The gender gap in stone-related surgery: A comprehensive analysis from an Israeli perspective

OBJECTIVE

To investigate the gender gap in the context of stone-related surgery within an Israeli population.

METHODS

We conducted a retrospective cohort study using administrative databases from Clalit Health Services to identify adults aged 18 and above who had their initial surgical treatment for upper tract urolithiasis. We employed descriptive statistics to outline the baseline patient characteristics, and the Cochran-Armitage test for trend was utilized to analyze surgical trends.

RESULTS

Between 2003 and 2020, a total of 36,624 adult patients underwent surgical treatment for upper tract urinary stones. The mean age of patients was 55.01 years (standard deviation (SD) 16.6) for ureteroscopy (URS), 55.05 years (SD 15.1) for percutaneous nephrolithotripsy (PCNL), and 51.07 years (SD 15.1) for shockwave lithotripsy (SWL). When considering the distribution of procedures by gender, males accounted for 69.5% of URS cases, 58.3% of PCNL cases, and 70.6% of SWL cases, whereas females represented 30.5%, 41.7%, and 29.4% of URS, PCNL, and SWL cases, respectively. Across all surgical modalities, the male-to-female ratio exhibited fluctuations without a consistent trend, with both increases and decreases observed. In URS, the ratio saw a modest increase from 1.967 in 2003 to 2.173 in 2020. For PCNL, the ratio initially increased from 2.361 in 2003 to 2.549 in 2014, followed by subsequent fluctuations, but an overarching trend was not apparent. In contrast, for SWL, the ratio decreased from 2.15 in 2003 to 1.32 in 2020, with varying changes in between.

CONCLUSION

This study highlights the dynamic nature of gender gap in stone-related surgery outcomes. While the male-to-female ratio exhibited fluctuations over a 17-year period, no consistent trend emerged. The absence of a clear trend underscores the complex and multifaceted factors influencing the gender gap in urolithiasis.

A retrospective cohort study, analyzing trends in management of upper urinary tract stones in the adult Israeli population

OBJECTIVE

To assess trends of surgical intervention in adults with upper urinary tract stones in Israel.

METHODS

A retrospective cohort study utilizing administrative databases held at Clalit Health Services, to identify all adults (⩾18 years) who underwent their first surgical treatment for upper tract urolithiasis. Descriptive statistics were employed to summarize baseline patient demographics and surgical trends were analyzed using the Cochrane-Armitage test for trend.

RESULTS

Between 2003 and 2020, 36,624 adult patients were treated surgically for upper tract urinary stones. Mean age was 53.6 years (SD16.1). During the period investigated, the number of insured by Clalit Health Services increased by 25% and the total number of surgically treated stones increased by 98.7%. By type of procedure: Ureteroscopy (URS) increased by 351%, percutaneous nephrolithotripsy (PCNL) increased by 67%, shockwave lithotripsy (SWL) declined by 79%. The number of procedures per 100,000 population grew from to 37.5 in 2003 to 58.05 in 2022. The percentage increase in total number of surgical procedures was 103% and 90% in males and females, respectively.

CONCLUSIONS

Our findings reveal significant increases in the total number of surgically treated stones over the investigated period. Notably, this increase far outpaced the growth in the number of individuals insured by Clalit Health Services. Further research and interventions are warranted to explore the underlying factors driving these trends and to develop targeted approaches for prevention, early detection, and minimally invasive treatment of upper urinary tract stones in Israel.

Shock wave lithotripsy in the era of COVID-19

Objective

The objective of the study y was to evaluate factors which can improve shock wave lithotripsy (SWL) results to keep up with COVID-19 pandemic.

Methods

Between June 2020 and June 2021, patients with radio-opaque or faint radio-opaque upper urinary tract stones, stone attenuation value ≤1200 HU, and stones size <2.5 cm were treated by electrohydraulic SWL. Patients with respiratory tract symptoms elevated temperature, contact with COVID-19 patients, or positive COVID-19 swab 2 weeks preoperatively, skin-to-stone distance >11 cm, and body mass index >30 kg/m2 were excluded from the study. Patients were prospectively enrolled in SWL done at a rate of 40-50 SWs/min under combined ultrasound and fluoroscopy-guided, ramped into high power in the 1st 300 shocks. Success rate and complications were recorded.

Results

Five hundred and ninety patients completed the study. The success rate after 1st session was 408/590 patients (69.15%) which was augmented by 2nd session to reach 527/590 patients 89.3%. The success rate was 96.2% at 3 months postoperatively. Most complications were mild (Grade 1 or 2).

Conclusions

SWL results improved using slow rate high power from the start of the session under combined fluoroscopy and ultrasound guidance. SWL may be a preferred option during a pandemic.

Use of artificial stones in training and laboratory studies, have we found the right material? Outcomes of a systematic review from the European School of Urology

Objective

In this review, we investigated the current literature to find out which artificial stones (AS) are available in endourology, and in which experimental and training schemes they are used.

Materials and Methods

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Twenty-one out of 346 studies met our inclusion criteria and are presented in the current review. The inclusion criteria were the existence of AS and their use for laboratory and training studies.

Results

There is a wide variety of materials used for the creation of AS. BegoStone powder (BEGO USA, Lincoln, Rhode Island) and plaster of Paris™ were used in most of the studies. In addition, Ultracal-30 (U. S. Gypsum, Chicago, IL) was also used. Other materials that were used as phantoms were AS created from plaster (Limbs and Things, UK), standardized artificial polygonal stone material (Chaton 1028, PP13, Jet 280; Swarovski), model stones consisting of spheres of activated aluminum (BASF SE, Ludwigshafen am Rhein, Deutschland), Orthoprint (Zhermack, Badia Polesine, Italy), and a combination of plaster of Paris, Portland cement, and Velmix (calcium sulfate powder). Many experimental settings have been conducted with the use of AS. Our research demonstrated nine studies regarding testing and comparison of holmium: yttrium-aluminum-garnet laser devices, techniques, and settings. Six studies were about extracorporeal shock wave lithotripsy testing and settings. Three experiments looked into treatment with percutaneous nephrolithotomy. Additionally, one study each investigated imaging perioperatively for endourological interventions, stone bacterial burden, and obstructive uropathy.

Conclusion

AS have been used in a plethora of laboratory experimental studies. Independent of their similarity to real urinary tract stones, they present a tremendous potential for testing and training for endourological interventions.

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.

A Rare Case of Spontaneous Steinstrasse

Spontaneous steinstrasse ("stone street") is a collection of stones within the ureter and is a rare and understudied event. Factors such as infection, altered kidney function, and degree of obstruction are used to define the most adequate therapeutic option. Treatment can be either conservative or surgical. The decision of which depends on the clinical presentation. This paper reports a rare case of a 59-year-old patient with spontaneous steinstrasse examined at a urology clinic. Surgical intervention was required because of altered kidney function. The patient is currently undergoing follow-up for the metabolic investigation.

Is Intravascular Lithotripsy (IVL) Alone a Therapy for the Treatment of Aortoiliac Occlusive Disease (AIOD)?

We present a rare case in which a 63-year-old male with a history of hypertension, diabetes mellitus, hyperlipidemia, and previous coronary artery bypass graft (CABG) presented with bilateral external iliac artery near occlusion. We describe the utilization of lithotripsy balloon angioplasty as opposed to the traditional double-barrel stenting method or modified endovascular repair (EVAR) to treat the occlusion. Pre-operative computed tomography (CT) angiography demonstrated a 90 percent occlusion of both the distal aorta and right external iliac artery, and 99 percent occlusion of the left external iliac. The patient remains symptom-free three years post-intervention with normal right and left ankle-brachial indices, 1.34 and 1.32 respectively. We review the available literature regarding aortoiliac occlusive disease (AIOD) and discuss the advantages and disadvantages of novel and traditional treatment modalities. Understanding all treatment options is crucial for physicians who are presented with similar cases.

Could twinkling artifact be a parameter in predicting the success of shock wave lithotripsy? A prospective study

Introduction

It is important to predict success before the treatment of urolithiasis. We aimed to predict the success of shock wave lithotripsy (SWL) by comparing twinkling artifact (TA) revealed through colour Doppler ultrasonography (CDUS) with stone density in non-contrast computed tomography (NCCT).

Material and methods

Eighty patients who underwent SWL between January 2021 and January 2022 were included in the study. Patients with stones of 5-20 mm in the renal pelvis and proximal ureter at NCCT were included. Patients' demographics, Hounsfield units (HU) in NCCT, and TA grades in CDUS were recorded. The stone-free rate after SWL, additional treatments, overall success rates, and the association between TA and success rates were evaluated.

