Ureteral stricture rate after endoscopic treatments for urolithiasis and related risk factors: systematic review and meta-analysis.

PURPOSE: We aimed to accurately determine ureteral stricture (US) rates following urolithiasis treatments and their related risk factors. METHODS: We conducted a systematic review and meta-analysis following the PRISMA guidelines using databases from inception to November 2023. Studies were deemed eligible for analysis if they included ≥ 18 years old patients with urinary lithiasis (Patients) who were subjected to endoscopic treatment (Intervention) with ureteroscopy (URS), percutaneous nephrolithotomy (PCNL), or shock wave lithotripsy (SWL) (Comparator) to assess the incidence of US (Outcome) in prospective and retrospective studies (Study design). RESULTS: A total of 43 studies were included. The pooled US rate was 1.3% post-SWL and 2.1% post-PCNL. The pooled rate of US post-URS was 1.9% but raised to 2.7% considering the last five years' studies and 4.9% if the stone was impacted. Moreover, the pooled US rate differed if follow-ups were under or over six months. Patients with proximal ureteral stone, preoperative hydronephrosis, intraoperative ureteral perforation, and impacted stones showed higher US risk post-endoscopic intervention with odds ratio of 1.6 (P = 0.05), 2.6 (P = 0.009), 7.1 (P < 0.001), and 7.47 (P = 0.003), respectively. CONCLUSIONS: The overall US rate ranges from 0.3 to 4.9%, with an increasing trend in the last few years. It is influenced by type of treatment, stone location and impaction, preoperative hydronephrosis and intraoperative perforation. Future standardized reporting and prospective and more extended follow-up studies might contribute to a better understanding of US risks related to calculi treatment.

Evolución y perfeccionamiento de técnicas endourológicas (urs y nlpc) sin fluoroscopia. Revisión sistemática de la literatura / Has fluoroless endourology (URS and PCNL) come of age? Evidence from a comprehensive literature review

Introducción La radiación es una herramienta fundamental en las técnicas de imagen ampliamente utilizadas en el manejo de los cálculos renales. Entre las medidas básicas que suelen adoptar los endourólogos para reducir la cantidad de exposición a la radiación, se encuentran el principio As Low As Reasonably Achievable (ALARA) —basado en reducir el uso de la radiación tanto como sea razonablemente posible— y el empleo de técnicas sin fluoroscopia. Se realizó una revisión exploratoria de la literatura para investigar el éxito y la seguridad de la ureteroscopia (URS) o la nefrolitotomía percutánea (NLPC) sin fluoroscopia para el tratamiento de los cálculos renales. Métodos Se realizó una revisión de la literatura mediante la búsqueda en las bases de datos bibliográficas PubMed, EMBASE y la biblioteca Cochrane, y se incluyeron en la revisión 14 artículos completos de acuerdo con las directrices de la declaración PRISMA. Resultados De un total de 2.535 procedimientos analizados, se realizaron 823 URS sin fluoroscopia frente a 556 URS con fluoroscopia, y 734 NLPC sin fluoroscopia frente a 277 NLPC con fluoroscopia. La tasa libre de cálculos (TLC) de la URS sin fluoroscopia frente a la guiada por fluoroscopia fue del 85,3 y el 77%, respectivamente (p=0,2), y las TLC de la NLPC sin fluoroscopia frente al grupo con fluoroscopia fueron del 83,8 y el 84,6%, respectivamente (p=0,9). Las complicaciones globales Clavien-Dindo I/II y III/IV para los procedimientos con y sin fluoroscopia fueron del 3,1 (n=71), 8,5 (n=131), 1,7 (n=23) y 3% (n=47), respectivamente. Solo 5 estudios informaron de un fracaso del abordaje realizado con fluoroscopia, con un total de 30 (1,3%) procedimientos fallidos. Conclusión Durante los últimos años han surgido diversas maneras de aplicar el protocolo ALARA en endourología en un esfuerzo por proteger tanto a los pacientes como al personal sanitario. ... (AU)

