Risk Factors Survey for Extracorporeal Shockwave Lithotripsy-Induced Renal Hematoma

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.

Extracorporeal shock wave lithotripsy for lower calyx stones: predicting treatment success

INTRODUCTION

The use of extracorporeal shock wave lithotripsy (ESWL) for lower calyx stones is associated with a high rate of residual fragments. Our aim is to analyse the effectiveness and complications of ESWL for lower calyx stones.

METHODS

Retrospective review of patients with lower renal calyx stones treated with ESWL between January-2014 and December-2020. Measurement of infundibular length, infundibular width and infundibulopelvic angle in lower renal pole to determine favourable anatomy. ESWL failure: fragments >3 mm detected in plain abdominal film, CT scan and/or renal ultrasound 3 months after treatment. Complications after ESWL, auxiliary procedures along with risk factors associated with perirenal haematoma were analysed. SPSS statistical software was used.

RESULTS

512 patients with lower calyx stones were treated with ESWL. 80.3% of patients had a favourable anatomy. Overall stone-free rate was 70.5%. Regarding main complications after ESWL, stainstrasse was described in 5 patients and urinary tract infection in 3 patients. 10 perirenal haematomas (2%) were reported. Statistical association was found between antiplatelet treatment and the risk of perirenal haematoma (p = 0.004). Logistic binary regression proved the association between unfavourable anatomy of the lower renal pole (p = 0.000), size of the stone (p = 0.001), number of shock waves (p = 0.003), energy applied (p = 0.038) and the need for additional treatment after ESWL.

CONCLUSIONS

ESWL can still be considered as the initial treatment option for lower renal pole stones. The size of the stone, an unfavourable anatomy of the lower renal calyx, number of shock waves and energy applied can help predict the need for additional treatment.

The effect of piezoelectric shockwave lithotripsy with 2- and 8-mm focus sizes on stone disintegration and renal injury

OBJECTIVES

To compare the efficacy and safety of shockwave lithotripsy (SWL) using a narrow focus or wide focus for renal stones.

PATIENTS AND METHODS

A double-blind randomised trial included adult patients with a solitary radio-opaque renal pelvic stone of 1-2 cm. Patients were randomised into two groups: narrow-focus (2 mm) SWL and wide-focus (8 mm) SWL. The stone-free rate (SFR) and presence of complications such as haematuria, fever, pain, and peri-renal haematoma were evaluated. Pre- and postoperative urinary markers (neutrophil gelatinase-associated lipocalin [NGAL] and kidney injury molecule 1 [KIM-1]) concentrations were compared to assess renal injury.

RESULTS

A total of 135 patients were recruited for this study. The SFR after the first SWL session was 79.2% and 69.1% in narrow- and wide-focus groups, respectively. There was a comparable rise in the median 2-h NGAL concentration in both groups (P = 0.62). However, the rise in the median (interquartile range [IQR]) 2-h KIM-1 concentration was significantly higher in the narrow-focus group at 4.9 (4.6, 5.8) ng/mL compared with the wide-focus group at 4.4 (3.2, 5.7) ng/mL (P = 0.02). Nevertheless, the 3-day NGAL and KIM-1 urinary marker concentrations were significantly improved (P = 0.263 and P = 0.963, respectively). The overall SFR after three sessions was 86.6% and 86.8% in the narrow- and wide-focus groups, respectively (P = 0.77). Both groups were comparable for complications, apart from the median pain score and the percentage of high-grade haematuria, which were significantly higher in the narrow-focus group (P < 0.001 and P = 0.03, respectively).

CONCLUSION

Narrow- and wide-focus SWL were associated with comparable outcomes and re-treatment rates. However, narrow-focus SWL was associated with significantly higher morbidity in terms of pain and haematuria.

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.