Results

The mean age was 47.41 ±15.08 years. The mean BMI was 24.49 ±3.67 kg/m2. Twenty-three (28.8%) patients were TA grade 0, 33 (41.2%) patients were grade 1, and 24 (30%) were grade 2. The mean HU of TA grades 0, 1, and 2 of stones were 628 ±107, 864 ±123, and 1166 ±292, respectively. The HU increased along with the increase in the TA grade of the stone (p <0.01). The mean number of SWL sessions was 2.26 ±0.75 in patients with TA grade 0, and 2.92 ±0.40 in patients with TA grade 2. The mean number of SWL sessions increased along with the increase in TA grade (p <0.01). The stone-free rate decreased as the TA grade increased. Stone diameter and TA were the only predictors of SWL success.

Conclusions

We think that TA may be useful in predicting SWL success.

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.

Ureteroscopy and Shock Wave Lithotripsy Trends from 2012 to 2019 Within the US Medicare Dataset: Sharp Growth in Ureteroscopy Utilization

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

Role of Patient Age and Stone Density in Predicting Outcomes of Shockwave Lithotripsy in Lower Ureteral Stones

Background

Shockwave lithotripsy (SWL) is an important tool for treating ureteral stones, especially when ureteroscoy (URS) is not readily available.

Objective

The aim of the study was to identify factors associated with the success of shockwave lithotripsy (SWL) in the treatment of lower ureteral stones.

Methods

Total of 105 consecutive patients with single lower ureteral stones treated with SWL between January 2021 and February 2022 were reviewed retrospectively. Clinical and stone parameters including age, gender, and body mass index (BMI), stone length, and stone density were analyzed. SWL procedures were done using electro-conductive lithotripter Sonolith i-sys (EDAP TMS, Vaulx-en-Velin, France). We evaluated available clinical and radiologic features that might have been related to successful SWL treatment.

Results

Treatment was successful in 67/105 patients (63.8%). Multivariate logistic regression revealed that a successful outcome was significantly related to mean stone density (MSD) (95% CI: 1.004- 1.009) and the patients age (95% CI: 1.022- 1.13). Gender, BMI, and stone length were not an independent predicting factors.

Conclusion

Stone density and patient age were independent predictors of successful outcome after two SWLs in the lower ureter. However, gender, BMI, and stone length did not independently predict treatment success.

Comparison of Shock Wave Lithotripsy and Flexible Ureterorenoscopy in the Treatment of 10-20 mm Lower Pole Stone: Prospective Non-randomized Study

INTRODUCTION

The objective of the study is to clarify the efficiency, safety, and limitations of shock wave lithotripsy (SWL) and flexible ureterorenoscopy (f-URS) in the management of lower pole stones (LPS).

METHODS

The present study was planned prospectively in a non-randomized manner. Patients who had LPS between 10 and 20 cm in size were enrolled in the study. Patient demographic characteristics, stone-related parameters, complications, and success were noted. Patients who underwent SWL and patients who underwent f-URS were compared according to demographic characteristics, procedure-related parameters, complications, and success rate.

RESULTS

A total of 82 patients matched the study inclusion criteria, with 44 patients treated with SWL and 38 patients treated with f-URS. The time between diagnosis and the end of the treatment was 29.2 days in the SWL group and 15.2 days in the f-URS group (p = 0.001). The success rate was 89.5% with f-URS and 72.7% with SWL (p = 0.036). Receiver operating curve analysis revealed that a stone size larger than 14 mm in the lower pole was significantly associated with SWL failure (area under the curve [AUC]: 0.711, p = 0.033), and a stone size larger than 16 mm was a predictive factor for f-URS failure.

CONCLUSION

The present study found that f-URS had a significantly higher stone-free rate in the management of 10-20 mm LPS compared to SWL. For the first time, this study showed that the time between diagnosis and the end of treatment was significantly shorter with f-URS. Moreover, LPS larger than 14 mm and 16 mm were predictive factors for SWL and f-URS failure, respectively.

Does quality of life in patients undergoing shock wave lithotripsy change with repeat procedures: a prospective pilot study from a teaching hospital

Introduction

Shock wave lithotripsy (SWL) is a well-established treatment for kidney stone disease (KSD) and despite its decreased popularity in the past, it has now gained renewed interest due to its minimally invasive nature and good outcomes, especially in the face of COVID-19 pandemic. The aim of our study was to perform a service evaluation to analyse and identify quality of life (QoL) changes [using Urinary Stones and Intervention Quality of Life (USIQoL) questionnaire] after repeat SWL treatments. This would enable a greater understanding of SWL treatment and reduce the current gap of knowledge regarding patient specific outcomes in the field.

Material and methods

Patients affected by urolithiasias underwent SWL treatment between September 2021 and February 2022 (6 months), were included in the study. A questionnaire was given to the patients in each SWL session and consisted of three main topic areas: a domain on Pain and Physical Health, on Psycho-social Health and on Work (see appendix below). Patients also completed a Visual Analogue Scale (VAS) in relation to the pain related to the treatment. Data from the questionnaires were collected and analysed.

Results

A total of 31 patients filled in two or more surveys, with a mean age of 55.8 years. On repeat treatments, pain and physical health domain was significantly better (p = 0.0046), psycho-social health domain was significantly better (p <0.001), work domain was significantly better (p = 0.009) and a correlation [on Visual Analog Scale (VAS)] was observed between pain decreasing in subsequent SWL procedures.

Conclusions

Our study found that the choice of SWL to treat KSD does improve a patient's QoL. This could be related to improvement of physical health, psychological and social wellbeing, and ability to work. Higher QoL and low pain scores are observed in relation to repeat SWL treatment and are not directly associated to stone-free status.

Prospective study on Comparison of outcomes of mini percutaneous nephrolithotomy versus retrograde intrarenal surgery for renal stones of 1-2 cm size

Aim and Objectives

The aim of this study is to demonstrate the outcomes of retrograde intrarenal surgery (RIRS) and Mini percutaneous nephrolithotomy (M-PCNL) in the management of 1-2 cm renal stones, with factors considered being operative time, duration of hospital stay, complication rate, and auxiliary procedure rate.

Materials and Methods

This is a single-center, prospective study on patients diagnosed with 1-2 cm renal calculi between April 2018 and March 2020. Informed written consent was obtained from all the patients. A total of 60 patients were included in the study. Patients were divided into two groups - Group I and Group II; Group I: 30 patients who underwent RIRS and Group II: 30 patients who underwent Mini-PCNL-Mini percutaneous nephrolithotomy. Data were collected to compare the operative data, postoperative complications, duration of hospital stay, stone-free rate, and auxiliary procedure rate associated with RIRS and Mini pcnl for the treatment of 1-2 cm renal calculi.

Inclusion criteria

All patients who presented with 1-2 cm renal calculi between April 2018 and March 2020Age >15 years.

Exclusion criteria

Stones larger than 2 cm and smaller than 1 cm. More than 3 stones in the pelvicalyceal systemPregnant women.

Results

The mean age in the Mini Perc and RIRS groups was 30.40 ± 14.36 years and 39.20 ± 12.45 years, respectively, with no statistical significance. Of the 60 renal units, 66.7% were male and 33.3% were female in the Mini Perc group. In the RIRS group, 73.3% were male and 26.7% were female. There was no statistical significance. In the Mini Perc group, 53.3% were operated on the right side and 46.7% were operated on the left side, and in the RIRS group, 33.3% were operated on the right side and 66.7% were operated on the left side, with no statistical significance. The mean stone size in the Mini Perc group was 1.4 ± 0.37 cm and the mean stone size in the RIRS group was 1.3 ± 0.27 cm, with no statistical significance. Of the 60 renal units, 3.3% and 6.7% in Mini Perc and RIRS groups had diabetes alone, and 3.3% and 16.7% in Mini Perc and RIRS groups had hypertension alone. 3.3% in RIRS group had tuberculosis, 6.7% and 13.3% in Mini Perc and RIRS groups had both hypertension and diabetes, and 6.7% in Mini Perc group had diabetes with hypertension with coronary artery disease. The mean operating time in the Mini Perc group was 44.07 ± 9.05 min. The mean operating time in the RIRS group was 72.23 ± 11.01 min. There is statistical significance noted in terms of operating time. There were complications noted in both the groups, of which 6.7% and 16.7% in Mini Perc and RIRS groups had postoperative fever, and 3.3% and 6.7% in Mini Perc and RIRS groups had postoperative hematuria with no statistical significance noted. The mean postoperative pain in the first 24 h was 3.63 ± 1.35 in Mini Perc group, whereas it was 1.43 ± 0.72 in RIRS group; the mean postoperative pain at 48 h was 1.80 ± 0.96 in Mini Perc group, whereas it was 1.03 ± 0.18 in RIRS group, with significance between both the groups. The mean hemoglobin drop in Mini Perc group was 0.88 ± 0.44 g in Mini Perc group, whereas it was 0.99 ± 0.65 in RIRS group, with no statistical significance between both the groups. The mean stone clearance rate for Mini Perc group is 99% ± 5.47%, whereas it was 96.33% ± 10.98% in RIRS group, with no statistical significance. In comparison with both the groups, the retreatment rate was 3.3% in Mini Perc group and 13.3% in RIRS group, with no statistical significance.

