International Alliance of Urolithiasis (IAU) guideline on staghorn calculi management.

BACKGROUND: The stone burden based management strategy reported in the guidelines published by different associations is well known for a long time. Staghorn calculi, representing the largest burden and most complex stones, is one of the most challenging cases to practicing urologists in clinical practice. The International Alliance of Urolithiasis (IAU) has released a series of guidelines on the management of urolithiasis. PURPOSE: To develop a series of recommendations for the contemporary management management of staghorn calculi and to provide a clinical framework for urologists treating patients with these complex stones. METHODS: A comprehensive literature search for articles published in English between 01/01/1976 and 31/12/2022 in the PubMed, OVID, Embase and Medline database is performed. A series of recommendations are developed and individually graded following the review of literature and panel discussion. RESULTS: The definition, pathogenesis, pathophysiology, preoperative evaluation, intraoperative treatment strategies and procedural advice, early postoperative management, follow up and prevention of stone recurrence are summarized in the present document. CONCLUSION: A series of recommendations regarding the management of staghorn calculi, along with related commentary and supporting documentation offered in the present guideline is intended to provide a clinical framework for the practicing urologists in the management of staghorn calculi.

Enabling national improvement in quality of care for renal colic.

OBJECTIVES: To report the results of a clinical audit conducted by the British Association of Urological Surgeons (BAUS) of ureteric stone care pathways, with results reported with reference to national quality standards. PATIENTS AND METHODS: The BAUS conducted a clinical audit of all patients presenting as an emergency to 107 hospitals in England during November 2020 with ureteric stones. All patients were followed up until 31 March 2021 and the inpatient and outpatient management received was recorded. RESULTS: Data for 2192 patients across 117 units were submitted. The median (interquartile range [IQR]) number of patients per unit was 16 (9-27); 70% of patients were male and the median (IQR) patient age was 46 (34-59) years. Initial management was conservative treatment for 70% of patients. Overall, primary shockwave lithotripsy was performed in 34% of patients and primary ureteroscopy in 23% of cases when surgical intervention was required to treat the stone. However, 40% of patients in whom active intervention was appropriate underwent placement of a temporizing ureteric stent rather than undergo definitive surgical intervention at the outset. Female patients were less likely to have a computed tomography (CT) scan of the kidneys, ureters and bladder performed within 24 h of presentation (13% vs 7.3% for men [chi-squared P = 0.01]) and to be given correct analgesia (66% vs 73% for men [chi-squared P = 0.03]). Patients aged 60 years or older were also significantly less likely to be offered nonsteroidal anti-inflammatory drug analgesia appropriately. In total, 87% of patients had their calcium measured within the last 2 years and 73% of patients had evidence of being offered stone prevention diet and fluid advice. CONCLUSIONS: The audit demonstrates that the National Institute of Health and Care Excellence Quality Standards are both measurable and achievable. However, there was considerable variation in the delivery of these standards, including with regard to sex and age, highlighting inequalities for patient care across the UK.

Nomogram predicting the probability of spontaneous stone passage in patients presenting with acute ureteric colic.

OBJECTIVES: To develop a nomogram that could predict spontaneous stone passage (SSP) in patients presenting with acute ureteric colic who are suitable for conservative management. SUBJECT/PATIENTS: A 2517 patient dataset was utilised from an international multi-centre cohort study (MIMIC, A Multi-centre Cohort Study Evaluating the role of Inflammatory Markers In Patients Presenting with Acute Ureteric Colic) of patients presenting with acute ureteric colic across 71 secondary care hospitals in the United Kingdom, Ireland, Australia, and New Zealand. Inclusion criteria mandated a non-contrast CT-KUB. METHODS: SSP was defined as the 'absence of the need for intervention'. The model was developed using logistic regression and backwards selection (to achieve lowest AIC) in a subset from 2009-2015 (n=1728) and temporally validated on a subset from 2016-2017 (n=789). RESULTS: Of the 2517 patients, 1874 had SSP (74.5%). Mean age (±[SD]) was 47 (±14.7) years and 1892 were male (75.2%). At the end of the modelling process, gender: male (OR 0.8, 95%CI 0.64-1.01, p=0.07), neutrophil count (OR 1.03, 95%CI 1.00-1.06, p = 0.08), hydronephrosis (OR 0.79, 95%CI 0.59-1.05, p=0.1), hydroureter (OR 1.3, 95%CI 0.97-1.75, p =0.08), stone size >5-7mm (OR 0.2, 95%CI 0.16-0.25, p<0.0001), stone size >7mm (OR 0.11, 95%CI 0.08-0.15, p<0.001), middle ureter stone position (OR 0.59, 95%CI 0.43-0.81, p=0.001), upper ureter stone position (OR 0.31, 95%CI 0.25-0.39, p<0.001) ), medical expulsive therapy use (OR 1.36, 95%CI 1.1 - 1.67, p = 0.001), oral NSAID use (OR 1.3, 95%CI 0.99 - 1.71, p=0.06), and rectal NSAID use (OR1.17, 95%CI 0.9 - 1.53, p=0.24) remained. Concordance-statistic (C-statistic) was 0.77 (95%CI 0.75 - 0.80) and a nomogram was developed based on these. CONCLUSION: The presented nomogram is available to use as an online calculator via www.BURSTurology.com and could allow clinicians and patients to make a more informed decision on pursuing conservative management versus early intervention.

