Emergency extracorporeal shockwave lithotripsy as opposed to delayed shockwave lithotripsy for the treatment of acute renal colic due to obstructive ureteral stone: a prospective randomized trial

The efficacy of early extracorporeal shockwave lithotripsy for the treatment of 5 to 10 mm upper ureteral stones: An observational study

This study aimed to determine the effectiveness of extracorporeal shockwave lithotripsy (SWL) performed in the early period (within the first 24 hours). Data of patients who underwent SWL with a diagnosis of unilateral radiopaque 5 to 10 mm upper ureteral stones were retrospectively examined. Patients were divided into 2 groups. Group 1 (early SWL) consisted of patients with SWL performed within 24 hours after the onset of colic pain (<24 hours), while group 2 (deferred SWL) comprised patients with SWL performed 24 hours or more from the onset of pain (≥24 hours). The primary endpoint of the study was planned to determine 1-month SFR in both groups. The secondary endpoint was determined to be the factor affecting SWL success. The mean age of 216 patients (130 men, 86 women) included in this study was 46.5 ± 12.1 years. SFR within 1 month was detected in 175 patients (81%). In the early SWL group, the average number of SWL sessions was fewer (1.26 vs 1.83 P = .026) and the time to the stone-free state was shorter (11 vs 15.4 days P = .044). SFR within 1 month was higher in the early SWL group (85.5% vs 71.8% P = .036). In multivariate analysis, stone size, Hounsfield Units, and early SWL were predictive factors for SWL success. Performing SWL within the first 24 hours is highly effective in patients with symptomatic 5 to 10 mm upper ureteral stones.

Management of urinary stones: state of the art and future perspectives by experts in stone disease

AIM

To present state of the art on the management of urinary stones from a panel of globally recognized urolithiasis experts who met during the Experts in Stone Disease Congress in Valencia in January 2024. Options of treatment: The surgical treatment modalities of renal and ureteral stones are well defined by the guidelines of international societies, although for some index cases more alternative options are possible. For 1.5 cm renal stones, both m-PCNL and RIRS have proven to be valid treatment alternatives with comparable stone-free rates. The m-PCNL has proven to be more cost effective and requires a shorter operative time, while the RIRS has demonstrated lower morbidity in terms of blood loss and shorter recovery times. SWL has proven to be less effective at least for lower calyceal stones but has the highest safety profile. For a 6mm obstructing stone of the pelviureteric junction (PUJ) stone, SWL should be the first choice for a stone less than 1 cm, due to less invasiveness and lower risk of complications although it has a lower stone free-rate. RIRS has advantages in certain conditions such as anticoagulant treatment, obesity, or body deformity. Technical issues of the surgical procedures for stone removal: In patients receiving antithrombotic therapy, SWL, PCN and open surgery are at elevated risk of hemorrhage or perinephric hematoma. URS, is associated with less morbidity in these cases. An individualized combined evaluation of risks of bleeding and thromboembolism should determine the perioperative thromboprophylactic strategy. Pre-interventional urine culture and antibiotic therapy are mandatory although UTI treatment is becoming more challenging due to increasing resistance to routinely applied antibiotics. The use of an intrarenal urine culture and stone culture is recommended to adapt antibiotic therapy in case of postoperative infectious complications. Measurements of temperature and pressure during RIRS are vital for ensuring patient safety and optimizing surgical outcomes although techniques of measurements and methods for data analysis are still to be refined. Ureteral stents were improved by the development of new biomaterials, new coatings, and new stent designs. Topics of current research are the development of drug eluting and bioresorbable stents. Complications of endoscopic treatment: PCNL is considered the most invasive surgical option. Fever and sepsis were observed in 11 and 0.5% and need for transfusion and embolization for bleeding in 7 and 0.4%. Major complications, as colonic, splenic, liver, gall bladder and bowel injuries are quite rare but are associated with significant morbidity. Ureteroscopy causes less complications, although some of them can be severe. They depend on high pressure in the urinary tract (sepsis or renal bleeding) or application of excessive force to the urinary tract (ureteral avulsion or stricture). Diagnostic work up:  Genetic testing consents the diagnosis of monogenetic conditions causing stones. It should be carried out in children and in selected adults. In adults, monogenetic diseases can be diagnosed by systematic genetic testing in no more than 4%, when cystinuria, APRT deficiency, and xanthinuria are excluded. A reliable stone analysis by infrared spectroscopy or X-ray diffraction is mandatory and should be associated to examination of the stone under a stereomicroscope. The analysis of digital images of stones by deep convolutional neural networks in dry laboratory or during endoscopic examination could allow the classification of stones based on their color and texture. Scanning electron microscopy (SEM) in association with energy dispersive spectrometry (EDS) is another fundamental research tool for the study of kidney stones. The combination of metagenomic analysis using Next Generation Sequencing (NGS) techniques and the enhanced quantitative urine culture (EQUC) protocol can be used to evaluate the urobiome of renal stone formers. Twenty-four hour urine analysis has a place during patient evaluation together with repeated measurements of urinary pH with a digital pH meter. Urinary supersaturation is the most comprehensive physicochemical risk factor employed in urolithiasis research. Urinary macromolecules can act as both promoters or inhibitors of stone formation depending on the chemical composition of urine in which they are operating. At the moment, there are no clinical applications of macromolecules in stone management or prophylaxis. Patients should be evaluated for the association with systemic pathologies.

