Experts' recommendations in laser use for the treatment of urolithiasis: a comprehensive guide by the European Section of Uro-Technology (ESUT) and Training-Research in Urological Surgery and Technology (T.R.U.S.T.)-Group.

PURPOSE: To identify laser lithotripsy settings used by experts for specific clinical scenarios and to identify preventive measures to reduce complications. METHODS: After literature research to identify relevant questions, a survey was conducted and sent to laser experts. Participants were asked for preferred laser settings during specific clinical lithotripsy scenarios. Different settings were compared for the reported laser types, and common settings and preventive measures were identified. RESULTS: Twenty-six laser experts fully returned the survey. Holmium-yttrium-aluminum-garnet (Ho:YAG) was the primary laser used (88%), followed by thulium fiber laser (TFL) (42%) and pulsed thulium-yttrium-aluminum-garnet (Tm:YAG) (23%). For most scenarios, we could not identify relevant differences among laser settings. However, the laser power was significantly different for middle-ureteral (p = 0.027), pelvic (p = 0.047), and lower pole stone (p = 0.018) lithotripsy. Fragmentation or a combined fragmentation with dusting was more common for Ho:YAG and pulsed Tm:YAG lasers, whereas dusting or a combination of dusting and fragmentation was more common for TFL lasers. Experts prefer long pulse modes for Ho:YAG lasers to short pulse modes for TFL lasers. Thermal injury due to temperature development during lithotripsy is seriously considered by experts, with preventive measures applied routinely. CONCLUSIONS: Laser settings do not vary significantly between commonly used lasers for lithotripsy. Lithotripsy techniques and settings mainly depend on the generated laser pulse's and generator settings' physical characteristics. Preventive measures such as maximum power limits, intermittent laser activation, and ureteral access sheaths are commonly used by experts to decrease thermal injury-caused complications.

Outcomes of Flexible Ureteroscopy vs Extracorporeal Shock Wave Lithotripsy for Renal Stones in Pediatric Patients: A European Association of Urology Urolithiasis Guidelines Systematic Review and Meta-Analysis.

PURPOSE: We sought to determine which treatment between flexible ureteroscopy and shock wave lithotripsy has a better stone-free rate in pediatric patients (<18 years) with renal or proximal ureteric stones (<2 cm). Subanalysis for all outcomes for randomized controlled trials only. MATERIALS AND METHODS: Using PubMed, Web of Science, and the Cochrane database, we identified studies (randomized clinical trials and prospective comparative nonrandomized studies) published until August 2022 reporting surgical outcomes of pediatrics patients undergoing flexible ureteroscopy and shock wave lithotripsy with renal or proximal ureteric stones <2 cm (PROSPERO ID: CRD42022378790). Only randomized controlled trials were considered for meta-analysis. Stone-free rate, operative time, and complications were analyzed. Analysis was performed in R. RESULTS: A total of 6 studies identified, of which 3 were randomized clinical trials and 4 had data on renal stones. A total of 669 patients were analyzed. Mean age ranged from 4.4 to 12.4 years. The shock wave lithotripsy group presented a range of stone-free rate between 21 and 90% while the flexible ureteroscopy group presented a range of stone-free rates between 37% and 97%. Meta-analysis of randomized controlled trials only (n=302) demonstrated significantly higher stone-free rate in flexible ureteroscopy vs shock wave lithotripsy (RR = 1.17, 95% CI: 1.04-1.33, P = 0.01), operative time (mean difference = +16.4 minutes, 95% CI: 7.3-25.5, P < 0.01) and hospital stay (mean difference = +0.25 days, 95% CI: 0.14-0.36, P < 0.001). But no difference in fluoroscopy exposure time (mean difference = -21.0 seconds, 95% CI: -42.6 to 0.56, P = 0.07), Clavien I-II (RR = 1.23, 95% CI: 0.71-2.12, P = 0.45) or Clavien III-V complications (RR = 1.04, 95% CI: 0.32-3.42, P = 0.95). CONCLUSIONS: Flexible ureteroscopy has a significantly higher stone-free rate than shock wave lithotripsy, with no difference in complication rate or fluoroscopy exposure time, and significantly higher operative times and hospital stay. However, the current evidence base for this is weak and further randomized trials are needed.

