Intrarenal pressure with hand-pump or pressurized-bag irrigation: randomized clinical trial at retrograde intrarenal surgery.

BACKGROUND: The aim was to ascertain the impact of irrigation technique on human intrarenal pressure during retrograde intrarenal surgery. METHODS: A parallel randomized trial recruited patients across three hospital sites. Patients undergoing retrograde intrarenal surgery for renal stone treatment with an 11/13-Fr ureteral access sheath were allocated randomly to 100 mmHg pressurized-bag (PB) or manual hand-pump (HP) irrigation. The primary outcome was mean procedural intrarenal pressure. Secondary outcomes included maximum intrarenal pressure, variance, visualization, HP force of usage, procedure duration, stone clearance, and clinical outcomes. Live intrarenal pressure monitoring was performed using a COMETTMII pressure guidewire, deployed cystoscopically to the renal pelvis. The operating team was blinded to the intrarenal pressure. RESULTS: Thirty-eight patients were randomized between July and November 2023 (trial closure). The final analysis included 34 patients (PB 16; HP 18). Compared with PB irrigation, HP irrigation resulted in significantly higher mean intrarenal pressure (mean(s.d.) 62.29(27.45) versus 38.16(16.84) mmHg; 95% c.i. for difference in means (MD) 7.97 to 40.29 mmHg; P = 0.005) and maximum intrarenal pressure (192.71(106.23) versus 68.04(24.16) mmHg; 95% c.i. for MD 70.76 to 178.59 mmHg; P < 0.001), along with greater variance in intrarenal pressure (log transformed) (6.23(1.59) versus 4.60(1.30); 95% c.i. for MD 0.62 to 2.66; P = 0.001). Surgeon satisfaction with procedural vision reported on a scale of 10 was higher with PB compared with HP irrigation (mean(s.d.) 8.75(0.58) versus 6.28(1.27); 95% c.i. for MD 1.79 to 3.16; P < 0.001). Subjective HP usage force did not correlate significantly with transmitted intrarenal pressure (Pearson R = -0.15, P = 0.57). One patient (HP arm) developed urosepsis. CONCLUSION: Manual HP irrigation resulted in higher and more fluctuant intrarenal pressure trace (with inferior visual clarity) than 100-mmHg PB irrigation. REGISTRATION NUMBER: osf.io/jmg2h (https://osf.io/).

The role of urology and radiology in prostate biopsy: current trends and future perspectives.

PURPOSE: Prostate biopsy is central to the accurate histological diagnosis of prostate cancer. In current practice, the biopsy procedure can be performed using a transrectal or transperineal route with different technologies available for targeting of lesions within the prostate. Historically, the biopsy procedure was performed solely by urologists, but with the advent of image-guided techniques, the involvement of radiologists in prostate biopsy has become more common. Herein, we discuss the pros, cons and future considerations regarding their ongoing role. METHODS: A narrative review regarding the current evidence was completed. PubMed and Cochrane central register of controlled trials were search until January 2024. All study types were of consideration if published after 2000 and an English language translation was available. RESULTS: There are no published studies that directly compare outcomes of prostate biopsy when performed by a urologist or radiologist. In all published studies regarding the learning curve for prostate biopsy, the procedure was performed by urologists. These studies suggest that the learning curve for prostate biopsy is between 10 and 50 cases to reach proficiency in terms of prostate cancer detection and complications. It is recognised that many urologists are poorly able to accurately interpret multi parametric (mp)-MRI of the prostate. Collaboration between the specialities is of importance with urology offering the advantage of being involved in prior and future care of the patient while radiology has the advantage of being able to expertly interpret preprocedure MRI. CONCLUSION: There is no evidence to suggest that prostate biopsy should be solely performed by a specific specialty. The most important factor remains knowledge of the relevant anatomy and sufficient volume of cases to develop and maintain skills.

Lean body mass in living kidney donors impacts postoperative renal function.