PROPHYLAXIS

Personalized medicine and public health interventions are complementary to prevent stone recurrence. Personalized medicine addresses a small part of stone patients with a high risk of recurrence and systemic complications requiring specific dietary and pharmacological treatment to prevent stone recurrence and complications of associated systemic diseases. The more numerous subjects who form one or a few stones during their entire lifespan should be treated by modifications of diet and lifestyle. Primary prevention by public health interventions is advisable to reduce prevalence of stones in the general population. Renal stone formers at "high-risk" for recurrence need early diagnosis to start specific treatment. Stone analysis allows the identification of most "high-risk" patients forming non-calcium stones: infection stones (struvite), uric acid and urates, cystine and other rare stones (dihydroxyadenine, xanthine). Patients at "high-risk" forming calcium stones require a more difficult diagnosis by clinical and laboratory evaluation. Particularly, patients with cystinuria and primary hyperoxaluria should be actively searched.

FUTURE RESEARCH

Application of Artificial Intelligence are promising for automated identification of ureteral stones on CT imaging, prediction of stone composition and 24-hour urinary risk factors by demographics and clinical parameters, assessment of stone composition by evaluation of endoscopic images and prediction of outcomes of stone treatments. The synergy between urologists, nephrologists, and scientists in basic kidney stone research will enhance the depth and breadth of investigations, leading to a more comprehensive understanding of kidney stone formation.

2022 Recommendations of the AFU Lithiasis Committee: Management of symptomatic urinary stones

The acute situation, caused by an obstructive stone, is defined by a renal colic that may be uncomplicated, complicated, or at risk in specific conditions. Its management may be medical or require interventional treatment by extracorporeal shockwave lithotripsy, endoscopic removal, or ureteroscopy. METHODOLOGY: These recommendations were developed using two methods, the Clinical Practice Recommendations (CPR) and the ADAPTE method, in function of whether the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis) [EAU Guidelines on urolithiasis. 2022] and whether they could be adapted to the French context.

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

Extracorporeal shock wave lithotripsy (ESWL) is a minimally invasive technique for the fragmentation of urinary tract stones using shock waves under fluoroscopic and/or ultrasound guidance. ESWL results depend on the indication (stone size/composition, clinical context) and also on how it is performed. The stone structure, nature and density (Hounsfield units; evaluated by CT without contrast agent) influence the fragmentation achieved by ESWL. The upper size limit of kidney stones has been lowered to 15mm (1.68cm3) due to the increased risk of steinstrasse with larger sizes and the potential need of anesthesia and ureteral stenting. Conversely, the development of endourological technologies allows a finer stone fragmentation and/or better elimination, thus reducing the risk of steinstrasse and decreasing the potential number of sessions or additional interventions. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendations method (CPR) and the ADAPTE method, depending on whether the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis [EAU 2022]) and their adaptability to the French context.