Tissue neutrophil elastase contributes to extracorporeal shock wave lithotripsy-induced kidney damage and the neutrophil elastase inhibitor, sivelestat, attenuates kidney damage with gratifying immunohistopathological and biochemical findings: an experimental study

Although the efficacy of extracorporeal shock wave lithotripsy (ESWL) has been well established within the literature, debate continues on the safety of the procedure while focusing on cellular injury and its long-term consequences. Here, we describe the role of neutrophil elastase (NE) in ESWL-related rat kidney damage and investigate the protective effects of sivelestat, an inhibitor of NE, during the early and late phases. Four groups including control, ESWL alone, ESWL with sivelestat 50 mg/kg and ESWL with treatment of 100 mg/kg, each consisting of ten rats were created. Biochemical parameters of kidney function and damage and immunohistopathological findings were compared in the early (72 h after ESWL) and late (1 week after ESWL) periods between the groups. During the early period, serum and urine creatinine levels and urine kidney injury molecule-1 (KIM-1) levels and the KIM-1/creatinine ratio increased in rats treated with ESWL compared to the control group. Furthermore, increased tissue inflammation, ductal dilatation and hemorrhage, and glomerular, tubular, and interstitial damage with increased NE staining were also detected in the ESWL treatment group. During the late phase, although urine KIM-1 levels remained stable at high levels, other parameters showed significant improvements. On the other hand, the administration of sivelestat 50 mg/kg decreased serum creatinine and urine KIM-1 and KIM-1/creatinine levels significantly in rats treated with ESWL, during the early and late periods. Significant decreases in tissue inflammation, tubular, and interstitial tissue damage were also observed during the early period. In conclusion, ESWL-related kidney tissue damage occurs primarily during the early period, and NE is involved in this process. On the other hand, the NE inhibitor sivelestat attenuated this ESWL-induced kidney damage.

Retrograde intrarenal surgery for the treatment of renal stones in patients with a solitary kidney: Does access sheath matter?

Background

Treating renal stones in patients with a solitary functioning kidney is challenging. The present study was aimed to assess the competence and safety of retrograde intrarenal surgery (RIRS) for the treatment of renal stones in a solitary kidney.

Methods

Between August of 2017 and August of 2019, 25 ensuing patients with a solitary kidney and renal calculi and who were treated with RIRS were prospectively enlisted in the study. All patients were assessed by non-contrast computed tomography before surgery. Stone-free status was determined if there were no residual fragments. The final stone-free rates (SFRs) were assessed 3 months after the last treatment session by plain X-ray KUB and ultrasonography. Patient demographics, perioperative and postoperative outcomes were prospectively evaluated. Serum creatinine levels and glomerular filtration rate (GFR) pre-procedure and during follow-up were correlated.

Results

Twenty-five patients underwent 26 procedures. The mean patient age was 42.81 ± 12.3 (range 22–67) years. The mean stone size was 18.23 ± 6.27 mm (range 9–25 mm) and the mean operative time was 46.15 ± 15.34 min (range 25–100 min). A ureteral access sheath (UAS) was used in five (19.2%) pre-stented patients. One patient (3.8%) required the second stage RIRS for residual stones. The SFR after the initial and final procedures, the SFR was 84% and 92%, respectively.

The mean serum creatinine levels were significantly reduced post-surgery compared to preoperative levels (1.76 ± 1.21 mg/dL; 1.37 ± 0.60 mg/dL; p value 0.001) while GFR not encounter any significant variation post-surgery (63.04 ± 33.16 ml/min) compared to preoperative rates (61.12 ± 34.76 ml/min, p value 0.502). Minor complications classified as Clavien I or II developed in 5 patients (20%). Clavien IIIb, a major complication, developed in one (4%) patient, which was caused by steinstrasse and necessitated emergency surgical intervention.

Conclusion

Renal stones in a solitary kidney can be managed using RIRS safely and effectively with and without the use of UAS, without compromising renal function.

How to maximize the efficacy of shockwave lithotripsy

Since its introduction in the early 1980s, extracorporeal shockwave lithotripsy (ESWL) has proven to be a minimally invasive and efficient procedure for the management of renal calculi. It is currently one of the most recommended treatments for small- and medium-sized stones (<20 mm) in most guidelines internationally. The recent coronavirus disease 2019 (COVID-19) outbreak could lead to a further increase in ESWL use as it avoids a general anesthetic and its potential complications in patients with COVID-19 infection. Most publications exhibit ESWL stone-free rates (SFRs) of 70%-80%; however, this is often not the case in many centers, with multiple factors affecting the efficacy of the intervention. Various stone and patient factors have been shown to influence the ESWL success. Stone position, density and size, skin-to-stone distance, and body-mass index contribute to SFRs. Modifications in the lithotripter design and revisions in the technique have also improved the SFRs over the years, with slower shock rates, power-ramping protocols, combined real-time ultrasound, and fluoroscopy imaging technology, all enhancing the efficacy. The adjuvant use of pharmacological agents, such as alpha-blockers, potassium citrate, and the emerging microbubble technology, has also been investigated and shown promising results. Arguably, the most significant determinant of the success of ESWL in a particular unit is how the lithotripsy service is set up and monitored. Careful patient selection, dedicated personnel, and post-treatment imaging review are essential for the optimization of ESWL. Through an analysis of the published studies, this review aimed to explore the measures that contribute to an effectual lithotripsy service in depth.

