture (1.44). Logistic regression revealed that SFS was impacted by the total stone burden (0.34), the presence of a preoperative stent (0.106), a positive preoperative urine culture (0.14), and stone location (0.09). Explainable AI results emphasised the key features and their contributions to the output.

Conclusions and clinical implications

Technological advances are helping urologists to overcome the classic limits of ureteroscopy, namely stone size and the risk of complications. ML represents an excellent aid for correct prediction of outcomes after training on pre-existing data sets. Our ML model achieved accuracy of >90% for prediction of SFS and complications, and represents a basis for the development of an accessible predictive model for endourologists and patients in the URSL setting.

Patient summary

We tested the ability of artificial intelligence to predict treatment outcomes for patients with kidney stones. We trained 16 different machine learning tools with data before surgery, such as patient age and the stone characteristics. Our final model was >90% accurate in predicting stone-free status after surgery and the occurrence of complications.

The Saudi urological association guidelines on urolithiasis

Aims

The Saudi Urolithiasis Guidelines are a set of recommendations for diagnosing, evaluating, and treating urolithiasis in the Saudi population. These guidelines are based on the latest evidence and expert consensus to improve patient outcomes and optimize care delivery. They cover the various aspects of urolithiasis, including risk factors, diagnosis, medical and surgical treatments, and prevention strategies. By following these guidelines, health-care professionals can improve care quality for individuals with urolithiasis in Saudi Arabia.

Panel

The Saudi Urolithiasis Guidelines Panel consists of urologists specialized in endourology with expertise in urolithiasis and consultation with a guideline methodologist. All panelists involved in this document have submitted statements disclosing any potential conflicts of interest.

Methods

The Saudi Guidelines on Urolithiasis were developed by relying primarily on established international guidelines to adopt or adapt the most appropriate guidance for the Saudi context. When necessary, the panel modified the phrasing of recommendations from different sources to ensure consistency within the document. To address areas less well covered in existing guidelines, the panel conducted a directed literature search for high quality evidence published in English, including meta analyses, randomized controlled trials, and prospective nonrandomized comparative studies. The panel also searched for locally relevant studies containing information unique to the Saudi Arabian population. The recommendations are formulated with a direction and strength of recommendation based on GRADE terminology and interpretation while relying on existing summaries of evidence from the existing guidelines.

Effect of preoperative ureteral stenting on the surgical outcomes of patients with 1-2 cm renal stones managed by retrograde intrarenal surgery using a ureteral access sheath

OBJECTIVE

To assess the surgical results of patients who underwent retrograde intrarenal surgery (RIRS) using a ureteral access sheath (UAS) for management of renal stones sized 1-2 cm compared between patients who did and did not undergo preoperative ureteral stenting.

MATERIALS AND METHODS

This prospective study included 83 patients (aged ≥ 20 years) who underwent RIRS from July 2021 to January 2023. All patients had renal calculi (stone size: 1-2 cm) located within the pelvicalyceal system. 43 and 40 patients were allocated to the non-prestent (group A) and prestent (group B), respectively. Patient baseline characteristics, renal stone details, operative data, stone-free rate (SFR) at 4 weeks and 6 months, and perioperative complications were compared between groups.

RESULTS

The baseline characteristics of all patients were comparable across the groups. Four weeks after surgery, the overall stone-free rate (SFR) stood at 62.65%. In the non-prestent and prestent groups, the SFRs were 58.12% and 67.5%, respectively (p = 0.89). By the sixth month post-surgery, the overall SFR rose to 80.72%. In the non-prestent and prestent groups, the SFRs were 76.74% and 85%, respectively (p = 0.081). No notable differences emerged in other variables, including perioperative complications, between the two groups.

CONCLUSIONS

The SFR showed no significant difference between the prestenting and non-prestenting groups at the 4-week and 6-month postoperative marks. Additionally, there were no substantial differences in complications during surgery and recovery between the groups. Notably, the SFR increased from 4 weeks to 6 months without any additional procedures in either group.

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.

2022 Recommendations of the AFU Lithiasis Committee: Ureteroscopy and ureterorenoscopy

Technical advances, including miniaturization, have improved the deflection and optical performance of the ureteroscopes, and the availability of dedicated disposable devices have led to their increasing use for kidney and ureteral stone management. Ureterorenoscopy brings diagnostic evidence through the endoscopic description of stones and renal papillary abnormalities. Currently, intracorporeal lithotripsy during ureterorenoscopy is based on laser sources. Routine ureteral stenting is not necessary before ureterorenoscopy, especially because preoperative stenting for>30 days is considered as an independent risk factor of infection. Ureteral access sheaths allow the easy and repeated access to the upper urinary tract and thus facilitate ureterorenoscopy. Their use improves vision, decreases intrarenal pressure, and possibly reduces the operative time, but they may cause ureteral injury. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendation (CPR) method and the ADAPTE method, depending on whether or not the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis [EAU 2022]) and their adaptability to the French context.

Flexible ureteroscopy for lower pole calculus: is it still a challenge?

PURPOSE

Flexible ureteroscopy (fURS) is steadily gaining popularity in the management of renal calculi, including those located in the lower pole (LP). Due to difficulty in accessing to the LP of kidney in minority of cases with fURS and reports of lower stone-free rate (SFR), it is still considered as a challenge in selected cases. The purpose of the review was to analyze the various aspects of fURS for LP stones.

METHODS

An extensive review of the recent literature was done including different factors such as anatomy, preoperative stenting, stone size, flexible scopes, types of lasers, laser fibers, suction, relocation, stone-free rates, and complications.

RESULTS

The significance of various lower pole anatomical measurements remain a subject of debate and requires standardization. Recent improvements in fURS such as single-use digital scopes with better vision and flexibility, high power laser, thulium fiber laser, smaller laser fiber, and accessories have significantly contributed to make flexible ureteroscopy  more effective and safer in the management of LP stone. The utilization of thulium fiber lasers in conjunction with various suction devices is being recognized and can significantly improve SFR.

CONCLUSIONS

With the significant advancement of various aspects of fURS, this treatment modality has shown remarkable efficacy and gaining widespread acceptance in management of LP kidney stones. These developments have made the fURS of LP stones less challenging.

Primary Ureteroscopy without Pre-Stenting for Proximal Ureteral Stones-Is It Feasible?

BACKGROUND

Primary ureteroscopy with laser lithotripsy is the treatment of choice for distal ureteral stones. However, in cases of proximal ureteral stones, some urologists recommend the preliminary insertion of a ureteral stent and deferred ureteroscopy. We aimed to evaluate the necessity of preliminary ureteral stent insertion in the management of proximal ureteral stones by comparing the surgical outcomes of patients undergoing primary ureteroscopy with laser lithotripsy for proximal vs. distal ureteral stones.