Conclusion

The result of this study revealed that between both the techniques, patients undergoing RIRS procedure had significantly less pain than Mini Perc, though RIRS procedure took longer operating times. We found that both the techniques were safe, in regard to complications (both intraoperative and postoperative), and there was no significant difference in hospital stay between the groups.

Determining whether previous SWL for ureteric stones influences the results of ureteroscopy as the second-line treatment: A clinical study

The purpose of the study was to establish whether shock wave lithotripsy (SWL) is a potential harmful first-line treatment for ureteric stones where ureteroscopy (URS) is necessary as a second-line treatment. Medical records of patients with ureteric stones who underwent either URS as the only therapy applied or SWL followed by URS over two years were retrospectively evaluated. In total, 158 patients were included: 79 patients in Group A (no SWL) and 79 in Group B (prior SWL before URS). There was no difference in major complications, Group A had higher stone-free rates, Group B had higher rates of ureteral edema and similar intraoperative ureteral lesions. In conclusion, the failure of SWL for lumbar or pelvic ureteral lithiasis does not appear to have a negative effect on the rate of intraoperative complications or the success rate of semi-rigid retrograde URS for this category of calculi, with the same safety profile as first-line endourological intervention.

Time-Resolved Passive Cavitation Mapping Using the Transient Angular Spectrum Approach

Passive cavitation mapping (PCM), which generates images using bubble acoustic emission signals, has been increasingly used for monitoring and guiding focused ultrasound surgery (FUS). PCM can be used as an adjunct to magnetic resonance imaging to provide crucial information on the safety and efficacy of FUS. The most widely used algorithm for PCM is delay-and-sum (DAS). One of the major limitations of DAS is its suboptimal computational efficiency. Although frequency-domain DAS can partially resolve this issue, such an algorithm is not suitable for imaging the evolution of bubble activity in real time and for cases in which cavitation events occur asynchronously. This study investigates a transient angular spectrum (AS) approach for PCM. The working principle of this approach is to backpropagate the received signal to the domain of interest and reconstruct the spatial-temporal wavefield encoded with the bubble location and collapse time. The transient AS approach is validated using an in silico model and water bath experiments. It is found that the transient AS approach yields similar results to DAS, but it is one order of magnitude faster. The results obtained by this study suggest that the transient AS approach is promising for fast and accurate PCM.

First In-Human Burst Wave Lithotripsy for Kidney Stone Comminution: Initial Two Case Studies

Purpose: To test the effectiveness (Participant A) and tolerability (Participant B) of urinary stone comminution in the first-in-human trial of a new technology, burst-wave lithotripsy (BWL). Materials and Methods: An investigational BWL and ultrasonic propulsion system was used to target a 7-mm kidney stone in the operating room before ureteroscopy (Participant A). The same system was used to target a 7.5 mm ureterovesical junction stone in clinic without anesthesia (Participant B). Results: For Participant A, a ureteroscope inserted after 9 minutes of BWL observed fragmentation of the stone to <2 mm fragments. Participant B tolerated the procedure without pain from BWL, required no anesthesia, and passed the stone on day 15. Conclusions: The first-in-human tests of BWL pulses were successful in that a renal stone was comminuted in <10 minutes, and BWL was also tolerated by an awake subject for a distal ureteral stone. Clinical Trial NCT03873259 and NCT02028559.

Role of Stone Heterogeneity Index in Determining Success of Shock Wave Lithotripsy in Urinary Calculi

INTRODUCTION

Various stone factors can affect the outcome of shock wave lithotripsy (SWL). A novel factor called the stone heterogeneity index (SHI) may have an impact on stone free rates. The objective of this study was to assess the role of SHI in SWL outcomes.

METHODS

Patients' medical records were reviewed for the collection of data variables. They were subjected to SWL, using an electromagnetic lithotripter machine (Storz Modulith SLX-MX). Computation of mean stone density (mean value of the Hounsfield units) and SHI was accomplished by generating elliptical regions of interest on the computed tomography (CT) scan images. Grouping was performed on the basis of stone free and failure outcomes. Relevant statistical tests were applied for continuous and categorical variables. P ≤ 0.05 was considered statistically significant.

RESULTS

Overall, 385 subjects were included having a mean age of 38.4 ± 14.7 years. The cohort comprised 276 (71.7%) males and 109 (28.3%) female patients. A total of 234 (60.8%) patients were rendered successful (stone free after one session) while 151 (39.2%) of the patients were declared to have failed the SWL procedure. Stone length, stone density, and SHI values were 13.7 ± 7.6 mm, 935 ± 404, and 201 ± 107, respectively. The stone density, SHI, and stone length were significantly different between the two groups (p-values of 0.001, 0.02, and 0.04, respectively).

CONCLUSIONS

SHI can be a helpful CT scan-based parameter to assess stone fragility. It can help clinicians in the judicious selection of patients before implementing SWL procedure.

RELEVANCE FOR PATIENTS

Non-contrast CT-based stone parameters have been found to be effective for predictions of outcomes. SHI can be a helping tool to better predict SWL success rates when treating the renal stones.

Large spontaneous steinstrasse: Our experience and management issues in tertiary care centre

BACKGROUND

Steinstrasse, is described as array of stone pieces in the ureter following extracorporeal shock wave lithotripsy (SWL). It is well-recognized, transient event. Steinstrasse clears spontaneously, however about 6% require intervention. Spontaneous steinstrasse without prior history of SWL is a rare occurrence and only few case reports are published in literature. Objective of the study was to assess the aetiology and management issues of large spontaneous steinstrasse in our centre.

METHOD

From February 2017 to March 2019, 684 patients underwent SWL for renal or ureteric stones. Twenty-eight patients presented with steinstrasse of which nine patients had no prior history of SWL. Detailed clinical profile and management issues have been discussed.

RESULT

Among the nine patients of spontaneous steinstrasse, there were six males and three females. Mean age of the patients was 39 years (±13 years SD). Bilateral large spontaneous steinstrasse was seen in one out of nine patients. Seven patients had associated renal stones. Five patients presented with obstructive uropathy and three out of them had urosepsis as initial presentation. Ureterolithotomy and percutaneous nephrolithotomy were commonly performed procedures for stone clearance. Metabolic work was done in all cases in follow up period. Three patients had hypercalciuria and hypocitraturia suggestive of renal tubular acidosis.

CONCLUSION

Large spontaneous steinstrasse is uncommon case scenario. It can be subtle in presentation and yet have significant patient consequence in terms of renal function and infection. Prompt management is essential to preclude permanent loss of renal function. Metabolic evaluation is indispensable in such cases.

Structure Types of Kidney Stones and Their Susceptibility to Shock Wave Fragmentation

Background:

The modern approach in the treatment of urolithiasis involves the use of non-invasive and minimally invasive techniques based on the stone fragmentation, among which shock wave lithotripsy (SWL) is considered as the first-line treatment for kidney stones < 2 cm and proximal ureter stones.

Objective:

To study the microstructure and mineral composition of kidney stones and to evaluate their influence on the stones’ susceptibility to fragmentation by shock waves.

Methods:

The microstructure and mineral composition of kidney stone samples obtained from shock wave lithotripsy in 87 patients were studied using crystal optical analysis and infrared spectroscopy. The volume fraction of amorphous and crystalline phases of the stone composition, the quantitative and qualitative composition of mineral components were assessed. The fragmentation features of stones with different microstructure were retrospectively analyzed based on the total number of shock waves required for complete stone fragmentation.

Results:

Three kidney stone structure types were identified: amorphous-crystalline structure stones predominantly including the amorphous phase (type A); amorphous-crystalline structure stones predominantly including the crystalline phase (type B); fully crystalline structure stones (type C). Significant positive correlation between the total number of shock waves required for complete stone fragmentation and the volume fraction of crystalline phase was found.

Conclusion:

The structure type of kidney stones is determined by the volume ratio between the amorphous and crystalline phases of their composition. The amorphous-crystalline structure stones with the predominant content of the amorphous phase are more sensitive to shock-wave exposure. The increase in the volume fraction of crystalline phase in the stone structure reduces the stone’s susceptibility to fragmentation by shock waves.

Efficacy and Safety of Surgical Kidney Stone Interventions in Autosomal Dominant Polycystic Kidney Disease: A Systematic Review

BACKGROUND

Reduced kidney function and distorted kidney anatomy in patients with autosomal dominant polycystic kidney disease (ADPKD) may complicate stone interventions more compared with the general population.

