Use of double-J stents prior to extracorporeal shock wave lithotripsy is not beneficial: results of a prospective randomized study

Does pre-stenting influence outcomes of shockwave lithotripsy? A systematic review and meta-analysis

OBJECTIVE

To determine whether preoperative use of JJ stents in patients undergoing shockwave lithotripsy (SWL) impacts on stone clearance and the rate of postoperative complications.

PATIENTS AND METHODS

We screened multiple databases from inception to January 2021, using the relevant search terms for SWL in patients with a preoperative stent. Inclusion criteria were randomised controlled trials of ≥20 patients aged >18 years who had had SWL with a JJ stent. This review has been registered in the International Prospective Register of Systematic Reviews (PROSPERO; registration number CRD42023443195). Statistical analysis was performed using 'meta' in R.

RESULTS

There were seven eligible studies (403 patients receiving JJ stents and 394 controls). There was no significant difference in the stone-free rate (SFR) following SWL with a JJ stent compared to SWL alone. When considering the complication rates, there was a significantly reduced risk of steinstrasse in patients with a JJ stent. However, there was no significant difference in the risk of other complications including pain, fever, and haematuria, and no significant difference in the likelihood of requiring auxiliary procedures or re-treatment.

CONCLUSIONS

There was a reduced risk of steinstrasse in patients undergoing SWL with a JJ stent compared to SWL alone. However, there was no significant difference in the risk of other postoperative complications. Use of a JJ stent had no effect on the efficacy of SWL, with no significant difference in the SFR.

Efficacy and Safety of Extracorporeal Shock Wave Lithotripsy (ESWL) in Patients With Infected Ureterohydronephrosis Due to Ureteral Stones Following Double-J Catheter Insertion

INTRODUCTION

Double-J ureteral catheters in patients with ureteral lithiasis undergoing extracorporeal shockwave lithotripsy (ESWL) procedures reduce the efficacy of the procedure or have no effect on the stone-free rate. However, the effect of double-J catheters on the patients in whom they were inserted for infected hydronephrosis is not known. The aim of our study was to evaluate the efficacy and safety of the ESWL procedure in patients with ureteral lithiasis and double-J catheters previously inserted for infected hydronephrosis.

METHOD

We conducted a comparative case-control, match-paired study in a group of patients with ureteral lithiasis treated by ESWL from January 1, 2018, to March 1, 2023, who were divided into two groups according to the presence of the double-J catheter. For each patient with the double-J catheter from the study group, we selected one patient for the control group without the double-J catheter and matched them in terms of size, location of stones, and body mass index (BMI). We analyzed the stone-free rate and complications that occurred in the two groups.

RESULTS

Forty patients with ureteral lithiasis and a double-J catheter inserted for infected hydronephrosis were enrolled in the study group. The control group included 40 patients with ureteral stones without double-J catheters. The patients in the two groups were predominantly men with stones located in the lumbar region and on the right side and with a BMI between 25 and 30 kg/m2. The stones had an average size of 0.9+/-0.12mm and 0.89+/-0.15mm, respectively (p=0.624). There was no statistically significant difference in stone-free rate between the two groups after the first session of ESWL (47.5% vs. 52.5%, p=0.502), the second (70% vs. 75%, p = 0.616), and the third session (85% vs. 87.5%, p=0.761). The rate of complications was similar in both groups (7.5% vs. 5%, p=0.761).

CONCLUSIONS

The presence of double-J catheters inserted in patients with ureteral stones who underwent ESWL for infected hydronephrosis does not affect the stone-free rate of the procedure or the complication rate. The procedure of ESWL in patients with ureteral lithiasis and double-J catheters inserted for infected hydronephrosis is a safe and efficient method that can be recommended as an initial treatment alongside retrograde ureteroscopy.

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.

2022 Recommendations of the AFU Lithiasis Committee: Extracorporeal shock wave lithotripsy (ESWL)

Extracorporeal shock wave lithotripsy (ESWL) is a minimally invasive technique for the fragmentation of urinary tract stones using shock waves under fluoroscopic and/or ultrasound guidance. ESWL results depend on the indication (stone size/composition, clinical context) and also on how it is performed. The stone structure, nature and density (Hounsfield units; evaluated by CT without contrast agent) influence the fragmentation achieved by ESWL. The upper size limit of kidney stones has been lowered to 15mm (1.68cm3) due to the increased risk of steinstrasse with larger sizes and the potential need of anesthesia and ureteral stenting. Conversely, the development of endourological technologies allows a finer stone fragmentation and/or better elimination, thus reducing the risk of steinstrasse and decreasing the potential number of sessions or additional interventions. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendations method (CPR) and the ADAPTE method, depending on whether 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.