PURPOSE: A living donor kidney transplant is the optimal treatment for chronic renal impairment. Our objective is to assess if lean skeletal muscle mass and donor factors such as body mass index, hypertension, and age impact on renal function following donor nephrectomy. METHODS: Potential donors undergo CT angiography as part of their work-up in our institution. Using dedicated software (Horos®), standardized skeletal muscle area measured at the L3 vertebrae was calculated. When corrected for height, skeletal muscle index can be derived. Skeletal muscle mass index below predefined levels was classified as sarcopenic. The correlation of CT-derived skeletal muscle index and postoperative renal function at 12 months was assessed. Co-variables including donor gender, age, body mass index (BMI), and presence of pre-op hypertension were also assessed for their impact on postoperative renal function. RESULTS: 275 patients who underwent living donor nephrectomy over 10 years were included. Baseline pre-donation glomerular filtration rate (GFR) and renal function at one year post-op were similar between genders. 29% (n = 82) of patients met the criteria for CT-derived sarcopenia. Sarcopenic patients were more likely to have a higher GFR at one year post-op (69.3 vs 63.9 mL/min/1.73 m2, p < 0.001). The main factors impacting better renal function at one year were the presence of sarcopenia and younger age at donation. CONCLUSION: When selecting donors, this study highlights that patients with low skeletal mass are unlikely to underperform in terms of recovery of their renal function postoperatively at one year when compared to patients with normal muscle mass and should not be a barrier to kidney donation.

Can you name that tablet? A cross-sectional study on recognition of common urology medications.

INTRODUCTION: Clinicians frequently rely on patients to accurately tell them what prescription medications and doses they are taking in outpatient visits. This information is essential to monitor the efficacy of a medication and to determine any adverse interactions. This study aimed to assess urologist and urology trainee's visual recognition of common urology medications. METHODS: An online survey was distributed to urologists and urology trainees in Ireland. Images of 11 commonly prescribed urological medications were presented with free text options for answering. Information was gathered on respondent's role and experience. Data was analysed using STATA version 17. RESULTS: The survey had a 90% response rate from 50 distributions. Respondents' roles were consultant (31.1%), specialist registrar (33.3%), registrar (22.2%), senior house officer (11.1%) and intern (2.2%). Forty six percent had more than six years urology experience. Average rate of correct responses was 39.4% ± 23.9. The most accurate group were consultants (46.1% ± 22.1), followed by specialist registrars (41.2% ± 24.9), registrars (39.1% ± 26.8), senior house officers (21.8% ± 10.4) and interns (9.1% ± 0). The most and least recognised medications were sildenafil (Viagra©) (84.4%) and fesoterodine (Toviaz©) (11.1%), respectively. Just 28.9% of respondents had previously handled any of the medications listed. CONCLUSION: Patients often do not reliably know their own medications other than to describe them or show an unpackaged tablet. Prescribing safety is paramount to ensuring patient safety and reducing the risk of adverse drug reactions. This study shows that even experienced clinicians do not recognise the medications they regularly prescribe, and decisions should not be made without accurate medication reconciliation.

Follow-up of urolithiasis patients after treatment: an algorithm from the EAU Urolithiasis Panel.

OBJECTIVE: To develop a follow-up algorithm for urinary stone patients after definitive treatment. MATERIALS AND METHODS: The panel performed a systematic review on follow-up of urinary stone patients after treatment (PROSPERO: CRD42020205739). Given the lack of comparative studies we critically evaluated the literature and reached a consensus on the follow-up scheme. RESULTS: A total of 76 studies were included in the analysis, including 17 RCTs. In the stone-free general population group, 71-100% of patients are stone-free at 12 months while 29-94% remain stone-free at 36 months. We propose counselling these patients on imaging versus discharge after the first year. The stone-free rate in high-risk patients not receiving targeted medical therapy is < 40% at 36 months, a fact that supports imaging, metabolic, and treatment monitoring follow-up once a year. Patients with residual fragments ≤ 4 mm have a spontaneous expulsion rate of 18-47% and a growth rate of 10-41% at 12 months, supporting annual imaging follow-up. Patients with residual fragments > 4 mm should be considered for surgical re-intervention based on the low spontaneous expulsion rate (13% at 1 year) and high risk of recurrence. Plain film KUB and/or kidney ultrasonography based on clinicians' preference and stone characteristics is the preferred imaging follow-up. Computed tomography should be considered if patient is symptomatic or intervention is planned. CONCLUSIONS: Based on evidence from the systematic review we propose, for the first time, a follow-up algorithm for patients after surgical stone treatment balancing the risks of stone recurrence against the burden of radiation from imaging studies.