Consultation on UTUC II Stockholm 2022: diagnostics, prognostication, and follow-up-where are we today?

PURPOSE: To summarise the current knowledge regarding diagnostics, prognostication and follow-up in upper tract urothelial carcinoma (UTUC). METHODS: A scoping review combined with expert opinion was applied to provide an overview of the current research field. Based on the published literature and the experts' own experience and opinions, consensus was reached through presentations and discussions at the meeting Consultation on UTUC II in Stockholm 2022. RESULTS: The strongest prognostic factors in UTUC are tumour grade and stage. They are correlated, and grade is used for indirect staging. The diagnostic examinations should include multiphase computed tomography urography (CTU) with corticomedullary phase, and urethrocystoscopy with cytology. If there is no clear diagnosis for clinical decision-making, ureterorenoscopy (URS) with focal cytology and biopsies should be performed. Both WHO classification systems (1973/1999 and 2004/2016) should be used. Novel biomarker tests are not yet widespread nor recommended for the detection of UTUC. Long-term, regular follow-up, including URS in patients who have had organ-sparing treatment, is important to check for tumour recurrences, intravesical recurrences, metastases and progression of the tumour. CONCLUSION: Proper diagnostics with correct grading of UTUC are necessary for appropriate treatment decisions. The diagnostics should include CTU with corticomedullary phase, urine or bladder cytology, URS with focal barbotage cytology, and biopsies when needed for proper diagnosis and risk stratification. Regular, long-term follow-ups are fundamental, due to the high rate of recurrence and risk of progression.

Consultation on kidney stones, Copenhagen 2019: aspects of intracorporeal lithotripsy in flexible ureterorenoscopy.

PURPOSE: To summarize current knowledge on intracorporeal laser lithotripsy in flexible ureterorenoscopy (fURS), regarding basics of laser lithotripsy, technical aspects, stone clearance, lithotripsy strategies, laser technologies, endoscopes, and safety. METHODS: A scoping review approach was applied to search literature in PubMed, EMBASE, and Web of Science. Consensus was reached through discussions at the Consultation on Kidney Stones held in September 2019 in Copenhagen, Denmark. RESULTS AND CONCLUSIONS: Lasers are widely used for lithotripsy during fURS. The Holmium laser is still the predominant technology, and specific settings for dusting and fragmenting have evolved, which has expanded the role of fURS in stone management. Pulse modulation can increase stone ablation efficacy, possibly by minimizing stone retropulsion. Thulium fibre laser was recently introduced, and this technology may improve laser lithotripsy efficiency. Small fibres give better irrigation, accessibility, and efficiency. To achieve optimal results, laser settings should be adjusted for the individual stone. There is no consensus whether the fragmentation and basketing strategy is preferable to the dusting strategy for increasing stone-free rate. On the contrary, different stone scenarios call for different lithotripsy approaches. Furthermore, for large stone burdens, all laser settings and lithotripsy strategies must be applied to achieve optimal results. Technology for removing dust from the kidney should be in focus in future research and development. Safety concerns about fURS laser lithotripsy include high intrarenal pressures and temperatures, and measures to reduce both those aspects must be taken to avoid complications. Technology to control these parameters should be targeted in further studies.

Consultation on UTUC, Stockholm 2018: aspects of treatment.

PURPOSE: To provide an overview of treatment modalities for management of upper tract urothelial carcinoma (UTUC). METHODS: In accordance with the standards for a scoping review, data presentation and discussion at the Consultation on UTUC in Stockholm, 6-7 September 2018, consensus was reached on the latest and most important treatment recommendations for UTUC. Using Pubmed, Web of Science, and Embase, publications were selected based on quality, clinical relevance, and level of evidence. RESULTS: Kidney-sparing surgery should be attempted for low-grade UTUC. Radical nephroureterectomy with bladder cuff excision is first option for high-grade disease. Post-operative bladder instillation of chemotherapy should be offered after RNU to reduce intravesical recurrence rate. Identification of tumor grade and stage is crucial when selecting treatment. Ureteroscopic management of low-grade and non-invasive UTUC achieves disease-free survival similar to that offered by radical nephroureterectomy but seems to be a risk factor for intravesical recurrence. Lymphadenectomy appears important for high-risk disease, although the therapeutic benefit needs further validation. There is little evidence supporting use of Bacillus Calmette-Guérin (BCG) and mitomycin C as monotherapy and adjuvant treatment in UTUC. A randomized clinical trial has indicated that platin-based chemotherapy for invasive UTUC improves disease-free survival, suggesting that adjuvant chemotherapy should be considered standard care for ≥ T2 N0-3M0 disease. CONCLUSIONS: Risk stratification assessment is feasible and mandatory in UTUC. Identification of tumor grade and stage is essential for optimal treatment selection. Kidney-sparing surgery should be offered in low-risk disease, whereas radical nephroureterectomy and adjuvant chemotherapy should be considered in high-risk disease.

