Trends in the use of radiation protection and radiation exposure of European endourologists: a prospective trial from the EULIS-YAU Endourology Group.

INTRODUCTION: Due to the radiation exposure for the urology staff during endourology, our aim was to evaluate the trends of radiation protection in the operation room by endourologists from European centers and to estimate their annual radiation. METHODS: We conducted a multicenter study involving experienced endourologists from different European centers to evaluate whether the protection and threshold doses recommended by the International Commission on Radiation Protection (ICRP) were being followed. A 36-question survey was completed on the use of fluoroscopy and radiation protection. Annual prospective data from chest, extremities, and eye dosimeters were collected during a 4-year period (2017-2020). RESULTS: Ten endourologists participated. Most surgeons use lead aprons and thyroid shield (9/10 and 10/10), while leaded gloves and caps are rarely used (2/10 both). Six out of ten surgeons wear leaded glasses. There is widespread use of personal chest dosimeters under the apron (9/10), and only 5/10 use a wrist or ring dosimeter and 4 use an eye dosimeter. Two endourologists use the ALARA protocol. The use of ultrasound and fluoroscopy during PCNL puncture was reported by 8 surgeons. The mean number of PCNL and URS per year was 30.9 (SD 19.9) and 147 (SD 151.9). The mean chest radiation was 1.35 mSv per year and 0.007 mSv per procedure. Mean radiation exposure per year in the eyes and extremities was 1.63 and 11.5 mSv. CONCLUSIONS: Endourologists did not exceed the threshold doses for radiation exposure to the chest, extremities and lens. Furthermore, the ALARA protocol manages to reduce radiation exposure.

Acoustic emission of kidney stones: a medical adaptation of statistical breakdown mechanisms.

Kidney stones have a prevalence rate of > 10% in some countries. There has been a significant increase in surgery to treat kidney stones over the last 10 years, and it is crucial that such techniques are as effective as possible, while limiting complications. A selection of kidney stones with different chemical and structural properties were subjected to compression. Under compression, they emit acoustic signals called crackling noise. The variability of the crackling noise was surprisingly great comparing weddellite, cystine and uric acid stones. Two types of signals were found in all stones. At high energies of the emitted sound waves, we found avalanche behaviour, while all stones also showed signals of local, uncorrelated collapse. These two types of events are called 'wild' for avalanches and 'mild' for uncorrelated events. The key observation is that the crossover from mild to wild collapse events differs greatly between different stones. Weddellite showed brittle collapse, extremely low crossover energies (< 5 aJ) and wild avalanches over 6 orders of magnitude. In cystine and uric acid stones, the collapse was more complicated with a dominance of local "mild" breakings, although they all contained some stress-induced collective avalanches. Cystine stones had high crossover energies, typically [Formula: see text] 750 aJ, and a narrow window over which they showed wild avalanches. Uric acid stones gave moderate values of crossover energies, [Formula: see text] 200 aJ, and wild avalanche behaviour for [Formula: see text] 3 orders of magnitude. Further research extended to all stone types, and measurement of stone responses to different lithotripsy strategies, will assist in optimisation of settings of the laser and other lithotripsy devices to insight fragmentation by targeting the 'wild' avalanche regime.

The Uniform grading tooL for flexIble ureterorenoscoPes (TULIP-tool): a Delphi consensus project on standardised evaluation of flexible ureterorenoscopes.

OBJECTIVE: To develop a standardised tool to evaluate flexible ureterorenoscopes (fURS). MATERIALS AND METHODS: A three-stage consensus building approach based on the modified Delphi technique was performed under guidance of a steering group. First, scope- and user-related parameters used to evaluate fURS were identified through a systematic scoping review. Then, the main categories and subcategories were defined, and the expert panel was selected. Finally, a two-step modified Delphi consensus project was conducted to firstly obtain consensus on the relevance and exact definition of each (sub)category necessary to evaluate fURS, and secondly on the evaluation method (setting, used tools and unit of outcome) of those (sub)categories. Consensus was reached at a predefined threshold of 80% high agreement. RESULTS: The panel consisted of 30 experts in the field of endourology. The first step of the modified Delphi consensus project consisted of two questionnaires with a response rate of 97% (n = 29) for both. Consensus was reached for the relevance and definition of six main categories and 12 subcategories. The second step consisted of three questionnaires (response rate of 90%, 97% and 100%, respectively). Consensus was reached on the method of measurement for all (sub)categories. CONCLUSION: This modified Delphi consensus project reached consensus on a standardised grading tool for the evaluation of fURS - The Uniform grading tooL for flexIble ureterorenoscoPes (TULIP) tool. This is a first step in creating uniformity in this field of research to facilitate future comparison of outcomes of the functionality and handling of fURS.