Factors associated with spontaneous stone passage in a contemporary cohort of patients presenting with acute ureteric colic: results from the Multi-centre cohort study evaluating the role of Inflammatory Markers In patients presenting with acute ureteric Colic (MIMIC) study.

OBJECTIVES: To assess the relationship of white blood cell count (WBC) and other routinely collected inflammatory and clinical markers including stone size, stone position, and medical expulsive therapy use (MET), with spontaneous stone passage (SSP) in a large contemporary cohort of patients with acute ureteric colic, as there are conflicting data on the role of WBC and other inflammatory markers in SSP in patients with acute ureteric colic. PATIENTS AND METHODS: Multicentre retrospective cohort study coordinated by the British Urology Researchers in Surgical Training (BURST) Research Collaborative at 71 secondary care hospitals across four countries (UK, Republic of Ireland, Australia, and New Zealand). In all, 4170 patients presented with acute ureteric colic and a computed tomography confirmed single ureteric stone. Our primary outcome measure was SSP, as defined by the absence of need for intervention to assist stone passage (SP). Multivariable mixed effects logistic regression was used to explore the relationship between key patient factors and SSP. RESULTS: In all, 2518 patients were discharged with conservative management and had further follow-up with a SSP rate of 74% (n = 1874/2518). Sepsis after discharge with conservative management was reported in 0.6% (n = 16/2518). On multivariable analysis neither WBC, neutrophils count, nor C-reactive protein (CRP) predicted SSP, with an adjusted odds ratio (OR) of 0.97 (95% confidence interval [CI] 0.91-1.04, P = 0.38), 1.06 (95% CI 0.99-1.13, P = 0.1) and 1.00 (95% CI 0.99-1.00, P = 0.17), respectively. MET also did not predict SSP (adjusted OR 1.11, 95% CI 0.76-1.61). However, stone size and stone position were significant predictors. SSP for stones <5 mm was 89% (95% CI 87-90) compared to 49% (95% CI 44-53) for stones ≥5-7 mm, and 29% (95% CI 23-36) for stones >7 mm. For stones in the upper ureter the SSP rate was 52% (95% CI 48-56), middle ureter was 70% (95% CI 64-76), and lower ureter was 83% (95% CI 81-85). CONCLUSION: In contrast to the previously published literature, we found that in patients with acute ureteric colic who are discharged with initial conservative management neither WBC, neutrophil count, nor CRP, helps determine the likelihood of SSP. We also found no overall benefit from the use of MET. Stone size and position are important predictors and our present findings represent the most comprehensive SP rates for each millimetre increase in stone size from a large contemporary cohort adjusting for key potential confounders. We anticipate that these data will aid clinicians managing patients with acute ureteric colic and help guide management decisions and the need for intervention.

A pilot study to assess the utility of a freely downloadable mobile application simulator for undergraduate clinical skills training: a single-blinded, randomised controlled trial.