Laparotomy for duodenal obstruction, caused by a renal haematoma after extracorporeal shockwave lithotripsy

Extracorporeal shockwave lithotripsy is a widely used, acceptable and common first line treatment for non-conservatively managed renal and ureteric stone disease. Although considered a relatively safe non invasive treatment for renal and ureteric stones, can carry with it significant associated morbiditiy especially in high risk patients, such as those who are anticoagulated. Renal haematomas are not an uncommon finding after extracorporeal shockwave lithotripsy, however, fewer than 1% of patients presenting with a symptomatic renal haematoma require intervention in the form of urgent embolisation under interventional radiology, or emergency nephrectomy. Rare cases of splenic and hepatic haematomas have been reported and rarer still cases of gastro-intestinal perforation following extracorporeal shockwave lithotripsy. We report a case with a significant renal haematoma needing emergency embolisation of the renal artery, and subsequent development of duodenal obstruction from direct haematoma compression requiring a laparotomy and intended duodenal jejunal bypass.

Level of evidence: 5

Attenuation of the human skull at broadband frequencies by using a carbon nanotube composite photoacoustic transducer

The shockwave generated from a focused carbon nanotube (CNT) composite photoacoustic transducer has a wide frequency band that reaches several MHz in a single pulse. The objective of this study was to measure the transmission characteristics of a shockwave generated by a CNT composite photoacoustic transducer through Asian skulls and compare the results with numerical simulation ones. Three Korean cadaver skulls were used, and five sites were measured for each skull. The average densities and sound speeds of the three skulls were calculated from computed tomography images. The sound pressure after skull penetration was about 11% of the one before skull penetration. High-frequency energy was mostly attenuated. The average attenuation coefficients measured at the five sites of the three skulls were 3.59 ± 0.29, 5.99 ± 1.07, and 3.90 ± 0.86 np/cm/MHz. These values were higher than those previously measured at 270, 836, and 1402 kHz from other groups. The attenuation coefficients simulated by Sim4life were slightly smaller than the experimental values, with similar trends at most sites. The attenuation coefficients varied with measurement sites, skull shape, and thickness. These results may provide important data for future applications of shockwaves in noninvasive neurological treatments.

Clinical use of renal point-of-care ultrasound after extracorporeal shock wave lithotripsy

Background

Extracorporeal shock wave lithotripsy is widely used to treat symptomatic nephrolithiasis. Complications of this procedure can occur and point-of-care ultrasound can help to diagnose and manage some of these cases.

Case presentation

A 61-year-old man was admitted to the hospital with intense right lumbar pain 24 h after being submitted to a extracorporeal shock wave lithotripsy. Bedside ultrasound showed a hyperechoic subcapsular lesion along the right kidney. This finding, along with the clinical examination, suggested the diagnosis of subcapsular renal hematoma. The patient was managed conservatively with clinical and ultrasound reassessments.

Conclusions

This case shows the use of bedside ultrasound to diagnose a subcapsular renal hematoma as a complication of extracorporeal shock wave lithotripsy. However, the sensitivity is low and other image methods can be necessary to make the diagnosis.

Nephrolithiasis in the Obese Patient

PURPOSE OF REVIEW

The link between metabolic syndrome (MetS)/obesity and kidney stone disease (KSD) has gained importance over recent years due to the increasing prevalence and healthcare burden worldwide. This review analyses the literature exploring the link between MetS/obesity and KSD and the impact that obesity has on KSD management.

RECENT FINDINGS

Metabolic syndrome has been shown to increase an individual's risk of developing kidney stone disease, with insulin resistance forming a core component of the pathophysiology. The body habitus of an individual also influences the type of intervention that is most appropriate, with flexible ureteroscopy increasingly being the preferred option in obese patients. It is important for urologists to consider the features of metabolic syndrome to effectively manage episodes of KSD in obese patients. In addition, better quality evidence is required to effectively compare different treatment options in this group of patients.