International Alliance of Urolithiasis Guideline on Shockwave Lithotripsy

Different international associations have proposed their own guidelines on urolithiasis. However, the focus is primarily on an overview of the principles of urolithiasis management rather than step-by-step technical details for the procedure. The International Alliance of Urolithiasis (IAU) is releasing a series of guidelines on the management of urolithiasis. The current guideline on shockwave lithotripsy (SWL) is the third in the IAU guidelines series and provides a clinical framework for urologists and technicians performing SWL. A total of 49 recommendations are summarized and graded, covering the following aspects: indications and contraindications; preoperative patient evaluation; preoperative medication; prestenting; intraoperative analgesia or anesthesia; intraoperative position; stone localization and monitoring; machine and energy settings; intraoperative lithotripsy strategies; auxiliary therapy following SWL; evaluation of stone clearance; complications; and quality of life. The recommendations, tips, and tricks regarding SWL procedures summarized here provide important and necessary guidance for urologists along with technicians performing SWL. PATIENT SUMMARY: For kidney and urinary stones of less than 20 mm in size, shockwave lithotripsy (SWL) is an approach in which the stone is treated with shockwaves applied to the skin, without the need for surgery. Our recommendations on technical aspects of the procedure provide guidance for urologists and technicians performing SWL.

Predictors of stone-free rate after a single-session extracorporeal shockwave lithotripsy for a single kidney stone measuring 10 to 20 mm: A private center experience

Background

Despite the continuous update of guidelines for the management of kidney stones, the ability to predict a successful response to extracorporeal shockwave lithotripsy (SWL) remains a topic of research. This is due to the need to refine the decision making in the context of technological advancements and current pandemics. This study aimed to determine the predictors of stone-free rate (SFR) after single-session SWL in adult patients with a single kidney stone 10 to 20 mm in diameter.

Materials and methods

A retrospective review of the records of patients with a single kidney stone 10 to 20 mm in diameter was performed at a private SWL center from December 2019 to February 2021. Univariate and multivariate analyses were performed for stone- and patient-related factors, using the Student t and Mann-Whitney U tests for the quantitative variables and the Fisher exact and Pearson correlation tests for the qualitative variables.

Results

A total of 138 patients were eligible for this study, including 92 men and 46 women. The mean age was 38.6 ± 12.4 years, and the mean body mass index (BMI) was 25.9 ± 3.4 kg/m2. Four weeks after SWL, 120 patients (87%) were free of stones, and 18 (13%) needed further treatment. Univariate analyses showed that SFR was negatively correlated with increased BMI (p = 0.0001), maximum stone length (p = 0.0001), transverse diameter of the stone (p = 0.0001), number of shocks per session (p = 0.052), and Hounsfield unit (HU) (p = 0.0001). Multivariate analysis revealed that HU (p = 0.009), maximum stone length (p = 0.01), BMI (p = 0.000), and presence of double-J stent (p = 0.034) were independent risk factors for failure of single-session SWL in the treatment of kidney stones 10 to 20 mm in diameter. The estimated average cost per case was USD 450.5.

Conclusions

Increased HU, maximum stone length, BMI, and presence of double-J stents were independent risk factors for low SFR after single-session SWL for a kidney stone 10 to 20 mm in diameter. The cost of SWL remains an advantage in the private sector.

Pediatric Nephrolithiasis

The prevalence of pediatric nephrolithiasis has increased dramatically in the past two decades for reasons that have yet to be fully elucidated. Workup of pediatric kidney stones should include metabolic assessment to identify and address any risk factors predisposing patients to recurrent stone formation, and treatment should aim to facilitate stone clearance while minimizing complications, radiation and anesthetic exposure, and other risks. Treatment methods include observation and supportive therapy, medical expulsive therapy, and surgical intervention, with choice of treatment method determined by clinicians' assessments of stone size, location, anatomic factors, comorbidities, other risk factors, and preferences and goals of patients and their families. Much of the current research into nephrolithiasis is restricted to adult populations, and more data are needed to better understand many aspects of the epidemiology and treatment of pediatric kidney stones.

Comparison of ultrasonography and fluoroscopy as guides for extracorporeal shock wave lithotripsy in nephrolithiasis patients: a systematic review

BACKGROUND Extracorporeal shock wave lithotripsy (ESWL) is one of the first-line treatment options for patients with renal stones <2 cm. The large variability in ESWL results may be due to the stone visualization methods using ultrasonography (USG), fluoroscopy, or a combination of both. This study aimed to review the efficacy and safety of the stone visualization method on the stone-free rate (SFR) and postprocedural complications in nephrolithiasis patients. METHODS We conducted a systematic review of USG and fluoroscopy on ESWL until July 2022, based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We assessed and collected summaries of the screened papers. The main outcomes assessed were the SFR of renal stones and postprocedural complications between imaging modalities. RESULTS A total of 7 studies were assessed, including 6 comparative assessments of USG versus fluoroscopy and 1 comparative assessment of USG and fluoroscopy versus fluoroscopy only. Although all studies showed that USG had a higher SFR than fluoroscopy, only 1 study showed a significant difference (p = 0.008). Additionally, superior results were obtained using a combination of USG and fluoroscopy compared with fluoroscopy only. Most studies agreed that USG was not inferior in post-ESWL complication results. CONCLUSIONS Overall, the use of USG is comparable to fluoroscopy because it does not provide a significant difference in the SFR and complications. In most cases, USG is preferred because of the absence of radiation. The combination of fluoroscopy and USG also provides more promising results than a single modality.

Predictors of success following extracorporeal shock-wave lithotripsy in a contemporary cohort

OBJECTIVES

The objectives of this study are to determine the predictors of success following extracorporeal shock-wave lithotripsy (ESWL) in a contemporary cohort at a high-volume stone center.