METHODS

Medical records of patients who underwent ureteroscopy between 2016 and 2017 in our institution were retrospectively reviewed. Data collected included demographic data, stone size, renal function, intra- and post-operative complications, and stone-free rate (SFR). Patients were divided into two groups: proximal ureteral stones and distal ureteral stones.

RESULTS

The cohort included 241 patients who underwent ureteroscopy. Among them, 106 had a proximal ureteral stone. The median age was 51 (IQR 41-65) years. Patients who underwent ureteroscopy for proximal ureteral stones were significantly older (p = 0.007). The median stone's maximal diameter was 7 (5-10) mm. The complication rate and stone-free rate (SFR) were similar in both groups (p = 0.657 and p = 1, respectively). The prevalence of post-procedural ureteral stent insertion was higher among patients who underwent ureteroscopy for proximal ureteral stones: 92.5% vs. 79.3% (p = 0.004).

CONCLUSIONS

Our study concludes that primary ureteroscopy with laser lithotripsy for proximal ureteral stones is a valid and feasible treatment with a similar surgical outcome compared to distal ureteral stones. Preliminary ureteral stent insertion seems to be unnecessary.

Influence of pre-stenting on RIRS outcomes. Inferences from patients of the Global Multicentre Flexible Ureteroscopy Outcome Registry (FLEXOR)

BACKGROUND

Retrograde Intrarenal Surgery (RIRS) is recommended as an alternative to percutaneous nephrolithotomy for stones up to 2 cm. Pre-stenting before RIRS remains controversial with various studies differing in outcomes and recommendations. We aim to understand how pre-stenting influences surgical outcomes.

METHODS

A number of 6579 patients from the TOWER group registry were divided into pre-stented (group 1) and non-pre-stented groups (group 2). Patients aged ≥18 years old, with normal calyceal anatomy were enrolled. Patients with ureteric stones, anomalous kidneys, bilateral stones, planned for ECIRS were excluded.

RESULTS

Patients are homogeneously distributed in both groups (3112 vs. 3467). The predominant indication for pre-stenting was symptom relief. Overall stone size was comparable, whilst group 1 had a significantly more multiple (1419 vs. 1283, P<0.001) and lower-pole (LP) stones (1503 vs. 1411, P<0.001). The mean operative time for group 2 was significantly longer (68.17 vs. 58.92, P<0.001). Stone size, LP stones, age, recurrence and multiple stones are contributing factors for residual fragments at the multivariable analysis. The incidence of postoperative day 1 fever and sepsis was significantly higher in group 2, indicating that pre-stenting is associated with a lower risk of post-RIRS infection and a lower overall complications rate (13.62% vs. 15.89%) (P<0.001).

CONCLUSIONS

RIRS without pre-stenting can be considered safe without significant morbidity. Multiple, lower-pole and large stone is a significant contributor towards residual fragments. Patients who were not pre-stented had significantly higher but low-grade complications, especially for lower pole and large volume stones. While we do not advocate routine pre-stenting, a tailored approach for these patients should include proper counselling regarding pre-stenting.

Optimal Dwelling Time for Ureteral Stents Placed for Passive Dilation after Impassable Ureteroscopy

INTRODUCTION

The aim of the study was to determine the correlation between the dwelling time for a ureteral stent placed for passive dilation after impassable ureteroscopy and success and complications.

METHODS

A retrospective evaluation was made of patients who underwent stent placement after impassable ureteroscopy and a repeat ureteroscopy due to kidney stones. A total of 161 patients were included in the study between 2015 and 2022. Demographic, clinical, preoperative, and perioperative data were collected. Logistic regression analyses were performed on the data showing a significant difference in the univariate analyses performed to determine the predictive factors of ureteroscopy after the stent dwelling period in terms of stone-free status and perioperative complications.

RESULTS

Stone-free status was achieved in 110 (68.3%) of 161 patients, and perioperative complications were observed in 41 (25.4%). Factors that affected the stone-free status were determined as the dwelling time and the S-ReSC score, while factors affecting perioperative complications were the stent dwelling time and the operation time. The stone-free rates were observed to increase from 46.4% in the first 2 weeks to 72.9% after the 2nd week, an increase of 1.5-fold. Perioperative complications were determined at the rate of 17.5% during the first 5 weeks and increased 2.1-fold to 37.5% after the 5th week.

CONCLUSION

It can be recommended that great care is taken during the stent dwelling period and ureteroscopy should be performed within 5 weeks (14-35 days) but no earlier than 2 weeks, so as not to affect the success of the procedure.

Surgical outcomes of patients who underwent retrograde intrarenal surgery using a ureteral access sheath to manage kidney stones sized 1-2 cm compared between patients who did and did not undergo preoperative ureteral stenting

Objective

To investigate the surgical outcomes of patients who underwent retrograde intrarenal surgery (RIRS) using a ureteral access sheath (UAS) to manage kidney stones sized 1-2 cm compared between patients who did and did not undergo preoperative ureteral prestenting.

Materials and methods

This retrospective cohort study included 166 patients (aged ≥18 years) who underwent RIRS at Siriraj Hospital (Bangkok, Thailand) during February 2015-February 2020. All patients had renal calculi (stone size: 1-2 cm) located within the pelvicalyceal system. 80 and 86 patients were allocated to the prestent and non-prestent groups, respectively. Patient baseline characteristics, renal stone details, operative equipment, stone-free rate (SFR) at 2 weeks and 6 months, and perioperative complications were compared between groups.

Results

All patient baseline characteristics were similar between groups. At 2 weeks after surgery, the overall SFR was 65.1%, and the SFRs in the prestent and non-prestent groups were 73.4% and 59.5%, respectively (p = 0.09). At 6 months after surgery, the overall SFR was 80.1%, and the SFRs in the prestent and non-prestent groups were 90.7% and 79.3%, respectively (p = 0.08). The incidence of perioperative complications was not significantly different between groups.

Conclusions

There was no significant difference in the SFR between the presenting and non-prestenting groups at both the 2-week and 6-month postoperative time points. There was also no significant difference in intraoperative and postoperative complications between groups. The SFR was higher at 6 months than at 2 weeks in both groups with no additional procedure.