Effects of Delayed Surgical Intervention Following Emergency Department Presentation on Stone Surgery Complexity

Introduction and Objective: Prior literature had demonstrated increased stone burden and higher rates of staged surgery in individuals of lower socioeconomic status (SES). Low SES individuals are more likely to experience delays in definitive stone surgery after initial presentation to the emergency department (ED) for kidney stones. This study aims to investigate the relationship between delays in definitive kidney stone surgery and the subsequent need for percutaneous nephrolithotomy (PNL) and/or staged surgical procedures using a statewide data set. Methods: This retrospective cohort study gathered longitudinal data from 2009 to 2018 using the California Department of Health Care Access and Information data set. Patient demographic characteristics, comorbidities, diagnosis/procedure codes, and distance were analyzed. Complex stone surgery was defined as initial PNL and/or undergoing more than one procedure within 365 days of initial intervention. Results: A total of 1,816,093 billing encounters from 947,798 patients were screened, resulting in 44,835 patients with ED visits for kidney stones followed by a urologic stone procedure. Multivariable analysis revealed that relative to patients who underwent surgery within 1 month of initial ED visit for stone disease, patients were at increased odds of undergoing complex surgery if waiting ≥6 months (odds ratio [OR] 1.18, p = 0.022), ≥1 year (OR 1.29, p < 0.001), and ≥3 years (OR 1.43, p < 0.001). Conclusions: Delays in definitive stone surgery after initial ED encounter for stone disease were associated with increased likelihood of undergoing a complex stone treatment.

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.

Efficacy of emergency extracorporeal shock wave lithotripsy in the treatment of ureteral stones: a meta-analysis

OBJECTIVE

To compare the clinical efficiency and safety of emergency extracorporeal shock wave lithotripsy (eESWL) and delayed extracorporeal shock wave lithotripsy (dESWL) in the treatment of ureteral stones.

METHODS

Cochrane Library, PubMed, Google Scholar, and Web of Science were searched from January 1, 1992 to September 30, 2022, and all comparative studies involving eESWL and dESWL for ureteral calculi were included. Statistical analysis was performed using Review Manager 5.3 software. Funnel plot was used to evaluated publication bias.

RESULTS

A total of 9 articles involving 976 patients diagnosed with ureteral stones were included. The results showed that the stone-free rate (SFR) after four weeks was significantly higher in the eESWL group than in the dESWL group [relative risk (RR) = 1.22, 95% confidence interval (CI): 1.13-1.32, P < 0.01]. In subgroup analysis of different stone locations, proximal ureteral calculi [RR = 1.25, 95% CI: 1.14-1.38, P < 0.01] and mid-to-distal ureteral calculi [RR = 1.18, 95% CI: 1.03-1.34, P < 0.05] all showed a higher SFR in the eESWL group. eESWL significantly shortened the stone-free time(SFT) [mean difference (MD) = -5.75, 95% CI: -9.33 to -2.17, P < 0.01]. In addition, eESWL significantly reduced auxiliary procedures [RR = 0.53, 95% CI: 0.40-0.70, P < 0.01]. No significant difference in complications was found between the two groups [RR = 0.90, 95% CI: 0.69-1.16, P > 0.05].

CONCLUSION

eESWL can significantly improve SFR, shorten SFT, and reduce auxiliary procedures.

Development and validation of a predictive model for treatment outcome after emergency extracorporeal shockwave lithotripsy in patients with symptomatic ureteral stones during the COVID-19 pandemic: in a large prospective cohort

The predictors of treatment outcome after emergency extracorporeal shockwave lithotripsy (SWL) are not well characterized. Therefore, based on a large prospective cohort, we aimed to develop and validate a nomogram for predicting treatment outcome after emergency SWL in patients with symptomatic ureteral stones. The development cohort included 358 patients with symptomatic ureteral stones who underwent emergency SWL between June 2020 and August 2021 in our hospital. One hundred and twenty-nine patients with symptomatic ureteral stones participated in the validation cohort from September 2021 to April 2022. The data were prospectively recorded. The backward stepwise selection was applied using the likelihood ratio test with Akaike's information criterion as the stopping rule. The efficacy of this predictive model was assessed concerning its clinical usefulness, calibration, and discrimination. Finally, 15.6% (56/358) of patients in the development cohort and 14.0% (18/129) of those in the validation cohort suffered from stone-free failure after emergency SWL. We identified four predictors for stone-free failure: stone size, stone density, skin to stone distance (SSD), and degree of hydronephrosis. This model showed good discrimination with an area under the receiver operating characteristic (AUROC) curves of 0.935 (0.899-0.971) and good calibration (P = 0.059). The decision curve analysis showed that the model was clinically valuable. In this large prospective cohort, we found that stone size, stone density, SSD, and degree of hydronephrosis were predictors of treatment outcome after emergency SWL. This nomogram will be helpful in preoperative risk stratification to provide individualized treatment recommendations for each patient. Furthermore, early identification and appropriate management of patients may increase the success rate of emergency SWL during the COVID-19 pandemic.