METHODS

We conducted a retrospective review all patients who underwent an elective ESWL within our institution over a 24-month period (January 2014 to December 2015). Data on patient demographics, stone variables, and inpatient treatment outcomes were evaluated.The presence of residual stone fragments larger than 4 mm on follow-up imaging was considered to be treatment failure. Using this threshold, clinically relevant variables between the treatment success and failure groups were identified. Multivariable logistic regression analyses (MVA) of clinically relevant variables were used to determine the independent factors predicting ESWL success.

RESULTS

Of 446 study eligible patients, 421 patients had complete follow-up data and were included in the analysis. Treatment was successful in 72.2% of patients in this study. Stone size, number of shocks delivered, and maximum treatment intensity were statistically different in the two groups. In a MVA where stone size, location, density, presence of ureteric stent, skin-stone distance (SSD), number of shocks, and maximum shock intensity were included, only stone size of <10 mm (odds ratio [OR] 3.4 [95% confidence interval [CI]: 1.98-5.84]) and SSD <15 cm (OR: 0.133, [95% CI: 0.027-0.65]) were the independent predictor of ESWL success.

CONCLUSION

We have demonstrated "real world" outcomes with high-volume use of ESWL. In our experience that with diligent patient selection, ESWL remains an effective tool for the management of upper tract calculi.

Guideline of the guidelines: urolithiasis

PURPOSE OF REVIEW

We reviewed the latest guidelines on urolithiasis to highlight the commonalities and differences in the most important recommendations.

RECENT FINDINGS

Most guidelines utilize systematic review of literature and grade evidence to generate the appropriate recommendations and statements. Only the latest versions of guidelines were included in this review.

SUMMARY

Four national and international guidelines were included in this review, including those of the EAU (European Association of Urology), the AUA (American Urological Association)/ES (Endourological Society), the UAA (Urological Association of Asia) and the NICE (National Institute for Health and Care Excellence) guidelines. There are general similarities in the most important recommendations. The EAU guidelines provide the latest evidence updates.

Immediate Shockwave Lithotripsy vs Delayed Shockwave Lithotripsy After Urgent Ureteral Stenting in Patients with Ureteral or Pyeloureteral Urolithiasis: A Matched-Pair Analysis

Introduction: The most common cause of acute renal colic is a ureteral obstruction caused by ureterolithiasis. Urgent intervention is often necessary due to intractable pain. Early extracorporeal shockwave lithotripsy (SWL) as an alternative treatment option to ureteral stenting becomes forgotten in times of rising ureterorenoscopy. However, definitive guidelines are lacking, in which urgent treatment should be preferred in the absence of signs of infection. Therefore, we assessed efficacy and safety of early SWL (eSWL) to secondary SWL (sSWL) after urgent ureteral stenting. Patients and Methods: One hundred four patients treated between January 2015 and November 2017 for obstructive ureterolithiasis were matched regarding stone size, stone localization, and assigned to group eSWL (n = 52) or group sSWL (n = 52). The eSWL group received shock waves (without prior ureteral stenting) and sSWL group ureteral stenting within 48 hours from diagnosis. Thereafter, patients in group sSWL were treated with shock waves for a median of 23 ± 14.6 days after ureteral stenting. Stone-free rates, complication rates, and reintervention rates were assessed. Univariable and multivariable logistic regression was applied to find predictors of outcomes in the two treatment groups. Results: Overall, there was no statistically significant difference between both groups regarding stone-free rate and complication rate. Reinterventions were more often addressed for patients in group sSWL (p = 0.05). eSWL was significantly superior to sSWL regarding stone-free rates for stones between 6 and 9 mm (p = 0.04). At the multivariable multinomial logistic regression none of the two treatment modalities was associated with better outcomes. A body mass index ≥30 was associated with a reduced 6-week stone-free status (p = 0.04), whereas stones ≥8 mm were associated with an increased need of reintervention (p = 0.04). Conclusion: eSWL seems to be an effective and safe emergency procedure compared with sSWL after urgent stenting within 6 weeks and should be considered as a treatment option in patients without absolute indications for immediate ureteral drainage. Clinical trial registration number: 2019-00155.

Effect of JJ stent on outcomes of extracorporeal shock wave lithotripsy treatment of moderate sized renal pelvic stones: A randomized prospective study

PURPOSE

To evaluate the effect of JJ stents on SWL treatment of moderate (15-25mm) renal pelvic stones.

MATERIALS AND METHODS

Between January 2016 and December 2017, a total of 152 adult patients who were planned to undergo SWL for a single radiopaque renal pelvic stone were included in the study. Patients with solitary kidney, congenital abnormality, skeletal tract abnormalities, previous urinary system surgery, hydronephrosis (grade 2 or more), untreated urinary tract infection, bleeding disorder, and suspected pregnancy were excluded. The remaining 114 patients were randomly divided into two groups; non-stented and stented. Twenty-two patients whose stone could not be fragmented despite 3 consecutive sessions were also excluded from the study. A total of 92 patients (54 non-stented and 38 stented) were included in the final analysis.