The lipid peroxidation in patients with nephrolithiasis before and after extracorporeal shock wave lithotripsy

AIM

To evaluate the level of lipid peroxidation in patients with nephrolithiasis before and after extracorporeal shock wave lithotripsy (ESWL).

MATERIALS & METHODS

Isoprostane concentration (8-isoPGF_2α) was measured in urine, and thiobarbituric acid reactive substance production in serum and erythrocytes. In addition, the concentrations of selected compounds (uric acid, glucose and creatinine) were measured in serum.

RESULTS

The patients (before and after ESWL) demonstrated significantly higher levels of two different biomarkers of lipid peroxidation compared with the control group. A correlation was identified between increased amounts of uric acid and biomarkers of lipid peroxidation in patients with nephrolithiasis, both before and after ESWL.

CONCLUSION

Uric acid may be associated with lipid peroxidation in patients with nephrolithiasis.

Indications and contraindications for shock wave lithotripsy and how to improve outcomes

For over 35 years shock wave lithotripsy has proven to be an effective, safe and truly minimally invasive option for the treatment of nephrolithiasis. Various technical factors as well as patient selection can impact the success of the procedure. We used published work focusing on outcomes of shock wave lithotripsy, risk of complications, and strategies for improving stone fragmentation to create this review. Multiple patient and technical factors have been found to impact success of treatment. Skin to stone distance, stone density and composition, size and location of the stone within the urinary system all influence stone free rates. A slower rate with a gradual increasing voltage, precise targeting, proper coupling will improve stone fragmentation and decrease risk of complications. The selection of appropriate patients through a shared decision making process and attention to the technical factors that improve stone free rates is key to providing an effective treatment and patient satisfaction.

Evaluation and physiopathology of minor transient shock wave lithotripsy - induced renal injury based on urinary biomarkers levels

Introduction

Extracorporeal shock wave lithotripsy (ESWL) is one of the most useful methods available for the treatment of urolithiasis. However, despite its significant benefits, adverse effects can occur. Oxidative stress mediated by ischemia-reperfusion might contribute to kidney injury after ESWL. Moreover, an acute kidney injury (AKI) may develop. AKI is typically diagnosed by measuring serum creatinine level, yet serum creatinine does not allow for early detection of sub-clinical AKI. The latest report has investigated multiple ways to determine ESWL - induced renal damage through the evaluation of various urine biomarkers of renal injury.

Materials and methods

The Medline and Web of Science databases were searched without a time limit in November 2017 using the terms 'ESWL' in conjunction with 'kidney failure', 'kidney damage', 'renal injury' and 'inflammation markers', 'biomarkers'. Boolean operators (NOT, AND, OR) were also used in succession to narrow and broaden the search. In this review, we described all the up-to-date reported urine markers of ESWL-induced renal damage.

Results

In recent years, several studies demonstrated evaluation of ESWL - induced renal injury based on urinary biomarkers levels and its utility in clinical practice. They have a beneficial role in the early detection of AKI, as well as in observation of a transition of this acute illness into chronic kidney disease.

Conclusions

Different markers have been evaluated in the urine before and after the ESWL treatment, but their number is still limited and results remain inconclusive. Further investigations are mandatory.

How can and should we optimize extracorporeal shockwave lithotripsy?

It is well recognized that the popularity of extracorporeal shock wave lithotripsy (SWL), despite its non-invasive character, has decreased during recent years. This is partly explained by the technological achievements in endoscopy and urologists’ enthusiasm for such procedures. Another explanation is that many urologists have been insufficiently successful with SWL. The latter effect might to some extent be a result of the performance of the lithotripter used, but in too many cases, it is evident that the principles of how shock wave lithotripsy should be carried out are poorly applied. The purpose of this article is to emphasize some important aspects on how SWL best should be used. Based on decades of experience, it stands to reason that success with SWL does not come automatically and attention has to be paid to all details of this technique.

Shockwave lithotripsy: techniques for improving outcomes

OBJECTIVES

Shock wave lithotripsy (SWL) remains the only effective truly non-invasive treatment for nephrolithiasis. While single-treatment success rates may not equal those of ureteroscopy and percutaneous nephrolithotomy, it has an important role to play in the management of stones. In this paper, we outline the latest evidence-based recommendations for maximizing SWL outcomes, while minimizing complications.

MATERIALS AND METHODS

A comprehensive review of the current literature was performed regarding maximizing SWL outcomes.

