Dopamine facilitates associative memory encoding in the entorhinal cortex.

Mounting evidence shows that dopamine in the striatum is critically involved in reward-based reinforcement learning1,2. However, it remains unclear how dopamine reward signals influence the entorhinal-hippocampal circuit, another brain network that is crucial for learning and memory3-5. Here, using cell-type-specific electrophysiological recording6, we show that dopamine signals from the ventral tegmental area and substantia nigra control the encoding of cue-reward association rules in layer 2a fan cells of the lateral entorhinal cortex (LEC). When mice learned novel olfactory cue-reward associations using a pre-learned association rule, spike representations of LEC fan cells grouped newly learned rewarded cues with a pre-learned rewarded cue, but separated them from a pre-learned unrewarded cue. Optogenetic inhibition of fan cells impaired the learning of new associations while sparing the retrieval of pre-learned memory. Using fibre photometry, we found that dopamine sends novelty-induced reward expectation signals to the LEC. Inhibition of LEC dopamine signals disrupted the associative encoding of fan cells and impaired learning performance. These results suggest that LEC fan cells represent a cognitive map of abstract task rules, and that LEC dopamine facilitates the incorporation of new memories into this map.

'Spin' in urology non-randomised studies comparing therapeutic interventions: a temporal analysis.

OBJECTIVE: To determine the prevalence of 'spin' (i.e., reporting practices that distort the interpretation of results by positively reflecting negative findings or downplaying potential harms) strategies and level of spin in urological observational studies and whether the use of spin has changed over time. MATERIALS AND METHODS: MEDLINE and Embase were searched to identify observational studies comparing therapeutic interventions in the top five urology journals and major urological subspecialty journals, published between 2000 and 2001, 2010 and 2011, and 2020 and 2021. RESULTS: A total of 235 studies were included. Spin was identified in 81% of studies, with a median of two strategies per study. The most commonly used strategies were inadequate implication for clinical practice (30%), causal language or causal claim (29%), and use of linguistic spin (29%). Moderate to high levels of spin were found in 55% of conclusions. From 2000 to 2020, the average number of strategies used has significantly decreased each decade (H = 27.459, P < 0.001), and the median level of spin in conclusions was significantly lower in studies published in the 2020s and 2010s than in the 2000s (H = 11.649, P = 0.003). CONCLUSIONS: Our results suggest that 81% of urological observational studies comparing therapeutic interventions contained spin. Over the past two decades, the use of spin has significantly declined, but this remains an area for improvement, with 70% of included studies published in the 2020s employing spin. Medical writing should scrupulously avoid words or phrases that are not supported by data in the manuscript.

Impact of early surgical complications on kidney transplant outcomes.

BACKGROUND: Kidney transplantation (KT) improves clinical outcomes of patients with end stage renal disease. Little has been reported on the impact of early post-operative surgical complications (SC) on long-term clinical outcomes following KT. We sought to determine the impact of vascular complications, urological complications, surgical site complications, and peri-graft collections within 30 days of transplantation on patient survival, graft function, and hospital readmissions. METHODS: We conducted a single-centre, observational cohort study examining adult patients (≥ 18 years) who received a kidney transplant from living and deceased donors between January 1st, 2005 and December 31st, 2015 with follow-up until December 31st, 2016 (n = 1,334). Univariable and multivariable analyses were performed with Cox proportional hazards models to analyze the outcomes of SC in the early post-operative period after KT. RESULTS: The cumulative probability of SC within 30 days of transplant was 25%, the most common SC being peri-graft collections (66.8%). Multivariable analyses showed significant relationships between Clavien Grade 1 SC and death with graft function (HR 1.78 [95% CI: 1.11, 2.86]), and between Clavien Grades 3 to 4 and hospital readmissions (HR 1.95 [95% CI: 1.37, 2.77]). CONCLUSIONS: Early SC following KT are common and have a significant influence on long-term patient outcomes.

Assessing "Spin" in Urology Randomized Controlled Trials With Statistically Nonsignificant Primary Outcomes.