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.

Impact of COVID-19 on the management and outcomes of ureteric stones in the UK: a multicentre retrospective study.

OBJECTIVES: To determine if management of ureteric stones in the UK changed during the coronavirus disease 2019 (COVID-19) pandemic and whether this affected patient outcomes. PATIENTS AND METHODS: We conducted a multicentre retrospective study of adults with computed tomography-confirmed ureteric stone disease at 39 UK hospitals during a pre-pandemic period (23/3/2019-22/6/2019) and a period during the pandemic (the 3-month period after the first severe acute respiratory syndrome coronavirus-2 case at individual sites). The primary outcome was success of primary treatment modality, defined as no further treatment required for the index ureteric stone. Our study protocol was published prior to data collection. RESULTS: A total of 3735 patients were included (pre-pandemic 1956 patients; pandemic 1779 patients). Stone size was similar between groups (P > 0.05). During the pandemic, patients had lower hospital admission rates (pre-pandemic 54.0% vs pandemic 46.5%, P < 0.001), shorter mean length of stay (4.1 vs 3.3 days, P = 0.02), and higher rates of use of medical expulsive therapy (17.4% vs 25.4%, P < 0.001). In patients who received interventional management (pre-pandemic 787 vs pandemic 685), rates of extracorporeal shockwave lithotripsy (22.7% vs 34.1%, P < 0.001) and nephrostomy were higher (7.1% vs 10.5%, P = 0.03); and rates of ureteroscopy (57.2% vs 47.5%, P < 0.001), stent insertion (68.4% vs 54.6%, P < 0.001), and general anaesthetic (92.2% vs 76.2%, P < 0.001) were lower. There was no difference in success of primary treatment modality between patient cohorts (pre-pandemic 73.8% vs pandemic 76.1%, P = 0.11), nor when patients were stratified by treatment modality or stone size. Rates of operative complications, 30-day mortality, and re-admission and renal function at 6 months did not differ between the data collection periods. CONCLUSIONS: During the COVID-19 pandemic, there were lower admission rates and fewer invasive procedures performed. Despite this, there were no differences in treatment success or outcomes. Our findings indicate that clinicians can safely adopt management strategies developed during the pandemic to treat more patients conservatively and in the community.

Impact of Ureteral Stent Material on Stent-related Symptoms: A Systematic Review of the Literature.

Context: Ureteral stents are essential implants that are used on a daily basis. Since their invention, advances in stent design have been directed towards alleviating stent-related symptoms. It remains unclear how the material composition of the stent affects stent-related symptoms. Objective: To review the literature and define the clinical impact of ureteral stent material on stent-related symptoms. Evidence acquisition: A literature search of the Embase, MEDLINE (PubMed), and Web of Science databases was conducted on December 17, 2021 to collect articles comparing stent composition materials regarding stent-related symptoms. Thirteen publications met the inclusion criteria, of which only one met the high-quality requirements of the Cochrane Collaboration tool for assessing the risk of bias in randomized trials. Evidence synthesis: Most trials, including the highest quality trial, seem to support that silicone double-J (DJ) stents reduce stent-related symptoms compared to nonsilicone DJ stents. Regarding physical properties, it seems that "soft" or "flexible" DJ stents reduce stent-related symptoms. However, since there was only one high-quality study with a low risk of bias, it is impossible to draw a definitive conclusion owing to the lack of quality data. Conclusions: Silicone DJ stents, and by extension "soft" DJ stents, appear to reduce stent-related symptoms compared to nonsilicone polymers and "hard" DJ stents. No definitive conclusion can be drawn owing to a lack of quality evidence. Creating a standard for measuring and reporting physical stent properties should be the first step for further research. Patient summary: A ureteral stent is a small hollow tube placed inside the ureter to help urine drain from the kidney. We reviewed the literature on the impact of stent material on stent-related symptoms. We found that silicone may reduce stent-related symptoms, but no definitive conclusion can be drawn and further studies are needed.

How Reliable Is Endoscopic Stone Recognition? A Comparison Between Visual Stone Identification and Formal Stone Analysis.