RESULTS

Several different considerations need to be made regarding patient selection with respect to body habitus, body mass index, anatomical location and underlying urologic abnormalities. Stone composition and stone density (Hounsfield Units) are important prognostic variables. Patient positioning is critical to allow for adequate stone localization with either fluoroscopy or ultrasound. Coupling should be optimized with a low viscosity gel applied to the therapy head first and patient movement should be limited. SWL energy should be increased slowly and shockwave rates of 60 or 90 Hz should be used. Medical expulsive therapy with alpha-blockers after SWL treatment has shown benefit, particularly with stones greater than 10 mm.

CONCLUSION

While single-treatment success rates may not equal those of ureteroscopy or percutaneous nephrolithotomy, with proper patient selection, optimization of SWL technique, and use of adjunctive treatment after SWL, success rates can be maximized while further reducing the already low rate of serious complications. SWL remains an excellent treatment option for calculi even in 2017.

Hospital admission for treatment of complications after extracorporeal shock wave lithotripsy for renal stones: a study of risk factors

The objective of this study was to determine risk factors of hospital admission for treatment of complications after extracorporeal shock wave lithotripsy (SWL). The electronic files and images of all patients who underwent SWL for treatment of renal stones between January 2011 and December 2015 were retrospectively reviewed. All patients underwent SWL with the same electromagnetic lithotripter (Dornier Lithotripot S). The data of those who needed hospital admission for treatment of complications within 30 days after SWL were compared with patients who did not require hospital admission. Compared data included patients' demographics (age, gender, BMI, ASA score, and pre-SWL stenting), renal characters (side, hydronephrosis, and solitary kidney), and stone characters (site, length, density, and previous treatment). Univariate and multivariate statistical analyses were used to identify risk factors. The study included 1179 patients. Complications that required hospital admission were observed in 108 patients (9.2%). They included obstructing steinstrasse in 91 (7.7%), peri-renal hematoma in 3 (0.25%), and fever (>38.0 °C) in 14 (1.2%). Independent risk factors on multivariate analysis were solitary kidney (OR 2.855, P = 0.017), pre-SWL stenting (RR 2.03, P = 0.044), ASA II (OR 1.965, P = 0.007), hydronephrosis (RR 1.639, P = 0.024), and stone length (RR 1.083, P < 0.001). Patients with medical co-morbidities, pre-SWL ureteral stents, large stones and those with obstructed and/or solitary renal unit are more liable to post-SWL complications that need hospital admission. The probability of hospital admission has to be explained to patients with these risk factors.

Perirenal Hematoma After Ureteroscopy: A Systematic Review

INTRODUCTION

With the broadening indications of ureteroscopy (URS) for complex stones and high-risk patients, more URS is being performed and hence there is an increasing risk of major potentially life-threatening complications. We wanted to define the incidence, predisposing factors, management, and long-term sequelae for post-URS perirenal hematoma (PRH).

MATERIAL AND METHODS

We conducted a systematic review of literature according to Cochrane and preferred reporting items for systematic reviews and meta-analysis guidelines for all studies reporting on post-URS PRH from 1980 to September 2016. A literature search was conducted through PubMed, EMBASE, CINAHL, and Cochrane Library for all English language articles.

RESULTS

Based on a literature search of 210 articles, seven studies (8929 patients) met the inclusion criteria with an incidence of post-URS PRH reported as 0.45% (40 patients, range: 0.15%-8.9% per study) with a mean age of 53 years and a mean stone size of 1.7 cm. The predisposing factors were moderate-severe hydronephrosis, thin renal cortex, prolonged operative duration, hypertension, and preoperative urinary tract infection (UTI). The management strategy varied from conservative management with blood transfusion and antibiotics (n = 22, 55%) to percutaneous drainage (n = 11, 27.5%). Surgical intervention was needed in seven (17.5%) patients. Two of these were emergency angiography of which one proceeded to open nephrectomy. Open surgery with clot removal was done in three patients, nephrostomy for severe hydronephrosis in one patient, and surgery to correct malpositioned stent in one patient. There was one mortality reported, wherein a patient who had postangiography nephrectomy died of multiple organ failure after the intervention.

CONCLUSION

URS related PRH is a rare, but potentially life threatening complication with a small risk of renal loss. Although most cases may be managed conservatively, incidence of PRH can be minimized by control of blood pressure, treatment of preoperative UTI, and reduction in intrarenal pressures and operative time duration.