BACKGROUND: Medical simulators offer an invaluable educational resource for medical trainees. However, owing to cost and portability restrictions, they have traditionally been limited to simulation centres. With the advent of sophisticated mobile technology, simulators have become cheaper and more accessible. Touch Surgery is one such freely downloadable mobile application simulator (MAS) used by over one million healthcare professionals worldwide. Nevertheless, to date, it has never been formally validated as an adjunct in undergraduate medical education. METHODS: Medical students in the final 3 years of their programme were recruited and randomised to one of three revision interventions: 1) no formal revision resources, 2) traditional revision resources, or 3) MAS. Students completed pre-test questionnaires and were then assessed on their ability to complete an undisclosed male urinary catheterisation scenario. Following a one-hour quarantined revision period, all students repeated the scenario. Both attempts were scored by allocation-blinded examiners against an objective 46-point mark scheme. RESULTS: A total of 27 medical students were randomised (n = 9 per group). Mean scores improved between baseline and post-revision attempts by 8.7% (p = 0.003), 19.8% (p = 0.0001), and 15.9% (p = 0.001) for no resources, traditional resources, and MAS, respectively. However, when comparing mean score improvements between groups there were no significant differences. CONCLUSIONS: Mobile simulators offer an unconventional, yet potentially useful adjunct to enhance undergraduate clinical skills education. Our results indicate that MAS's perform comparably to current gold-standard revision resources; however, they may confer significant advantages in terms of cost-effectiveness and practice flexibility. TRIAL REGISTRATION: Not applicable.

Can Artificial Intelligence Accurately Detect Urinary Stones? A Systematic Review.

Objectives: To perform a systematic review on artificial intelligence (AI) performances to detect urinary stones. Methods: A PROSPERO-registered (CRD473152) systematic search of Scopus, Web of Science, Embase, and PubMed databases was performed to identify original research articles pertaining to AI stone detection or measurement, using search terms ("automatic" OR "machine learning" OR "convolutional neural network" OR "artificial intelligence" OR "detection" AND "stone volume"). Risk-of-bias (RoB) assessment was performed according to the Cochrane RoB tool, the Joanna Briggs Institute Checklist for nonrandomized studies, and the Checklist for Artificial Intelligence in Medical Imaging (CLAIM). Results: Twelve studies were selected for the final review, including three multicenter and nine single-center retrospective studies. Eleven studies completed at least 50% of the CLAIM checkpoints and only one presented a high RoB. All included studies aimed to detect kidney (5/12, 42%), ureter (2/12, 16%), or urinary (5/12, 42%) stones on noncontrast computed tomography (NCCT), but 42% intended to automate measurement. Stone distinction from vascular calcification interested two studies. All studies used AI machine learning network training and internal validation, but a single one provided an external validation. Trained networks achieved stone detection, with sensitivity, specificity, and accuracy rates ranging from 58.7% to 100%, 68.5% to 100%, and 63% to 99.95%, respectively. Detection Dice score ranged from 83% to 97%. A high correlation between manual and automated stone volume (r = 0.95) was noted. Differentiate distal ureteral stones and phleboliths seemed feasible. Conclusions: AI processes can achieve automated urinary stone detection from NCCT. Further studies should provide urinary stone detection coupled with phlebolith distinction and an external validation, and include anatomical abnormalities and urologic foreign bodies (ureteral stent and nephrostomy tubes) cases.

Use of Temporally Validated Machine Learning Models To Predict Outcomes of Percutaneous Nephrolithotomy Using Data from the British Association of Urological Surgeons Percutaneous Nephrolithotomy Audit.

BACKGROUND AND OBJECTIVE: Machine learning (ML) is a subset of artificial intelligence that uses data to build algorithms to predict specific outcomes. Few ML studies have examined percutaneous nephrolithotomy (PCNL) outcomes. Our objective was to build, streamline, temporally validate, and use ML models for prediction of PCNL outcomes (intensive care admission, postoperative infection, transfusion, adjuvant treatment, postoperative complications, visceral injury, and stone-free status at follow-up) using a comprehensive national database (British Association of Urological Surgeons PCNL). METHODS: This was an ML study using data from a prospective national database. Extreme gradient boosting (XGB), deep neural network (DNN), and logistic regression (LR) models were built for each outcome of interest using complete cases only, imputed, and oversampled and imputed/oversampled data sets. All validation was performed with complete cases only. Temporal validation was performed with 2019 data only. A second round used a composite of the most important 11 variables in each model to build the final model for inclusion in the shiny application. We report statistics for prognostic accuracy. KEY FINDINGS AND LIMITATIONS: The database contains 12 810 patients. The final variables included were age, Charlson comorbidity index, preoperative haemoglobin, Guy's stone score, stone location, size of outer sheath, preoperative midstream urine result, primary puncture site, preoperative dimercapto-succinic acid scan, stone size, and image guidance (https://endourology.shinyapps.io/PCNL_Demographics/). The areas under the receiver operating characteristic curve was >0.6 in all cases. CONCLUSIONS AND CLINICAL IMPLICATIONS: This is the largest ML study on PCNL outcomes to date. The models are temporally valid and therefore can be implemented in clinical practice for patient-specific risk profiling. Further work will be conducted to externally validate the models. PATIENT SUMMARY: We applied artificial intelligence to data for patients who underwent a keyhole surgery to remove kidney stones and developed a model to predict outcomes for this procedure. Doctors could use this tool to advise patients about their risk of complications and the outcomes they can expect after this surgery.