Impact of Preoperative Ureteral Stenting in Retrograde Intrarenal Surgery for Urolithiasis

Background and Objectives: Ureteral stent insertion passively dilates the ureter. Therefore, it is sometimes used preoperatively before flexible ureterorenoscopy to make the ureter more accessible and facilitate urolithiasis passage, especially when ureteroscopic access has failed or when the ureter is expected to be tight. However, it may cause stent-related discomfort and complications. This study aimed to assess the effect of ureteral stenting prior to retrograde intrarenal surgery (RIRS). Materials and Methods: Data from patients who underwent unilateral RIRS for renal stone with the use of a ureteral access sheath from January 2016 to May 2019 were retrospectively analyzed. Patient characteristics, including age, sex, BMI, presence of hydronephrosis, and treated side, were recorded. Stone characteristics in terms of maximal stone length, modified Seoul National University Renal Stone Complexity score, and stone composition were evaluated. Surgical outcomes, including operative time, complication rate, and stone-free rate, were compared between two groups divided by whether preoperative stenting was performed. Results: Of the 260 patients enrolled in this study, 106 patients had no preoperative stenting (stentless group), and 154 patients had stenting (stenting group). Patient characteristics except for the presence of hydronephrosis and stone composition were not statistically different between the two groups. In surgical outcomes, the stone-free rate was not statistically different between the two groups (p = 0.901); however, the operation time for the stenting group was longer than that of the stentless group (44.8 ± 24.2 vs. 36.1 ± 17.6 min; p = 0.001). There were no differences in the complication rate between the two groups (p = 0.523). Conclusions: Among surgical outcomes for RIRS with a ureteral access sheath, preoperative ureteral stenting does not provide a significant advantage over non-stenting with respect to the stone-free rate and complication rate.

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Are adrenergic α1- antagonists beneficial for the access of retrograde ureteral access sheath or semi-rigid ureteroscope access? A systematic review and meta-analysis

Introduction

To evaluate the clinical benefit of preoperative adrenergic α1-antagonist therapy in the management of upper urinary calculi.

Materials and methods

Publications were searched for The Cochrane Central Register of Controlled Trials, EMBASE, and MEDLINE until 1 March 2022 that related to the adrenergic α1- antagonist intake as adjunctive therapy before retrograde surgery. Dichotomous data were reported with risk ratios (RR) with 95% confidence intervals (CIs) and the continuous data were reported with mean difference (MD) with 95% CIs.

Results

There were nine studies with 867 patients included in this meta-analysis. Preoperative adrenergic α1- antagonists could significantly elevate the compared with the placebo. Higher successful access rate to the stone was found in patients who received preoperative adrenergic α1- antagonists than those who received the placebo (RR 1.24; 95% CI 1.17-1.33). Besides, the application of preoperative adrenergic α1- antagonists can also elevate 4th-week stone-free rate (RR 1.20; 95% CI 1.12-1.28), decrease postoperative analgesia (RR 0.30;95% CI 0.20-0.46) and result in a lower risk of overall complications (RR 0.38; 95% CI 0.24-0.61).

Conclusion

Preoperative adjunctive adrenergic α1- antagonist therapy is effective and safe in the management of retrograde surgery with a higher successful access rate and lower risk of severe complications.

Ileal ureteral replacement for the management of ureteral avulsion during ureteroscopic lithotripsy: a case series

INTRODUCTION

To describe our initial experience with ileal ureteral replacement (IUR) for the management of ureteral avulsion (UA) during ureteroscopic lithotripsy.

METHODS

Between September 2010 and April 2021, ten patients received ileal ureteral replacement for ureteral avulsion during ureteroscopic lithotripsy. Anterograde urography and computed tomography urography (CTU) were applied to evaluate the lesion. Follow-up was performed with magnetic resonance urography and renal ultrasound as well as clinical assessment of symptoms. We retrospectively analysed the clinical data of ten patients treated with ileal ureteral replacement for the treatment of ureteral avulsion.

RESULTS

Four patients underwent open ileal ureteral replacement, two underwent laparoscopic ileal ureteral replacement, and four underwent robotic-assisted ileal ureteral replacement. The mean operative time (OT) was 310 min (range 191-530). The mean estimated blood loss (EBL) was 193 mL (range 10-1000). The mean length of the ileal graft was 21 cm (range 12-25). The median postoperative hospital time was 13 days (range 7-19). All surgeries were effectively completed, and no case required open conversion in laparoscopic and robotic-assisted surgeries. There was no obvious hydronephrosis according to contrast-enhanced computed tomography 3-dimensional reconstruction images without serious complications or progressive hydronephrosis during a median follow-up duration of 51 months (range 5-131), and the success rate was 100%.

CONCLUSIONS

Our initial results and experience showed that ileal ureteral replacement for the management of ureteral avulsion during ureteroscopic lithotripsy is safe and feasible.

Comparison of long-term results following ureteroscopic stone fragmentation with removal versus stone dusting without removal

Purpose:

To compare long-term results following ureteroscopic stone fragmentation and removal versus stone dusting.

Methods:

We conducted a retrospective analysis of patients who underwent ureteroscopy for renal calculi at two high-volume tertiary centres between 2012 and 2013, therefore allowing long-term follow-up. The surgeons differed in their technique, some performing dusting for the most part and the others fragmentation. Inclusion criteria were stone free at the first follow-up and the sole use of laser lithotripsy is either by dusting or by fragmentation. Operative and post-operative data as well as re-treatment rates were compared between the groups. Stone-free rates and long-term stone recurrence rates were analysed by a single radiologist blinded to the treatment technique.

Results:

Between 2012 and 2013, 669 ureteroscopies were performed at both centres. The study group included 100 patients, which met the inclusion criteria, equally distributed between dusting and fragmentation. The cumulative stone diameter in patients treated with dusting was significantly larger (12.7 mm versus 17 mm, p = 0.006). Operative time was shorter in patients treated with dusting (56 minutes versus 47.2 minutes, p = 0.6). The mean follow-up was 58.9 (standard deviation (SD) 17.2) and 69.4 (SD 13.8) months for the fragmentation and dusting-treated patients, respectively( p = 0.06). The long-term recurrence rate in the fragmentation group was 22% compared to 38% in the dusting group ( p = 0 .08). Most of the patients in the dusting group required a repeat ureteroscopy during their follow-up (28% versus 6%, p = 0.003). A multivariable logistic regression analysis revealed that the fragmentation was not associated with a lower stone recurrence rate when compared to dusting (OR 0.6, 95% CI 0.199-1.810, p = 0.3).

Conclusions:

The recurrence rate of renal stones was not significantly influenced by the choice of surgical techniques. However, dusting was associated with a greater need for repeat ureteroscopy than fragmentation with removal.