Peri-operative and long-term outcomes of kidney transplantation in patients with cystic fibrosis.

INTRODUCTION: There is a lack of data regarding the peri-operative and long-term outcomes of kidney transplantation in cystic fibrosis (CF) patients. Herein, we report the peri-operative and long-term outcomes of kidney transplantation in CF patients. MATERIALS AND METHODS: All CF patients who received a kidney transplant at the national kidney transplant center between 1993 and 2022 were identified. Recipients of the contralateral donor kidney were selected as a control group. Primary outcomes included 1-, 5-, and 10- year death-censored graft survival and overall survival. Secondary outcomes included peri-operative morbidity, acute graft rejection, delayed graft function (DGF), and length of stay (LOS). RESULTS: Fourteen patients received a kidney transplant over the study period. Median age at transplantation was 35 (IQR 31, 40) years. The 1-, 5-, and 10-year death-censored graft survival was 92, 74, and 74% in the CF group compared to 100, 92, and 92% in the control group (p = .44). The 1-, 5-, and 10-year overall survival in the CF group was 85, 66, and 57% compared to 100, 92, and 82% in the control group (p = .036). There was no significant difference in peri-operative outcomes including LOS (10 vs. 11 days, p = .84), ICU admission (1 vs. 0 patients, p > .99), acute rejection episodes (2 vs. 1 patients, p > .99), and DGF (1 vs. 2 patients, p = .60). CONCLUSION: CF patients have good long-term graft survival, however, overall survival was worse compared to a matched cohort. These data provide important information for transplant surgeons when considering suitable donor allografts in this unique patient population.

Urological Guidelines for Kidney Stones: Overview and Comprehensive Update.

BACKGROUND: Evidence-based guidelines are published by urological organisations for various conditions, including urolithiasis. In this paper, we provide guidance on the management of kidney stone disease (KSD) and compare the American Urological Association (AUA) and European Association of Urologists (EAU) guidelines. METHODS: We evaluate and appraise the evidence and grade of recommendation provided by the AUA and EAU guidelines on urolithiasis (both surgical and medical management). RESULTS: Both the AUA and EAU guidelines provide guidance on the type of imaging, treatment options, and medical therapies and advice on specific patient groups, such as in paediatrics and pregnancy. While the guidelines are generally aligned and based on evidence, some subtle differences exist in the recommendations, but both are generally unanimous for the majority of the principles of management. CONCLUSIONS: We recommend that the guidelines should undergo regular updates based on recently published material, and while these guidelines provide a framework, treatment plans should still be personalised, respecting patient preferences, surgical expertise, and various other individual factors, to offer the best outcome for kidney stone patients.

Environmental Impact of Flexible Cystoscopy: A Comparative Analysis Between Carbon Footprint of Isiris® Single-Use Cystoscope and Reusable Flexible Cystoscope and a Systematic Review of Literature.