PURPOSE: "Spin" refers to a form of language manipulation that positively reflects negative findings or downplays potential harms. Spin has been reported in randomized controlled trials of other surgical specialties, which can lead to the recommendation of subpar or ineffective treatments. The goal of this study was to characterize spin strategies and severity in statistically nonsignificant urology randomized controlled trials. MATERIALS AND METHODS: A comprehensive search of MEDLINE and Embase for the top 5 urology journals, major urology subspecialty journals, and high-impact nonurology journals from 2019 to 2021 was conducted. Statistically nonsignificant randomized controlled trials with a defined primary outcome were included. Screening, data extraction, and spin assessment were performed in duplicate by 2 independent reviewers. RESULTS: From the database search of 4,339 studies, 46 trials were included for analysis. Spin was identified in 35 studies (76%), with the majority of abstracts (n = 26, 57%) and main texts (n = 35, 76%) containing some level of spin. "Obscuring the statistical nonsignificance of the primary outcome and focusing on statistically significant secondary results" was the most frequently used strategy in abstracts, while "other" strategies not previously defined were the most commonly used strategies in main texts. Moderate or high spin severity was identified in 21 (46%) abstract and 22 (48%) main text conclusions. CONCLUSIONS: Overall, our results suggest that 76% of statistically nonsignificant urology randomized controlled trials contained some level of spin. Readers and writers should be aware of common spin strategies when interpreting nonsignificant results and critically appraise the significance of results when making decisions for clinical practice.

Thulium fibre laser vs holmium: yttrium-aluminium-garnet laser lithotripsy for urolithiasis: meta-analysis of clinical studies.

OBJECTIVE: To compare and assess the clinical outcomes between thulium fibre laser (TFL) and holmium: yttrium-aluminium-garnet (Ho:YAG) laser endoscopic lithotripsy of urolithiasis through a meta-analysis of comparative clinical studies. METHODS: A systematic literature search was performed in May 2022, grey literature search in July 2022. Comparative clinical studies were evaluated according to Cochrane recommendations. Assessed outcomes include the stone-free rate (SFR), complication rate, operative time (OT), laser utilisation time (LUT), ablation rate (stone volume/laser time), ablation efficiency (energy use/stone volume), total energy usage, degree of retropulsion, and hospital stay. Risk ratios (RRs) and standardised mean differences (SMDs) were extrapolated. Subgroup analyses, heterogeneity, publication bias, and Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) assessment were performed. International Prospective Register of Systematic Reviews (PROSPERO) registration: CRD42022300788. RESULTS: A total of 15 studies with 1698 cases were included in this review. The outcome of SFR showed no significant between-group difference (RR 1.09, 95% confidence interval [CI] 0.99-1.20). However, subgroup analysis of TFL vs Ho:YAG with no pulse modulation showed a SFR favouring TFL (RR 1.11, 95% CI 1.01-1.23). The composite postoperative complication rate was comparable between the two intervention groups (RR 0.97, 95% CI 0.66-1.43). OT, LUT and ablation rate were significantly better for TFL than Ho:YAG (SMD -1.19, 95% CI -1.85 to -0.52; SMD -1.67, 95% CI -2.62 to -0.72; SMD 0.59, 95% CI 0.15-1.03; respectively). The degree of retropulsion was significantly lower for TFL than Ho:YAG without pulse modulation (SMD -1.23, 95% CI -1.74 to -0.71). Ablation efficiency, total energy usage, and hospital stay were all comparable. Based on GRADE criteria, the evidence certainty was determined to be very low. CONCLUSION: Overall, there was no between-group difference for the SFR. However, compared to Ho:YAG with no pulse modulation, TFL rendered a better SFR. Shorter OT and LUT, a lesser degree of retropulsion, and a better ablation rate were noted in favour of the TFL. There was no overall between-group difference for composite postoperative complication rate, ablation efficiency, total energy usage, and hospital stay. Currently, the available clinical evidence was assessed to be of very low certainty.

Renal cell carcinoma in kidney transplant recipients: incidence, trends, clinical management & outcomes.