RESULTS

There was no significant difference in terms of age, sex, body mass index, renal parancyhimal thickness, hydronephrosis, skin-to-stone distance, Hounsfield units, and stone size between the groups. Success was significantly higher in the stented group than in the non-stented group (71% vs. 39%, P=.002). In stone-free patients, the number of emergency department visits and analgesic tablet consumption was significantly lower in the stented group than in the non-stented group (P<.001 and P<.001, respectively). In non- stone-free patients, analgesic tablet consumption was significantly lower in the stented group than in the non-stented group (P=.004).

CONCLUSIONS

Pre-stenting before SWL treatment of moderate sized renal pelvic stones has some advantages in terms of success, emergency service visits, and analgesic tablet consumption.

Minimally Invasive Management of Uroliths in Cats and Dogs

Urolithiasis commonly affects cats and dogs. The American College of Veterinary Internal Medicine established guidelines for the treatment of uroliths that reflect modern techniques prioritizing minimally invasive procedures with an emphasis on prevention strategies to limit morbidity and mortality. Extracorporeal shockwave lithotripsy and endoscopic nephrolithotomy constitute some of the minimally invasive treatment modalities available for upper urinary tract uroliths. Cystoscopic-guided basket retrieval, cystoscopic-guided laser lithotripsy, and percutaneous cystolithotomy are minimally invasive options for the management of lower urinary tract uroliths. Following stone removal, prevention strategies are essential to help reduce morbidity and mortality associated with stone recurrence.

Factors Affecting the Outcome of Extracorporeal Shockwave Lithotripsy in Urinary Stone Treatment

Objectives

We sought to evaluate the factors affecting the outcome of extracorporeal shockwave lithotripsy (ESWL) in urinary stone treatment.

Methods

We conducted a retrospective review of 235 adult patients treated with ESWL, for radiopaque renal or ureteric stones between January 2015 and December 2016. Patient's age, sex, stone size, laterality, location, density, skin-to-stone distance (SSD), and presence of double J stent were studied as potential predictors. At the end of three months, the patients were divided into success and failure groups and the significance was determined.

Results

Of the 235 patients (188 males and 47 females) analyzed, ESWL was successful in 79.1%. Univariate analysis of both groups revealed no significant difference in patient's age and stone laterality. Statistically significant differences in gender, stone size, stone site, stone density, SSD, and patients with stents were observed. Statistically significant factors in multivariate logistic regression analysis were sex and stent. Females had three-times higher risk for ESWL failure than males (odds ratio (OR) = 3.213; 95% confidence interval (CI): 1.194-8.645; p = 0.021) and a higher failure rate when a stent was used (OR = 6.358; 95% CI: 2.228-18.143; p = 0.001).

Conclusions

This study revealed that ESWL can treat renal and ureteric stones successfully with an inverse association between outcome and predictors such as stone size and density, SSD, and stent presence. These factors can help us in improving patient selection and ensure better results at lower cost.

Complications in extracorporeal shockwave lithotripsy: a cohort study

OBJECTIVE

The aim of this study was to evaluate clinically relevant complications within 14 days after extracorporeal shockwave lithotripsy (ESWL) in a modern setting.

MATERIALS AND METHODS

Consecutive ESWL treatments between 2009 and 2015 in Ängelholm Hospital, Sweden, were analyzed retrospectively. The primary outcome was complications in patients seeking medical attention within 14 days after ESWL. Multivariable analysis was used to adjust for confounders such as diabetes, stone size and location, and presence of a urinary stent.

RESULTS

In total, 1838 stones were treated: 1185 (64.4%) localized in the renal pelvis, and 415 (22.5%) in the upper two-thirds and 205 (11.1%) in the lower third of the ureter. Overall, 116 out of 1838 cases (6.4%) needed medical attention within 14 days after ESWL and 75 (4%) crequired hospital care. Infection was found in 44 cases (2.4%), with a positive urine culture in 33 cases. Invasive/operative interventions were performed in 41 cases (2.2%). Distal stones had a lower risk of complications (p = 0.02) with ESWL. Diabetes (p = 0.02), larger stones (11-20 mm, p = 0.03; 21-30 mm, p = 0.009) and a need for antiemetics during treatment (p = 0.02) were significantly associated with an increased risk of complications.

CONCLUSIONS

Few complications are associated with modern ESWL treatment. A frequency of 1 Hz should be used to reduce complications (p = 0.025). Diabetes and larger stone size increase the risk of complications. The need for antiemetics during ESWL requires special consideration and further study. Distal stones seem to carry a lower risk of complications (p = 0.017).

Efficacy of commercialised extracorporeal shock wave lithotripsy service: a review of 589 renal stones

BACKGROUND

Extracorporeal shockwave lithotripsy (ESWL) is the management of choice for renal stones 20 mm or smaller, with a stone clearance rate of up to 89%. The purpose of the present is to investigate the efficacy of a commercialised ESWL service, being performed as an outsourced treatment using a mobile lithotripsy system on an outpatient basis. Furthermore, the study aims to evaluate the risk of needing treatment with an internal ureteral double-J stent (JJ) after ESWL treatment.

METHODS

During an eight-year period, 461 patients with a total of 589 renal stones were treated using a mobile lithotripsy system at a single Danish institution. A commercial company performed all treatments using a Storz Modulith SLK® system. Each stone was prospectively registered according to size, intra renal location and the presence of a JJ at the time of treatment. The number of required ESWL treatments and auxiliary procedures were retrospectively evaluated.