Introduction Radiation via the use of imaging is a key tool in management of kidney stones. Simple measures are largely taken by the endourologists to implement the ‘As Low As Reasonably Achievable’ (ALARA) principle, including the use of fluoroless technique. We performed a scoping literature review to investigate the success and safety of fluoroless ureteroscopy (URS) or percutaneous nephrolithotomy (PCNL) procedures for the treatment of KSD. Methods A literature review was performed searching bibliographic databases PubMed, EMBASE and Cochrane library, and 14 full papers were included in the review in accordance with the PRISMA guidelines. Results Of the 2535 total procedures analysed, 823 were fluoroless URS vs. 556 fluoroscopic URS; and 734 fluoroless PCNL vs. 277 fluoroscopic PCNL. The SFR for fluoroless vs. fluoroscopic guided URS was 85.3% and 77%, respectively (P=.2), while for fluoroless PCNL vs. fluoroscopic group was 83.8% and 84.6%, respectively (P=.9). The overall Clavien-Dindo I/II and III/IV complications for fluoroless and fluoroscopic guided procedures were 3.1% (n=71) and 8.5% (n=131), and 1.7% (n=23) and 3% (n=47) respectively. Only 5 studies reported a failure of the fluoroscopic approach with a total of 30 (1.3%) failed procedures. Conclusion The ALARA protocol has been implemented in endourology in numerous ways to protect both patients and healthcare workers during recent years. Fluoroless procedures for treatment of KSD are safe and effective with outcomes comparable to standard procedures and could become the new frontier of endourology in selected cases. (AU)

Has fluoroless endourology (URS and PCNL) come of age? Evidence from a comprehensive literature review.

INTRODUCTION: Radiation via the use of imaging is a key tool in management of kidney stones. Simple measures are largely taken by the endourologists to implement the 'As Low As Reasonably Achievable' (ALARA) principle, including the use of fluoroless technique. We performed a scoping literature review to investigate the success and safety of fluoroless ureteroscopy (URS) or percutaneous nephrolithotomy (PCNL) procedures for the treatment of KSD. METHODS: A literature review was performed searching bibliographic databases PubMed, EMBASE and Cochrane library, and 14 full papers were included in the review in accordance with the PRISMA guidelines. RESULTS: Of the 2535 total procedures analysed, 823 were fluoroless URS vs. 556 fluoroscopic URS; and 734 fluoroless PCNL vs. 277 fluoroscopic PCNL. The SFR for fluoroless vs. fluoroscopic guided URS was 85.3% and 77%, respectively (p=0.2), while for fluoroless PCNL vs. fluoroscopic group was 83.8% and 84.6%, respectively (p=0.9). The overall Clavien-Dindo I/II and III/IV complications for fluoroless and fluoroscopic guided procedures were 3.1% (n=71) and 8.5% (n=131), and 1.7% (n=23) and 3% (n=47) respectively. Only 5 studies reported a failure of the fluoroscopic approach with a total of 30 (1.3%) failed procedures. CONCLUSION: The ALARA protocol has been implemented in endourology in numerous ways to protect both patients and healthcare workers during recent years. Fluoroless procedures for treatment of KSD are safe and effective with outcomes comparable to standard procedures and could become the new frontier of endourology in selected cases.

Experimental and clinical applications and outcomes of using different forms of suction in retrograde intrarenal surgery. Results from a systematic review.

OBJECTIVE: To identify the latest advances in suction devices and evaluate their effect in Retrograde intrarenal surgery (RIRS) and ureteroscopy for stones. BASIC PROCEDURES: A systematic literature search was performed on 4th January 2023 using Scopus, PubMed, and EMBASE. Only English papers were included; both pediatric and adult studies were accepted. Duplicate studies, case reports, letters to the editor, and meeting abstracts were excluded. MAIN FINDINGS: Twenty-one papers were selected. Several methods have been proposed for suction use in RIRS, such as through the ureteral access sheath or directly to the scope. Artificial intelligence can also regulate this system, monitoring pressure and perfusion flow values. All the proposed techniques showed satisfactory perioperative results for operative time, stone-free rate (SFR), and residual fragments. Moreover, the reduction of intrarenal pressure (induced by aspiration) was also associated with a lower infection rate. Even the studies that considered kidney stones with a diameter of 20 mm or higher reported higher SFR and reduced postoperative complications. However, the lack of well-defined settings for suction pressure and fluid flow prevents the standardization of the procedure. CONCLUSION: Aspiration device in the surgical treatment of urinary stones favours a higher SFR, reducing infectious complications, as supported by the included studies. RIRS with a suction system provided to be a natural successor to the traditional technique, regulating intrarenal pressure and aspirating fine dust.