OBJECTIVE: To describe the incidence, characteristics, clinical management, and outcomes of renal cell carcinoma (RCC) among a large, single-centre cohort of kidney transplant recipients (KTR). METHODS: We conducted an observational cohort study looking at KTR transplanted between January 2000-December 2017 (n = 2443) with ≥ 1 year of follow-up. Simultaneous kidney/pancreas transplants were excluded. The Kaplan-Meier product-limit method was used to determine the incidence of RCC. Characteristics and management of RCC were examined using descriptive statistics. Risk factors and clinical outcomes were analyzed using Cox regression models. RESULTS: The incidence of RCC among our cohort was 0.32 per 100 person-years, 2.1% of all KTRs. Almost half (47.1%) of cases occurred within 4 years post-transplant. The majority of cases were T1a (86.3%), clear-cell (45.1%), and in the native kidney (80.4%). KTR diagnosed with RCC had a twofold higher incidence of other malignancies versus KTR without RCC. Overall mortality, but not cancer-specific mortality, at 2- and 5-years post-transplant was threefold higher among KTR with RCC than those without. CONCLUSIONS: Incidence of RCC among our KTR was slightly higher than the general population; majority of cases occur in the native kidneys and are low stage, low grade. Indolent histologic variants were more common than the general population. KTR with RCC had a higher incidence of other malignancies. Overall, but not cancer-specific, mortality was higher among KTRs diagnosed with RCC.

The epidemiology of early deep vein thrombosis in kidney transplant recipients.

BACKGROUND: Because kidney transplant recipients may be at increased risk for deep vein thrombosis (DVT) following transplantation, we investigated the incidence, risk factors, treatments and outcomes of early DVT among kidney transplant recipients. METHODS: An observational, single-centre cohort study was conducted among adult kidney transplant recipients from Jan. 1, 2005, to Dec. 31, 2016 with 1-year followup. Time to DVT was assessed using the Kaplan-Meier method. Cox proportional hazards and linear regression models were used to analyze risk factors for and outcomes of DVT. RESULTS: The cumulative incidence of DVT was 4.25% at 3 months after transplant. In multivariable analysis, the use of depleting induction agents (hazard ratio [HR] 2.13, 95% confidence interval [CI] 1.05-4.35]), white recipient race (HR 1.84. 95% CI 1.08-3.12), the use of kidneys from expanded criteria donors (HR 2.13, 95% CI 1.05-4.32) and lower recipient body mass index (HR 0.95, 95% CI 0.91-1.00) increased the risk for early DVT. Peritransplant DVT prophylaxis was not associated with early DVT. Early DVT was not associated with reduced graft function, death, graft failure or first hospital readmission. CONCLUSION: Risk factors for early DVT in our cohort of kidney transplant recipients included white recipient race, use of depleting agents, lower recipient body mass index and use of expanded criteria donors. As practice patterns of donor and recipient selection in kidney transplantation evolve, the results of this study may aid in perioperative risk assessments and decision-making about the use of DVT prophylaxis.

Standardized Reporting on the Preoperative CT Assessment of Potential Living Renal Transplant Donors: Can We Create a Universal Report Standard to Meet the Needs of Transplant Urologists?

Purpose: Determine whether standardized template reporting for the preoperative assessment of potential living renal transplant donors improves the comprehensiveness of radiology reports to meet the needs of urologists performing renal transplants. Methods: Urologist and radiologist stakeholders from renal transplant centres in our province ratified a standardized reporting template for evaluation of potential renal donors. Three centres (A, B, and C) were designated "intervention" groups. Centre D was the control group, given employment of a site-specific standardized template prior to study commencement. Up to 100 consecutive CT scan reports per centre, pre- and post-implementation of standardized reporting, were evaluated for reporting specific outcome measures. Results: At baseline, all intervention groups demonstrated poor reporting of urologist-desired outcome measures. Centre A discussed 5/13 variables (38%), Centre B discussed 6/13 variables (46%), and Centre C only discussed 1/13 variables (8%) with ≥90% reliability. The control group exhibited consistent reporting, with 11/13 variables (85%) reported at ≥90% reliability. All institutions in the intervention group exhibited excellent compliance to structured reporting post-template implementation (Centres A = 95%, B = 100%, and C = 77%, respectively). Additionally, all intervention centres demonstrated a significant improvement in the comprehensiveness of reports post-template implementation, with statistically significant increases in the reporting of all variables under-reported at baseline (P > .01). Conclusion: Standardized templates across our province for CT scans of potential renal donors promote completeness of reports. Radiologists can reliably provide our surgical colleagues with needed preoperative anatomy and incidental findings, helping to determine suitable transplant donors and reduce potential complications associated with organ retrieval.

Quantifying the "Assistant Effect" in Robotic-Assisted Radical Prostatectomy (RARP): Measures of Technical Performance.