Successful evacuation of large perirenal hematoma after extracorporeal shock wave lithotripsy (ESWL) - step 1 of the IDEAL recommendations of surgical innovation

Larger perirenal hematomas after extracorporeal shock wave lithotripsy (ESWL) are sometimes related to the loss of renal function due to compression of the normal renal tissue. After computed tomography-guided drainage and locally applied urokinase, the hematoma was fractionally evacuated. This procedure is a save and fast way to recover normal renal function.

A Prospective Randomized Study Comparing the Effect of Different Kidney Protection Treatment Protocols on Acute Renal Injury After Extracorporeal Shockwave Lithotripsy

OBJECTIVES

To perform a prospective study to evaluate the renal protective effects of ramping protocol and pause protocol for extracorporeal shockwave lithotripsy (SWL) in human subjects.

PATIENTS AND METHODS

Three hundred twenty patients with solitary renal stone <15 mm were randomized to receive one of four protocols: (1) 80% power from beginning until the end of treatment; (2) the first 100 shockwaves (SWs) at 40% power, and then 80% power until the end of treatment; (3) the first 100 shocks at 40% power, followed by a 3-minute pause, and then further SWs at 80% power until the end of treatment; and (4) the first 100 shocks at 80% power, followed by a 3-minute pause, and then further SWs at 80% power until the end of treatment. The primary endpoint was the incidence of renal hematoma assessed by imaging on day 2. Spot urine samples were also collected before and after treatment for acute renal injury marker measurement.

RESULTS

The baseline information and treatment parameters of the four groups were comparable. The overall incidence of hematoma formation was 7.69% (24 patients). The number of patients developing hematoma in the four groups was 8 (10.26%), 7 (8.97%), 6 (7.59%), and 3 (3.90%), respectively, and the incidence of hematoma among the four groups was not significantly different. Only patient's body mass index and mean blood pressure during treatment were predictors for hematoma formation. There was also no significant difference in changes in the levels of all markers and complication and hospitalization rates between the four groups.

CONCLUSION

Comprehensive assessment of clinical parameters, imaging results, and urinary markers showed no obvious improvement in post-SWL renal insult by either protocol.

Autophagy activation protects shock wave induced renal tubular epithelial cell apoptosis may through modulation of Akt/ GSK-3β pathway

Purpose: Extracorporeal shock wave lithotripsy (ESWL) is well documented to exert destructive effect to renal cells and its mechanism is not clear. Autophagy is one of cell basic response for stressful conditions and it is important to determine cell's fate. The aim of this study is to elucidate the role of autophagy in the process of shock wave-induced renal cells injury.

Methods: NRK-52E cell, a rat renal tubular epithelial cell, was exposed to shock wave at the voltage of 14KV. GFP-LC3 puncta was used to monitor Autophagy flux in the process of shock wave injury. Autophagic relative proteins, such as light chain 3 (LC3), beclin-1 and p62, were also examined. Cell variability and apoptosis were detected when inhibition autophagy with 3-methyladenine (3MA) or stimulating its activity with rapamycin during the process of shock wave injury. The role of Akt/ GSK-3β and its connection with autophagy in the process of shock wave injury were also investigated.

Results: Shock wave was confirmed to activate autophagy in renal cells, which was manifested in LC3-II turnover, beclin-1 induction and degradation of p62. Inhibition autophagy enhanced cell damage or apoptosis, whereas its stimulating was able to exert protection from shock wave injury. Akt/ GSK-3β, a cell-survival signaling pathway, can also be activated during the process. And its activation could be suppressed by blockade autophagy.

Conclusion: Autophagy is a self-protective response for renal cells from shock wave injury. The cyto-protection of autophagy may be connected with modulation Akt/ GSK-3β pathway.