Atlas of 35 patient reported outcome measures (PROMs) in andrology: a comprehensive overview of literature.

INTRODUCTION: Disorders of male sexual health and functioning are complex and can have significant deleterious effects on patients psychological wellbeing and interpersonal relationships. It is well recognised that clinicians have an overall poor understanding of the true effect that disease has on their patients and self-reported patient-reported outcome measures (PROMs) aim to better communicate these issues. PROMs are generally welcomed by patients and their use in this highly sensitive area of clinical practice is well recognised. An atlas of available PROMs for key conditions in andrology is presented in this article. METHODS: A comprehensive search of world literature was conducted from the inception of databases to June 2022, to identify male-specific PROMs relevant to four key andrological disorders: hypogonadism, erectile dysfunction, penile curvature and disorders of ejaculation. Each tool was evaluated in narrative format. RESULTS: 35 PROMs were identified. 6 were designed for the assessment of hypogonadism, 18 for erectile dysfunction, one for penile curvature and 10 for ejaculatory disorders. In general, PROMs were brief, self-administered and user-friendly. There was sufficient scope and variety in all categories (apart from penile curvature) to give the clinician flexibility in tool selection and find an appropriate tool for different scenarios. CONCLUSION: A number of PROMs exist within andrology that can be utilised in both research and clinical settings. PROMs enable subjective evaluation of difficult-to-assess aspects of the patient experience.

Global outcomes and lessons learned in the management of Fournier's gangrene from high-volume centres: findings from a literature review over the last two decades.

INTRODUCTION: Fournier's Gangrene (FG) carries a high mortality and morbidity with underreported short and long-term outcomes. Our aim was to perform a review of the recent literature to evaluate the short and long-term outcomes in patients with FG in the acute setting from large-scale studies. METHODS: A PubMed search was performed between January 2000 and December 2021 for studies reporting on patients with FG. Exclusion criteria included small samples (n < 100), review articles and animal studies. Primary outcomes of interest were mortality, number of operative episodes for surgical debridement and admission to intensive care unit (ICU). Other outcomes assessed included rate of faecal and urinary diversion, orchidectomy rate, penectomy rate and length of hospital stay. RESULTS: From a total of 1182 studies, 18 were eligible for inclusion and included in this review. In total, data were analysed from 13,903 FG patients. Mean inpatient mortality rate was 7.3% (range 4.7-40.4%). Mean number of surgical debridement operations performed was 1.8 (range 1.5-4.2). On average, 6.8% (range 3.6-50.5%) and 7% (range 1.2-53.2%) underwent faecal and urinary diversions, respectively. Mean rate of orchidectomy was 5.6%, with rate of penectomy being lower at 0.2%. The mean length of hospital stay was 18.5 days (range 13.0-26.6). On average, 17.5% (range 10.1%-67.5%) required ICU admission for at least a single-system support. CONCLUSION: Our review from the past twenty years of literature suggests that the mortality for FG, whilst still high, has fallen compared to previous years. Whilst inpatient metrics are well-covered in the literature there is a lack of large-scale studies detailing long-term patient outcomes.

Role of pre-operative ureteral stent on outcomes of retrograde intra-renal surgery (RIRS): systematic review and meta-analysis of 3831 patients and comparison of Asian and non-Asian cohorts.