Endoscopic observations as a tool to define underlying pathology in kidney stone formers.

PURPOSE: Advancements in endoscopy offer the possibility of inspection of intrarenal anatomy and pathology. The aim of the study was to evaluate renal papillary appearance in kidney stone formers and to correlate papillary findings with stone type and patient metabolic data. MATERIALS AND METHODS: A consecutive cohort of 46 kidney stone formers undergoing retrograde intrarenal surgery was enrolled. During surgery, renal papillae were characterized in the domains of ductal Plugging (DP), surface Pitting, Loss of papillary contour, and Amount of Randall's plaque (RP, PPLA scoring). Stone material was analyzed using micro-CT and infrared spectroscopy, and blood and urine were collected for metabolic evaluation. RESULTS: In all patients, renal papillae had changes in at least one of the domains of the PPLA score. Examining the total population, it was evident that patients with predominantly plugging (DP > 0) all had very low RP scores. There were no significant trends between mean PPLA scores and urinary analytes for the total group. CONCLUSION: Efforts to prevent renal stone formation have so far been insufficient in majority of patients. Digital endoscopy reveals that kidney stone formers have different and distinct papillary morphologies that seem to be linked to specific stone-forming pathways. Since renal papillary abnormalities may be easily identified during endoscopy, this may in the future prove to be an important method for tailoring prevention strategies in kidney stone patients.

Anatomic variations and stone formation.

PURPOSE OF REVIEW: The pathophysiological mechanisms in kidney stone formation are insufficiently understood. In order to achieve a better understanding of the complexity of stone formation, studies evaluating anatomical variations in the renal papillae have been performed. This review intends to illuminate recent findings. Moreover, new techniques to improve the understanding and interpretation of crystallization mechanisms are reviewed. RECENT FINDINGS: Due to improvements of digital ureteroscopes, detailed endoscopic mapping of renal papillae is now possible. Connections between papillary morphology and histopathological changes in different subsets of stone formers have been documented. The formation of kidney stones seems to take place in relation to Randall's plaques, Ducts of Bellini or by free formation. Additionally, theories of kidney stone formation because of vascular injury or inflammatory events in the papillae have been suggested. SUMMARY: Novel techniques including improved digital endoscopic visualization, microcomputed tomography (CT), electron microscopy and energy dispersive compositional analyses of kidney stones seem essential in the search for effective and reliable methods to understand stone forming processes, which ultimately should result in effective measures for more personalized stone prevention strategies in the future.

Histopathological correlations to ureteral lesions visualized during ureteroscopy.

PURPOSE: To correlate ureteral lesions visualized during ureteroscopy with histopathological findings. MATERIALS AND METHODS: Ureteral access sheaths (UAS) sized 13/15 Fr. were inserted bilaterally in 22 laboratory pigs. During retraction of the UAS with a semirigid ureteroscope inside, ureteral lesions were evaluated and registered using the Post-ureteroscopic lesion scale (PULS). Ureters were excised in vivo between the uretero-pelvic junction and the uretero-vesical junction. Embedded in paraffin, 4-µm thick sections were step sectioned at 250-300 µm intervals and haematoxylin and eosin (HE) stained. Histopathological scoring of ureteral wall lesions was subsequently performed according to PULS. RESULTS: In 72.1% of ureters, the highest histopathological score was at least 1 grade higher than the highest endoscopic PULS score. For 12 (27.9%) lesions, the difference was 2 scores higher, and for 1 (2.3%), it was 3 scores higher. The histopathological PULS grade was higher than the endoscopical PULS grade at all minimum, quartile, and maximum scores. There was a significant difference in the distribution of highest lesional scores between the endoscopic and histopathological PULS (p = 0.002). The calculated mean of the highest scores was 1.49 for endoscopic PULS and 2.51 for histopathological PULS (p < 0.0001). CONCLUSION: Histopathological evaluation of ureteral wall lesions after UAS placement revealed a significantly higher degree of severity than observed endoscopically. Thus, endoscopy underestimated the histopathological extent of the lesion in the majority of cases.