Level of evidence:

Not applicable

Silicone vs. Polyurethane Stent: The Final Countdown

Ureteric stents are conventionally used in daily urological practice. There is ongoing debate on the superiority of different stent materials, particularly in terms of patient tolerance. We conducted a literature review to compare silicone stents and stents made of other materials from a patient tolerability perspective. We conclude that silicone stents are better tolerated but further research is required.

Safety and Efficacy of Flexible Ureterorenoscopy Surgery: Results of Our Large Patient Series

Introduction: The aim of our study is to evaluate the success rates of our retrograde intrarenal surgery operations and the complications we encountered and to determine in which kidney segment the operations were more successful with flexible ureterorenoscopy.

Methods: The records of retrograde intrarenal surgery operations performed between March 2013 and January 2021 in Health Sciences University, Adana City Training and Research Hospital, urology clinic were analyzed retrospectively. Patients’ age, body mass index, operation side, stone size, stone density, duration of operation, first-day and first-month operation success status, presence of preoperative and postoperative ureteral stent, preoperative and postoperative first-day and first-month creatinine levels, and preoperative and postoperative first-day and first-month hematocrit levels were recorded.

Results: Our study consisted of a total of 1128 patients, 618 males (54.7%) and 510 (45.2%) females, with an average age of 42.3±14.4. Kidney stones were most commonly found in the renal pelvis (54.2%). The postoperative first-day success rate was highest in the pelvis stone group (P=0.009). The first month’s success rates were highest in those with pelvic stones (93.1%), and the lowest in patients with multiple stones (85.7%). Patients’ operation time, postoperative hematocrit and creatinine levels, and complications did not differ statistically between the groups (P>0.05).

Conclusion: Retrograde intrarenal surgery is an acceptable minimally invasive and effective surgery with low complication rates. There is a high success rate, especially in pelvis stones.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Optimum duration of ureteral prestenting dwelling time in children undergoing retrograde intrarenal surgery

INTRODUCTION AND OBJECTIVES

Ureteral prestenting before retrograde intrarenal surgery (RIRS) causes passive dilatation of the ureter, improves stone-free rate and is associated with shorter operative time. However, the presence of a ureteric stent may increase the risk for septic complications, which accelerates with increased dwelling time duration. The aim of the present study is to explore the impact of ureteral prestenting timing in a group of children undergoing retrograde intrarenal surgery (RIRS) on perioperative outcomes and complication rates and to define the optimum duration of prestenting dwelling time.

PATIENTS AND METHODS

A retrospective study on 60 children aged less than 14 years, presented with upper tract urinary stones, who were subdivided into two groups: Group 1 and 2, each included 30 children who had undergone RIRS after ureteric stenting for two weeks and four weeks respectively. Success of ureteroscope introduction, operative time, stone free rate (SFR), intraoperative and postoperative complications and number of retreatment procedures after definitive RIRS were recorded and compared between the two treatment groups.

RESULTS

Ureteric access was successfully obtained in all children in both groups. Patients in group 1 and 2 had a SFR of 86.6% and 90%, respectively (p = 0.199). The mean operative time of group 1 and 2 were 56.5 and 52.9 min (p = 0.612). Postoperative UTI rates increased with prolonged dwelling time from 6.7% in group 1 to 30% in group 2. No patient in both groups developed high grade complications.

CONCLUSIONS

Increasing prestenting dwelling time from two to four weeks had no statistically significant effect on the successful ureteroscopic access nor the stone free rate in children undergoing RIRS. Reducing the ureteric stent dwelling time minimizes the rate of postoperative UTI without compromising the success of operative outcomes.

The Outcomes of Pre-Stenting on Renal and Ureteral Stones: A Meta-Analysis

BACKGROUND

Pre-stenting (PS) on the outcomes of semirigid and flexible ureteroscopic lithotripsy for a different upper urinary urolithiasis remains controversial. We performed a meta-analysis comparing the outcomes of ureteroscopic lithotripsy between PS and non-PS.

MATERIALS AND METHODS

Randomized, controlled trials and observational studies comparing PS and non-PS were identified from electronic databases. Stone-free rate (SFR), operative time, and complications were compared by qualitative and quantitative syntheses (meta-analyses).

RESULTS

Eleven articles were included in this study. Nearly, all of recently published studies exhibited relatively moderate or high quality during quality assessment. PS was more likely to achieve good SFR compared with non-PS (p < 0.00001). The subgroup results indicated that PS improved the SFR for renal stones and the stones dealt by flexible ureteroscopy (p = 0.0002; p < 0.0001, respectively; some ureteral stones were dealt by flexible ureteroscopy). Ureteral stones and the stones dealt by semirigid ureteroscopy were not influenced by PS (p = 0.62; p = 0.90, respectively). PS is equal as non-PS in terms of operative time for renal stones and the renal and ureteral stones dealt by flexible ureteroscopy (p = 0.47; p = 0.05). No significant difference was found in major complications between the 2 groups for total or for the subgroup of renal stones (p = 0.3; p = 0.69).

CONCLUSIONS

For ureteral stones or the stones dealt by semirigid ureteroscopy, PS does not show any benefits. For renal stones or the stones dealt by flexible ureteroscopy, PS improves the SFR and may be as safe as non-PS.

Impact of Preoperative Stenting on the Outcome of Flexible Ureterorenoscopy for Upper Urinary Tract Urolithiasis: A Systematic Review and Meta-Analysis

PURPOSE

This study aimed to investigate the effect of preoperative stenting (POS) on the perioperative outcomes of flexible ureterorenoscopy (fURS).

MATERIALS AND METHODS

A systematic review and meta-analysis was conducted based on the PRISMA statement. From the initially retrieved 609 reports, we excluded the ineligible studies at 2 stages. We only included studies that contained fURS patients with and without POS in the same report. Data of patients who underwent semirigid ureteroscope only were excluded from the analysis. The Newcastle-Ottawa Scale (NOS) system was applied for risk of bias assessment.

RESULTS

A total of 20 studies including 5,852 patients were involved. 48.5% of the patients had preoperative stent. Stone-free rate was significantly higher with prestenting; odds ratio (OR) was 1.98 (95% CI: 1.51-2.58) (Z = 5.02; p = 0.00001). It also displayed tendency toward lower complications; OR was 0.74 (95% CI: 0.52-1.05) (Z = 1.67; p = 0.09). POS significantly increased the use of ureteral access sheath; OR was 1.49 (95% CI: 1.05-2.13) (Z = 2.22; p = 0.03). Risk of bias assessment showed 13 and 7 studies with low and moderate risk, respectively.