PURPOSE: To evaluate the outcomes of pre-stented (PS) versus non-pre-stented (NPS) patients who have undergone retrograde intrarenal surgery (RIRS) for renal calculi with subgroup analysis of Asian and non-Asian cohorts. METHODS: Protocol is registered in PROSPERO, CRD42021261123. Eligible studies identified from four electronic databases. Meta-analysis was done to enumerate the outcomes of RIRS in between PS and NPS. Secondary sub-analysis was done to look for differences in outcomes in Asian and non-Asian cohorts. RESULTS: Fourteen studies involving 3831 patients (4 prospective, 10 retrospective studies) were included. PS patients experienced higher success rates of ureteral access sheath (UAS) insertion than NPS (RR 1.09, 95% CI 1.05-1.13, p < 0.00001). PS patients had lower risk of ureteral injuries from UAS placement (RR 0.69, 95% CI 0.50-0.96, p = 0.03). No significant differences in intra- and postoperative complications between two groups were found. Stone-free rate (SFR) outcomes for residual fragment (RF) cut-off of < 1 mm and < 4 mm favoured the PS patients (RR 1.10, 95% CI 1.04-1.17, p = 0.002 for < 4 mm, RR1.10, 95% CI 1.02-1.19, p = 0.02 for < 1 mm). In the subgroup analysis, PS Asian patients had similar SFR as NPS patients for SFR(< 4 mm) but non-Asian population showed better outcomes in the PS patients for SFR(< 4 mm) (RR 1.31, 95% CI 1.13-1.52, p = 0.0005). CONCLUSIONS: This meta-analysis suggests that pre-stenting results in a higher success for UAS placement, minimising intraoperative ureteric injury, with higher overall SFR for any RF cut-off in PS cohorts. In non-Asian cohort, significant differences occurred at SFR < 4 mm but not for SFR < 1 mm. No difference was seen in our Asian cohort for any SFR cut-off in both PS and NPS patients.

Association of Kidney Stone Disease (KSD) with Primary Gastrointestinal Surgery: a Systematic Review over Last 2 Decades.

PURPOSE OF REVIEW: We aim to provide an up-to-date literature review to further characterise the association of kidney stone disease (KSD) with gastrointestinal (GI) surgery. As KSD is associated with significant morbidity, it is important to quantify and qualify this association to provide better care and management for the patient subgroup. OBJECTIVE: To perform a systematic review of the existing literature to evaluate the association of KSD following GI surgery. METHODS: A literature search was performed of the following databases: MEDLINE, EMBASE, Scopus, Google Scholar, Key Urology, Uptodate and Cochrane Trials from January 2000 to June 2020. RECENT FINDINGS: A total of 106 articles were identified, and after screening for titles, abstracts and full articles, 12 full papers were included. This involved a total of 9299 patients who underwent primary GI surgery. Over a mean follow-up period of 5.4 years (range: 1-14.4 years), 819 (8.8%) developed KSD, varying from 1.2 to 83% across studies. The mean time to stone formation was approximately 3 years (range: 0.5-9 years). In the 4 studies that reported on the management of KSD (n = 427), 38.6% went on to have urological intervention. There is a high incidence of KSD following primary GI surgery, and after a mean follow-up of 3 years, around 9% of patients developed KSD. While the GI surgery was done for obesity, inflammatory bowel disease or cancer, the risk of KSD should be kept in mind during follow-up, and prompt urology involvement with metabolic assessment, medical and or surgical management offered as applicable.

Safety and Outcomes of using ureteric access sheath (UAS) for treatment of Pediatric renal stones: Outcomes from 2 tertiary endourology centers.

OBJECTIVE: To look at the safety and outcomes of using ureteral access sheath (UAS) for pediatric renal stones. The use of UAS is variable in urological practice with very little clinical work on their use in pediatric kidney stone disease. PATIENTS AND METHODS: Data was retrospectively collected from 2 large European tertiary endourology centers for all pediatric patients (≤16 years) with renal stones who underwent flexible ureteroscopy and lasertripsy (FURSL) via UAS. Data was collected on patient details, stone demographics and clinical outcomes of the FURSL procedure. RESULTS: Forty-eight patients with a mean age of 10.7 years were treated with FURSL for a mean single and cumulative stone size of 10.4 mm and 15 mm respectively, with two-third having multiple stones and stones in the lower pole. The initial and final stone free rate (SFR) was 66.7% and 100% respectively with 1.3 procedures/patient. One patient each had intra-operative grade 1 ureteric injury and post-operative UTI, with no other injuries or complications noted. Over a mean follow-up of 17 months, no other complications were noted. CONCLUSION: Ureteral access sheath is safe for treatment of pediatric renal stones with excellent outcomes and are especially useful for larger or multiple stones. While there does not seem to be any medium-term sequalae, to avoid risk of ureteral injury, we would suggest using the smallest size sheath possible. We would argue these procedures are best done in specialist high-volume endourology units for optimal results.