OBJECTIVES

To review studies describing the safety and efficacy of the 3 main stone interventions in adults with ADPKD: shock wave lithotripsy (SWL), ureteroscopy, and percutaneous nephrolithotomy (PCNL).

DESIGN

Systematic review.

SETTING

Any country of origin.

PATIENTS

Adults with ADPKD who underwent SWL, ureteroscopy, or PCNL.

MEASUREMENTS

Being stone free after the intervention and postoperative complications as reported by each study, which included pain, bleeding, and fever.

METHODS

Relevant studies published until February 2019 were identified through a comprehensive search of MEDLINE, EMBASE, Web of Science, BIOSIS PREVIEW, and CINAHL. Studies were eligible for review if they reported at least one outcome following SWL, ureteroscopy, and/or PCNL in adults with ADPKD. We then abstracted information on study characteristics, patient characteristics, intervention details, and postintervention outcomes and assessed the methodological quality of each study using a modified Downs and Black checklist.

RESULTS

We screened 221 citations from which we identified 24 studies that met our review criteria. We identified an additional article when manually reviewing the reference list of an included article, yielding a total of 25 studies describing 311 patients (32 SWL, 42 ureteroscopy, and 237 PCNL). The percentage of patients who were stone free after 1 session ranged from 0% to 69% after SWL, 73% to 100% after ureteroscopy, and 45% to 100% after PCNL. The percentage of patients with ADPKD that experienced at least one postoperative complication ranged from 0% to 33% for SWL, 0% to 27% for ureteroscopy, and 0% to 100% for PCNL.

LIMITATIONS

The number and quality of studies published to date are limited.

CONCLUSIONS

The efficacy and safety of stone interventions in patients with ADPKD remains uncertain, with wide-ranging estimates reported in the literature.

TRIAL REGISTRATION

We did not register the protocol of this systematic review.

Obstructing Pancreatic Ductal Calculus: A Case Report and Literature Review

Pancreatic calculi are typically a sequela of chronic pancreatitis. Here, we present a patient who was found to have an obstructing one-centimeter pancreatic calculus secondary to recurrent gallstone pancreatitis. Recent retrospective studies have focused on the optimal treatment of large pancreatic calculi that were defined as greater than five millimeters. But most studies fail to comment on much larger stone as in this case report. Further guidelines and investigation need to be done aiming toward the optimal treatment of relatively large pancreatic stones. 

Comparison of the efficacy and safety of shockwave lithotripsy, retrograde intrarenal surgery, percutaneous nephrolithotomy, and minimally invasive percutaneous nephrolithotomy for lower-pole renal stones: A systematic review and network meta-analysis

BACKGROUND

Shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS), percutaneous nephrolithotomy (PCNL), and minimally invasive PCNL are currently therapeutic options for lower-pole renal stones (LPS). However, the optimal treatment for LPS remains unclear. A comprehensive evaluation of the efficacy and safety of each intervention is needed to inform clinical decision-making. This study aimed at assessing the efficacy and safety of different interventions for LPS.

METHODS

PubMed, Embase, ScienceDirect, ClinicalKey, Cochrane Library, ProQuest, Web of Science, and ClinicalTrials.gov were searched from inception to December 6th 2018. Only randomized controlled trials (RCTs) including the patients treated for LPS were included. The frequentist models of network meta-analysis were used to compare the effect sizes. The primary outcome was stone free rate, and the secondary outcomes were overall complication rate, major complication rate, retreatment rate, and auxiliary procedure rate.

RESULTS

This study included 13 RCTs comprising 1832 participants undergoing 6 different interventions, including RIRS, PCNL, Mini-PCNL, Micro-PCNL, SWL, and conservative observation. PCNL had the best stone free rate (odds ratio [OR] = 3.45, 95% confidence interval [CI] = 1.30-9.12), followed by Mini-PCNL (OR = 2.90, 95% CI = 1.13-7.46). Meta-regression did not find any association of the treatment effect with age, sex, and stone size. Although PCNL tended to exhibit a higher complication rate, the difference of complication rate among various interventions did not achieve a statistical significance. SWL was the less effective and associated with higher retreatment rate compared with PCNL, Mini-PNCL, and RIRS.

CONCLUSIONS

PCNL was associated with the best stone free rate for LPS regardless of age, sex, and stone size. Each treatment achieved a similar complication rate compared with the others. Future large-scale RCTs are warranted to identify the most beneficial management for renal stones at a more complicated location.

Percutaneous nephrolithotomy versus shock wave lithotripsy for high-density moderate-sized renal stones: A prospective randomized study

Context:

The management of renal stones of high density (>1000 Hounsfield units) on non-contrast computed tomography (NCCT), and moderate sized (15-25 mm) is still debatable.

Aims:

The aim of this study was to compare the outcomes of percutaneous nephrolithotomy (PCNL) and shock wave lithotripsy (SWL) for the high-density and moderate-sized renal stones regarding the stone-free rate (SFR), morbidity, and patients' quality of life.

Settings and Design:

This is a prospective randomized study.

Patients and Methods:

Eighty consecutive patients with renal stones, excluding those with lower calyceal stones, were randomized to receive either PCNL or SWL (40 in each arm). Patients were followed up by abdominal ultrasound and plain X-ray (NCCT if indicated) till clearance of stone. Outcomes, complications, costs, and SF-8 Health Survey scoring were recorded for each group.

Statistical Analysis:

We used Stata software, version 9.2 (Intercooled STATA®; StataCorp LP College Station, Texas, USA). Comparison of the two groups was made with regard to patient and stone criteria and the procedure details. Continuous variables were compared using the Mann–Whitney U-test with values shown as the median and interquartile range. Categorical variables were compared using the Pearson's Chi-square/Fisher's exact test. Multivariate logistic regression analysis was used to identify variables independently associated with the stone clearance after two sessions of SWL. P < 0.05 was considered statistically significant.

Results:

The basic characteristics of both groups were comparable. After a single treatment session, the SFR was 80% and 27.5% for PCNL and SWL, respectively (P < 0.001). The overall 3-month SFR was 87.5% versus 90%, respectively (P = 0.723). The median number of the required maneuvers was 1 (range: 1–3) for PCNL versus 2 (range: 1–4) for SWL (P < 0.001). The complication rate was 10% and 7.5%, respectively (P = 0.692). The cost of SWL was significantly lower (P < 0.001). On multivariate analysis, a single stone was an independent predictor for stone clearance after two sessions of SWL (odds ratio: 7.26, 95% confidence interval: 1.13–46.62, P = 0.037).

Conclusions:

PCNL for the dense, and moderate-sized renal stone provides higher initial success and lower re-treatment rates compared with SWL with comparable outcome after 3 months of therapy. However, SWL is an alternative, especially for a single stone.

The clinical role of X-ray computed tomography to predict the clinical efficiency of extracorporeal shock wave lithotripsy

AIM

To evaluate the clinical efficiency of computed tomography for diagnostics of patients with urolithiasis and the choice of treatment strategy.

MATERIAL AND METHODS

The study was carried out at the Urological Clinic of I.M. Sechenov First Moscow State Medical University and included 1044 patients with urinary stones. The ultimate goal of this study was to predict the clinical efficiency of extracorporeal shock wave lithotripsy using a combination of computed tomography and densitometry. Extracorporeal shock wave lithotripsy was performed on "Siemens Lithostar Plus," "Siemens Modularis Uro," and "Dornier Gemini" lithotripters. Statistical analysis of clinical data included evaluation of individual sampling groups and calculation of weighted arithmetic mean ( M).

RESULTS

The efficiency of extracorporeal shock wave lithotripsy has been determined primarily using X-ray analysis of the concrement outlines and the structure (homogeneous or heterogeneous) of its central zone. However, in terms of efficiency and repetition rate (the number of fragmentation procedures required for complete clearance) of extracorporeal shock wave lithotripsy, the mean density of the concrement along the whole length of its three-dimensional structure (expressed in Hounsfield units) appeared to be the most reliable and informative predictive index in this study.

CONCLUSION

The combination of computed tomography with densitometry in the treatment of patients with urolithiasis allows one (1) to determine the exact localization, size, X-ray structure, and structural density of urinary stones and (2) to predict, on the basis of densitometric data histograms, the clinical efficiency and repetition rate of extracorporeal shock wave lithotripsy with due regard to the X-ray structure of peripheral and central zones, and mean density (in Hounsfield units) of urinary concrements.