CONCLUSIONS

POS clearly improves the stone-free rates after fURS. It might reduce the complications, especially ureteral injury. These findings might help solve the current debate and can be useful for urologists during patient counselling for a proper decision-making.

A randomized prospective study: assessment of transient ureteral stenting by mono-J insertion after primary URS and stone extraction (FaST 3)

To compare the outcome of a short-term insertion of a mono-J catheter for 6 h following ureteroscopic stone removal to a conventional double-J catheter. This single-center academic study (Fast Track Stent study 3) evaluated stenting in 108 patients with urinary calculi after ureterorenoscopy. Patients were prospectively randomized into two study arms before primary ureterorenoscopy: (1) mono-J insertion for 6 h after ureterorenoscopy and (2) double-J insertion for 3-5 days after ureterorenoscopy. Study endpoints were stent-related symptoms assessed by an ureteral stent symptom questionnaire (USSQ) and reintervention rates. Stone sizes and location, age, operation duration, BMI, and gender were recorded. Of 67 patients undergoing ureterorenoscopy, 36 patients were analyzed in the double-J arm and 31 patients in the mono-J arm. Mean operation time was 27.5 ± 1.3 min versus 24.0 ± 1.3 min, and stone size was 5.2 mm versus 4.5 mm for mono-J versus double-J, respectively (p = 0.06 and p = 0.15). FaST 3 was terminated early due to a high reintervention rate of 35.5% for the mono-J group and 16.7% for the double-J group (p = 0.27). One day after ureterorenoscopy, USSQ scores were similar between the study arms (Urinary Index: p = 0.09; Pain Index: p = 0.67). However, after 3-5 weeks, the Pain Index was significantly lower in those patients who had a double-J inserted after ureterorenoscopy (p = 0.04). Short-term insertion of mono-J post-ureterorenoscopy results in similar micturition symptoms and pain one day after ureterorenoscopy compared to double-J insertion. The reintervention rate was non-significant between the treatment groups most likely due to the early termination of the study (p = 0.27). Ethics approval/Trail Registration: No. 18-6435, 2018.

Advanced ureteroscopic techniques for the management of kidney stones

PURPOSE OF REVIEW

Recent years witnessed significant changes in the endourological management of renal tones because of the development of new, more advanced instruments. Retrograde intrarenal surgery (RIRS) has gained particular advantage from such technological progress and now tends to be considered the gold standard treatment for uncomplicated less than 20 mm renal stones. Using a step-by-step approach, this review aims to highlight current achievements but also unsolved problems in RIRS.

RECENT FINDINGS

Several technical details of RIRS, including preoperative stenting, use of ureteral access sheets, lithotripsy method, and renal drainage, remain open to discussion and linked to surgeon's preference. Moreover, there is a wide range of variation in efficacy and safety data, with major complications being episodic but often under-reported.

SUMMARY

RIRS has gained increased popularity among the urological community. This is certainly because of the continuous technological advancements, which have continuously improved the RIRS performance but also to the perception of ease and safety of this procedure when compared with the other available treatment modalities, particularly percutaneous nephrolitotomy. Indeed, the reported advances in RIRS technique have significantly improved the outcomes of this procedure but care should be taken not to underestimate its potential challenges.

Initial experience with slimmest single-use flexible ureteroscope Uscope PU3033A (PUSEN™) in retrograde intrarenal surgery and its comparison with Uscope PU3022a: a single-center prospective study

PURPOSE

Single-use disposable digital flexible ureterorenoscope has become an attractive option to reusable scope with many advantages. Currently available single-use digital fURS have outer shaft diameter above 9 Fr which requires large access sheath insertion and sometimes double J stent placement. Recently, 7.5 Fr single-use digital fURS is introduced in market by Pusen. Objective of this study is to compare two Pusen single-use scopes in the clinical setting: 7.5 Fr Uscope PU3033A and 9.5 Fr Uscope PU3022A.

METHODS

30 patients, having renal stones < 2 cm, planned for RIRS were prospectively randomized to two groups: group 1 had 15 patients in which 7.5 Fr Uscope PU3033A and group 2 had 15 patients in which 9.5 Fr Uscope PU3022A was used. The various pre-operative, intra-operative, and post-operative parameters at 1 month along with complications were evaluated for both the scopes by a single surgical team.

RESULTS

Pre-operative parameters including stone characteristics were comparable in both the groups. Three patients in group 2 needed ureteric dilatation prior to 11/13 access sheath insertion, while 10/12 Fr access sheath was placed in all patients in group 1 without manipulation (p = 0.06). Intra-operative vision was comparable in both scopes with an empty working channel and with laser. Hazy vision while lasing in two and one patient in group 1 and group 2, respectively (p = 0.54). In group 1, one had fever and UTI, while in group 2, one had fever post-operatively.

CONCLUSION

7.5 Fr Uscope PU3033A could be introduced with smaller access sheath. The vision, deflection, maneuverability is comparable to 9.5 Fr Uscope PU3022a.

Prestenting Versus Nonprestenting on the Outcomes of Flexible Ureteroscopy for Large Upper Urinary Stones: A Systematic Review and Meta-Analysis

INTRODUCTION

The purpose of this article is to evaluate the efficacy and safety of prestenting (PS) versus non-PS (NPS) of flexible ureteroscopy (fURS) to treat large upper urinary stones.

METHODS

We conducted a systematic literature research of PubMed, Ovid, Scopus (up to August 2019), and citation lists to identify eligible studies. All studies comparing PS versus NPS of fURS were included. Data were analyzed using the Cochrane Collaboration's Review Manager (RevMan) 5.3 software.

RESULTS

Overall, 7 studies including 3,145 patients (PS 1,408; NPS 1,737) were included in this article. PS group was associated with older age (weighted mean difference [WMD] 0.91 year; p < 0.001) and more male patients (odds ratio [OR] 1.34; p < 0.001). There were no statistical differences between PS and NPS in BMI (WMD 0.34 kg/m2; p = 0.13), stone size (WMD 0.13 mm; p = 0.77), and operative time (WMD 0.44 min; p = 0.86). Compared with NPS, PS showed better initial success rate (OR 4.04; p < 0.001) and higher SFR (OR 1.64; p < 0.001). There were no statistical differences for complications (OR 0.84; p = 0.42) and Clavien-Dindo score ≥3 complications (OR 1.04; p = 0.93).

CONCLUSION

PS could improve initial success rate and avoid secondary general anesthesia for first ureteral access sheath failed patients. PS could provide better SFR than NPS in the treatment of large upper urinary stones with fURS.