Water vapor therapy (Rezum) for lower urinary tract symptoms related to benign prostatic hyperplasia: early results from the first Italian multicentric study.

PURPOSE: Rezum is the latest developed minimally invasive treatment for benign prostatic hyperplasia (BPH). We aimed to carefully assess the functional outcomes of patients treated with Rezum for BPH. METHODS: We prospectively followed 135 consecutive patients treated by Rezum at 5 institutions from June 2019 to August 2020. The International Prostate Symptom Score (IPSS), International Consultation on Incontinence Questionnaire-Short Form (ICIQ-UI SF), the Overactive Bladder Questionnaire-Short Form (OAB-q SF) score, the International Index of Erectile Function (IIEF-5) and questions 9 and 10 to assess ejaculatory dysfunction were recorded. Election criteria were age > 18, no prior prostate interventions, IPSS ≥ 13, post-void residual ≤ 250 mL, prostate volume between 30 and 120 cc. RESULTS: The median operative time was 10.5 (IQR 8.7-15) min. All patients were dismissed few hours after surgery with indwelling urinary catheter that was removed after a median of 7 (IQR 7-10) days. A significantly decrease of IPSS from baseline at first (p = 0.001) and third (p < 0.0001) month after surgery was reported. No difference was reported in terms of ICIQ-UI SF score postoperatively. A mild reduction of the OAB-q SF score was reported at 1 month from surgery (p = 0.06) that turned significant at 3 months postoperatively (p < 0.0001). A slight but statistically significant increase of the IIEF-5 score was reported from baseline at 6 months (p = 0.04). Postoperatively, patients reported a significantly decrease of ejaculatory dysfunction after alpha-blocker interruption. CONCLUSION: Rezum treatment is a feasible minimally invasive option for patients with BPH symptoms and showed optimal early functional outcomes.

Polyethylene glycol-based hydrogel rectal spacers for prostate brachytherapy: a systematic review with a focus on technique.

INTRODUCTION: Radiation dose to the rectum in prostate brachytherapy (PBT) can be reduced by the use of polyethylene glycol (PEG) hydrogel spacers. This reduces the rate of rectal toxicity and allows dose escalation to the prostate. Our objectives were to provide an overview of technique for injection of a PEG hydrogel spacer, reduction in rectal dosimetry, gastrointestinal toxicity and potential complications. METHODS: We systematically reviewed the role of PEG hydrogel spacers in PBT using the Cochrane and PRISMA methodology for all English-language articles from January 2013 to December 2019. Data was extracted for type of radiotherapy, number of patients, type of PEG-hydrogel used, mean prostate-rectum separation, rectal dosimetry, acute and late GI toxicity, procedure-related complications and the technique used for hydrogel insertion. RESULTS: Nine studies (671 patients and 537 controls) met our inclusion criteria. Of these 4 used DuraSeal® and 5 used SpaceOAR®. The rectal spacing achieved varied between 7.7-16 mm. Failure of hydrogel insertion was seen only in 12 patients, mostly related to failure of hydrodissection in patients undergoing salvage PBT. Where reported, the rectal D2 cc was reduced by between 21.6 and 52.6% and the median rectal V75% cc was reduced by between 91.8-100%. Acute GI complications were mostly limited to grade 1 or 2 toxicity (n = 153, 33.7%) with low levels of grade 3 or 4 toxicity (n = 1, 0.22%). Procedure-related complications were limited to tenesmus (0.14%), rectal discomfort (1.19%), and bacterial prostatitis (0.44%). CONCLUSIONS: PEG hydrogel spacers are safe to insert. Gel insertion is easy, fast and has a low rate of failure. These studies convincingly demonstrate a significant reduction in rectal dosimetry. Although the results of spacers in reducing rectal toxicity is promising, these need to be confirmed in prospective randomised trial.

Role of Complementary Medicine (Music, Acupuncture, Acupressure, TENS and Audio-Visual Distraction) in Shockwave Lithotripsy (SWL): A Systematic Review From EAU Sections of Urolithiasis (EULIS) and Uro-Technology (ESUT).