Evaluation of Renal Stone Comminution and Injury by Burst Wave Lithotripsy in a Pig Model

Introduction: Burst wave lithotripsy is an experimental technology to noninvasively fragment kidney stones with focused bursts of ultrasound (US). This study evaluated the safety and effectiveness of specific lithotripsy parameters in a porcine model of nephrolithiasis. Methods: A 6- to 7-mm human kidney stone was surgically implanted in each kidney of three pigs. A burst wave lithotripsy US transducer with an inline US imager was coupled to the flank and the lithotripter focus was aligned with the stone. Each stone was exposed to burst wave lithotripsy at 6.5 to 7 MPa focal pressure for 30 minutes under real-time image guidance. After treatment, the kidneys were removed for gross, histologic, and MRI assessment. Stone fragments were retrieved from the kidney to determine the mass comminuted to pieces <2 mm. Results: On average, 87% of the stone mass was reduced to fragments <2 mm. In three of five treatments, stones were completely comminuted to <2-mm fragments. In two of five treatments, stones were partially disintegrated, but larger fragments remained. One stone was not treated because no suitable acoustic window was identified. No injury was detected through gross, histologic, or MRI examination in the parenchymal tissue, although petechial damage and surface erosion were identified on the urothelium of the collecting system limited to the area around the stone. Conclusion: Burst wave lithotripsy can consistently produce stone fragments small enough to spontaneously pass by transcutaneous administration of US pulses. The data suggest that such exposures produce minimal injury to the kidney and urinary tract.

Impact of Case Volume on Shock Wave Lithotripsy Outcomes: Data from the National Shock Wave Lithotripsy Database of New Zealand

Purpose: To assess the impact of individual operator case volume on shock wave lithotripsy (SWL) treatment outcomes in more than 9000 stone cases over a 20-year period in New Zealand. Materials and Methods: Stone cases treated with SWL on the Mobile Medical Technology (MMT) vehicle between June 19, 1995, and December 1, 2014, were identified. Data collection was undertaken prospectively for patient, stone, and treatment characteristics, and retrospectively for treatment outcomes. Multivariate analysis using binary logistic regression was undertaken to assess whether radiographer stone case volume (stones/year) was an independent predictor of SWL success (stone free or clinically insignificant residual fragments ≤4 mm at follow-up). Results: Sixteen radiographers delivered treatment to the included cohort (9039 stone cases), with a median case volume (stones/year) of 73 (range: 37-197) and median total of 425 stones treated (range: 71-1721). The two radiographers with highest case volumes achieved the highest success rates. Radiographer case volume (stones/year) was independently associated with SWL success (odds ratio [OR]: 1.004, 95% confidence interval [CI]: 1.003-1.005, p < 0.0001) and reduced need for post-SWL hospital admission (OR: 0.997, 95% CI: 0.994-1.000, p = 0.028), but there was no associated decrease in post-SWL urosepsis (OR: 0.999, 95% CI: 0.974-1.025, p = 0.941), perinephric hematoma (OR: 1.003, 95% CI: 0.985-1.020, p = 0.778), or need for auxiliary procedures (OR: 1.000, 95% CI: 0.998-1.002, p = 0.871). Conclusions: SWL success rates can be improved by increasing the frequency of cases performed by individual operators. In this multicenter cohort of more than 9000 stone cases treated over a 20-year period, the best outcomes were seen for those radiographers performing >150 cases per year.

Total Surface Area Influences Stone Free Outcomes in Shock Wave Lithotripsy for Distal Ureteral Calculi

Introduction: Current American Urological Association guidelines recommend ureteroscopy (URS) as primary management of distal ureteral stones and shock wave lithotripsy (SWL) as a secondary option. Utilization of SWL in the management of nephrolithiasis in North America has decreased. We hypothesized that SWL continues to be an effective option in the management of distal ureteral calculi and studied data from our center in patients who received SWL for distal ureteral stones. Methods: A retrospective review was performed of 104 patients treated initially with SWL for distal ureteral calculi between 2011 and 2018 at this institution. The success rate of SWL was assessed through radiologic imaging and if subsequent procedures were required to render patients stone free. Results: Operative note and chart review identified 104 patients who presented with distal ureteral stones and were treated with SWL as the initial form of management. Average patient age was 52.2 ± 15.3 years, average BMI was 27.4 ± 5.7, and average total axial stone surface area was 25.96 ± 14.32 mm². Of these patients, 78.8% (n = 82) were stone free following one SWL and required no subsequent procedures. Of these patients, 87.5% (n = 91) were stone free following a second SWL, and 87.5% (n = 91) were stone free following a secondary URS. After the initial SWL, residual stones were identified in 21.2% of patients (n = 22). Four patients, 3.8%, required a salvage URS following a failed second SWL to achieve stone-free status. Conclusion: One SWL procedure offers a stone-free rate (SFR) of 78.8% and after two SWLs an 87.5% SFR. Only 12.5% of patients undergoing SWL at our center required URS to achieve a stone-free status. SWL is an effective modality in the treatment of distal ureteral stones.

Factors that affect outcome of pediatric shock waves lithotripsy with sedoanalgesia

Introduction:

Performing shock wave lithotripsy (SWL) under intravenous sedoanalgesia and the ability to predict the effectiveness of SWL is essential in determining the most appropriate treatment for patients.

Patients and Methods:

This study consisted of 56 children aged between 1 and 16 years mean age 6.7 ± 4.3 years with renal and ureteric stones who underwent SWL. Incomplete child data were excluded from the study, leaving 47 patients. The procedure was performed under sedoanalgesia with diazepam and ketamine was given intravenously during SWL session. We study the effect of the following factors (age, site, size, opacity of stone, degree of pelvicalyceal dilation, previous urological surgery, number of shock waves, and number of sessions) on stone clearance after SWL.

Results:

Forty-seven children range from 1 to 16 years, mean age 6.7 ± 4.3 years. There were 39 (83%) with renal stone and 8 (17%) with ureteric stone. The mean size of stone was 12.2 ± 4.4 mm ranging 6–25 mm. Of 47 children, 36 (76.6%) were stone-free. Age below 6 years, pelvic stones, children without surgery, number of shock waves, and number of sessions were significant factors that affect the stone-free rate after SWL, while the stone size, opacity, and calyceal system dilatation were not statistically significant factors.

Conclusions:

The present analysis shows that stone-free status for children with urolithiasis depends on the age of presentation, previous history of ipsilateral stone treatment, stone location, and number of sessions. Pediatric lithotripsy under intravenous sedoanalgesia is feasible, general anesthesia is not mandatory, and any anesthetic complications were not encountered.

Retroperitoneal Abscess Formation Extending to the Lumbar Area After Extracorporeal Shock Wave Lithotripsy

Background: Renal rupture and retroperitoneal abscess formation after extracorporeal shock wave lithotripsy (SWL) is a rare and potentially life-threatening complication if left untreated with a high morbidity rate. In this study, we present a rare case of renal rupture after SWL, with formation of an extensive retroperitoneal abscess extending to the left abdominal and lumbar area. Case Presentation: A 48-year-old Caucasian woman presented to the outpatient department with left abdominal and lumbar redness and swelling caused by renal rupture and massive perinephric abscess formation, 10 days after SWL treatment of her left renal pelvic stones. She was treated first with drainage of the retroperitoneal abscess and simultaneous Double-J stent placement in her left kidney. A left open nephrectomy was subsequently performed because of persistence of kidney infection. Conclusion: Retroperitoneal abscess formation after SWL is a serious and highly morbid complication, which should be early diagnosed and timely treated.

Can intervals in extracorporeal shock wave lithotripsy sessions affect success in the treatment of upper ureteral stones?

Introduction

Managing upper ureteral stones with shock wave lithotripsy (SWL) has been done for many years. However, no conclusive data have been found on the intervals required between repeated SWL sessions.

Aim

To identify the most optimal intervals between SWL sessions.

Material and methods

Between September 2015 and December 2016, 80 patients undergoing elective outpatient lithotripsy who required repeated SWL sessions for ureteral stones were evaluated. These patients were categorised into two groups according to different SWL session intervals. The intervals between SWL sessions (n = 40) for the first group lasted one day, whereas those for the second group (n = 40) lasted 1 week. The data recorded during SWL included visual analogue scale (VAS) scores, total number of shocks, total energy used and number of sessions. The stone clearance rates, number of urinary tract infections, complication rates and VAS scores were compared between the two groups.

Results

All patients’ clinical outcomes after SWL therapy are shown in Table I. The stone clearance rate for group 1 was 70%, whereas that for group 2 was 72.5% (p = 0.805). Additionally, the number of urinary tract infections, complications and VAS scores were similar for both groups. In group 1, 3 patients had steinstrasse, two suffered from severe renal colic, and one had a urinary tract infection. In group 2, 3 patients endured steinstrasse, and 2 patients experienced severe renal colic during the study.

Conclusions

Short-interval SWL sessions are safe and effective for treating upper ureteral stones, and such sessions do not increase complication rates.

Different managements of horseshoe kidney stones, any difference in the outcome?