Predictors of successful emergency shock wave lithotripsy for acute renal colic

The role of emergency shockwave lithotripsy (SWL) in persistent pain control in patients with ureteral stones is not well established. The aim of this study is to evaluate efficacy as well as the predicting variables for successful early SWL patients with symptomatic ureteral stones. Eighty-six patients with a persistent renal colic secondary to single ureteral stone (6–12 mm) were prospectively enrolled in this study. SWL was performed within 24 h of the onset of flank pain. Pain control and stone-free rate after emergency SWL session were 58.1% and 44.2%, respectively. Seven patients required post-SWL ureteroscopy and ureteral stent placement for uncontrolled pain. The overall 3-month stone-free rate after SWL monotherapy was 83.7%. On multivariate analysis, predictors for pain relief after emergency SWL were lower Hounsfield (HU) stone density, mild hydronephrosis (HN) at presentation and presentation during the first colic episode. Lower HU stone density was the single predictor of successful stone clearance after single emergency SWL session on multivariate analysis. In conclusion, early SWL is feasible and effective in management of ureteral stones presented by renal colic with low HU.

Shockwave lithotripsy compared with ureteroscopic stone treatment for adults with ureteric stones: the TISU non-inferiority RCT

BACKGROUND

Urinary stone disease affects 2-3% of the general population. Ureteric stones are associated with severe pain and can have a significant impact on a patient's quality of life. Most ureteric stones are expected to pass spontaneously with supportive care; however, between one-fifth and one-third of patients require an active intervention. The two standard interventions are shockwave lithotripsy and ureteroscopic stone treatment. Both treatments are effective, but they differ in terms of invasiveness, anaesthetic requirement, treatment setting, number of procedures, complications, patient-reported outcomes and cost. There is uncertainty around which is the more clinically effective and cost-effective treatment.

OBJECTIVES

To determine if shockwave lithotripsy is clinically effective and cost-effective compared with ureteroscopic stone treatment in adults with ureteric stones who are judged to require active intervention.

DESIGN

A pragmatic, multicentre, non-inferiority, randomised controlled trial of shockwave lithotripsy as a first-line treatment option compared with primary ureteroscopic stone treatment for ureteric stones.

SETTING

Urology departments in 25 NHS hospitals in the UK.

PARTICIPANTS

Adults aged ≥ 16 years presenting with a single ureteric stone in any segment of the ureter, confirmed by computerised tomography, who were able to undergo either shockwave lithotripsy or ureteroscopic stone treatment and to complete trial procedures.

INTERVENTION

Eligible participants were randomised 1 : 1 to shockwave lithotripsy (up to two sessions) or ureteroscopic stone treatment.

MAIN OUTCOME MEASURES

The primary clinical outcome measure was resolution of the stone episode (stone clearance), which was operationally defined as 'no further intervention required to facilitate stone clearance' up to 6 months from randomisation. This was determined from 8-week and 6-month case report forms and any additional hospital visit case report form that was completed by research staff. The primary economic outcome measure was the incremental cost per quality-adjusted life-year gained at 6 months from randomisation. We estimated costs from NHS resources and calculated quality-adjusted life-years from participant completion of the EuroQol-5 Dimensions, three-level version, at baseline, pre intervention, 1 week post intervention and 8 weeks and 6 months post randomisation.

RESULTS

In the shockwave lithotripsy arm, 67 out of 302 (22.2%) participants needed further treatment. In the ureteroscopic stone treatment arm, 31 out of 302 (10.3%) participants needed further treatment. The absolute risk difference was 11.4% (95% confidence interval 5.0% to 17.8%); the upper bound of the 95% confidence interval ruled out the prespecified margin of non-inferiority (which was 20%). The mean quality-adjusted life-year difference (shockwave lithotripsy vs. ureteroscopic stone treatment) was -0.021 (95% confidence interval 0.033 to -0.010) and the mean cost difference was -£809 (95% confidence interval -£1061 to -£551). The probability that shockwave lithotripsy is cost-effective is 79% at a threshold of society's willingness to pay for a quality-adjusted life-year of £30,000. The CEAC is derived from the joint distribution of incremental costs and incremental effects. Most of the results fall in the south-west quadrant of the cost effectiveness plane as SWL always costs less but is less effective.