RESULTS

The success rate after the initial ESWL procedure was 69%, which increased to an overall success rate of 93% after repeated treatment. A negative correlation was found between stone size and the overall success rate (r = -0.2, p < 0.01). The upper calyx was associated with a significantly better success rate, but otherwise intra renal stone location was not predictive for treatment success. A total of 17 patients (2.9%) required treatment with a JJ after the ESWL procedure. No significant difference was observed between the stone size or intra renal location and the risk of needing treatment with JJ after ESWL.

CONCLUSIONS

Commercialised ESWL treatment can achieve an overall success rate of more than 90% using a mobile lithotripsy system. As expected, an inverse relation between stone size and success rate was found. Patients who do not require treatment with a JJ prior to ESWL will only rarely need treatment with a JJ after ESWL, irrespective of stone size and intra renal stone location.

Ureteral stenting can be a negative predictor for successful outcome following shock wave lithotripsy in patients with ureteral stones

Purpose

To evaluate ureteral stenting as a negative predictive factor influencing ureteral stone clearance and to estimate the probability of one-session success in shock wave lithotripsy (SWL) patients with a ureteral stone.

Materials and Methods

We retrospectively reviewed the medical records of 1,651 patients who underwent their first SWL. Among these patients, 680 had a ureteral stone measuring 4–20 mm and were thus eligible for our study. The 57 patients who underwent ureteral stenting during SWL were identified. Maximal stone length (MSL), mean stone density (MSD), skin-to-stone distance (SSD), and stone heterogeneity index (SHI) were determined by pre-SWL noncontrast computed tomography.

Results

After propensity score matching, 399 patients were extracted from the total patient cohort. There were no significant differences between stenting and stentless groups after matching, except for a higher one-session success rate in the stentless group (78.6% vs. 49.1%, p=0.026). In multivariate analysis, shorter MSL, lower MSD, higher SHI, and absence of a stent were positive predictors for one-session success in patients who underwent SWL. Using cutoff values of MSL and MSD obtained from receiver operator curve analysis, in patients with a lower MSD (≤784 HU), the success rate was lower in those with a stent (61.1%) than in those without (83.5%) (p=0.001). However, in patients with a higher MSL (>10 mm), the success rate was lower in those with a stent (23.6%) than in those without (52.2%) (p=0.002).

Conclusions

Ureteral stenting during SWL was a negative predictor of one-session success in patients with a ureteral stone.

Has the pelvic renal stone position inside the upper loop of JJ stent any influence on the extracorporeal shock wave lithotripsy results?

Background

JJ stents are often encountered in patients with pelvic renal stones referred for shock wave lithotripsy, most of them being placed either for obstructive renal pelvic stones or for ureteric stones mobilized retrograde during the JJ stent insertion. The aim of the study was to determine whether the relative stone position in the upper loop of the JJ stent during extracorporeal shock wave lithotripsy (SWL) influences the efficiency of the procedure. The study was designed as a prospective cohort study on 162 patients addressing the same urological department, with single renal pelvic stone (primary or mobilized to the renal pelvis during the insertion of JJ stent), smaller than 15 mm, with JJ stent, treated by SWL using a second generation spark gap lithotripter, 18 kV, 3000 waves/session. Patients were divided in three groups according to the relative position of the stone to the upper loop of the JJ stent as appears on plain X-ray: stone-inside-loop, loop-crossing-stone and stone-outside the loop. The SWL success rate was the primary outcome of the study. p Value, Chi square and Kruskal–Wallis tests were used for statistical analysis.

Results

For stone-inside-loop cases, SWL efficiency was 22.7 versus 42 % for all the other cases (p = 0.002). Other factors for decreased SWL success rate were: higher stone radio-opacity, larger JJ of stent and obese patients. Study limitation is represented by the relative small study group and by the evaluation of stone density using plain X-ray instead of computer tomography.

Conclusions

For pelvic renal stones having the same density characteristics studied by plain X-ray, the SWL efficiency is lower in stone-inside-loop cases comparing with the other positions. The overall stone free rate for renal pelvic stones could be explained by the second generation lithotripter used for all procedures.

CUA Guideline: Management of ureteral calculi

The focus of this guideline is the management of ureteral stones. Specifically, the topics covered include: conservative management, medical expulsive therapy, active intervention with either shockwave lithotripsy (SWL) or ureteroscopy (URS), factors affecting SWL treatment success, optimizing success, and special considerations (e.g., pregnancy, urinary diversion). By performing extensive literature reviews for each topic evaluated, we have generated an evidence-based consensus on the management of ureteral stones. The objective of this guideline is to help standardize the treatment of ureteral stones to optimize treatment outcomes.

Does ureteral stenting matter for stone size? A retrospectıve analyses of 1361 extracorporeal shock wave lithotripsy patients

Introduction

The aim of our study was to determine the efficacy of ureteral stents for extracorporeal shock wave lithotripsy (SWL) treatment of pelvis renalis stones and to compare the results and complications in stented and non-stented patients.