Urolithiasis: evaluation, dietary factors, and medical management: an update of the 2014 SIU-ICUD international consultation on stone disease.

PURPOSE: The aim of this review was to provide current best evidence for evaluation, dietary, and medical management of patients with urolithiasis. METHODS: Literature addressing evaluation, dietary, and medical management of urolithiasis was searched. Papers were analyzed and rated according to level of evidence (LOE), whereupon a synthesis of the evidence was made. Grade of recommendation (GOR) was judged from individual clinical experience and knowledge of the evidence according to the Oxford Centre for Evidence-based Medicine. RESULTS: It is obvious that different stone diseases influence the life of stone-forming individuals very differently, and that evaluation and medical management should be personalized according to risk of recurrence, severity of stone disease, presence of associated medical conditions, and patient's motivation. With regard to evaluation, dietary and medical management of patients with urolithiasis evidence from the literature suggest that selective metabolic evaluation may lead to rational dietary and medical management. Statements based on LOE and GOR are provided to guide clinical practice. CONCLUSION: The provided evidence for evaluation of patients with urolithiasis aims at defining patients at high risk for recurrent/complicated stone disease. Based on this approach, evidence-based dietary and medical management regimes are suggested.

Pathophysiological aspects of ureterorenoscopic management of upper urinary tract calculi.

PURPOSE OF REVIEW: Indications for ureterorenoscopy are expanding without hard scientific evidence to support its efficacy. Therefore, it is extremely important to focus on potential harmful effects of the procedure itself. This review explores how physiology of the upper urinary tract reacts to ureterorenoscopy, potentially translating into harmful effects, and how such pathophysiological processes may be minimized. RECENT FINDINGS: Complications to ureterorenoscopy and postoperative pain seem to be related to intrarenal pressure and/or access. Mean intrarenal pressures in the range of 60-100 mmHg during ureterorenoscopy without access sheaths have been measured, thus by far exceeding the threshold for intrarenal backflow, potentially resulting in septic complications. Intrarenal pressure may be reduced by use of ureteral access sheaths, which, however, may cause ureteral damage due to the limited size of the ureter and strain-induced ureteral contractions (peristalsis). Different receptor types modulate this peristaltic activity. ß-receptor agonists have been investigated in animal and human trials for the purpose of relaxing the ureter. In randomized, placebo-controlled trials in pigs and humans, usage of the ß-receptor agonist isoproterenol in the irrigation fluid has shown a potential for reducing both intrarenal pressure and ureteral tone during ureterorenoscopy. SUMMARY: Upper urinary tract physiology has unique features that may be pushed into pathophysiological processes by the unique elements of ureterorenoscopy: access and irrigation. Pharmacological ureteral relaxation during ureterorenoscopy deserves further attention with regard to reducing complications and postoperative pain.

Acute management of stones: when to treat or not to treat?

INTRODUCTION: Stone management is often conservative due to a high spontaneous stone passage rate or non-symptomatic calyceal stones that do not necessarily require active treatment. However, stone disease may cause symptoms and complications requiring urgent intervention. MATERIAL AND METHODS: In this review, we update latest research and current recommendations regarding acute management of stones, with particular focus on imaging, pain management, active stone interventions, medical expulsive therapy, and urolithiasis in pregnancy and childhood. RESULTS: Acute stone management should be planned with careful consideration of stone size and location, symptoms, patient comorbidity and radiation dose. CONCLUSION: In case of infective hydronephrosis, compromised renal function or persistent pain despite adequate analgesic treatment acute intervention is indicated.

Metabolic Evaluation and Recurrence Prevention for Urinary Stone Patients: An EAU Guidelines Update.