We performed a systematic review to look at the role of alternative or complementary medicine such as music, acupressure, acupuncture, transcutaneous electrical nerve stimulation (TENS) and audiovisual distractions to decrease analgesia requirement and alleviate anxiety during SWL. Twenty-three papers(2439 participants) were included: Music (n = 1056.6%), Acupuncture (n = 517.7%), Acupressure (n = 13.8%), TENS (n = 617.2%), and audiovisual distraction (n = 14.6%). Most of the studies showed that complementary therapy, lowered pain, and anxiety with higher patient satisfaction and willingness to undergo the procedure. With its feasibility and convenience, urological guidelines need to endorse it, and more should be done to promote its use in outpatient urological procedures.

Treatment of isolated small renal stones leads to resolution of symptoms and should be routinely offered to patients: retrospective outcomes from a university hospital.

INTRODUCTION: Treatment of smaller renal stones and the symptomatic value it offers to patients is often debated. We wanted to analyse surgical outcomes for treatment of small renal stones and whether treatment resulted in symptom resolution. MATERIALS AND METHODS: All patients who underwent ureterorenoscopy (URS) for isolated symptomatic small renal stones ≤10 mm over a 7-year period were retrospectively included and subdivided into those with stones of ≤7 mm (Group A) and stones of 8-10 mm (Group B). Patients with multiple renal stones, ureteric stones, or combined renal and ureteric stones were excluded. Based on the symptoms, the patient groups were those with pain, urinary tract infection (UTI) and haematuria. Resolution of symptoms was defined as no symptoms during the follow-up period. RESULTS: A total of 109 patients with a single small renal stone ≤10 mm underwent URS and stone treatment, with mean age of 50 years and a male:female ratio of 1:1.2. The mean operative time was significantly longer in Group B (55.9 min vs 33.07 min, p = 0.001). In total, 97.2% (n = 70) of patients in Group A and 83.7% (n = 31) of patients in Group B were stone free (p = 0.017). Complete resolution of symptoms was seen in 63 (92.6%), 24 (85.7%) and 13 (100%) patients with pain, UTI and haematuria, respectively. There were no statistically significant differences in symptom resolution between patients with stones ≤7 mm and those with stones 8-10 mm in size. CONCLUSION: Ureteroscopic treatment is a feasible option for small symptomatic stones, since it may lead to symptom resolution. Based on our study we would recommend that patients with symptomatic small renal stones are offered endoscopic treatment.

Fluoroless Endourological Surgery for Stone Disease: a Review of the Literature-Tips and Tricks.

PURPOSE OF REVIEW: Urologists are at significant risk due to radiation exposure (RE) from endourological procedures for stone disease. Many techniques described have shown a reduction of RE. The purpose of this article is to review available protocols to decrease RE during such procedures and provide tips and tricks for their implementation. RECENT FINDINGS: Several low-radiation and radiation-free protocols for percutaneous nephrolithotomy and flexible ureteroscopy have been described as an attempt to reduce RE during surgery. Beginning with specific checklists to ensure adequate C-arm usage, fluoroless procedures are based on endoscopic assessment, tactile guidance, and use of ultrasound to avoid fluoroscopy. A specific preoperative checklist and low radiation or complete fluoroless radiation endourological procedures have shown to be effective, feasible, and safe. It is recommended for urologists to be aware of the risks of RE and apply the "ALARA" (As Low As Reasonably Achievable) protocols.

Is remote live urologic surgery a reality? Evidences from a systematic review of the literature.

INTRODUCTION AND OBJECTIVES: The possibility of performing remote-surgery has been the goal to achieve, since the early development of the first surgical robotic platforms. This systematic review aims to analyse the state of the art in the field and to provide an overview of the possible growth of this technology. METHODS: All English language publications on Telementoring and Telesurgery for minimally invasive urologic procedures were evaluated. We followed the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) statement to evaluate PubMed®, Scopus®, and Web of Science™ databases (up to June 2019). RESULTS: Our electronic search identified a total of 124 papers in PubMed, Scopus, and Web of Science. Of these, 81 publications were identified for detailed review, which yielded 22 included in the present systematic review. Our results showed that remote surgery has been under-utilised until today, mostly due to the lack of appropriate telecommunication technologies. CONCLUSION: Remote live surgery is a growing technology that is catalyzing incremental interest. Despite not being yet reliable today on a regular basis in its most advanced applications, thanks to the advent of novel data-transmission technologies, telepresence might become a critical educational methodology, highly impacting the global healthcare system.