Material and methods

Between 1995 and 2011, 1361 patients with pelvis renalis stones were treated with SWL. Patients were subdivided into three groups according to stone burden: ≤1 cm² (group 1; n = 514), 1.1 to 2 cm² (group 2; n = 530) and >2 cm² (group 3; n = 317). Each group was divided into subgroups of patients who did and did not undergo ureteral stent implantation before SWL treatment. The efficacy of treatment was evaluated by determining the effectiveness quotient (EQ). Statistical analysis was performed by chi-square, Fisher's exact and Mann-Whitney U tests.

Results

Of the 514, 530 and 317 patients in groups 1, 2 and 3 respectively, 30 (6%), 44 (8%) and 104 (33%) patients underwent auxiliary stent implantation. Steinstrasse rates did not differ significantly between stented and non-stented patients in each group. The EQ was calculated as 62%, 33% and 70% respectively in non-stented, stented and totally for group 1. This ratio calculated as 58%, 25% and 63% for group 2 and 62%, 26% and 47% for group 3. Stone-free rates were significantly higher for non-stented than for stented patients in groups 2 and 3.

Conclusions

Stone free rates are significantly higher in non-stented than in stented patients with pelvis renalis stones >1 cm², whereas steinstrasse rates are not affected.

History of Ureteral Stenting Negatively Affects the Outcomes of Extracorporeal Shockwave Lithotripsy. Results of a Matched-pair Analysis

To evaluate the impact of ureteral stenting history to the outcomes of extracorporeal shockwave lithotripsy, we retrospectively analysed patients who underwent shockwave lithotripsy with Dornier Gemini lithotripter between September 2010 and August 2012. Forty seven patients (group A) who had a double J stent which was removed just before the procedure were matched-paired with another 47 patients (group B) who underwent shockwave lithotripsy having no stent history. The correlation between ureteral stenting history and stone-free rates was assessed. Stone-free rates were 68.1% and 87.2% for patients of group A and B, respectively (p=0.026). Postoperative complications were not different between groups. Multivariate analysis revealed that stone size (p=0.007), stone location (p=0.044) and history of ureteral stenting (p=0.046) were independent predictors for stone clearance after shockwave lithotripsy. Ureteral stents adversely affect shockwave lithotripsy outcome, even if they are removed before the procedure. Stenting history should divert treatment plan towards intracorporeal lithotripsy.

Efficacy Management of Urolithiasis: Flexible Ureteroscopy versus Extracorporeal Shockwave Lithotripsy

OBJECTIVES

To evaluate the efficacy of flexible ureterscopy (fURS) and extracorporal shockwave lithotripsy (SWL) in the treatment of urolithiasis, complemented by a subgroup analysis of lower pole calyx.

METHODS

Retrospective analysis of patients treated by fURS or SWL was performed by independent variables such as gender, age, nephrolith size, double-J stent (DJ stent) and stone localisation.

RESULTS

Out of 326 patients, 165 were treated by SWL and 161 by fURS. Complete stone removal was achieved by fURS in 83.2% and by SWL in 43.0% (p < 0.001). Asymptomatic behaviour (88-89%) and complication rate (10-11%) were nearly the same in both methods. A higher retreatment rate for SWL was necessary; otherwise, an auxillary DJ stent was performed more often preoperative before fURS. The subgroup analysis of lower pole calyx confirmed these evaluations.

CONCLUSIONS

Complete stone-free removal was almost 8 times higher after fURS compared to SWL. The efficacy of fURS in treatment of urolithiasis is substantially higher than the efficacy of SWL.

EAU Guidelines on Interventional Treatment for Urolithiasis

CONTEXT

Management of urinary stones is a major issue for most urologists. Treatment modalities are minimally invasive and include extracorporeal shockwave lithotripsy (SWL), ureteroscopy (URS), and percutaneous nephrolithotomy (PNL). Technological advances and changing treatment patterns have had an impact on current treatment recommendations, which have clearly shifted towards endourologic procedures. These guidelines describe recent recommendations on treatment indications and the choice of modality for ureteral and renal calculi.

OBJECTIVE

To evaluate the optimal measures for treatment of urinary stone disease.

EVIDENCE ACQUISITION

Several databases were searched to identify studies on interventional treatment of urolithiasis, with special attention to the level of evidence.

EVIDENCE SYNTHESIS

Treatment decisions are made individually according to stone size, location, and (if known) composition, as well as patient preference and local expertise. Treatment recommendations have shifted to endourologic procedures such as URS and PNL, and SWL has lost its place as the first-line modality for many indications despite its proven efficacy. Open and laparoscopic techniques are restricted to limited indications. Best clinical practice standards have been established for all treatments, making all options minimally invasive with low complication rates.

CONCLUSION

Active treatment of urolithiasis is currently a minimally invasive intervention, with preference for endourologic techniques.

PATIENT SUMMARY

For active removal of stones from the kidney or ureter, technological advances have made it possible to use less invasive surgical techniques. These interventions are safe and are generally associated with shorter recovery times and less discomfort for the patient.

Impact of colic pain as a significant factor for predicting the stone free rate of one-session shock wave lithotripsy for treating ureter stones: a Bayesian logistic regression model analysis

Purpose

This study was conducted to evaluate colic pain as a prognostic pretreatment factor that can influence ureter stone clearance and to estimate the probability of stone-free status in shock wave lithotripsy (SWL) patients with a ureter stone.