PURPOSE: Surgeons are reliant on the bedside assistant during robotic surgeries. Using a modified global rating scale (GRS), we aim to assess the association between an assistant's technical skill on surgeon performance in Robotic-Assisted Radical Prostatectomy (RARP). METHODS: Prospective, intraoperative video from RARP cases at three centers were collected. Baseline demographic and RARP-experience data were collected from participating surgeons and trainees. The dissection of the prostatic pedicle and neurovascular bundle step (NVB) was analyzed. Expert analysts scored the console surgeon performance using the Global Evaluative Assessment of Robotic Skills (GEARS), and the bedside assistant performance using a modified Objective Structured Assessment of Technical Skills (aOSATS). The primary outcome is the association between console surgeon performance, as measured by GEARS, and assistant skill, as measured by aOSATS. Spearman's rho correlations were used to test the relationship between assistant and surgeon technical performance, and a multivariable linear regression model was created to test this association while controlling for patient factors. RESULTS: 92 RARP cases were available for the analysis, comprising 14 console surgeons and 22 different bedside assistants. In only 5 (5.4%) cases, the neurovascular bundle step was completed by a trainee, and in 13 (14.1%) of cases, a staff-level surgeon acted as the bedside assistant. aOSATS score was significantly associated with robotic console experience (P = 0.011), and prior laparoscopic experience (P < 0.001). Assistant aOSATS score showed a weak but significant correlation with surgeon GEARS score during the neurovascular bundle step (spearman's rho = 0.248, P = 0.028). On linear regression, aOSATS remained a significant predictor of console surgeon performance (P = 0.016), after controlling for patient age and BMI, prostate volume, tumor stage, and presence of nerve-sparing. CONCLUSIONS: This is the first study to assess the association between assistant technical skill and surgeon performance in RARP. Additionally, we have provided validity evidence for a modified OSATS global rating scale for training and assessing bedside assistant performance.

Lymphoceles: impact on kidney transplant recipients, graft, and healthcare system.

INTRODUCTION: Following kidney transplantation, lymphoceles can impact patient and graft outcomes, while resulting in significant hospital resource utilization. We aimed to characterize the incidence, risk factors, outcomes, and clinical management of lymphoceles among kidney transplant recipients and review impact on health system utilization at a high-volume center. MATERIALS AND METHODS: We conducted a single-center, observational cohort study on adults transplanted between January 1, 2005 and December 31, 2017. Incidence, risk factors, and clinical outcomes were assessed using the Kaplan-Meier product-limit method, multivariable logistic regression model, and Cox proportional hazards model, respectively. RESULTS: Lymphoceles developed in 72 of 1881 patients (3.8%). Multivariate analysis demonstrated that a longer time on dialysis before transplant [HR 1.09 (95% CI: 1.02, 1.17)], laparoscopic donor nephrectomy [HR 2.31 (95% CI: 1.04, 5.12)], and depleting induction therapy [HR 0.39 (95% CI: 0.18, 0.87)] were significant risk factors for lymphocele development. Lymphoceles independently increased the likelihood of hospital readmission [HR 3.96 (95% CI: 2.99, 5.25)] but had no significant effect on the likelihood of graft failure or death with graft function. Of 72 cases, 44 received a radiological or surgical intervention. Fifteen of 44 lymphoceles required further intervention due to re-accumulation or complications. CONCLUSION: Patients with longer dialysis times, kidneys from laparoscopic donor nephrectomy, and depleting induction therapy were associated with an increased risk for developing symptomatic lymphoceles. Our center's treatment for symptomatic lymphoceles did not result in significant graft dysfunction, but significantly higher healthcare resource utilization was noted.

A Prospective Randomized Controlled Trial of Irrigation "Bag Squeeze" to Manage Pain for Patients Undergoing Flexible Cystoscopy.