Etiology and Ureteral Reconstruction Strategy for Iatrogenic Ureteral Injuries: A Retrospective Single-Center Experience

OBJECTIVE

To analyze the etiology, characteristics, and ureteral reconstruction strategies of iatrogenic ureteric injuries in a high-volume center.

METHODS

Between September 2010 and August 2019, we retrospectively collected patients who underwent ureteral reconstruction due to iatrogenic ureteric injuries. Patient profiles, laboratory data, imaging studies, perioperative data, and complications were recorded.

RESULTS

Sixty-eight patients were enrolled in this study. The upper, middle, and lower thirds of the ureter were affected in 30, 2, and 36 cases, respectively. Of the 68 ureteric injuries, 69.1% occurred during urological procedures, followed by gynecological procedures, general surgery, radiotherapy, and orthopedic surgery. The majority of urological injuries (41, 87.2%) occurred due to stone removal. There was a significant difference in the age, sex, and location of ureteric injuries between the urological and nonurological groups. The median follow-up time was 17.9 months. The overall symptom remission rate was 91.2% and ranged from 87.5 to 100% for different reconstructive surgeries.

CONCLUSIONS

Urological procedures were the most common cause of iatrogenic ureteric injury; thus, extra care should be taken. Timely detection and appropriate treatment of the ureteric injuries are necessary. Treatment strategies should be depended on the location and length of injury.

The feasibility of one-stage flexible ureteroscopy lithotripsy in solitary kidney patients with 1-3 cm renal stones and risk factors of renal function changes

Purpose

To compare perioperative outcomes and long-term renal function changes between prior stenting (PS) and not prior stenting (NPS) before flexible ureteroscopy lithotripsy (f-URS) for solitary kidney patients.

Methods

Solitary kidney patients with 10–30 mm renal stones were enrolled in this historical control study. Perioperative parameters and complications were compared. Stone-free was defined as the absence of any residual stones on a CT scan. Renal function changes were evaluated by estimated glomerular filtration rate (eGFR) and adjusted for body surface area. A decrease in the eGFR over 20% was identified as ‘deterioration’ in renal function. The follow-up period was at least 6 months. Logistic regression was used to identify risk factors of renal function deterioration.

Results

Of the 76 patients included, 40 cases experienced prior stenting before f-URS. The average stone diameter was 16.8 ± 4.7 mm, ranging from 10.0 to 28.4 mm. Initial SFR was 85.0 and 83.3% in the PS and NPS groups, respectively (p = 0.842), while SFR after the second procedure was 97.5 and 94.4% (p = 0.926). Seven PS and 5 NPS patients developed complications (p = 0.666). At the postoperative 6 months, seven patients showed a deteriorated renal function. Surgical time in minutes was identified as a risk factor for renal function deterioration after the operation (OR = 1.061, 95% CI: 1.015–1.109, p = 0.009, per minute).

Conclusion

It appears that one-stage f-URS without PS could be feasible for 10–30 mm renal stones in solitary kidney patients, and less surgical time might be beneficial to protect renal function.

Comparison of the Effects of Four Treatment Techniques Commonly Used in Ureteral Stone Treatment on Patients' Daily Physical Functioning: An Observational Randomized-Controlled Study

Objective: To investigate the effect of four different techniques used in the treatment of ureteral stones on patients' daily physical functioning (PF) and quality of life (QoL). Materials and Methods: Patients who underwent ureterorenoscopy (URS)-with or without Double-J stenting (DJS)-and extracorporeal shock wave lithotripsy (SWL) were divided into four groups: Group I: SWL (n = 29), Group II: URS (n = 43), Group III: URS +4.8F DJS (n = 39), Group IV: URS +6F DJS (n = 42), and Group V: Control (n = 30). Short Form-36 (SF-36) was administered to each participant both preoperatively and 14 days after operation. Based on the SF-36 results, the changes in patients' PF and QoL were evaluated. Results: Ureteral stone treatment was performed in 202 patients. Of these, 153 patients who underwent an effective SWL or URS procedure in the first attempt were included in the study. Success rates in the first session were 53.7% (29/54) and 83.8% (124/148) for SWL and URS, respectively (p < 0.001). All the four groups were similar with regard to age, gender, body mass index, stone size, preoperative PF, and QoL. However, although postoperative PF, role limitations due to physical health, and energy/fatigue scores were similar in Group I, III, and IV, they were significantly higher in Group II. No major complication associated with SWL or URS occurred in any patient. However, in Group 2, DJS was inserted in three (7.7%) patients in the early postoperative period (within the first 48 hours) due to renal colic attacks secondary to ureterovesical junction mucosal edema. Conclusion: URS without DJS seems to be the most advantageous technique in the treatment of ureteral stones in terms of daily PF and QoL. However, it should be noted that patients undergoing URS may require postoperative emergency stenting, although rarely.

The role of preoperative ureteral stenting in retrograde intrarenal surgery in renal stone patients: a propensity score-matched study

Background

The purpose of this study was to investigate the effect of preoperative ureteral stenting on retrograde intrarenal surgery (RIRS).

Methods

We retrospectively analyzed RIRS cases from October 2014 to June 2017. Patients were divided into two groups according to preoperative ureteral stent insertion. The characteristics of the patients [age, body mass index (BMI), sex, previous disease history, hemoglobin, creatinine, estimated glomerular filtration rate (eGFR)], characters of stone (size, number, density, location), ureteral access sheath (UAS) success rate, perioperative complication, operative time, hospitalization time, period with stent, postoperative urinary tract infection (UTI) rate, stone free rate (SFR), and additional treatment rate were analyzed.

Results

RIRS was performed for 122 patients. Seventy-three patients had preoperative ureteral stents before RIRS, while 49 patients did not have preoperative ureteral stents. The median size of the stone was 14.5 mm. Overall SFR was 87.7%. Preoperative eGFR was relatively high in patients who underwent preoperative stenting (68.18 vs. 79.01 mL/min/1.73 m², P=0.042). Preoperative stenting led to improvement in the success rate of UAS insertion (97.3% vs. 87.8%, P=0.038) during surgery. Before and after propensity score matching revealed a significant difference in operation time when the diameter of the stone was smaller than 1 cm (P=0.019 and P=0.004). However, there was no significant difference in operation time, postoperative UTI rate, additional treatment rate, or SFR.

Conclusions

Preoperative ureteral stenting can facilitate UAS insertion, and reduce operation time in RIRS for stones with a diameter less than 1 cm.

A treatment strategy to help select patients who may not need secondary intervention to remove symptomatic ureteral stones after previous stenting

PURPOSE

This study aimed at evaluating whether removal of the ureteral stent the day before scheduled secondary intervention facilitates spontaneous ureteral stone passage and thus can spare the pre-stented patient this surgery.