LIMITATIONS

A limitation of the trial was low return and completion rates of patient questionnaires. The study was initially powered for 500 patients in each arm; however, the total number of patients recruited was only 307 and 306 patients in the ureteroscopic stone treatment and shockwave lithotripsy arms, respectively.

CONCLUSIONS

Patients receiving shockwave lithotripsy needed more further interventions than those receiving primary ureteroscopic retrieval, although the overall costs for those receiving the shockwave treatment were lower. The absolute risk difference between the two clinical pathways (11.4%) was lower than expected and at a level that is acceptable to clinicians and patients. The shockwave lithotripsy pathway is more cost-effective in an NHS setting, but results in lower quality of life.

FUTURE WORK

(1) The generic health-related quality-of-life tools used in this study do not fully capture the impact of the various treatment pathways on patients. A condition-specific health-related quality-of-life tool should be developed. (2) Reporting of ureteric stone trials would benefit from agreement on a core outcome set that would ensure that future trials are easier to compare.

TRIAL REGISTRATION

This trial is registered as ISRCTN92289221.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 19. See the NIHR Journals Library website for further project information.

Contemporary treatment trends for upper urinary tract stones in a total population analysis in Germany from 2006 to 2019: will shock wave lithotripsy become extinct?

PURPOSE

To describe the change in upper urinary tract stone management in Germany over a 14-year period.

METHODS

Using remote data processing we analyzed the nationwide German billing data from 2006 to 2019. To analyze the clinics' case numbers and regional trends, we used the reimbursement.INFO tool based on standardized quality reports of all German hospitals. To also cover shock wave lithotripsy (SWL) as an outpatient procedure, we analyzed the research database of the Institute for Applied Health Research with a representative anonymous sample of 4 million insured persons.

RESULTS

The number of inpatient interventional therapies for upper tract urolithiasis in Germany increased from 70,099 cases in 2006 to 94,815 cases in 2019 (trend p < 0.0001). In-hospital SWL declined from 41,687 cases in 2006 to 10,724 cases in 2019 (decline of 74%; trend p < 0.0001). The percentage of SWL as an outpatient procedure increased between 2013 and 2018 from 36 to 46% of all performed SWL, while total SWL case numbers declined. Contrarily, the number of ureteroscopies increased from 32,203 cases in 2006 to 78,125 cases in 2019 (increase of 143%; trend p < 0.0001). The number of percutaneous nephrolithotomy also increased from 1673 cases in 2006 to 8937 in 2019 (increase of 434%; trend p < 0.0001).

CONCLUSION

We observed an increase in interventional therapy for upper tract urolithiasis in Germany with a dramatic shift from SWL to endoscopic/percutaneous treatment. These changes may be attributed to enormous technological advances of the endoscopic armamentarium and to reimbursement issues.

The impact of delaying acute kidney stone surgery on outcomes

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Emergency vs elective ureteroscopy for a single ureteric stone

Objective

To compare emergency with elective ureteroscopy (URS) for the treatment of a single ureteric stone.

Patients and methods

The files of adult patients with a single ureteric stone were retrospectively reviewed. Patients with fever or turbid urine on passage of the guidewire beside the stone underwent ureteric stenting or nephrostomy drainage. Patients who underwent URS were included and divided into two groups: the emergency (EM) Group, those who presented with persistent renal colic and underwent emergency URS within 24 h; and the elective (EL) Group, who underwent elective URS after ≥14 days of diagnosis. Patients with ureteric stents were excluded. The technique for URS was the same in both groups. Safety was defined as absence of complications. Efficacy was defined as the stone-free rate after a single URS session.

Results

From March 2015 to September 2018, 179 patients (107 in the EM Group and 72 in the EL Group) were included. There were significantly more hydronephrosis and smaller stones in the EM Group (P = 0.002 and P = 0.001, respectively). Laser disintegration was needed in more patients in the EL Group (83% vs 68%, P = 0.023). Post-URS ureteric stents were inserted in more patients in the EM Group (91% vs 72%, P = 0.001). Complications were comparable for both groups (4.2% for EL and 5.6% for EM, P = 0.665). Stone-free rates were also comparable (93% in the EL Group and 96% in the EM Group, P = 0.336).