BACKGROUND AND OBJECTIVE: The aim of this review was to define patients who are at high risk of recurrence of urolithiasis, to delineate diagnostic and therapeutic algorithms for each type of stone, and to clarify general guidelines and recommendations for prevention of recurrence. METHODS: A professional research librarian carried out literature searches for all sections of the urolithiasis guidelines, covering the timeframe between 1976 and June 2023. KEY FINDINGS AND LIMITATIONS: For every patient with urolithiasis, an attempt should be made to analyse the stone. Patients should be given general instructions on how to prevent recurrence, including adequate fluid and calcium intake, and low consumption of sodium and protein. Identifying and correcting the causative factors is a cornerstone in preventing the recurrence of urolithiasis. Diagnostic and therapeutic algorithms by stone composition are available. Every patient should undergo baseline metabolic screening, while patients with calcium stones, who are at high risk of relapse and complications, should undergo extensive metabolic screening with two 24-h urine collections and should receive targeted therapy. Patients with uric acid, infection, or cystine stones are at high risk of relapse. All patients at high risk of recurrence should be closely monitored, especially those not complying with therapy in the long term. CONCLUSIONS AND CLINICAL IMPLICATIONS: Metabolic stone evaluation and patient follow-up are highly recommended to prevent urolithiasis recurrence.

Gadolinium-enhanced MRI visualizing backflow at increasing intra-renal pressure in a porcine model.

INTRODUCTION: Intrarenal backflow (IRB) is known to occur at increased intrarenal pressure (IRP). Irrigation during ureteroscopy increases IRP. Complications such as sepsis is more frequent after prolonged high-pressure ureteroscopy. We evaluated a new method to document and visualize intrarenal backflow as a function of IRP and time in a pig model. METHODS: Studies were performed on five female pigs. A ureteral catheter was placed in the renal pelvis and connected to a Gadolinium/ saline solution 3 ml/L for irrigation. An occlusion balloon-catheter was left inflated at the uretero-pelvic junction and connected to a pressure monitor. Irrigation was successively regulated to maintain steady IRP levels at 10, 20, 30, 40 and 50 mmHg. MRI of the kidneys was performed at 5-minute intervals. PCR and immunoassay analyses were executed on the harvested kidneys to detect potential changes in inflammatory markers. RESULTS: MRI showed backflow of Gadolinium into the kidney cortex in all cases. The mean time to first visual damage was 15 minutes and the mean registered pressure at first visual damage was 21 mmHg. On the final MRI the mean percentage of IRB affected kidney was 66% after irrigation with a mean maximum pressure of 43 mmHg for a mean duration of 70 minutes. Immunoassay analyses showed increased MCP-1 mRNA expression in the treated kidneys compared to contralateral control kidneys. CONCLUSIONS: Gadolinium enhanced MRI provided detailed information about IRB that has not previously been documented. IRB occurs at even very low pressures, and these findings are in conflict with the general consensus that keeping IRP below 30-35 mmHg eliminates the risk of post-operative infection and sepsis. Moreover, the level of IRB was documented to be a function of both IRP and time. The results of this study emphasize the importance of keeping IRP and OR time low during ureteroscopy.

Comparison of Treatment Outcomes for Fluoroscopic and Fluoroscopy-free Endourological Procedures: A Systematic Review on Behalf of the European Association of Urology Urolithiasis Guidelines Panel.