Purpose

The aim is to assess the outcomes of different approaches for the management of renal stones associated with horseshoe kidneys (HSKs) in our institution over a 12-year period.

Methods

A retrospective review of 144 patients with HSKs who presented from 2000 to 2012 was performed. Twenty-eight patients (19.4%) were found to have renal stones. Demographic data were collected; the method of treatment and the outcomes of stone management were reviewed. We excluded patients with non-functioning moieties and associated genitourinary anomalies, and those with incomplete data.

Results

We included 25 patients, of which 16 males (64%) and 9 females (36%), with a mean age of 37 years. Mean serum creatinine level was 66 mmol/L. Eleven patients with a stone size <8 mm were treated expectantly with medical treatment, with only one patient requiring endoscopic intervention. Six patients (24%) with a stone size between 1 cm and ≤2 cm were treated with extracorporeal shock wave lithotripsy (ESWL) with the placement of double J stents, and seven patients (28%) with a stone size of >2 cm were treated with percutaneous nephrolithotomy. One patient with a 10 mm stone was treated using flexible ureteroscopy. No significant perioperative complications were encountered.

Conclusions

Indications, methods of treatment, and outcomes of management of stones associated with HSKs were comparable to those for stones associated with normal kidneys. Tailored approach based on stone size is highly recommended. ESWL accompanied with ureteric stenting is a promising strategy for the management of stones associated with HSKs in selected patients requiring intervention.

Laparoscopic ureterolithotomy: Experience of 60 cases from a developing world hospital

Objective

Laparoscopic ureterolithotomy, which has been quoted to have a success rate equivalent to open ureterolithotomy for uretric stones, can be performed transperitoneally and retroperitoneally. The aim of the present study is to report our experience with laparoscopic retroperitoneal ureterolithotomy, its results and advantages in the current era of minimally invasive surgery in a developing country.

Patients and Methods

It was a prospective study carried from May 2010 to December 2012. 60 patients diagnosed with upper and middle uretric calculi, with sizes more than 1 cm and with value of more than 1500 hu on CT Urography ,underwent laparoscopic retroperitoneal ureterolithotomy.

Results

All patients underwent retroperitoneal laparoscopic ureterolithotomy successfully. The mean operative time was 64.53 min. The mean blood loss was 39.83 ml. 3 patients had minor intra-operative complications which were tackled on table. Post-operative complications developed in 3 patients, all minor. There were no major complications. The removal of drain was at (2.7 days). Mean hospital stay was of 3.3 days. Patients reported to their routine activities in 1.78 weeks. During follow-up 3 months later, CT urography revealed normal ureter in all cases.

Conclusion

Laparoscopic retroperitoneal ureterolithotomy has low rate of conversion to open surgery and an acceptable overall complication rates. In selected patients with impacted, hard, large ureteral stones, which are likely to cause diffi-culty in endo-urological procedures, laparoscopic ureterolithotomy is a reason-able treatment option.

Protective effects of diltiazem and tadalafil on shock wave-induced kidney injury in rats

BACKGROUND

We aimed to compare the protective effects of tadalafil and diltiazem on renal histology after ischemia and reperfusion injury in a rat model of shock wave lithotripsy.

METHODS

A total of 40 adult, male Sprague-Dawley rats were randomized into four groups as follows; control group (group C), group S (SWL + nephrectomy), group T (SWL + tadalafil given before nephrectomy) and group D (SWL + diltiazem given before nephrectomy). Both kidneys were evaluated regarding tubular damage, peritubular fibrosis and heat shock protein-70 (HSP-70) immune-expression of glomeruli, cortical and medullar collector tubules on light microscopy.

RESULTS

HSP-70 levels of cortical and medullar collector tubules, tubular damage and peritubular fibrosis scores were decreased in group T compared with group S. Similarly, HSP-70 immunostaining levels on cortical and medullar collector tubules, tubular damage and peritubular fibrosis scores were decreased in group D compared with group S. No significant difference was detected between group D and group T for all parameters.

CONCLUSION

As a result, shock waves induced renal cell damage due to increment of HSP-70 levels, morphological irregularity in tubules and increased peritubular fibrosis. Tadalafil and diltiazem had beneficial effects in decreasing renal tissue damage which was caused by SWL (Tab. 2, Fig. 6, Ref. 29).

Comparison of safety and outcomes of shock wave lithotripsy between elderly and non-elderly patients

Background

This study compared the clinical outcomes of extracorporeal shock wave lithotripsy between elderly (aged $65 years) and non-elderly (aged <65 years) patients.

Methods

A retrospective review of medical records was performed on 483 (non-elderly: 245, elderly: 238) patients with upper urinary tract stones who underwent shock wave lithotripsy between 2007 and 2015. The demographic data, stone parameters, stone-free rate, retreatment rate, and complication rate were analyzed in both elderly and non-elderly patient groups.

Results

There was no significant difference between non-elderly and elderly patients in terms of stone-free rate (46.5% vs 41.1%, P>0.05) regardless of stone site or stone size and overall retreatment rate (41.6% vs 37.0%, P>0.05). Elderly patients had a higher complication rate than non-elderly patients (15.5% vs 23.5%, P=0.026). The most common complication was flank pain. Receiver operating characteristic curves predicted that elderly patients (cutoff value: 65 years of age) had a higher risk of complications and that patients with smaller stones (cutoff value: 0.8 cm) had a higher stone-free rate.

Conclusion

This study showed that elderly patients with upper urinary tract stones undergoing shock wave lithotripsy had comparable efficacy for stone-free rates and retreatment rates, but higher complication rates.

Can we predict the need for intervention in steinstrasse following shock wave lithotripsy?

Introduction:

Steinstrasse (SS) is a known complication of shock wave lithotripsy (SWL). Although the majority of SS clears spontaneously, about 6% require intervention. This study was carried out to identify the factors that determine the need for intervention in SS.

Materials and Methods:

This was a retrospective study of all patients who developed steinstrasse following SWL at our center. They were divided into two groups: a) Those cleared spontaneously and b) Those required intervention. The two groups were compared with regard to demographic profile, stone factors and factors related to steinstrasse.

Results:

Out of 2436 cases of SWL, 89 (3%) formed steinstrasse. The majority of the patients (35%) who required intervention had stone sizes of 10-14 mm. Coptcoat type III steinstrasse required significantly more interventions for clearance (P = 0.001). The site and the size of the SS was not a predictor of intervention for SS.

Conclusions:

Early intervention is warranted in patients with steinstrasse where the lead fragment is >5 mm (Coptcoat type III).

Lower calyceal and renal pelvic stones in preschool children: A comparative study of mini-percutaneous nephrolithotomy versus extracorporeal shockwave lithotripsy

OBJECTIVES

To compare outcomes of the mini-percutaneous nephrolithotripsy technique and extracorporeal shockwave lithotripsy for lower calyceal and renal pelvic stones in preschool children.

METHODS

From January 2010 to December 2014, single renal pelvic or lower calyceal calculi 10-25 mm in size in children (age ≤6 years) treated by either extracorporeal shockwave lithotripsy (64 patients) or the mini-percutaneous nephrolithotripsy technique (54 patients) were included. Extracorporeal shockwave lithotripsy was carried out by using a Dornier electromagnetic lithotripter. The mini-percutaneous nephrolithotripsy technique was through 14-Fr renal access using a 9.5-Fr semirigid ureteroscope with holmium:yttrium aluminium garnet lithotripsy. The two study groups were compared using Mann-Whitney, χ(2) -test or Fisher's exact test.

RESULTS

Stone parameters were similar in the mini-percutaneous nephrolithotripsy technique and extracorporeal shockwave lithotripsy groups in all patients, and in the pelvic (39 Miniperc, 52 extracorporeal shockwave lithotripsy) and lower calyceal (15 Miniperc, 12 extracorporeal shockwave lithotripsy) subgroups. Stone-free rates in the mini-percutaneous nephrolithotripsy technique and extracorporeal shockwave lithotripsy groups were 88.9% versus 43.8% (P < 0.001) and 94.4% versus 81.2% (P = 0.032) after first and last sessions, respectively. In the renal pelvis, they were 87.2% versus 50% (P < 0.001) and 94.9% versus 84.6% (P = 0.179), whereas in the lower calyx, they were 93.3% versus 16.7% (P < 0.001) and 93.3% versus 66.7% (P = 0.139) after first and last sessions, respectively. Retreatment rates in the mini-percutaneous nephrolithotripsy technique versus extracorporeal shockwave lithotripsy were 7.4% versus 50% (P < 0.001), 7.7% versus 46.2% (P < 0.001), and 6.7% versus 66.7% (P = 0.003) in all patients, renal pelvic and lower calyceal stones, respectively. No significant difference was found in complications (P = 0.521). Auxiliary procedures were required in 9.4% and 1.9% of children in the extracorporeal shockwave lithotripsy and mini-percutaneous nephrolithotripsy technique groups, respectively.