A low or high BMI is a risk factor for renal hematoma after extracorporeal shock wave lithotripsy for kidney stones

The purpose of this study was to evaluate risk factors for renal hematoma after extracorporeal shock wave lithotripsy (SWL) for kidney stones in a matched case-control analysis of a subgroup of patients recruited from a prospective randomized cohort. Between 06/2010 and 03/2013, 418 patients underwent SWL with the MODULITH^®-SLX-F2-lithotripter for kidney stones. In 39/418 patients (9 %), ultrasound at post-treatment day 1 revealed renal hematomas. For 37 of these patients, a matched group without hematoma could be selected according to the following matching criteria: age, gender, number and energy of shock waves, stone burden and localization. Risk factors for renal hematoma after SWL were compared between the two groups. The rates of diabetes, stopped anticoagulant/antiplatelet medications and arterial hypertension were not different between the two groups (p > 0.2). The skin-kidney distance was virtually the same in both groups (p = 0.5). In the hematoma group, significantly more patients had a high (>30: n = 16) as well as a low (<21.5: n = 4) BMI when compared to the control group (n = 4; n = 0; p < 0.001). Importantly, all patients with BMI <21.5 developed renal hematomas after SWL. Patients with a high (>30) or low (<21.5) BMI had a higher risk for renal damage after SWL. Therefore, alternative endoscopic treatment options should be considered in these patients.

Safety and feasibility of day case ureteroscopy and laser lithotripsy (URSL) in patients with a solitary kidney

Introduction

The management of nephrolithiasis in patients with a solitary kidney poses a treatment challenge. The study aimed to evaluate the outcomes of ureteroscopy and laser stone fragmentation (URSL) for renal stones in these patients treated in our university teaching hospital.

Material and methods

Between July 2012 and December 2014, seventeen cases of URSL for stones in a solitary kidney were reviewed. Patient demographics, stone dimensions, perioperative and post-operative outcomes were recorded in a prospectively maintained database. Serum creatinine levels pre-procedure and at follow-up were also compared.

Results

Seventeen cases of URSL were conducted with a mean age of 52.9 ±19.9 years. 8 of the 17 (47%) patients had stones in multiple locations and 13 (76%) were in the lower pole. The mean ± SD stone size and BMI were 13.0 ±8.9 mm and 31.6 ±5.8 kg/m², respectively. The stone free rate (SFR) was 82.5%. Fourteen (82.5%) patients were discharged the same day and 16 cases (94%) were discharged within 24 hours. For patients with deranged pre-operative serum creatinine, the mean serum creatinine level improved from 131.2 ±68.3 µmol/L pre-URSL to 106.5 ±36.7 µmol/L at follow-up. There was one Clavien grade II complication with a patient requiring additional antibiotics for post-operative urinary tract infection. There were no other major or minor complications.

Conclusions

Day case ureteroscopy for stone disease in a solitary kidney is safe and feasible with a low complication rate and an overall improvement in renal function.

Retrograde intrarenal surgery for urinary stone disease in patients with solitary kidney: A retrospective analysis of the efficacy and safety

OBJECTIVES

To compare outcomes of retrograde intrarenal surgery for urolithiasis between patients with solitary kidneys and patients who have single-side urolithiasis with bilateral kidneys.

METHODS

We retrospectively analyzed outcomes of retrograde intrarenal surgery in solitary kidney patients (group A) carried out during 2007-2014, and in patients with bilateral kidneys with comparable stone burdens (group B). Stone-free status was defined as no residual fragment on computed tomography 1 month later.

RESULTS

There were 19 patients in group A (mean age 62.5 ± 18.4 years, range 14-76 years). The mean stone diameter and burden were 6.0 mm (range 3-24 mm) and 10.42 ± 6.92 mm, respectively. The stone-free rate was 94.7%, and no repeat procedure was required. The glomerular filtration rate tended to rise post-surgery (postoperative day 1: 48.67 ± 15.92 mL/min, 100.2%, P = 0.940; postoperative month 1: 51.32 ± 16.90 mL/min, 105.7%, P = 0.101) compared with preoperative rates. The stone-free rate and surgery time were not significantly different between the two groups, although post-surgical hospitalization time was longer for group A (4.05 vs 3.08 days, P = 0.037). The change in glomerular filtration rate was not significantly different between groups A and B (postoperative day 1: +0.101 vs +0.547 mL/min, respectively, P = 0.857; postoperative month 1: +2.749 vs 3.161 mL/min, respectively, P = 0.882). No significant difference was found in terms of complication rate.

CONCLUSIONS

Retrograde intrarenal surgery in solitary kidney patients is as safe and effective as in bilateral kidney patients.