CONTEXT: Endourological procedures frequently require fluoroscopic guidance, which results in harmful radiation exposure to patients and staff. One clinician-controlled method for decreasing exposure to ionising radiation in patients with urolithiasis is to avoid the use of intraoperative fluoroscopy during stone intervention procedures. OBJECTIVE: To comparatively assess the benefits and risks of "fluoroscopy-free" and fluoroscopic endourological interventions in patients with urolithiasis. EVIDENCE ACQUISITION: A systematic review of the literature from 1970 to 2022 was performed using the MEDLINE/PubMed, Embase, and Cochrane controlled trials databases and ClinicalTrials.gov. Primary outcomes assessed were complications and the stone-free rate (SFR). Studies reporting data on ureteroscopy and percutaneous nephrolithotomy (PCNL) were eligible for inclusion. Secondary outcomes were operative duration, hospital length of stay, conversion from a fluoroscopy-free to a fluoroscopic procedure, and requirement for an auxiliary procedure to achieve stone clearance. EVIDENCE SYNTHESIS: In total, 24 studies (12 randomised and 12 observational) out of 834 abstracts screened were eligible for analysis. There were 4564 patients with urolithiasis in total, of whom 2309 underwent a fluoroscopy-free procedure and 2255 underwent a comparative fluoroscopic procedure for treatment of urolithiasis. Pooled analysis of all procedures revealed no significant difference between the groups in SFR (p = 0.84), operative duration (p = 0.11), or length of stay (p = 0.13). Complication rates were significantly higher in the fluoroscopy group (p = 0.009). The incidence of conversion from a fluoroscopy-free to a fluoroscopic procedure was 2.84%. Similar results were noted in subanalyses for ureteroscopy (n = 2647) and PCNL (n = 1917). When only randomised studies were analysed (n = 12), the overall complication rate was significantly in the fluoroscopy group (p < 0.001). CONCLUSIONS: For carefully selected patients with urolithiasis, fluoroscopy-free and fluoroscopic endourological procedures have comparable stone-free and complication rates when performed by experienced urologists. In addition, the conversion rate from a fluoroscopy-free to a fluoroscopic endourological procedure is low at 2.84%. These findings are important for clinicians and patients, as the detrimental health effects of ionising radiation are negated with fluoroscopy-free procedures. PATIENT SUMMARY: We compared treatments for kidney stones with and without the use of radiation. We found that kidney stone procedures without the use of radiation can be safely performed by experienced urologists in patients with normal kidney anatomy. These findings are important, as they indicate that the harmful effects of radiation can be avoided during kidney stone surgery.

Kidney stone disease.

Kidney stone disease is rapidly increasing with a strong relationship to metabolic syndrome. This review gives a brief overview of the current state and current treatment modalities. Increasing use of CT and ultrasound scans leads to increased diagnosis of asymptomatic kidney stones, which rarely require treatment. The trend in stone treatment goes towards endoscopic lithotripsy which together with ESWL enables a personalised approach. Obstructive stones with infection require urgent intervention to reduce mortality. Increased fluid intake, dietary changes as well as potassium citrate supplements are the most important elements in stone prevention in the common idiopathic stone disease.

The Danish linguistic validation of the Ureteral Stent Symptoms Questionnaire.

INTRODUCTION: The aim of the study was to validate the Ureteral Stent Symptom Questionnaire (USSQ) in Danish for patients with indwelling ureteral stents. METHODS: The linguistic validation of the original USSQ was performed following standardised multi-step translation procedures. Seventy patients with indwelling ureteral stents were asked to complete the Danish USSQ one and two weeks after stent placement and four weeks after stent removal. RESULTS: A total of 65 patients (92.9%) completed the USSQ. Statistical evaluation revealed good internal consistency in all domains except work performance. Satisfactory convergent validity (less-than -0.4 or greater-than 0.4) was demonstrated for urinary symptoms, body pain and global quality of life. The test-retest reliability-coefficient was statistically significant for urinary symptoms, general health, pain and sexual matters. Inter-domain associations were positive and monotone for all subscales. All sub-scores, except sexual matters, significantly decreased from one week after stent insertion to four weeks after stent removal (p less-than 0.001). CONCLUSION: The Danish USSQ is a reliable and valid instrument with which to evaluate urinary symptoms and general health in patients with indwelling ureteral stents. FUNDING: Ideforum, Vejle Hospital, University Hospital of Southern Denmark, granted 80,000 DKK to support this work. TRIAL REGISTRATION: The Danish National Ethics Committee and Region Syddanmark approved the study (Study approval number 20192000-168 and journal number 19-52219, respectively).

Market Readiness for Single-Use Cystoscopes According to Urologists and Procurement Managers Worldwide.