CONCLUSIONS

The mini-percutaneous nephrolithotripsy technique has significantly higher stone-free rates than extracorporeal shockwave lithotripsy for renal pelvic and lower calyceal stones (10-25 mm), with a lower retreatment rate and without a significant increase in complications.

Assessing the risk of incident hypertension and chronic kidney disease after exposure to shock wave lithotripsy and ureteroscopy

In this study we sought to determine if among individuals with urolithiasis, extracorporeal shock wave lithotripsy (SWL) and ureteroscopy are associated with a higher risk of incident arterial hypertension (HTN) and/or chronic kidney disease (CKD). This was measured in a population-based retrospective study of 11,570 participants with incident urolithiasis and 127,464 without urolithiasis in The Health Improvement Network. Patients with pre-existing HTN and CKD were excluded. The study included 1319 and 919 urolithiasis patients with at least one SWL or URS procedure, respectively. Multivariable Cox regression was used to estimate the hazard ratio for incident CKD stage 3-5 and HTN in separate analyses. Over a median of 3.7 and 4.1 years, 1423 and 595 of urolithiasis participants developed HTN and CKD, respectively. Urolithiasis was associated with a significant hazard ratio each for HTN of 1.42 (95% CI: 1.35, 1.51) and for CKD of 1.82 (1.67, 1.98). SWL was associated with a significant increased risk of HTN 1.34 (1.15, 1.57), while ureteroscopy was not. When further stratified as SWL to the kidney or ureter, only SWL to the kidney was significantly and independently associated with HTN 1.40 (1.19, 1.66). Neither SWL nor ureteroscopy was associated with incident CKD. Since urolithiasis itself was associated with a hazard ratio of 1.42 for HTN, an individual who undergoes SWL to the kidney can be expected to have a significantly increased hazard ratio for HTN of 1.96 (1.67, 2.29) compared with an individual without urolithiasis.

Previous shock-wave lithotripsy treatment does not impact the outcomes of flexible ureterorenoscopy

OBJECTIVE

Shock-wave lithotripsy (SWL) is the first-line treatment for the active removal of small and medium-sized kidney stones. Flexible ureterorenoscopy (fURS) is recommended after failed SWL treatment. The aim of this retrospective analysis is to evaluate whether prior unsuccessful SWL treatments affect the outcomes of fURS.

MATERIAL AND METHODS

Data from 206 patients who underwent fURS for the treatment of renal stones between September 2009 and January 2011 were collected, and the patients were divided into two groups according to their previous SWL treatment. The patient demographics, stone characteristics, operation and fluoroscopy times, stone-free rates and complications were compared.

RESULTS

Of the patients, 114 (55.3%) did not undergo SWL prior to fURS (Group 1), whereas 92 (44.6%) completed a minimum of 3 sessions of SWL and waited at least 2 weeks before the fURS operation (Group 2). Although the mean stone number was higher in Group 2, this difference was not significant (p=0.06). The mean operation (p=0.12) and fluoroscopy times (p=0.69) were similar between the groups. The mean operation time per mm(2) stone and fluoroscopy time per mm(2) stone were not significantly different (p=0.64 and p=0.76, respectively). The length of the hospitalization and the overall complication rates were similar. After the third postoperative month, the stone-free rates were not different between the groups (82.5% and 86.9%, respectively, p=0.38).

CONCLUSION

The stone-free and complication rates of fURS were not affected by previous SWL therapy.

Ultrasonic propulsion of kidney stones: preliminary results of human feasibility study

One in 11 Americans has experienced kidney stones, with a 50% average recurrence rate within 5-10 years. Ultrasonic propulsion (UP) offers a potential method to expel small stones or residual fragments before they become a recurrent problem. Reported here are preliminary findings from the first investigational use of UP in humans. The device uses a Verasonics ultrasound engine and Philips HDI C5-2 probe to generate real-time B-mode imaging and targeted "push" pulses on demand. There are three arms of the study: de novo stones, post-lithotripsy fragments, and the preoperative setting. A pain questionnaire is completed prior to and following the study. Movement is classified based on extent. Patients are followed for 90 days. Ten subjects have been treated to date: three de novo, five post-lithotripsy, and two preoperative. None of the subjects reported pain associated with the treatment or a treatment related adverse event, beyond the normal discomfort of passing a stone. At least one stone was moved in all subjects. Three of five post-lithotripsy subjects passed a single or multiple stones within 1-2 weeks following treatment; one subject passed two (1-2 mm) fragments before leaving clinic. In the pre-operative studies we successfully moved 7 - 8 mm stones. In four subjects, UP revealed multiple stone fragments where the clinical image and initial ultrasound examination indicated a single large stone.

Impact of urinary stone volume on computed tomography stone attenuations measured in Hounsfield units in a large group of Austrian patients with urolithiasis

INTRODUCTION

To investigate retrospectively the impact of urinary stone volume on computed tomography stone attenuations measured in Hounsfield units in 253 patients with urolithiasis.

MATERIAL AND METHODS

CT scans were performed in 253 patients with suspected urinary stone disease from 2008 to 2010 using CT-Scanner Siemens, SOMATOM, Sensation 64. One experienced radiologist (A.L) who was blinded to the chemical composition of the stones retrospectively reviewed images and analyzed data to determine the composition of the stones. The results were compared with the biochemical analysis results obtained by infrared spectroscopy (100 FTIR, PerkinElmer).

RESULTS

253 consecutive patients from 2008 to 2010 were included into analysis: 189 males, and 64 females. Mean age was 51.2. According to stone volume, stones were divided into 2 groups: 126 stones with volume of 4.3 mm or more, 127 stones with volume less than 4.3 mm. There was a significant relationship between stone volume and its CT attenuation only in stones with a volume 4.3 mm or more (p <0.05).

CONCLUSIONS

We failed to show a significant relationship between stone volume and its attenuations in Hounsfield units. We could not distinguish uric acid stones from non uric acid stones.

The effect of tamsulosin on pain and clearance according to ureteral stone location after shock wave lithotripsy

Background

Medical expulsion therapy has shown encouraging results in facilitating spontaneous clearance of ureteral stones after extracorporeal shock wave lithotripsy. However, no other study has yet determined the benefit of medical expulsion therapy for stones in different ureteral locations.

Objective

The aim of the study was to evaluate tamsulosin as adjunctive therapy to extracorporeal shock wave lithotripsy (SWL) in terms of pain clearance of stones in the upper, middle, and lower ureter.

Methods

Between June 2008 and July 2011, patients with a solitary ureteral stone that was ≥6 mm up to 15 mm and located in the upper, middle, or lower ureter undergoing SWL were evaluated. The patients were randomly allocated to a conservative treatment (group 1) and a tamsulosin treatment group (group 2). Administration of the drug was started immediately after SWL and was continued for a maximum of 28 days. Patients were evaluated for stone clearance, time to stone clearance, and number of SWL sessions. The pain intensity was evaluated by visual analog scale.

Results

There were 64 patients in the control group and 59 in the tamsulosin group. The average stone sizes were 10.70 (3.20) mm and 11.40 (3.01) mm (P = 0.24). Group 1 and group 2 received 2507 (984) and 2759 (775) shock waves (P = 0.86), 1.53 (0.8) and 1.49 (0.75) sessions (P = 0.85), respectively. Mean visual analog scale scores and times to clearance were 3.81 (2.74) and 2.73 (2.28) (P = 0.00) and 12.59 (8.63) days and 8.34 (7.60) days (P = 0.00), respectively, for all stones in groups 1 and 2. Only the clearance time of upper ureteral stones between groups showed statistical significance (13.54 [8.32] days vs 7.10 [6.40] days; P = 0.00).

Conclusions

Tamsulosin may help in the treatment of all ureteral stones after SWL, particularly stones in the upper ureter, with a shorter time to clearance and less need for analgesic drugs.

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.

High recurrence rate at 5-year followup in children after upper urinary tract stone surgery

PURPOSE

Pediatric urolithiasis has been treated with shock wave lithotripsy, ureteroscopy and percutaneous nephrolithotomy with high success rates during short-term followup. We studied our success rate and modifiable risk factors in patients with at least 5 years of followup postoperatively.

MATERIALS AND METHODS

Retrospective chart review was performed for patients younger than 18 years who underwent upper tract stone surgery between 1999 and 2007, were stone-free afterward and had at least 5 years of followup. Recurrence rate, and anatomical and metabolic abnormalities were assessed.