Long-term Outcomes of Minimally Invasive Rendezvous Procedures to Treat Complex Ureteric Strictures and Injuries.

Background: Complex ureteric strictures and injuries occurring during major abdominal and pelvic operations may cause significant morbidity and distress to patients. A rendezvous procedure is an endoscopic technique used in case of such injuries. Objective: To evaluate perioperative and long-term outcomes of rendezvous procedures to treat complex ureteric strictures and injuries. Design setting and participants: We retrospectively reviewed patients undergoing a rendezvous procedure for ureteric discontinuity including strictures and injuries, treated between 2003 and 2017 at our Institution and completing at least 12 mo of follow-up. We divided patients into two groups: early postsurgical obstruction, leakage, or detachment (group A) and late strictures (oncological/postsurgical; group B). Outcome measurements and statistical analysis: If appropriate, we performed a retrograde study ± rigid ureteroscopy to assess the stricture 3 mo after the rendezvous procedure, followed by a MAG3 renogram at 6 wk, 6 mo, and 12 mo, and annually thereafter for 5 yr. Results and limitations: Forty-three patients underwent a rendezvous procedure, 17 in group A (median age 50 yr, range 30-78) and 26 in group B (median age 60 yr, range: 28-83). Ureteric strictures and ureteric discontinuities were stented successfully in 15 out of 17 patients in group A (88.2%) and 22 out of 26 patients (84.6%) in group B. For both groups, the median follow-up was 6 yr. In group A, of 17 patients, 11 (64.7%) were stent free with no further interventions, two (11.7%) had a subsequent Memokath stent insertion (38%), and two (11.7%) required reconstruction. Of 26 patients in group B, eight (30.7%) required no further interventions and were stent free, ten (38.4%) were maintained with long-term stenting, and one was managed with a Memokath stent (3.8%). Of the 26 patients, only three (11.5%) required major reconstruction, while four patients with malignancy (15%) died during follow-up. Conclusions: With a combined antegrade and retrograde approach, the majority of complex ureteric strictures/injuries can be bridged and stented with an overall immediate technical success rate of above 80%, avoiding major surgery in unfavourable circumstances and allowing time for stabilisation and recovery of the patient. Additionally, in case of technical success, further interventions may be unnecessary in up to 64% of patients with acute injury and about 31% of patients with late stricture. Patient summary: The majority of complex ureteric strictures and injuries can be resolved using a rendezvous approach, avoiding major surgery in unfavourable circumstances. Moreover, this approach can help avoid further interventions in 64% of such patients.

Does unenhanced computerized tomography as imaging standard post-retrograde intrarenal surgery paradoxically reduce stone-free rate and increase additional treatment for residual fragments? Outcomes from 5395 patients in the FLEXOR study by the TOWER group.