Materials and Methods

We retrospectively reviewed the medical records of 1,418 patients who underwent their first SWL between 2005 and 2013. Among these patients, 551 had a ureter stone measuring 4–20 mm and were thus eligible for our analyses. The colic pain as the chief complaint was defined as either subjective flank pain during history taking and physical examination. Propensity-scores for established for colic pain was calculated for each patient using multivariate logistic regression based upon the following covariates: age, maximal stone length (MSL), and mean stone density (MSD). Each factor was evaluated as predictor for stone-free status by Bayesian and non-Bayesian logistic regression model.

Results

After propensity-score matching, 217 patients were extracted in each group from the total patient cohort. There were no statistical differences in variables used in propensity- score matching. One-session success and stone-free rate were also higher in the painful group (73.7% and 71.0%, respectively) than in the painless group (63.6% and 60.4%, respectively). In multivariate non-Bayesian and Bayesian logistic regression models, a painful stone, shorter MSL, and lower MSD were significant factors for one-session stone-free status in patients who underwent SWL.

Conclusions

Colic pain in patients with ureter calculi was one of the significant predicting factors including MSL and MSD for one-session stone-free status of SWL.

[Uretero(reno)scopy: management of complications]

Rigid and flexible uretero(reno)scopy (URS) are safe and effective methods in interventional calculus therapy. Complications are rare and can be avoided in advance in many cases. In ureteroliths, URS has in many cases replaced extracorporeal shock wave lithotripsy (ESWL) as the method of first choice. However, it is important to describe in detail the advantages and disadvantages as well as the risks of the procedure to the patient.

Managing caliceal stones

The natural course of untreated asymptomatic caliceal calculi has not been clearly defined, especially in terms of disease progression, and the indications for and outcomes of surgical intervention are not precise. Caliceal stones may remain asymptomatic but, in case of migration, ureteral calculi can cause acute ureteric colic with severe complications. The decision for an active treatment of caliceal calculi is based on stone composition, stone size and symptoms. Extracorporal shock-wave lithotripsy (ESWL) has a low complication rate and is recommended by the current guidelines of the European Association of Urology as a first-line therapy for the treatment of caliceal stones <2 cm in diameter. However, immediate stone removal is not achieved with ESWL. The primary stone-free rates (SFR) after ESWL depend on stone site and composition and, especially for lower pole calculi, the SFR differ widely from other caliceal stones. Minimally-invasive procedures including percutaneous nephrolithotomy and ureteroscopy are alternatives for the treatment of caliceal stones, associated with low morbidity and high primary SFR when performed in centers of excellence.

Double J stent reduces the efficacy of extracorporeal shock wave lithotripsy in the treatment of lumbar ureteral stones

Introduction

We evaluated the effect of the presence of a double J stent on the efficacy of extracorporeal shock wave lithotripsy (ESWL) in the treatment of lumbar ureteral stones.

Material and methods

Between January 2007 and February 2012, we performed a retrospective cohort study. Forty–four patients were treated by ESWL for lumbar ureteral stones and included into two groups for the analysis: group 1, non–stented (n = 27) and group 2, stented patients (n = 17). Treatment efficacy was evaluated by abdominal X–ray or CT–scan at 1 month. Stone–free patients and those with a residual stone ≤4 mm were considered to be cured.

Results

Mean stone size and density in groups 1 and 2 were 8.2mm/831HU, and 9.7 mm/986HU respectively. Both groups were comparable for age, BMI, stone size and density, number, and power of ESWL shots given. The success rates in groups 1 and 2 where 81.5% and 47.1%, respectively (p = 0.017). There was no difference between the groups for stones measuring 8 mm or less (p = 0.574). For stones >8 mm, the success rates were respectively 76% and 22.2% for groups 1 and 2 (p = 0.030). Logistic regression analysis revealed a higher failure rate when a double J stent was associated with a stone >8 mm (p = 0.033).

Conclusions

The presence of a double J stent affects the efficacy of ESWL in the treatment of lumbar ureteral stones. This effect is significant for stones >8 mm. Ureteroscopy should be considered as the first–line treatment in such patients.

[Calyceal stones]

The natural course of untreated, asymptomatic calyceal calculi has not yet been clearly defined regarding disease progression and risk of surgical interventions. The decision for an active treatment of calyceal calculi is based on stone composition, stone size and symptoms. Extracorporeal shockwave lithotripsy (ESWL) has a low complication rate and is recommended by the current guidelines of the German (DGU) and European (EAU) Associations of Urology as a first-line therapy for the treatment of calyceal stones <2 cm in diameter. However, immediate removal of stones is not achieved with ESWL. The primary stone-free rates (SFR) after ESWL depend on stone location and stone composition and can show remarkable differences. Minimally invasive procedures, such as percutaneous nephrolitholapaxy and ureteroscopy are alternatives for the treatment of calyceal stones which have low morbidity and high primary SFR when performed in centres of excellence.