Introduction: There is an absence of data on the environmental impact of single-use flexible cystoscopes. We wanted to review the existing literature about carbon footprint of flexible cystoscopy and analyze the environmental impact of the Isiris® (Coloplast©) single-use flexible cystoscope compared to reusable flexible cystoscopes. Methods: First, a systematic review on single-use and reusable cystoscope carbon footprint was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Second, carbon footprints of Isiris single-use flexible cystoscope and reusable cystoscope were analyzed and compared. Life cycle of the single-use flexible cystoscope was divided in three steps: manufacturing, sterilization, and disposal. For the reusable cystoscope, several steps were considered to estimate the carbon footprint over the life cycle: manufacturing, washing/sterilization, repackaging, repair, and disposal. For each step, the carbon footprint values were collected and adapted from previous comparable published data on flexible ureteroscope. Results: The systematic literature review evidenced total carbon emissions within a range of 2.06 to 2.41 kg carbon dioxide (CO2) per each use of single-use flexible cystoscope compared to a wide range of 0.53 to 4.23 kg CO2 per each case of reusable flexible cystoscope. The carbon footprint comparative analysis between Isiris single-use flexible cystoscope and reusable cystoscope concluded in favor of the single-use cystoscope. Based on our calculation, the total carbon emissions for a reusable flexible cystoscope could be refined to an estimated range of 2.40 to 3.99 kg CO2 per case, depending on the endoscopic activity of the unit, and to 1.76 kg CO2 per case for Isiris single-use cystoscope. Conclusion: The results and our systematic literature review demonstrated disparate results depending on the calculation method used for carbon footprint analysis. However, the results tend rather toward a lower environmental impact of single-use devices. In comparison to a reusable flexible cystoscope, Isiris compared favorably in terms of carbon footprint.

Diagnosis and management of indeterminate testicular lesions.

The sophistication and accessibility of modern-day imaging result in frequent detection of small or equivocal lesions of the testes. Traditionally, diagnosis of a testicular lesion with any possibility of malignancy would usually prompt radical orchidectomy. However, awareness is growing that a substantial proportion of these lesions might be benign and that universal application of radical orchidectomy risks frequent overtreatment. Given the potentially profound effects of radical orchidectomy on fertility, endocrine function and psychosexual well-being, particularly in scenarios of an abnormal contralateral testis or bilateral lesions, organ-preserving strategies for equivocal lesions should be considered. Image-based active surveillance can be applied for indeterminate lesions measuring ≤15 mm with a low conversion rate to surgical treatment. However, these outcomes are early and from relatively small, selected cohorts, and concerns prevail regarding the metastatic potential of even small undiagnosed germ cell tumours. No consensus exists on optimal surveillance (short interval (<3 months) ultrasonography is generally adopted); histological sampling is a widespread alternative, involving inguinal delivery of the testis and excisional biopsy of the lesion, with preoperative marking or intraoperative ultrasonographic localization when necessary. Frozen section analysis in this context demonstrates excellent diagnostic accuracy. Histological results support that approximately two-thirds of marker-negative indeterminate solitary testicular lesions measuring ≤25 mm overall are benign. In summary, modern imaging detects many small indeterminate testicular lesions, of which the majority are benign. Awareness is growing of surveillance and organ-sparing diagnostic and treatment strategies with the aim of minimizing rates of overtreatment with radical orchidectomy.

Perspectives on technology: to use or to reuse, that is the endoscopic question-a systematic review of single-use endoscopes.

OBJECTIVE: To compare clinical outcomes of single-use endoscopes with those of reusable endoscopes to better define their role within urology. METHODS: A systematic search of electronic databases was performed. All studies comparing the clinical outcomes of participants undergoing urological procedures with single-use endoscopes to those of participants treated with reusable endoscopes were included. Results are reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. RESULTS: Twenty-one studies in 3943 participants were identified. Six different single-use flexible ureteroscopes and two different single-use flexible cystoscopes were assessed. There were no differences in mean postoperative infection rates (4.0% vs 4.4%; P = 0.87) or overall complication rates (11.5% vs 11.9%; P = 0.88) between single-use and reusable endoscopes. For patients undergoing flexible ureteroscopy there were no differences in operating time (mean difference -0.05 min; P = 0.96), length of hospital stay (LOS; mean difference 0.06 days; P = 0.18) or stone-free rate (SFR; 74% vs 74.3%; P = 0.54) between the single-use and reusable flexible ureteroscope groups. CONCLUSION: This study is the largest to compare the clinical outcomes of single-use endoscopes to those of reusable endoscopes within urology, and demonstrated no difference in LOS, complication rate or SFR, with a shorter operating time associated with single-use flexible cystoscope use. It also highlights that the cost efficiency and environmental impact of single-use endoscopes is largely dependent on the caseload and reprocessing facilities available within a given institution. Urologists can therefore feel confident that whether they choose to 'use' or to 'reuse' based on the financial and environmental implications, they can do so without negatively impacting patient outcomes.