RESULTS

Of 60 eligible children 30 (33 kidneys) had at least 5 years of followup. Average patient age at surgery was 10 years, 17 patients were female and 20 kidneys had anatomical abnormalities. Overall recurrence rate at 5 years was 55% (95% CI 38%-70%). Ureteral stones had a lower recurrence rate than renal stones (5 of 19 and 13 of 14, respectively, p <0.001). Patients with abnormal anatomy had a 65% (95% CI 43%-82%) chance of recurrence within 5 years vs 38% (95% CI 18%-65%) in those with normal anatomy (p = 0.17). Of the 18 recurrences 10 required a second operation, 7 demonstrated abnormal anatomy and 14 involved calcium based stones. A 24-hour urine test in 13 children revealed 10 with hypercalciuria and 11 with hypocitraturia, with 9 patients exhibiting both conditions.

CONCLUSIONS

We found a high recurrence rate in children with stones requiring surgical intervention, particularly those with abnormal anatomy. This finding should be confirmed in a larger multicenter study of recurrence rates. In the meantime our results suggest a need for aggressive diagnosis and treatment of metabolic abnormalities.

Focused ultrasound to expel calculi from the kidney: safety and efficacy of a clinical prototype device

PURPOSE

Focused ultrasound has the potential to expel small stones or residual stone fragments from the kidney, or move obstructing stones to a nonobstructing location. We evaluated the efficacy and safety of ultrasonic propulsion in a live porcine model.

MATERIALS AND METHODS

Calcium oxalate monohydrate kidney stones and laboratory model stones (2 to 8 mm) were ureteroscopically implanted in the renal pelvicalyceal system of 12 kidneys in a total of 8 domestic swine. Transcutaneous ultrasonic propulsion was performed using an HDI C5-2 imaging transducer (ATL/Philips, Bothell, Washington) and the Verasonics® diagnostic ultrasound platform. Successful stone relocation was defined as stone movement from the calyx to the renal pelvis, ureteropelvic junction or proximal ureter. Efficacy and procedure time was determined. Three blinded experts evaluated histological injury to the kidney in the control, sham treatment and treatment arms.

RESULTS

All 26 stones were observed to move during treatment and 17 (65%) were relocated successfully to the renal pelvis (3), ureteropelvic junction (2) or ureter (12). Average ± SD successful procedure time was 14 ± 8 minutes and a mean of 23 ± 16 ultrasound bursts, each about 1 second in duration, were required. There was no evidence of gross or histological injury to the renal parenchyma in kidneys exposed to 20 bursts (1 second in duration at 33-second intervals) at the same output (2,400 W/cm(2)) used to push stones.

CONCLUSIONS

Noninvasive transcutaneous ultrasonic propulsion is a safe, effective and time efficient means to relocate calyceal stones to the renal pelvis, ureteropelvic junction or ureter. This technology holds promise as a useful adjunct to surgical management for renal calculi.

Morbidity and efficacy of ureteroscopic stone treatment in patients with neurogenic bladder

PURPOSE

There is a lack of information on the safety and efficacy of ureteroscopy in the neurogenic bladder population. We hypothesized that ureteroscopy in patients with neurogenic bladder would be associated with an increased risk of complications and a lower stone clearance rate than in patients without neurological impairment.

MATERIALS AND METHODS

We reviewed a local registry of patients with ICD-9 codes for urolithiasis between 2004 and 2012. The study cohort was assembled from all eligible patients with neurogenic bladder and a randomly selected control group that had undergone ureteroscopy. Statistical analysis of demographic variables and surgical outcomes was performed. Complications were classified according to the Clavien system. Clearance was defined by computerized tomography, renal/bladder ultrasound or direct ureterorenoscopy.

RESULTS

Ureteroscopy was performed a total of 173 times in 127 controls and a total of 45 times in 20 patients with neurogenic bladder. There was no difference between presenting episodes by gender (p = 1.0), race (p = 0.654) or body mass index (p = 0.519). Bacteriuria was associated with the stone episode in 16.4% of controls and 67% of neurogenic bladder cases (p <0.001). Median operative time was significantly longer in those with neurogenic bladder (80.5 minutes, IQR 50-110.5 vs 52, IQR 33-78, p = 0.0003). The proportion of complications was significantly different (p = 0.013). Stones cleared in 86.6% of controls compared to 63% of neurogenic bladder cases (p = 0.004).

CONCLUSIONS

Patients with neurogenic bladder have increased morbidity after ureteroscopy for upper tract calculi compared to neurologically unaffected controls. Infection has a role in this morbidity. The clearance rate is lower but the stone burden is more significant in those with neurogenic bladder.

Assessment of a modified acoustic lens for electromagnetic shock wave lithotripters in a swine model

PURPOSE

The acoustic lens of the Modularis electromagnetic shock wave lithotripter (Siemens, Malvern, Pennsylvania) was modified to produce a pressure waveform and focal zone more closely resembling that of the original HM3 device (Dornier Medtech, Wessling, Germany). We assessed the newly designed acoustic lens in vivo in an animal model.

MATERIALS AND METHODS

Stone fragmentation and tissue injury produced by the original and modified lenses of the Modularis lithotripter were evaluated in a swine model under equivalent acoustic pulse energy (about 45 mJ) at 1 Hz pulse repetition frequency. Stone fragmentation was determined by the weight percent of stone fragments less than 2 mm. To assess tissue injury, shock wave treated kidneys were perfused, dehydrated, cast in paraffin wax and sectioned. Digital images were captured every 120 μm and processed to determine functional renal volume damage.

RESULTS

After 500 shocks, the mean ± SD stone fragmentation efficiency produced by the original and modified lenses was 48% ± 12% and 52% ± 17%, respectively (p = 0.60). However, after 2,000 shocks, the modified lens showed significantly improved stone fragmentation compared to the original lens (mean 86% ± 10% vs 72% ± 12%, p = 0.02). Tissue injury caused by the original and modified lenses was minimal at a mean of 0.57% ± 0.44% and 0.25% ± 0.25%, respectively (p = 0.27).

CONCLUSIONS

With lens modification the Modularis lithotripter demonstrates significantly improved stone fragmentation with minimal tissue injury at a clinically relevant acoustic pulse energy. This new lens design could potentially be retrofitted to existing lithotripters, improving the effectiveness of electromagnetic lithotripters.

Recent finding and new technologies in nephrolitiasis: a review of the recent literature

This review summarizes recent literature on advances regarding renal and ureteral calculi, with particular focus in areas of recent advances in the overall field of urolithiasis. Clinical management in everyday practice requires a complete understanding of the issues regarding metabolic evaluation and subgrouping of stone-forming patients, diagnostic procedures, effective treatment regime in acute stone colic, medical expulsive therapy, and active stone removal. In this review we focus on new perspectives in managing nephrolitihiasis and discuss recentadvances, including medical expulsive therapy, new technologies, and refinements of classical therapy such as shock wave lithotripsy, give a fundamental modification of nephrolithiasis management. Overall, this field appears to be the most promising, capable of new developments in ureterorenoscopy and percutaneous approaches. Further improvements are expected from robotic-assisted procedures, such as flexible robotics in ureterorenoscopy.

Novel instrumentation in urologic surgery: Shock wave lithotripsy

Extracorporeal shock wave lithotripsy (SWL) was first introduced in 1980 and it rapidly revolutionized the treatment of stone disease. SWL is a non-invasive, outpatient procedure that now accounts for the majority of stone removal procedures. Since the introduction of first generation lithotripter, the Dornier HM3 machine, SWL devices have undergone many modifications secondary to limitations, in efforts to create a more effective and efficient way to treat stones and decrease possible morbidities. Herein, we review the evolution of the technology and advances in the instrumentation over the last three decades.

Surgical management of pediatric urolithiasis

Pediatric urolithiasis poses a technical challenge to the urologist. A review of the recent literature on the subject was performed to highlight the various treatment modalities in the management of pediatric stones. A Medline search was used to identify manuscripts dealing with management options such as percutaneous nephrolithotomy, shock wave lithotripsy, ureteroscopy and cystolithotripsy in pediatric stone diseases. We also share our experience on the subject.

Shock wave lithotripsy should be the treatment modality for renal stone less than 1cm or < 150 mm² and proximal non-impacted ureteric stone less than 1 cm with normal renal function, no infection and favorable anatomy. Indications for PCNL in children are large burden stone more than 2cm or more than 150mm² with or without hydronephrosis, urosepsis and renal insufficiency, more than 1cm impacted upper ureteric stone, failure of SWL and significant volume of residual stones after open surgery. Shock wave lithotripsy can be offered for more soft (< 900 HU on CT scan) renal stones between 1-2cm. Primary vesical stone more than 1cm can be tackled with percutaneous cystolithomy or open cystolithotomy. Open renal stone surgery can be done for renal stones with associated structural abnormalities, large burden infective and staghorn stones, large impacted proximal ureteric stone. The role of laparoscopic surgery for stone disease in children still needs to be explored.