Treatment of Kidney Stones Using Extracorporeal Shock Wave Lithotripsy (ESWL) and Double-J Stent in Infants

Background. Extracorporeal shock wave lithotripsy (ESWL) has progressively acquired popularity as being the gold standard treatment for upper urinary tract lithiasis in infants since 1980. Our aim was to evaluate the outcome of ESWL for kidney stones and the use of double-J stent in infants. Material and Methods. A prospective clinical trial study performed on 50 infants with renal calculi at pelvic admitted in the Urology ward of Shafa Hospital, Sari, Iran, between 2001 and 2010. Main outcome measure of our study was clearing stones after one or more consecutive sessions of ESWL. Results. The study included 50 patients with renal calculi at pelvic. Among them, there were 35 (70%) boys and 15 (30%) girls with the age ranging from 1 to 13 months (mean of 7 month ± 3 days). All of them were treated by standard ESWL using Simons Lithostor plus machine. The stone sizes ranged from 6 mm to 22 mm. Double-J stents were placed in 11 infants (22%) with stones larger than 13 mm. Most of the patients required only one ESWL session. Conclusion. Since there were no complications following ESWL treatment, we can conclude that, in short term, ESWL is an effective and safe treatment modality for renal lithiasis in infants. In addition, we recommend double-J stent in infants with stones larger than 13 mm.

Modern management of stone disease in patients with a solitary kidney

Analysing the data available in the literature, contemporary methods of treatment of nephrolithiasis are limited to the methods of minimally invasive percutaneous nephrolithotomy (PCNL) and ureterorenoscopic lithotripsy (URSL), not excluding their use in the presence of developmental abnormalities and kidney impairment only. Minimally invasive methods have become standard procedures. A complement to ineffective URSL and PCNL treatment is extracorporeal shock wave lithotripsy. This is confirmed by 30 years of observation in the only treatment of kidney calculi by Alken launched in 1981 and continued by Jones et al. Before the era of endoscopic procedures (PCNL and URSL) effectively removed the only deposits in the kidney in open operations. Minimally invasive treatments are recommended for patients with localized deposits in the pelvicalyceal system or solitary kidney ureter. They are recognized as safe and effective treatment in a solitary kidney in particular in patients who have already been operated on.

Impact of ureteral stenting prior to ureterorenoscopy on stone-free rates and complications

Objective

To date, only few studies have evaluated the impact of ureteral stenting prior to ureterorenoscopy. This study is to clarify the role of preoperative ureteral stenting in the treatment for ureteral stones.

Methods

We retrospectively reviewed 550 ureterorenoscopies from 1998 to 2008. Patients were classified into two groups depending on whether they had a stent placed before URS. Baseline characteristics of patients and stone properties, stone-free rates, complications, and operation times were compared between both groups. Subanalysis was performed regarding stone localization. We retrospectively reviewed data from patient documentation, X-ray imagery, intravenous urography, and operation reports.

Results

Baseline characteristics of patients were similar in both groups. The majority of patients underwent stent placement before the ureteroscopic stone treatment (88.4%). The mean operation time in the prestented group was longer (43.3 vs. 38.4 min). Stone-free rate of patients with stent was 72.2%, compared to 59.4% without preoperative stenting. The rate of minor complications was 4.7% with stent versus 9.4% without stent, major complications 0.6% versus 1.6%, respectively. Patients with distal ureter stones had similar stone-free rates regardless of a stent placement (90.1% with stent vs. 87.6% without), and no difference in complication rates was observed (3.5% with stent vs. 3.1% without), respectively.

Conclusions

Stent placement prior to ureteroscopic stone treatment in distal ureter is not reasonable and does not considerably improve stone-free rates.

Prognostic variables for shockwave lithotripsy (SWL) treatment success: no impact of body mass index (BMI) using a third generation lithotripter

OBJECTIVE

• To investigate the effect of different variables including body mass index (BMI) on therapy outcome in patients with upper urinary tract stones treated with a third generation lithotripter, as BMI has been reported to be an independent predictor for stone-free status after extracorporeal shockwave lithotripsy (SWL) performed with first or second generation lithotripters.

PATIENTS AND METHODS

• In all, 172 patients with kidney stones with a mean (range) size of 9.2 (3.0-32.0) mm were included in the study. • In all, 91 patients (52.9%) were treated with a ureteric stent in situ. • For SWL therapy a third generation, electromagnetic lithotripter (Siemens Lithoskop™) was used. Stone-free status was reached, when no more treatable stones were present (no stone or stone < 3 mm). • BMI, stone size and localization, age, gender, treatment parameters and ureteric stent in situ were evaluated for their prognostic relevance on therapy success.

RESULTS

• The mean (range) BMI of all patients was 27.8 (19.0-58.6) kg/m(2). • Patients were categorized into two groups: A) patients that were stone free after one treatment; B) patients with residual stones. The mean (sd) BMI was 27.4 (4.6) kg/m(2) and 28.4 (6.1) kg/m(2) for A and B, respectively. • Univariate and multivariate analysis for freedom of stones showed that only stone size (P < 0.01) and presence of a ureteric stent (P = 0.01) were independent prognostic variables. • BMI had no significant influence on therapy outcome (P = 0.51).

CONCLUSIONS

• Using a third generation lithotripter, BMI was not an independent predictor of stone-free rate after SWL therapy of kidney stones. • This effect might be attributed to a greater penetration depth of the shockwave energy. Stone size and a ureteric stent in situ were the only variables with prognostic significance.