Cost-effectiveness of a novel urethral catheter safety device in preventing catheterization injuries in the UK.

AIMS: Intraurethral catheter balloon inflation is a substantial contributor to significant catheter-related urethral injury. A novel safety valve has been designed to prevent these balloon-inflation injuries. The purpose of this evaluation was to assess the cost-effectiveness of urethral catheterisation with the safety valve added to a Foley catheter versus the current standard of care (Foley catheter alone). MATERIALS AND METHODS: The analysis was conducted from the UK public payer perspective on a hypothetical cohort of adults requiring transurethral catheterization. A decision tree was used to capture outcomes in the first 30 days following transurethral catheterization, followed by a Markov model to estimate outcomes over a person's remaining lifetime. Clinical outcomes included catheter balloon injuries [CBIs], associated short-term complications, urethral stricture disease, life years and QALYs. Health-economic outcomes included total costs, incremental cost-effectiveness ratio, net monetary benefit (NMB) and net health benefit. RESULTS: Over a person's lifetime, the safety valve was predicted to reduce CBIs by 0.04 per person and CBI-related short-term complications by 0.03 per person, and nearly halve total costs. The safety valve was dominant, resulting in 0.02 QALYs gained and relative cost savings of £93.19 per person. Probabilistic sensitivity analysis indicated that the safety valve would be cost-saving in 97% of simulations run versus standard of care. CONCLUSIONS: The addition of a novel safety valve aiming to prevent CBIs during transurethral catheterization to current standard of care was estimated to bring both clinical benefits and cost savings.

Mechanical characteristics of the ureter and clinical implications.

The ureteric wall is a complex multi-layered structure. The ureter shows variation in passive mechanical properties, histological morphology and insertion forces along the anatomical length. Ureter mechanical properties also vary depending on the direction of tensile testing and the anatomical region tested. Compliance is greatest in the proximal ureter and lower in the distal ureter, which contributes to the role of the ureter as a high-resistance sphincter. Similar to other human tissues, the ureteric wall remodels with age, resulting in changes to the mechanical properties. The passive mechanical properties of the ureter vary between species, and variation in tissue storage and testing methods limits comparison across some studies. Knowledge of the morphological and mechanical properties of the ureteric wall can aid in understanding urine transport and safety thresholds in surgical techniques. Indeed, various factors alter the forces required to insert access sheaths or scopes into the ureter, including sheath diameter, safety wires and medications. Future studies on human ureteric tissue both in vivo and ex vivo are required to understand the mechanical properties of the ureter and how forces influence these properties. Testing of instrument insertion forces in humans with a focus on defining safe upper limits and techniques to reduce trauma are also needed. Last, evaluation of dilatation limits in the mid and proximal ureter and clarification of tensile strength anisotropy in human specimens are necessary.

In vivo ureteroscopic intrarenal pressures and clinical outcomes: a multi-institutional analysis of 120 consecutive patients.