Conclusions

Emergency URS can be as safe and effective as elective URS for the treatment of a single ureteric stone if it is performed in patients without fever or turbid urine.

Abbreviations: EL Group: elective group; EM Group: emergency group; KUB: plain abdominal radiograph of the kidneys, ureters and bladder; MET: medical expulsive therapy; NCCT: non-contrast CT; SFR: stone-free rate; SWL: shockwave lithotripsy; URS: ureteroscopy

Urology highlights 2017 to 2018

The final clinical session of the British Association of Urological Surgeons (BAUS) annual meeting is the Updates and Highlights session, where the most important advances in the main urological sub-specialities are summarised and presented by sub-specialist experts representing each BAUS section. The aim of the session is to disseminate knowledge on the latest research, new guidelines and changes to general and specialist clinical practice. This paper covers contemporary urological advances as presented at the Liverpool BAUS meeting in June 2018.

The effects of shock wave lithotripsy and retrograde intrarenal surgery on renal function

Introduction: The aim of this study was to compare the early effects of shock wave lithotripsy (SWL) and retrograde intrarenal surgery (RIRS) on renal function using the cystatin C levels.Material and methods: Serum samples were taken from each of the patients preoperatively, on the first postoperative day, and on the 30th postoperative day in order to evaluate the renal damage. The cystatin C level was determined using a particle-enhanced turbid metric immunoassay with a clinical chemistry analyzer.Results: In the comparison between the preoperative and postoperative cystatin C levels on day 1, there was an increase in the SWL group (p = .001); however, the decrease in the RIRS group was statistically significant (p = .007). There were statistically significant differences in the cystatin C levels on the first postoperative day in both groups (p = .001). In the SWL group, there was a statistically significant increase between the preoperative and the 30th postoperative day cystatin C levels (p = .006), but no differences were found between these levels in the RIRS group or between the two groups (p = .255).Conclusions: RIRS may be the preferred procedure for patients who need more renal function protection when treating renal stones <2 cm.

Extracorporeal shock-wave lithotripsy: is it still valid in the era of robotic endourology? Can it be more efficient?

PURPOSE OF REVIEW

The aim of the article is to evaluate the actual role of extracorporeal shock-wave lithotripsy (ESWL) in the management of urolithiasis based on the new developments of flexible ureterorenoscopy (FURS) and percutaneous nephrolithotomy (PCNL).

RECENT FINDINGS

In Western Europe, there is a significant change of techniques used for treatment of renal stones with an increase of FURS and a decrease of ESWL. The reasons for this include the change of indications, technical improvement of the endourologic armamentarium, including robotic assistance. Mostly relevant is the introduction of digital reusable and single-use flexible ureterorenoscopes, whereas micro-PCNL has been abandoned. Some companies have stopped production of lithotripters and novel ideas to improve the efficacy of shock waves have not been implemented in the actual systems. Promising shock-wave technologies include the use of burst-shock-wave lithotripsy (SWL) or high-frequent ESWL. The main advantage would be the very fast pulverization of the stone as shown in in-vitro models.

SUMMARY

The role of ESWL in the management of urolithiasis is decreasing, whereas FURS is constantly progressing. Quality and safety of intracorporeal shock-wave lithotripsy using holmium:YAG-laser under endoscopic control clearly outweighs the advantages of noninvasive ESWL. To regain ground, new technologies like burst-SWL or high-frequent ESWL have to be implemented in new systems.

Artificial intelligence and neural networks in urology: current clinical applications

INTRODUCTION

As we enter the era of "big data," an increasing amount of complex health-care data will become available. These data are often redundant, "noisy," and characterized by wide variability. In order to offer a precise and transversal view of a clinical scenario the artificial intelligence (AI) with machine learning (ML) algorithms and Artificial neuron networks (ANNs) process were adopted, with a promising wide diffusion in the near future. The present work aims to provide a comprehensive and critical overview of the current and potential applications of AI and ANNs in urology.

EVIDENCE ACQUISITION

A non-systematic review of the literature was performed by screening Medline, PubMed, the Cochrane Database, and Embase to detect pertinent studies regarding the application of AI and ANN in Urology.