Background: Assessment of residual fragments (RFs) is a key step after treatment of kidney stones. Objective: To evaluate differences in RFs estimation based on unenhanced computerized tomography (CT) versus X-rays/ultrasound after retrograde intrarenal surgery (RIRS) for kidney stones. Design: A retrospective analysis of data from 20 centers of adult patients who had RIRS was done (January 2018-August 2021). Methods: Exclusion criteria: ureteric stones, anomalous kidneys, bilateral renal stones. Patients were divided into two groups (group 1: CT; group 2: plain X-rays or combination of X-rays/ultrasound within 3 months after RIRS). Clinically significant RFs (CSRFs) were considered RFs ⩾ 4 mm. One-to-one propensity score matching for age, gender, and stone characteristics was performed. Multivariable logistic regression analysis was performed to evaluate independent predictors of CSRFs. Results: A total of 5395 patients were included (1748 in group 1; 3647 in group 2). After matching, 608 patients from each group with comparable baseline and stone characteristics were included. CSRFs were diagnosed in 1132 patients in the overall cohort (21.0%). Post-operative CT reported a significantly higher number of patients with RFs ⩾ 4 mm, before (35.7% versus 13.9%, p < 0.001) and after matching (43.1% versus 23.9%, p < 0.001). Only 21.8% of patients in the matched cohort had an ancillary procedure post-RIRS which was significantly higher in group 1 (74.8% versus 47.6%, p < 0.001). Age [OR 1.015 95% confidence interval (CI) 1.009-1.020, p < 0.001], stone size (OR 1.028 95% CI 1.017-1.040, p < 0.001), multiple stones (OR 1.171 95% CI 1.025-1.339, p = 0.021), lower pole stone (OR 1.853 95% CI 1.557-2.204, p < 0.001) and the use of post-operative CT scan (OR 5.9883 95% CI 5.094-7.037, p < 0.001) had significantly higher odds of having CSRFs. Conclusions: CT is the only reliable imaging to assess the burden of RFs following RIRS and urologist should consider at least one CT scan to determine the same and definitely plan reintervention only based on CT rather than ultrasound and X-ray combination.

Worldwide trends of practice and intervention in paediatric endourology: comparison of European versus Non-European responses.

Introduction: The area of paediatric endourology is unique and is recognised to be challenging, and it requires a certain level of focused training and expertise. Our aim was to conduct a worldwide survey in order to gain an overview regarding the current practice patterns for minimally invasive treatments of paediatric upper urinary tract stone patients. Material and methods: The survey was distributed between December 2021 and April 2022 through urology sections and societies in United Kingdom, Latin America and Asia. The survey was made up of 20 questions and it was distributed online using the free online Google Forms (TM). Results: 221 urologists answered the survey with 56 responses each from India, South America and UK and 53 responses from the rest of Europe (15 countries). In total, 163 responders (73.7%) managed paediatric stone patients in their daily practice. Of the responders, 60.2% were adult urologists and 39.8% were paediatric urologists. 12.9% adult urologists and 20.4% paediatric urologists run independent clinics while some run combined adult and paediatric clinics sometimes with the support of the nephrologists. Only 33.9% urologists offered all surgical treatments [extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL), ureteroscopy (URS) and retrograde intrarenal surgery (RIRS)]. Conclusions: Treatment of paediatric stones can vary according to country and legislations. Based on the results of this survey, minimally invasive methods such as URS and mini PCNL seem to have become more popular. In most institutions a collaboration exists between adult and paediatric urologists, which is the key for a tailored decision making, counselling and treatment success.

Consensus Statement on Urinary Stone Treatment During a Pandemic: A Delphi Process from the Endourological Society TOWER Research Initiative.

Introduction: The novel coronavirus disease (COVID-19) pandemic has had a significant impact on the care of patients with urolithiasis. Recommendations and prioritization of endourologic surgical procedures vary among regions, and a comprehensive overall international directive is needed. We used the Delphi method to obtain international consensus on managing urolithiasis patients during the pandemic. Methods: A three-round Delphi process was used to elicit expert consensus (53 global key opinion leaders within the Endourological Society from 36 countries) on an extensive survey on management of endourologic patients in a pandemic. Questions addressed general management, inpatient and outpatient procedures, clinic visits, follow-up care, and best practices for suspension and resumption of routine care. Results: Consensus was achieved in 64/84 (76%) questions. Key consensus findings included the following: consultations should be delivered remotely when possible. Invasive surgical procedures for urolithiasis patients should be reserved for high-risk situations (infection, renal failure, etc.). To prevent aerosolization, spinal anesthesia is preferred over general, whenever feasible. Treatment of asymptomatic renal stones should be deferred. Primary definitive treatment of obstructing or symptomatic stones (both renal and ureteral) is preferred over temporizing drainage. Extracorporeal shockwave lithotripsy should be continued for obstructive ureteral stones. There was consensus on treatment modalities and drainage strategies depending on location and size of the stone. Conclusion: International endourologist members of the Endourological Society participated in this Delphi initiative to provide expert consensus on management of urolithiasis during a pandemic. These results can be applied currently and during a future pandemic.

Influence of Webinar-Based Learning on Practice of Percutaneous Nephrolithotomy: Outcomes of a Global Survey.