OBJECTIVES: To evaluate the pressure range generated in the human renal collecting system during ureteroscopy (URS), in a large patient sample, and to investigate a relationship between intrarenal pressure (IRP) and outcome. PATIENTS AND METHODS: A prospective multi-institutional study was conducted, with ethics board approval; February 2022-March 2023. Recruitment was of 120 consecutive consenting adult patients undergoing semi-rigid URS and/or flexible ureterorenoscopy (FURS) for urolithiasis or diagnostic purposes. Retrograde, fluoroscopy-guided insertion of a 0.036-cm (0.014″) pressure guidewire (COMET™ II, Boston Scientific, Marlborough, MA, USA) to the renal pelvis was performed. Baseline and continuous ureteroscopic IRP was recorded, alongside relevant operative variables. A 30-day follow-up was completed. Descriptive statistics were applied to IRP traces, with mean (sd) and maximum values and variance reported. Relationships between IRP and technical variables, and IRP and clinical outcome were interrogated using the chi-square test and independent samples t-test. RESULTS: A total of 430 pressure traces were analysed from 120 patient episodes. The mean (sd) baseline IRP was 16.45 (5.99) mmHg and the intraoperative IRP varied by technique. The mean (sd) IRP during semi-rigid URS with gravity irrigation was 34.93 (11.66) mmHg. FURS resulted in variable IRP values: from a mean (sd) of 26.78 (5.84) mmHg (gravity irrigation; 12/14-F ureteric access sheath [UAS]) to 87.27 (66.85) mmHg (200 mmHg pressurised-bag irrigation; 11/13-F UAS). The highest single pressure peak was 334.2 mmHg, during retrograde pyelography. Six patients (5%) developed postoperative urosepsis; these patients had significantly higher IRPs during FURS (mean [sd] 81.7 [49.52] mmHg) than controls (38.53 [22.6] mmHg; P < 0.001). CONCLUSIONS: A dynamic IRP profile is observed during human in vivo URS, with IRP frequently exceeding expected thresholds. A relationship appears to exist between elevated IRP and postoperative urosepsis.

Membranous urethral length and urinary incontinence following robot-assisted radical prostatectomy: a systematic review and meta-analysis.

OBJECTIVE: To provide an update on the association between preoperative membranous urethral length (MUL) and postoperative urinary incontinence (UI) in men who undergo robot-assisted radical prostatectomy (RARP)/robot-assisted laparoscopic prostatectomy (RALP). MATERIALS AND METHODS: Urinary incontinence is common after RARP/RALP, and early recovery of continence is one of the most important functional outcomes following surgery. MUL has been identified as a factor associated with continence recovery after RARP/RALP. A systematic review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, using PubMed, Embase, and Scopus databases. Inclusion criteria were English language full journal articles authored within the last 5 years that assessed continence using the Expanded Prostate Cancer Index Composite. The Critical Appraisal Skills Programme tool for retrospective cohort studies was used to evaluate study quality. A random-effects meta-analysis was performed to pool odds ratios (ORs) from available studies relating to continence as a function of MUL. The Grading of Recommendations, Assessment, Development and Evaluations framework was used to synthesise evidence. RESULTS: Six studies including 970 patients reported an association between MUL and continence at 12 months. Longer MUL was associated with reduced UI odds at 12 months after surgery (pooled OR 0.74, 95% confidence interval 0.68-0.87, P < 0.001). Significant methodological and statistical heterogeneity was encountered. CONCLUSIONS: Preoperative MUL measured on magnetic resonance imaging (MRI) is significantly associated with postoperative continence in men undergoing RARP/RALP. We recommend consideration of MRI measurement of MUL prior to RARP/RALP to guide treatment decisions in this population.

Perceptions and Practice Patterns of Urologists Relating to Intrarenal Pressure During Ureteroscopy: Findings from a Global Cross-Sectional Analysis.

Objectives: To explore beliefs and practice patterns of urologists regarding intrarenal pressure (IRP) during ureteroscopy (URS). Methods: A customized questionnaire was designed in a 4-step iterative process incorporating a systematic review of the literature and critical analysis of topics/questions by six endourologists. The 19-item questionnaire interrogated perceptions, practice patterns, and key areas of uncertainty regarding ureteroscopic IRP, and was disseminated via urologic societies, networks, and social media to the international urologic community. Consultants/attendings and trainees currently practicing urology were eligible to respond. Quantitative responses were compiled and analyzed using descriptive statistics and chi-square test, with subgroup analysis by procedure volume. Results: Responses were received from 522 urologists, practicing in six continents. The individual question response rate was >97%. Most (83.9%, 437/515) respondents were practicing at a consultant/attending level. An endourology fellowship incorporating stone management had been completed by 59.2% (307/519). The vast majority of respondents (85.4%, 446/520) scored the perceived clinical significance of IRP during URS ≥7/10 on a Likert scale. Concern was uniformly reported, with no difference between respondents with and without a high annual case volume (p = 0.16). Potential adverse outcomes respondents associated with elevated ureteroscopic IRP were urosepsis (96.2%, 501/520), collecting system rupture (80.8%, 421/520), postoperative pain (67%, 349/520), bleeding (63.72%, 332/520), and long-term renal damage (26.1%, 136/520). Almost all participants (96.2%, 501/520) used measures aiming to reduce IRP during URS. Regarding the perceived maximum acceptable threshold for mean IRP during URS, 30 mm Hg (40 cm H2O) was most frequently selected [23.2% (119/463)], with most participants (78.2%, 341/463) choosing a value ≤40 mm Hg. Conclusions: This is the first large-scale analysis of urologists' perceptions of ureteroscopic IRP. It identifies high levels of concern among the global urologic community, with almost unanimous agreement that elevated IRP is associated with adverse clinical outcomes. Equipoise remains regarding appropriate IRP limits intraoperatively and the most appropriate technical strategies to ensure adherence to these.