PURPOSE: Single-use endoscopes have been subjected to increase awareness in recent years, and several new single-use cystoscopes (eg Ambu® aScope 4 Cysto) have entered the market. However, the market readiness for such single-use cystoscopes remains unknown. This study investigates the worldwide market readiness for single-use cystoscopes among urologists and procurement managers (PMs) from Europe, Japan, and the US. MATERIALS AND METHOD: An online survey using QuestionPro® was distributed to urologists and PMs in France, Germany, Italy, Japan, Spain, the UK, and the US between March 10, 2020 and July 14, 2020. All surveys were translated into the respective local language. Statistical analyses were performed using the software package Stata/SE version 16.1, StataCorp. Fisher's exact test was used to analyze categorical variables and simple linear regression was applied to continuous variables. RESULTS: A total of 415 urologists and PMs completed the survey (343 [82.7%] urologists and 72 [17.3%] PMs). Seventy (16.9%) were from Japan, 100 (24.1%) were from the US, and 245 (59.0%) were evenly distributed across the following European countries: France, Germany, Italy, Spain, and the UK. On average, respondents indicated that they would consider converting to single-use in 44.5% of their cystoscopy procedures. Respondents anticipated significantly higher conversion (p<0.05) when they (1) used single-use ureteroscopes in their department, (2) were concerned about cystoscopy-related infection as a result of contaminated cystoscopes, (3) were members of their institution's value committee, or (4) considered cost-transparency to be important when purchasing cystoscopes. CONCLUSION: This study investigated the marked readiness for single-use cystoscopes according to urologists and PMs worldwide. Respondents indicated a willingness to convert to single-use cystoscopes in nearly half (44.5%) of their cystoscopy procedures. Respondents that were concerned about cystoscopy-related infections as a result of contaminated cystoscopes indicated a significantly higher anticipated conversion rate (p<0.05).

Can Dual Energy CT with Fast kV-Switching Determine Renal Stone Composition Accurately?

RATIONALE AND OBJECTIVES: To determine whether a single source computed tomography (CT) system utilizing fast kV switching and low dose settings can characterize (diameter and chemical composition) renal stones accurately when compared infrared spectroscopy. MATERIALS AND METHODS: The chemical composition of 15 renal stones was determined using Fourier transform infrared spectroscopy. The stones were inserted into a porcine kidney and placed within a water tank for CT scanning using both fast kV switching dual energy and standard protocols. Effective atomic number of each stone was measured using scanner software. Stone diameter measurements were repeated twice to determine intra-rater variation and compared to actual stone diameter as measured by micro CT. RESULTS: The chemical composition of three stones (one calcium phosphate and two carbonite apatite) could not be determined using the scanner software. The composition of 10/12 remaining stones was correctly identified using dual energy computed tomography (83% absolute agreement; k = 0.69). No statistical difference (p = 0.051) was noted in the mean stone diameter as measured by clinical CT and micro CT. CONCLUSION: Dual energy computed tomography using fast kV switching may potentially be developed as a low dose clinical tool for identifying and classifying renal stones in vivo supporting clinical decision-making.

Renal stone detection using a low kilo-voltage paediatric CT protocol - a porcine phantom study.

INTRODUCTION: Reducing tube voltage is an effective dose saving method in computed tomography (CT) assuming tube current is not concurrently increased. Recent innovations in scanner technology now enable CT tube voltage reduction to 70 kV thereby increasing opportunities for dose reduction in paediatric patients, but it is unclear if the increased image noise associated with 70 kV impacts on ability to visualise renal stones accurately. The purpose was to assess detectability of nephrolithiasis using a bespoke paediatric phantom and low kV, non-contrast CT and to assess inter-observer agreement. METHODS: Forty-two renal stones of different size and chemical composition were inserted into porcine kidneys and positioned in a bespoke, water-filled phantom mimicking a 9-year-old child weighing approximately 33kg. The phantom was scanned using 120 and 70 kV CT protocols, and the detectability of the stones was assessed by three radiologists. Absolute agreement and Fleiss' kappa regarding detectability were assessed. RESULTS: The mean diameter of renal stones as measured physically was 4.24 mm ranging from 1 to 11 mm. Four stones were missed by at least one observer. One observer had a sensitivity of 93 and 95% at 70 and 120 kV, respectively, while the sensitivity for observers 2 and 3 was 98% at both kV levels. Specificity was 100% across readers and kV levels. Absolute agreement between the readers at 70 kV was 92% (kappa = 0.86) and 98% (kappa = 0.96) at 120 kV indicating a strong agreement at both kV levels. CONCLUSIONS: The results suggest that lowering the kV does not affect the detection rate of renal stones and may be a useful dose reduction strategy for assessment of nephrolithiasis in children.