Background: With webinars looking to be the mainstay post-pandemic, it is important to demonstrate whether webinars are, indeed, effective educational tools for professional training and skill acquisition. We aim at demonstrating, via a global survey, the efficacy of webinars on percutaneous nephrolithotomy (PCNL) and how this knowledge transforms clinical practice. Methods: A structured online survey covering the following sections: (1) Demographics, (2) PCNL techniques, and (3) PCNL equipment was circulated. The target study population were practicing urologists and residents. Categorical data were presented with counts and percentages, and they were compared by using Chi-square test. Continuous data were analyzed with non-parametric methods. Respondents were dichotomized according to attendance of webinar type, attendees of dedicated PCNL webinars (Group A), or attendees of endourological webinars that discussed some aspects of PCNL (Group B). Results: A total of 303 respondents from 38 countries participated. Overall, 91.7% (n = 278) were in Group A and 8.3% (n = 25) were in Group B; 77.9% were younger than 50 years, whereas 51.8% had more than 10 years of urology experience. In group A, urologists of all ages, in academic institutions and private practitioners, significantly benefited in gaining knowledge about the merits of newer devices and the role of suction-assisted devices in modern PCNL. The majority of group A also reflected that by attending a dedicated PCNL-based webinar they benefited in learning newer positions for PCNL access, especially supine, and how to effectively use laser as energy devices for lithotripsy. In Group B, the only area of benefit was in lasing techniques and the use of newer lasers such as the thulium fibre laser. Conclusion: Our survey positively validates the two proposed hypothesis, that is, webinars as a medium of education do benefit practicing urologists in knowledge and the clinical practice domains. Age, experience, or place of practice is no barrier to adopting newer mediums of education such as webinars.

International Alliance of Urolithiasis (IAU) guidelines on the metabolic evaluation and medical management of urolithiasis.

The aim of this study was to construct the fourth in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis (IAU) that by providing a clinical framework for the metabolic evaluation, prevention, and follow-up of patients with urolithiasis based on the best available published literature. All recommendations were summarized following a systematic review and assessment of the literature in the PubMed database from January 1976 to June 2022. Each generated recommendation was graded using a modified GRADE methodology. Guideline recommendations were developed that addressed the following topics: initial evaluation, metabolic testing, dietary measures, medical management, and follow-up of recurrent stone formers. It was emphasized by the Panel that prevention of new stone formation is as important as the surgical removal of the stones. Although general preventive measures may be effective in reducing stone recurrence rates in some patients, specific medical and dietary management should be well considered and eventually applied in an individualized manner based on the outcomes of metabolic work-up, stone analysis and some certain patient related factors. A detailed follow-up of each case is essential depending on the metabolic activity of each individual patient.

European Association of Urology Section of Urolithiasis and International Alliance of Urolithiasis Joint Consensus on Percutaneous Nephrolithotomy.

CONTEXT: Although percutaneous nephrolithotomy (PCNL) has been performed for decades and has gone through many refinements, there are still concerns regarding its more widespread utilization because of the long learning curve and the potential risk of severe complications. Many technical details are not included in the guidelines because of their nature and research protocol. OBJECTIVE: To achieve an expert consensus viewpoint on PCNL indications, preoperative patient preparation, surgical strategy, management and prevention of severe complications, postoperative management, and follow-up. EVIDENCE ACQUISITION: An international panel of experts from the Urolithiasis Section of the European Association of Urology, International Alliance of Urolithiasis, and other urology associations was enrolled, and a prospectively conducted study, incorporating literature review, discussion on research gaps (RGs), and questionnaires and following data analysis, was performed to reach a consensus on PCNL. EVIDENCE SYNTHESIS: The expert panel consisted of 36 specialists in PCNL from 20 countries all around the world. A consensus on PCNL was developed. The expert panel was not as large as expected, and the discussion on RGs did not bring in more supportive evidence in the present consensus. CONCLUSIONS: Adequate preoperative preparation, especially elimination of urinary tract infection prior to PCNL, accurate puncture with guidance of fluoroscopy and/or ultrasonography or a combination, keeping a low intrarenal pressure, and shortening of operation time during PCNL are important technical requirements to ensure safety and efficiency in PCNL. PATIENT SUMMARY: Percutaneous nephrolithotomy (PCNL) has been a well-established procedure for the management of upper urinary tract stones. However, according to an expert panel consensus, core technical aspects, as well as the urologist's experience, are critical to the safety and effectiveness of PCNL.