Reducing deposition of encrustation in ureteric stents by changing the stent architecture: A microfluidic-based investigation.

Ureteric stents are clinically deployed to retain ureteral patency in the presence of an obstruction of the ureter lumen. Despite the fact that multiple stent designs have been researched in recent years, encrustation and biofilm-associated infections remain significant complications of ureteral stenting, potentially leading to the functional failure of the stent. It has been suggested that "inactive" side-holes of stents may act as anchoring sites for encrusting crystals, as they are associated with low wall shear stress (WSS) levels. Obstruction of side-holes due to encrustation is particularly detrimental to the function of the stent, since holes provide a path for urine to by-pass the occlusion. Therefore, there is an unmet need to develop novel stents to reduce deposition of encrusting particles at side-holes. In this study, we employed a stent-on-chip microfluidic model of the stented and occluded ureter to investigate the effect of stent architecture on WSS distribution and encrustation over its surface. Variations in the stent geometry encompassed (i) the wall thickness and (ii) the shape of side-holes. Stent thickness was varied in the range 0.3-0.7 mm, while streamlined side-holes of triangular shape were evaluated (with a vertex angle in the range 45°-120°). Reducing the thickness of the stent increased WSS and thus reduced the encrustation rate at side-holes. A further improvement in performance was achieved by using side-holes with a triangular shape; notably, a 45° vertex angle showed superior performance compared to other angles investigated, resulting in a significant increase in WSS within "inactive" side-holes. In conclusion, combining the optimal stent thickness (0.3 mm) and hole vertex angle (45°) resulted in a ∼90% reduction in encrustation rate within side-holes, compared to a standard design. If translated to a full-scale ureteric stent, this optimised architecture has the potential for significantly increasing the stent lifetime while reducing clinical complications.

Ureteroscopy and laser stone fragmentation (URSL) for large (≥1 cm) paediatric stones: Outcomes from a university teaching hospital.

INTRODUCTION: The treatment of large renal stones (≥1 cm) in paediatric patients is challenging. The usual treatment options include percutaneous nephrolithotomy (PCNL) or shockwave lithotripsy (SWL). There is a rise in the use of ureteroscopy and laser stone fragmentation (URSL) for paediatric stones; however, outcomes of treatment for large renal stones in this age group are still largely unknown. OBJECTIVE: To investigate the outcome of URSL for large paediatric renal stones ≥1 cm treated at the present institution over the last 5 years. METHODS: A retrospective review was performed of outcomes from the prospectively maintained stone database. Only paediatric patients undergoing ureteroscopic (rigid or flexible ureteroscopy (URS)) procedures for stones ≥1 cm were included. Patient demographics, operative details, stone burden, hospital stay, complications and stone clearance were recorded and analysed. RESULTS: From April 2010 to June 2015, 18 paediatric patients with a mean age of 10.4 years (range 3.6-15) underwent 35 ureteroscopic procedures for large stones (≥1 cm). The stone location was in the kidney (n = 14), ureter (n = 1), and in both the kidney and ureter for the remaining three patients. Nine patients had multiple stones. There was a preceding history of PCNL in four patients, with one patient having URS combined with a PCNL. The mean follow-up was 2.7 years (range 0-5). A postoperative stent was inserted in 21 (60%) patients. The overall stone-free rate (SFR) was 89% for a mean of 1.8 procedures per patient (range 1-4) - see Summary Table below. There was an inability to access stone within a lower pole calyx in one patient, despite maximum deflection of the ureteroscope. No intra- or post-operative complications were noted, and mean hospital stay was 1.1 days (range 0-5). DISCUSSION: Published papers in adult literature have shown that ureteroscopy and laser fragmentation (URSL) is a viable alternative to PCNL. Newer equipment and improved techniques have resulted in SFRs being comparable with PCNL. A recent systematic review reported an SFR of 91% for large adult stones (>2 cm) for a mean 1.45 procedures per patient, and an overall complication rate of 8.6%. The present study has also demonstrated excellent outcomes in the use of ureteroscopy and laser fragmentation for the management of large paediatric stones with no complications. CONCLUSION: The results show that paediatric URSL for large stones achieves a good SFR with minimal morbidity and is a good treatment option in established endourological units.