Objective: To assess the diagnostic accuracy and intra-observer agreement of endoscopic stone recognition (ESR) compared with formal stone analysis. Introduction: Stone analysis is a corner stone in the prevention of stone recurrence. Although X-ray diffraction (XRD) and infrared spectroscopy are the recommended techniques for reliable formal stone analysis, this is not always possible, and the process takes time and is costly. ESR could be an alternative, as it would give immediate information on stone composition. Materials and Methods: Fifteen endourologists predicted stone composition based on 100 videos from ureterorenoscopy. Diagnostic accuracy was evaluated by comparing the prediction from visual assessment with stone analysis by XRD. After 30 days, the videos were reviewed again in a random order to assess intra-observer agreement. Results: The median diagnostic accuracy for calcium oxalate monohydrate was 54% in questionnaire 1 (Q1) and 59% in questionnaire 2 (Q2), whereas calcium oxalate dihydrate had a median diagnostic accuracy of 75% in Q1 and 50% in Q2. The diagnostic accuracy for calcium hydroxyphosphate was 10% in Q1 and 13% in Q2. The median diagnostic accuracy for calcium hydrogen phosphate dihydrate and calcium magnesium phosphate was 0% in both questionnaires. The median diagnostic accuracy for magnesium ammonium phosphate was 20% in Q1 and 40% in Q2. The median diagnostic accuracy for uric acid was 22% in both questionnaires. Finally, there was a diagnostic accuracy of 60% in Q1 and 80% in Q2 for cystine. The intra-observer agreement ranged between 45% and 72%. Conclusion: Diagnostic accuracy of ESR is limited and intra-observer agreement is below the threshold of acceptable agreement.

Silicone vs. Polyurethane Stent: The Final Countdown.

Ureteric stents are conventionally used in daily urological practice. There is ongoing debate on the superiority of different stent materials, particularly in terms of patient tolerance. We conducted a literature review to compare silicone stents and stents made of other materials from a patient tolerability perspective. We conclude that silicone stents are better tolerated but further research is required.

European Association of Urology Section of Urolithiasis and International Alliance of Urolithiasis Joint Consensus on Retrograde Intrarenal Surgery for the Management of Renal Stones.

BACKGROUND: Retrograde intrarenal surgery (RIRS) has become the preferred treatment modality for nephrolithiasis. However, because of ongoing uncertainties regarding the optimal perioperative management, operative technique, and postoperative follow-up, as well as a lack of standardization for outcome reporting, consensus is needed to achieve more uniform clinical practice worldwide. OBJECTIVE: To develop recommendations for RIRS on the basis of existing data and expert consensus. DESIGN, SETTING, AND PARTICIPANTS: A protocol-driven, three-phase study was conducted by the European Association of Urology Section of Urolithiasis (EULIS) and the International Alliance of Urolithiasis (IAU). The process included: (1) a nonsystematic review of the literature to define domains for discussion; (2) a two-round modified Delphi survey involving experts in this field; and (3) an additional group meeting and third-round survey involving 64 senior representative members to formulate the final conclusions. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The results from each previous round were returned to the participants for re-evaluation of their decisions during the next round. The agreement threshold was set at 70%. RESULTS AND LIMITATIONS: The panel included 209 participants who developed 29 consensus statements on the following topics of interest: (1) perioperative infection management; (2) perioperative antithrombotic therapy; (3) fundamentals of the operative technique; and (4) standardized outcome reporting. Although this consensus can be considered as a useful reference for more clinically oriented daily practice, we also acknowledge that a higher level of evidence from further clinical trials is needed. CONCLUSIONS: The consensus statements aim to guide and standardize clinical practice and research on RIRS and to recommend standardized outcome reporting. PATIENT SUMMARY: An international consensus on the best practice for minimally invasive surgery for kidney stones was organized and developed by two international societies. It is anticipated that this consensus will provide further guidance to urologists and may help to improve clinical outcomes for patients.

Retrograde migration of a vesicoureteric junction calculus: A potential pitfall of the noncontrast limited pelvic computerized tomography.

Retrograde ureteric calculus migration is a rare phenomenon. Herein, we report two such cases where each patient presented with a calculus, measured at 5 mm and 6 mm, respectively, at the vesicoureteric junction (VUJ) on noncontrast computerized tomography kidneys, ureters, and bladder (CTKUB). Following acute presentation with renal colic, each patient opted for conservative management of their ureteric stone and became asymptomatic when undergoing their follow-up imaging. The first patient underwent a follow-up noncontrast limited pelvic computerized tomography (CT) where it had appeared that the radiolucent VUJ calculus had passed. This stone was then discovered incidentally 3 months later in the upper ureter when the patient had undergone a CT colonography. The other patient underwent a follow-up X-ray KUB where the stone was shown to have migrated to the lower renal pole calyx which was confirmed with noncontrast CTKUB imaging. In all reported cases of retrograde VUJ calculus migration, the use of a noncontrast limited pelvic CT scan either missed or would have missed this phenomenon. This potential pitfall of the noncontrast limited pelvic CT scan should be appreciated and the use of full upper renal tract imaging should be considered for the follow-up of radiolucent VUJ calculus cases whereby there is no clear history of calculus passage.