METHODS

Retrospective analysis of a single-centre consecutive series of 216 patients after previous stenting due to a symptomatic ureteral stone from 01/2013 to 01/2018. Indwelling stents were removed under local anaesthesia. Patients were told to filter their urine overnight. Multivariate analysis was performed to assess predictive factors for spontaneous stone passage.

RESULTS

34% (74/216) of patients had spontaneous stone passage while the stent was indwelling. Of the remaining 142 patients, 41% (58/142) had spontaneous stone passage within 24 h after stent removal. Only 84/216 (39%) patients needed secondary intervention. Multivariate logistic regression analysis of all 216 patients showed a significant association between spontaneous stone passage and smaller stone size (p < 0.001), distal stone location (p = 0.046) and stent dwell time (p = 0.02). Predictive factors for spontaneous stone passage after stent removal were smaller size (p < 0.001), distal location (p = 0.001), and stone movement while the stent was indwelling (p = 0.016). A treatment strategy was established that helps select patients suitable for conservative management.

CONCLUSIONS

The majority (61%) of ureteral stones passed spontaneously after pre-stenting; 34% while the stent was indwelling, 27% within 24 h after stent removal. Besides distal stone location, stone size (< 6 mm) and stone movement (≥ 5 cm) while the stent is indwelling indicate patients who are likely to pass their ureteral stone spontaneously after stent removal. The treatment strategy (decision tree) presented here helps identify those patients.

TRIAL REGISTRATION

https://doi.org/10.1186/ISRCTN12112914 .

Two-shift operation mode can improve the efficiency and comfort of flexible ureteroscopic holmium laser lithotripsy for the treatment of renal calculi larger than 1.5cm

Purpose:

To compare two-shift operation mode and single player mode different impact on surgical results and operator comfort in flexible ureteroscopic holmium laser lithotripsy for renal calculi larger than 1.5cm.

Materials and Methods:

From december 2017 to december 2018, 92 patients with renal calculi admitted to Qilu Hospital and were treated through flexible ureteroscopy. They were randomized in two-shift group (n=50) and single player group (n=42). The operative time, blood loss, hospitalization stay after operation, residual fragments (≥4mm) rate, fragmentation speed, postoperative complications and operator's fatigue score were compared.

Results:

There was no significant difference between two groups regarding age, gender, illness side, stone size, blood loss, operative time, postoperative hospitalization stay, complications, etc (p >0.05). The fragmentation speed was 44.5±20.0mm3/min in two-shift group compared with 34.2±17.3mm3/min in single player group (p=0.037). Residual fragments (≥4mm) rate after first surgery was 18% in two-shift group, while the residual fragments (≥4mm) rate was 40.5% after first surgery in single player group (p=0.017). The total fatigue score of two-shift group was 8.4 compared to 29.9 in single player group (p <0.001).

Conclusion:

In flexible ureteroscopic holmium laser lithotripsy for the treatment of renal calculi larger than 1.5cm, two-shift operation mode can raise the fragmentation speed and stone clearance rate, as well as significantly lower operator's fatigue level and improve operator's comfort.

Ureteroscopy: a population based study of clinical complications and possible risk factors for stone surgery

Introduction

The aim of this study was to describe the complications of ureteroscopy (URS) and to investigate whether performing URS outside normal working hours leads to increased risk for clinically significant complications.

Material and methods

A cohort of 486 consecutive patients treated with URS, with a total of 567 sessions between 2009 and 2015 at Helsingborg/Ängelholm Hospital, Sweden, was analyzed. Outcome was complications within 14 days after URS treatment.

Results

We found no increased risk of complications related to URS performed outside normal working hours. Stone-free rate (SFR) in the distal third of the ureter was 95.2% (315/331), in the middle ureter 92.8% (90/97), in the proximal ureter 84.0% (63/75) and 69.0% (40/58) in renal pelvis. The overall complication rate was 10.6% (n = 60). None of the potential risk factors for complications showed any significance when adjusted for age and gender. We found an inverse relationship between stenting and SFR (p = 0.002). The most common preoperatively cultured bacteria was Escherichia coli. With adequate antibiotics, there was no increased risk of complications. There was an increased risk of complications after URS related to age, but not with gender.

Conclusions

URS in modern setting provides excellent results with adequate SFR and low morbidity. Time of day, the presence of urological specialized operating nurses did not affect the risk of complications and we found no other significant risk factors for complications. Escherichia coli was the most commonly found bacteria in preoperative cultures. The risk of complications increases with age. For patients >65 years old, this should be considered in preoperative counseling.

Double J stenting evaluation after ureteroscopy for urolithiasis

OBJECTIVES

During ureteroscopy for urolithiasis, postoperative ureteral drainage with double J stent is frequently used. It may reduce acute postoperative pain and late ureteral stenosis. Double J stent can have negative impact on life quality. After uncomplicated intervention, double J stent is not mandatory. Objective of our study was to evaluate pain and complications after ureteroscopy with or without stent.

METHODS

We retrospectively analyzed ureteroscopy performed between May 2014 and January 2017. Interventions were compared regarding ureteral drainage with double J stent or not. Our primary outcome was early postoperative pain evaluated with an oral pain scale form 1 to 10 on day one after intervention. Clinical characteristics, per- and postoperative data were collected. We also looked for risks factors of complications.

RESULTS

Three hundred and sixty-six interventions were included, 259 (70.8%) with and 107 (29.2%) without double J stent. Stone burden was higher in stented group (18.3 vs 9.4mm, P<0.0001). Patients without postoperative stents had more ureteral preparation with double J stent (78.5% vs 62.5%, P=0.0032) and had more ambulatory interventions (75.7% vs 52.5%, P<0.0001). Postoperative pain was not different (22% vs 17.75%, P=0.398). Complication rate was similar (29% vs 20.5%, P=0.1181), so was rehospitalization rate (0.8% vs 0.9%, P=1). In multivariate analysis, complications factors were unprepared ureter, experienced surgeons and access sheath.

CONCLUSION

Not stenting after ureteroscopy do not increase pain or complications. Stenting should not be used after uncomplicated interventions for centimetric stones.

LEVEL OF EVIDENCE

4.