A Good Craftsperson Knows Their Tools: Understanding of Laser and Ureter Mechanics in Training Urologists.

Introduction: Recent decades have seen a move to minimally invasive techniques to manage urolithiasis. Trainees are expected to develop competency in common endourology procedures. Knowledge of ureter mechanics and the theory behind new technologies is important to ensure safe and efficient techniques. We aim to evaluate the exposure to endourology, self-reported competency in common techniques and knowledge of basic ureter biomechanics and technology in training urologists. Methods: An online survey was circulated to all training urologists in the Republic of Ireland. Questions focused on self-reported competency, clinical knowledge, ureter mechanical properties and laser technology. Results: Thirty responses were received with a range of 1-8 years of urology experience (mean=4 years). The respondents reported high levels of exposure to endourology with the majority reporting competency in flexible ureterorenoscopy (FURS) (n=18, 60%) and semi-rigid ureteroscopy (URS) (n=21, 70%). The respondents demonstrated good clinical knowledge but variable knowledge of laser settings, laser thermodynamics and ureter mechanics. Half of the respondents (n=15, 50%) correctly described fragmentation laser settings, with 10 trainees (n=33%) accurately identifying both factors that increase ureteral access sheath (UAS) insertion force. Most of the respondents (n=20, 67%) described the proximal ureter as the site with the greatest compliance, while the site of the greatest force during ureteroscope insertion was correctly identified by 17% (n=5). Conclusion: To our knowledge, this represents the first study evaluating urologist understanding of laser technology and the mechanical properties of the human ureter. Despite trainees reporting high levels of experience in endourology, there is a variable understanding of the principles of laser technology and ureter mechanics. Further research and education are needed with a focus on laser safety, suitable laser settings and the safe limit of insertion forces.

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.

Mechanical and morphological characterisation of porcine urethras for the assessment of paediatric urinary catheter safety.

Paediatric urinary catheters are often necessary in critical care settings or to address congenital anomalies affecting the urogenital system. Iatrogenic injuries can occur during the placement of such catheters, highlighting the need for a safety device that can function in paediatric settings. Despite successful efforts to develop devices that improve the safety of adult urinary catheters, no such devices are available for use with paediatric catheters. This study investigates the potential for utilising a pressure-controlled safety mechanism to limit the trauma experienced by paediatric patients during inadvertent inflation of a urinary catheter anchoring balloon in the urethra. Firstly, we establish a paediatric model of the human urethra using porcine tissue by characterising the mechanical and morphological properties of porcine tissue at increasing postnatal timepoints (8, 12, 16 and 30 weeks). We identified that porcine urethras harvested from pigs at postnatal week 8 and 12 exhibit morphological properties (diameter and thickness) that are statistically distinct from adult porcine urethras (postnatal week 30). We therefore utilise urethra tissue from postnatal week 8 and 12 pigs as a model to evaluate a pressure-controlled approach to paediatric urinary catheter balloon inflation intended to limit tissue trauma during inadvertent inflation in the urethra. Our results show that limiting catheter system pressure to 150 kPa avoided trauma in all tissue samples. Conversely, all of the tissue samples that underwent traditional uncontrolled urinary catheter inflation experienced complete rupture. The findings of this study pave the way for the development of a safety device for use with paediatric catheters, thereby alleviating the burden of catastrophic trauma and life changing injuries in children due to a preventable iatrogenic urogenital event.