Silicone-hydrocoated ureteral stents encrustation and biofilm formation after 3-week dwell time: results of a prospective randomized multicenter clinical study.

OBJECTIVE: To explore the risk of encrustation and biofilm formation for silicone ureteral stents compared to percuflex polymer stents, through a randomized multicenter study. PATIENTS AND METHODS: Design, setting and participants: A Multicenter, prospective, randomized, single blind, comparative study of hydrocoated silicone stent (Coloplast Imajin® hydro) versus Percuflex™ Plus stent (Boston Scientific), in 141 patients treated by flexible URS for a kidney stone. The study had ethical committee approval in the respective hospitals. Outcome measurements and statistical analysis: Endpoints related to encrustation were biofilm formation and mineral encrustation after a period of 3-week indwelling time. They were evaluated at removal through a scoring scale of ureteral stents encrustation, infrared spectroscopy and optical microscopy of inner and outer surfaces of tips, angles and along the stent's body. Comparison was performed using ANOVA. RESULTS: 119 stents were available after removal for analysis, 56 in the silicone and 63 in the Percuflex TM Plus group. Mean dwelling duration was 21.8 days for silicone, 22.1 days for PercuflexTM Plus. There was significantly more biofilm on Percuflex™ Plus compared to silicone (1.24 ± 0.08 vs 0.93 ± 0.09, p = 0.0021), and more mineral encrustation (1.22 ± 0.10 vs 0.78 ± 0.11, p = 0.0048), respectively. CONCLUSIONS: This multicenter randomized study shows that silicone-hydrocoated stents are less prone to encrustation than PercuflexTM Plus after a 3-week dwelling period and confirms the low encrustation potential of silicone.

Quality of life in patients with kidney stones. / Calidad de vida en pacientes con litiasis urinarias.

Patient reported outcome measures (PROMs) are essential to fully understand the impact of diseases and the effectiveness of treatment from a patient's perspective. Generic and disease-specific tools have been used to assess the impact of nephrolithiasis on patients' quality of life (QoL), as well as the impact of various treatment modalities. Additionally, various studies have investigated the factors that might determine the impact of the disease on the patients' QoL. Here were view the available knowledge on this nascent topic and highlight the need for extensive future research in this crucial area.

Las mediciones de los resultados informados por los pacientes (PROMs) son esenciales para entender completamente el impacto de las enfermedades y la efectividad de los tratamientos desde la perspectiva del paciente. Se han utilizado herramientas genéricas y específicas de la enfermedad para evaluar el impacto de la nefrolitiasis en la calidad de vida de los pacientes (QoL) y también el impacto de varias modalidades de tratamiento. Además, varios estudios han investigado los factores que pueden determinar el impacto de la enfermedad sobre la QoL de los pacientes. Aquí revisamos el conocimiento disponible sobre este tema emergente y subrayamos la necesidad de una futura eintensa investigación en esta crucial área.

Double JJ Ureteral Stenting: Encrustation and Tolerability.

Indications for stenting should be considered and the stent indwelling time should be minimised. Silicone stents are superior in terms of lower rates of encrustation and stent symptoms. α-Blockers may have an off-label role in reducing both pain and urinary symptoms, while keeping an up-to-date stent register may help in ensuring that stents are not forgotten.

Survey on ureTEric draiNage post uncomplicaTed ureteroscopy (STENT).