Updates in endourological management of urolithiasis

Urinary stone disease, or urolithiasis, is a very common disease with increasing prevalence and incidence. With the advancement of endoscopic techniques, the treatment outcomes of ureteroscopy (or transureteral lithotripsy) and percutaneous nephrolithotomy are continuously improving. In recent years, there have been many new developments in the field, including new endoscopy design, more effective auxiliary tools, improvement in treatment protocols, introduction of robotic technology, combining both ureteroscopy and percutaneous nephrolithotomy (endoscopic combined intrarenal surgery or transureteral lithotripsy-assisted percutaneous nephrolithotomy), improvement in laser technology, and so on. All these new inputs will further improve the treatment efficacy and safety of the procedures, thus benefiting our patients. In the present review, we briefly go through the main steps of ureteroscopy and percutaneous nephrolithotomy, with a concise description and application of these new advances.

Predictors of spontaneous ureteral stone passage in the presence of an indwelling ureteral stent

Patients presenting acutely with obstructing stones often have a ureteral stent placed as a temporizing solution. Ureteroscopy is then commonly performed in a staged fashion, but occasionally the stone is found to have passed. We aimed to identify the frequency and predictors of ureteral stone passage with a stent in place. Records were reviewed to identify patients who had a stent placed for a single ureteral stone. Subsequent ureteroscopy or CT scan was used to ascertain stone passage. Effect of age, gender, BMI, stone diameter, alpha blocker use, urinary tract infection, hydronephrosis, and stent duration on stone passage was assessed. Inclusion and exclusion criteria were met in 209 patients. Mean maximum stone diameter was 6.5 ± 2.5 mm. Passage rates for stones < 3 mm, 3-4.9 mm, 5-6.9 mm, and ≥ 7 mm were 50%, 13%, 10%, and 0%, respectively. The overall rate of passage was 8%. Stone passage was associated with smaller maximum stone diameter, more distal stone location, and longer duration of stent before ureteroscopy/CT on univariate analysis (p < 0.01). Stone diameter and stent duration remained significantly associated on multivariable analysis (p = 0.001 and p = 0.05, respectively). Our findings suggest ureteral stone passage with a concurrent ureteral stent is not a rare event as it occurred in 14% of stones less then 7 mm in maximum diameter. Stone size and duration of stent before ureteroscopy or CT were found to be independent predictors of passage. Select patients with small ureteral stones who have been stented should be considered for a trial of urine straining or repeat imaging before subsequent ureteroscopy.

Ureteral stents in urolithiasis

Ever since the ureteral stent design was fitted with a curl on both sides to prevent it from migrating up or down the ureter some 40 years ago, its use has gained tremendous momentum, aiding in the rise and evolution of endourology and has confidently kept its place in modern time urology. Over the past four decades, several designs, coating and biomaterials have been developed, trying to reduce infection, encrustation and other stent related symptoms. As the ideal stent has not yet been discovered, different ways of helping patients with their complaints have been researched. This review will cover these aspects of stent use in urolithiasis.

Retrograde intrarenal surgery: An expanding role in treatment of urolithiasis

During the past 3 decades, the surgical management of kidney stones has undergone many technological advances and one is the development of the flexible ureteroscopy. The development of this instrument as well as ancillary equipment such as baskets, graspers, and others, and improvements in lithotripsy with Holmium: YAG laser have led to expand its indications with diagnostic and therapeutic management of medical issues of the upper urinary tract such as urolithiasis and urothelial tumors. The objective of this review is to describe its indications and results in the different scenarios for the treatment of urinary stones.

Digital Videoscopic Retrograde Intrarenal Surgeries for Renal Stones: Time-to-Maximal Stone Length Ratio Analysis

PURPOSE

To investigate 100 consecutive cases of videoscopic retrograde intrarenal surgery (RIRS) by a single surgeon and to evaluate factors associated with stone-free status and the learning curve thereof.

MATERIALS AND METHODS

We analyzed the results of videoscopic RIRS in 100 patients who underwent primary treatment for renal stones from January 2015 to August 2016. Videoscopic RIRS were performed with URF-V and URF-V2 flexible video uteroscopes (Olympus) or a Flex-Xc flexible ureterorenoscope (KARL STORZ). Non-contrast computed tomography was taken at 3 months postoperatively to confirm the absence of stones. The stone characteristics included the location, maximal stone length (MSL), stone heterogeneity index (SHI), and mean stone density (MSD). Fragmentation efficacy was calculated as operative time (min) divided by removed MSL (mm), and was evaluated in the sequential order of operations.

RESULTS

The mean age of the total patient was 60.0±14.0 years. The mean MSL was 13.1±6.2 mm. The average MSD was 734.2±327.6 Hounsfield unit (HU) and the SHI was 241.0±120.0 HU. The mean operation time was 65.1±45.7 min considering each renal unit. The stone-free rate at 3 months post-surgery was 87%. The estimated cut-off of the time-to-MSL ratio below 5 min/mm was 50. Multivariate analyses indicated a lower MSD [odds ratio (OR): 0.998; 95% confidence interval (CI): 0.996-0.999; p=0.047) and the last 50 cases (OR: 5.408, 95% CI: 1.337-30.426; p=0.030) as independent predictors of stone-free status after videoscopic RIRS.

CONCLUSION

Low MSDs and the last 50 cases were significant predictors of stone-free rate in videoscopic RIRS.

A ureteral stent crossing the bladder midline leads to worse urinary symptoms

Introduction

To investigate the correlation between the position of a ureteral stent and stent-related symptoms, excluding the influence of ureteroscopic maneuvers.

Material and methods

From January 2016 to December 2016, we analyzed 130 patients who placed a ureteral stent before ureteroscopic lithotripsy (URSL). A total of 108 patients were enrolled, including 77 (71.3%) men and 31 (28.7%) women, and the mean age was 58.9 ±14.3 years. On the day before URSL, plain radiography (kidney, ureter, bladder X-ray [KUB]) was used to confirm the stone location and ureteral stent position. According to KUB, we defined the crossing midline group as when the distal loop of the ureteral stent was crossing the bladder midline, and the not crossing midline group as when the distal loop of the ureteral stent was not crossing the bladder midline. We assessed urinary symptoms of the two groups using the overactive bladder symptom score (OABSS) on the day before URSL.

Results

The crossing midline group had a worse total OABSS (p <0.001) and worse scores for each item of daytime frequency (p = 0.047), nocturia (p <0.001), urgency (p = 0.002), and urgency incontinence (p = 0.045) than did the not crossing group. In multivariate analysis, stent position had the strongest association with the total OABSS (p = 0.002) among the other factors of age, sex, body mass index, stent side, stent diameter, stent length and stent indwelling time.

Conclusions

This study shows that a ureteral stent crossing the bladder midline leads to worse urinary symptoms. Choosing the appropriate stent length for each patient is important for improving stent-related symptoms.