Ultra-low-dose, low-dose, and standard-dose CT of the kidney, ureters, and bladder: is there a difference? Results from a systematic review of the literature.

AIM: To investigate whether reducing the radiation dose of computed tomography (CT) of the kidney, ureters, and bladder (KUB) for acute renal colic impacts upon the specificity, sensitivity, and detection of urolithiasis. MATERIALS AND METHODS: A systematic review of the literature over a 20-year period between 1995 and 2015 was conducted of all prospective studies in the English language reporting on adult patients who underwent CT KUB or non-contrast CT for renal colic or urolithiasis. Retrospective studies and those that included pregnant females, children, non-human test subjects, cadaveric use, and simulations were excluded. Data were collected using an Excel spreadsheet and ultra-low-dose (ULD CT) and low-dose CT KUB (LD CT) was defined as a radiation dose ≤1.9 and <3.5 mSv, respectively. RESULTS: A total of 417 articles were identified, and after screening, seven articles (1,104 patients) were included in the present study with a male:female ratio of 3:2. Of the four studies with ULD CT for both males and females, the prevalence of urolithiasis ranged from 36% and 73%, with additional pathologies found in 12-15%. The effective radiation dose of ULD CT ranged from 0.5-1.9 mSv. Overall, ULD CT and LD CT had a sensitivity of 90-100% and a specificity of 86-100% across all studies. CONCLUSIONS: ULD CT and LD CT are effective techniques and yield high sensitivity and specificity. Although they yield comparable results against standard-dose CT KUB in detecting alternative diagnoses, they may not be as effective in detecting stones <3 mm in size or in patients with a body mass index of >30 kg/m2; however, this should be the first-line investigation for the majority of renal colic patients in the modern era.

Complications associated with ureterorenoscopy (URS) related to treatment of urolithiasis: the Clinical Research Office of Endourological Society URS Global study.

INTRODUCTION: Ureterorenoscopy (URS) is a popular and growing option for management of ureteric and renal stones. The CROES URS Global Study was set up to assess the outcomes of URS in a large worldwide cohort of patients involving multiple centres. In this paper, we analysed the database for intra-operative and post-operative complications associated with ureterorenoscopy. METHODS: The CROES database was established via collaboration between 114 centres in 32 countries worldwide, and information on both intra-operative and post-operative complications was collected electronically between January 2010 and October 2012. RESULT: On analysis of a total of 11,885 patients, the overall complication and stone-free rates were found to be 7.4 and 85.6 %, respectively. The intra-operative and post-operative complication rates were 4.2 and 2.6 %, respectively, and in total 5 deaths were reported in the study period. Taking into account different world economies, there were no differences in the complication rates between the developing and developed nations or between different centres from different continents. CONCLUSION: Ureterorenoscopy is a safe and effective procedure for treatment of stones, the outcomes of which are broadly comparable in different parts of the world for similar patient and stone demographics.

Outcome-Based Comparison of Percutaneous Procedures for Urinary Lithiasis with Calibre of Instrumentation less than 12Fr.

Renal stone disease is becoming increasingly prevalent globally. With a rise in stone disease worldwide, there is also a relative increase in the rates of surgical intervention. Technological advances have allowed a move towards minimising the complications rates and length of stay with a reduction in invasiveness and size of instruments. A trend for minimising the percutaneous tract size has been noted in percutaneous nephrolithotomy (PCNL) for renal stones. The management has shifted from open surgery to standard PCNL, mini-PCNL and the latest ultra-mini and micro-PCNL techniques. There is a need to compare outcomes for the ever-advancing technologies, such as the smaller calibre of instruments, to assess risk-benefit in practice. This review looks at outcome-based comparison of percutaneous procedures for urinary lithiasis with instruments <12Fr in size.