Objectives: To assess the feasibility of conducting a randomised controlled trial (RCT) to assess whether avoiding ureteric drainage is superior to performing ureteric drainage after Uncomplicated Ureteroscopy and/or Flexible Ureterorenoscopy (URS/FURS) treatment of a urinary tract stone in improving patient reported outcome measures (PROMs) and 30-day unplanned readmission rates. A secondary objective was to understand current practice of urologists regarding ureteric drainage after uncomplicated URS/FURS (UU). Material and methods: We undertook an online survey of urologists, circulated amongst members of international urological societies and through social media platforms. Uncomplicated URS/FURS was defined as completion of URS/FURS treatment for a urinary tract stone, with the absence of: ureteral trauma, residual fragments requiring further lithotripsy procedures, significant bleeding, perforation, prior urinary tract infection or pregnancy. The ureteric drainage options considered included an indwelling stent, stent on a string or a ureteric catheter. The primary outcome was to determine the proportion of urologists willing to take part in a RCT, randomising patients after UU to a "no ureteric drainage" arm or ureteric drainage arm. Secondary outcomes included determining in their current practice, the proportion of clinicians performing routine ureteric drainage after UU, the reasons for performing ureteric drainage following UU and their preferred optimal duration for ureteric drainage if it is used. The study was reported according to the Checklist for Reporting Results of Internet E-Surveys (CHERRIES). Results: Total of 468 respondents from 45 countries took part in the survey, of whom 303 completed the entire survey (65%). The majority agreed that they would be willing to randomise patients (244/303, 81%) in the proposed RCT. Perceived lack of equipoise to randomise was the most common reason for not being willing to participate (59/303, 19%).92% (308/335) reported that they use ureteric drainage after UU. This was most often due to wanting to prevent possible complications from post-operative ureteric oedema (77%) or to aid passage of small fragments (43%). Complexity of the case (i.e. impacted stone 90%) and length of the procedure (46%) were the most important intraoperative factors influencing the decision to use ureteric drainage post procedure. If required, the median stated ideal duration of ureteric drainage was 5 days (IQR: 3-7 days) after UU. If having UU personally, 30% would want no stent postoperatively and over half would prefer a stent on a string. Conclusion: We have highlighted wide variation in practice regarding ureteric drainage after UU. Our results support the feasibility of an RCT evaluating if no ureteric drainage is superior to ureteric drainage in improving PROMs and 30-day unplanned readmission rates following UU.

Percutaneous Cystolitholapaxy Using the LithoClast Trilogy for Multiple Bladder Stones.

Background: Multiple large bladder calculi are traditionally managed through open cystolithotomy or transurethrally in patients who have an open bladder neck. Open procedures are technically challenging in patients who may have had multiple previous open surgeries, and may be associated with significant morbidity in patients with a high comorbid burden. Therefore, a percutaneous approach to such stones has been used especially when there is a closed bladder neck, and has been shown to be effective. There are a number of available devices for breaking stones in these approaches, the newest of which is the LithoClast Trilogy™ (EMS, Nyon, Switzerland) device, a probe that provides ultrasonic and mechanical calculi fragmentation and suction in a single instrument. Case Presentation: We describe the first reported case of percutaneous cystolitholapaxy using the LithoClast Trilogy device in a 41-year-old woman with spina bifida, and multiple large bladder calculi with a history of ileocystoplasty and Mitrofanoff formation, and a bladder neck closure for neuropathic bladder. The calculi measured 31 and 25 mm, and had a volume of 19.6 and 7.9 cm3 and average HU of 408 and 462, respectively. The calculi were composed of 37% calcium phosphate and 63% magnesium ammonium phosphate. Conclusion: We demonstrate that this approach can be used as a viable alternative to open surgery, which is of particular importance for complex patients who have undergone multiple previous open operations, and who may have a high comorbid burden.

Development and content validation of the percutaneous nephrolithotomy assessment score.

OBJECTIVES: To develop and content validate a percutaneous nephrolithotomy assessment score, taking into consideration the procedure-specific risks. METHODS: This prospective international study utilized the Healthcare Failure Mode and Effect Analysis to systematically outline percutaneous nephrolithotomy and failure modes for each step. A total of 25 h was spent observing percutaneous nephrolithotomy carried out by six expert surgeons. Hazard analysis scoring was carried out by 11 experts. It was determined if the steps were single point weaknesses. Single point weaknesses and those assigned a hazard score ≥4 were included in the percutaneous nephrolithotomy assessment score. The tool was then content validated by 16 experts from 10 countries. RESULTS: Application of the Healthcare Failure Mode and Effect Analysis identified 64 failure modes; 37 failure modes had a hazard score ≥4. After adaptations based on expert feedback the final percutaneous nephrolithotomy assessment score was developed containing 10 phases, 21 processes and 47 subprocesses. All participants agreed that the tool contained pertinent procedural steps. CONCLUSIONS: This study has developed and shown the international content validity of a novel percutaneous nephrolithotomy assessment score. The tool can be utilized in modular operating room training to quantify operator progress, and can be used in conjunction with other modules as part of a complete percutaneous nephrolithotomy curriculum for trainees.