EVIDENCE SYNTHESIS

The main application of AI in urology is the field of genitourinary cancers. Focusing on prostate cancer, AI was applied for the prediction of prostate biopsy results. For bladder cancer, the prediction of recurrence-free probability and diagnostic evaluation were analysed with ML algorithms. For kidney and testis cancer, anecdotal experiences were reported for staging and prediction of diseases recurrence. More recently, AI has been applied in non-oncological diseases like stones and functional urology.

CONCLUSIONS

AI technologies are growing their role in health care; but, up to now, their "real-life" implementation remains limited. However, in the near future, the potential of AI-driven era could change the clinical practice in Urology, improving overall patient outcomes.

Factors predictive of shockwave lithotripsy failure for ureteral stones: why we need to hurry

BACKGROUND

The aims of this study are to evaluate the prognostic factors of extracorporeal shockwave lithotripsy in patients with ureteric stones, and to identify which patients might directly benefit of an endoscopic treatment.

METHODS

We performed a prospective study from January 2013 and July 2016 on patients with single ureteric stone and undergoing extracorporeal shockwave lithotripsy (SWL). We divided patients into two groups: first group (success group) included cases resolved with SWL only, and a second group (failure group) including patients with stone not resolved by SWL and requiring an endoscopic treatment. We evaluated age, weight, height, body mass index, stone size, hydronephrosis, laterality, location, days elapsed from onset of symptoms to SWL and stone density when computed tomography was performed. In case of stone fragments >4 mm, the procedure was repeated up to a maximum of three times. SWL was considered as failed if patients had a residual stone of any size after a follow-up of 3 months or if a complication occurred.

RESULTS

274 patients completed follow-up and were enrolled in the study. Mean age was 53.22 years (standard deviation: 13.98). SWL overall success rate was 84.3% (231 patients successfully treated with shockwaves) and failure rate was 15.7% (43 patients underwent auxiliary endoscopic procedure). At the univariate analysis, we observed a statistically significant difference for hydronephrosis (P=0.006), time elapsed from symptoms onset (P=0.013), patients' age (P=0.06) and mean stone density (0.023). In the multivariate logistic regression, patients' age (OR: 1.517), and time elapsed from obstruction to SWL (OR: 3.005) were independent predictive factors for SWL failure. Furthermore, moderate and severe hydronephrosis seemed to be independent predictive factors for SWL failure, presenting an OR of 2.451 and 4.207 respectively. High stone density resulted to be a predictive factor for SWL failure (OR: 2.293 if density was higher than 1100 Hounsfield Units).

CONCLUSIONS

We report a large series of patients undergone primary SWL for ureteric stones. Our data demonstrated the role of hydronephrosis, time elapsed from obstruction onset to treatment and stone density as independent predictive factors of SWL failure.

External validation of Imamura nomogram as a tool to predict preoperatively laser semi-rigid ureterolithotripsy outcomes

BACKGROUND

We aimed to validate Imamura nomogram for prediction of stone free rate in patients undergoing ureterolithotripsy (ULT).

METHODS

From January 2013 to June 2016, patients undergoing laser semi-rigid ULT were prospectively enrolled at our center. All patients were preoperatively assessed with clinical history, blood samples, uranalysis and non-contrast enhanced computed tomography (CT). Treatment efficacy was assessed 1 month later by non-contrast enhanced CT. ROC curve was used to evaluate the performance characteristics of Imamura nomogram.

RESULTS

Overall, we enrolled 275 patients. Median age was 55 years (IQR: 46/64), median length of stone was 9.8 mm (IQR: 7.5/12). Pyuria was detected in 6/275 (2.1%) patients. Stones were located at ureteropelvic junction in 55/275 (19%) patients, proximal ureter in 74/275 (26%) patients, middle and distal ureter in 66/275 (24%) patients and 82/275 (30%) patients, respectively. At 1-month follow-up, 209/275 (76%) patients were stone free. Imamura nomogram presented an AUC of 0.67 (95% CI: 0.580-0.761) for the prediction of stone free rate. At the best cut-off value of 75%, sensitivity was 76%, specificity was 55%, positive predictive value (PPV) was 83% and negative predictive value was 45%.

CONCLUSIONS

We firstly validated Imamura nomogram in a European cohort study. It proved a reasonable accuracy (area under curve: 0.67) and a good PPV (83%). Further studies should confirm our results to support the routine clinical use of Imamura nomogram as a tool to predict ULT outcomes.