Arguments for choosing extracorporeal shockwave lithotripsy for removal of urinary tract stones

At a time when there is an almost unlimited enthusiasm and preference among urologists for endoscopic stone removal, we have found it essential to meet some of the frequently presented arguments on why extracorporeal shockwave lithotripsy (SWL) should not be used. We have based our considerations in this brief article on our 30-35 years' experience with the non-invasive or least invasive technique that SWL represents. Stone disintegration, requirement of repeated treatment sessions, the concern of residual fragments, complications and economic aspects are some points that are discussed.

Does Stepwise Voltage Ramping Protect the Kidney from Injury During Extracorporeal Shockwave Lithotripsy? Results of a Prospective Randomized Trial

BACKGROUND

Renal damage is more frequent with new-generation lithotripters. However, animal studies suggest that voltage ramping minimizes the risk of complications following extracorporeal shock wave lithotripsy (SWL). In the clinical setting, the optimal voltage strategy remains unclear.

OBJECTIVE

To evaluate whether stepwise voltage ramping can protect the kidney from damage during SWL.

DESIGN, SETTING, AND PARTICIPANTS

A total of 418 patients with solitary or multiple unilateral kidney stones were randomized to receive SWL using a Modulith SLX-F2 lithotripter with either stepwise voltage ramping (n=213) or a fixed maximal voltage (n=205).

INTERVENTION

SWL.

OUTCOMES MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was sonographic evidence of renal hematomas. Secondary outcomes included levels of urinary markers of renal damage, stone disintegration, stone-free rate, and rates of secondary interventions within 3 mo of SWL. Descriptive statistics were used to compare clinical outcomes between the two groups. A logistic regression model was generated to assess predictors of hematomas.

RESULTS AND LIMITATIONS

Significantly fewer hematomas occurred in the ramping group(12/213, 5.6%) than in the fixed group (27/205, 13%; p=0.008). There was some evidence that the fixed group had higher urinary β2-microglobulin levels after SWL compared to the ramping group (p=0.06). Urinary microalbumin levels, stone disintegration, stone-free rate, and rates of secondary interventions did not significantly differ between the groups. The logistic regression model showed a significantly higher risk of renal hematomas in older patients (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.00-1.05; p=0.04). Stepwise voltage ramping was associated with a lower risk of hematomas (OR 0.39, 95% CI 0.19-0.80; p=0.01). The study was limited by the use of ultrasound to detect hematomas.

CONCLUSIONS

In this prospective randomized study, stepwise voltage ramping during SWL was associated with a lower risk of renal damage compared to a fixed maximal voltage without compromising treatment effectiveness.

PATIENT SUMMARY

Lithotripsy is a noninvasive technique for urinary stone disintegration using ultrasonic energy. In this study, two voltage strategies are compared. The results show that a progressive increase in voltage during lithotripsy decreases the risk of renal hematomas while maintaining excellent outcomes.

TRIAL REGISTRATION

ISRCTN95762080.

Safety and efficacy of retrograde intrarenal surgery for renal stones in patients with a solitary kidney: a single-center experience

BACKGROUND AND PURPOSE

The management of urolithiasis in patients with a solitary kidney is challenging for endourologists. This study was aimed at evaluating the safety and efficacy of retrograde intrarenal surgery (RIRS) in the treatment of such patients with renal stones.

PATIENTS AND METHODS

Between January 2010 and January 2014, we enrolled 45 patients who had a solitary kidney and underwent RIRS and holmium:yttrium-aluminum-garnet lithotripsy for the management of renal stones. We collected data pertaining to the preoperative patient characteristics, stone dimensions, and postoperative outcomes.

RESULTS

Sixty-eight procedures were performed in all. The mean stone diameter was 1.84±0.19 cm (range 0.5-6.0 cm), and the mean operative time, 76.4±40.14 minutes (range 18-190 min). The percentages of patients free of renal stones at the initial and final procedures were 64.44% and 93.33%, respectively. The mean number of procedures needed for the patients with renal stones of diameters ≥20 mm and <20 mm were 1.93 per patient and 1.23 per patient, respectively (P=0.009). Postoperative complications (graded by the Clavien system) were noted in 26.6% of the patients (12/45): Grade I complications, in 20% (9/45); grade II complications, in 4.4% (2/45); and grade III complication, in 2.2% (1/45). The grade III complication was anuria because of Steinstrasse, which necessitated emergency surgery.

CONCLUSIONS

RIRS for the removal of renal stones in patients with a solitary kidney affords a high success rate and low morbidity rate. For patients with large stones, however, a multistaged approach may be needed.