Single-Use Ureteroscopy and Environmental Footprint: Review of Current Evidence.

PURPOSE OF REVIEW: Ureteroscopy is a well-established treatment modality for kidney and ureteric calculi in addition to playing a key role in upper tract cancer diagnostics. Traditional reusable flexible ureteroscopes are technologically advanced and expensive pieces of equipment that require repeat sterilisation and periodical repair. These issues have led to the development of single-use flexible ureteroscopes that are disposed of after each case. Whilst this may be advantageous in many respects, the environmental impact of such technology is yet to be fully determined. The aim of this review is to therefore identify and summarise the available literature concerning the environmental footprint of single-use ureteroscopy. RECENT FINDINGS: To identify the latest research on this topic, a systematic search of world literature was conducted using the Medline, Embase, and PsycINFO databases. PRISMA guidelines were followed and articles were assessed by all authors and relevant study results were included in a narrative format. Only one relevant article was identified and included. This study found that a single-use flexible ureteroscope (LithoVueTM by Boston Scientific) generated an equivalent amount of carbon dioxide per case to a contemporary reusable flexible ureteroscope. Literature concerning the environmental footprint of single-use ureteroscopy is worryingly lacking. No conclusions can be definitively drawn from a single study and further research is imperative given the global climate crisis and the significant contribution that healthcare services have to the environmental problem.

Upper urinary tract pressures in endourology: a systematic review of range, variables and implications.

OBJECTIVES: To systematically review the literature to ascertain the upper tract pressures generated during endourology, the relevant influencing variables and clinical implications. MATERIALS AND METHODS: A systematic review of the MEDLINE, Scopus and Cochrane databases was performed by two authors independently (S.C., N.D.). Studies reporting ureteric or intrarenal pressures (IRP) during semi-rigid ureteroscopy (URS)/flexible ureterorenoscopy (fURS)/percutaneous nephrolithotomy (PCNL)/miniaturized PCNL (mPCNL) in the period 1950-2021 were identified. Both in vitro and in vivo studies were considered for inclusion. Findings were independently screened for eligibility based on content, with disagreements resolved by author consensus. Data were assessed for bias and compiled based on predefined variables. RESULTS: Fifty-two studies met the inclusion criteria. Mean IRP appeared to frequently exceed a previously proposed threshold of 40 cmH2 O. Semi-rigid URS with low-pressure irrigation (gravity <1 m) resulted in a wide mean IRP range (lowest reported 6.9 cmH2 O, highest mean 149.5 ± 6.2 cmH2 O; animal models). The lowest mean observed with fURS without a ureteric access sheath (UAS) was 47.6 ± 4.1 cmH2 O, with the maximum peak IRP being 557.4 cmH2 O (in vivo human data). UAS placement significantly reduced IRP during fURS, but did not guarantee pressure control with hand-operated pump/syringe irrigation. Miniaturization of PCNL sheaths was associated with increased IRP; however, a wide mean human IRP range has been recorded with both mPCNL (lowest -6.8 ± 2.2 cmH2 O [suction sheath]; highest 41.2 ± 5.3 cmH2 O) and standard PCNL (lowest 6.5 cmH2 O; highest 41.2 cmH2 O). Use of continuous suction in mPCNL results in greater control of mean IRP, although short pressure peaks >40 cmH2 O are not entirely prevented. Definitive conclusions are limited by heterogeneity in study design and results. Postoperative pain and pyrexia may be correlated with increased IRP, however, few in vivo studies correlate clinical outcome with measured IRP. CONCLUSIONS: Intrarenal pressure generated during upper tract endoscopy often exceeds 40 cmH2 O. IRP is multifactorial in origin, with contributory variables discussed. Larger prospective human in vivo studies are required to further our understanding of IRP thresholds and clinical sequelae.