PURPOSE: We determined if the "bag squeeze" technique decreases pain during flexible cystoscopy in men. MATERIALS AND METHODS: This single center, prospective, double-blind, randomized controlled trial recruited 200 consenting participants who were ambulatory, outpatient males who had undergone prior cystoscopy and were not expected to require any secondary procedures. Men with prior urethral stricture or bladder neck contracture were excluded from study. Once eligibility was assessed and consent obtained, participants were randomized to undergo cystoscopy with the bag squeeze (group A) or the sham bag squeeze procedure (group B). Following cystoscopy, participants completed a pain questionnaire (visual analogue scale). Differences in mean pain score between groups were evaluated using Students' t-test with a 2-sided alpha of 0.05. RESULTS: A total of 200 patients were randomized and underwent flexible cystoscopy. Ten participants were ineligible because they required secondary procedures. Among the 190 eligible patients 97 were randomized to bag squeeze (group A) and 93 to sham bag squeeze (group B) with mean pain scores of 1.91 and 3.39, respectively (p <0.005). CONCLUSIONS: This study demonstrated a clinically meaningful decrease in pain for men undergoing flexible cystoscopy when the irrigation bag squeeze technique was used vs placebo bag squeeze. Accordingly, this useful, simple and free method to improve patient comfort during flexible cystoscopy should be adopted by clinicians.

Is extracorporeal shockwave lithotripsy a risk factor for the development of diabetes mellitus? A population-based study.

OBJECTIVE: To determine if patients treated with extracorporeal shockwave lithotripsy (ESWL) are at a greater risk of developing diabetes mellitus (DM) than those treated with ureteroscopy (URS). PATIENTS AND METHODS: A retrospective population-based cohort study was performed of all ESWL and URS stone treatments done in Ontario between January 1994 and March 2014, utilising linked encoded healthcare databases. The primary outcome was the development of DM >90 days after treatment. The Kaplan-Meier method was used for unadjusted survival analysis and multivariable analysis with Cox proportional hazards regression was used to assess the risk of DM between the ESWL and URS groups whilst controlling for age, gender, region of residence, income quintile, year of treatment, and comorbidity index. A sensitivity analysis with a subset of ESWL patients treated for left renal or proximal ureteric stones was completed. RESULTS: We identified 106 963 patients who underwent ESWL or URS over the study period with a median follow-up of 6.6 years (ESWL 8.5 years, URS 5.6 years). Unadjusted survival analysis showed an increased risk of developing DM in the ESWL group compared to the URS group (P < 0.001); however, multivariable analysis showed no increased risk of DM in the ESWL cohort (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.91-1.02; P = 0.25). Similarly, sensitivity analysis showed no increased risk of DM in the left renal/proximal ureteric stone ESWL cohort compared to the URS cohort (HR 1.04, 95% CI 0.96-1.13; P = 0.35). CONCLUSIONS: Our population-based cohort study demonstrated no increased risk of DM in patients undergoing ESWL compared to URS.

Implementing assessments of robot-assisted technical skill in urological education: a systematic review and synthesis of the validity evidence.

OBJECTIVES: To systematically review and synthesise the validity evidence supporting intraoperative and simulation-based assessments of technical skill in urological robot-assisted surgery (RAS), and make evidence-based recommendations for the implementation of these assessments in urological training. MATERIALS AND METHODS: A literature search of the Medline, PsycINFO and Embase databases was performed. Articles using technical skill and simulation-based assessments in RAS were abstracted. Only studies involving urology trainees or faculty were included in the final analysis. RESULTS: Multiple tools for the assessment of technical robotic skill have been published, with mixed sources of validity evidence to support their use. These evaluations have been used in both the ex vivo and in vivo settings. Performance evaluations range from global rating scales to psychometrics, and assessments are carried out through automation, expert analysts, and crowdsourcing. CONCLUSION: There have been rapid expansions in approaches to RAS technical skills assessment, both in simulated and clinical settings. Alternative approaches to assessment in RAS, such as crowdsourcing and psychometrics, remain under investigation. Evidence to support the use of these metrics in high-stakes decisions is likely insufficient at present.

Surgical Education, Simulation, and Simulators-Updating the Concept of Validity.

PURPOSE OF REVIEW: Competency-based medical education (CBME) is rooted in the use of iterative assessments. We must ensure that the assessments used in CBME are valid, to make acceptable and accurate decisions regarding the competency of a trainee. Until recently, much of the educational and assessment literature in urology have used a now-outdated method of determining validity, based on theory and recommendations from over 50 years ago. We describe a contemporary approach to gathering construct validity evidence for the assessment of urologic trainees, for use in both clinical and simulation environments. RECENT FINDINGS: Five sources of evidence make up Messick's contemporary framework of validity: test content, response process, internal structure, relationship to other variables, and consequences. These are all components of construct validation and concern the accuracy, quality, reproducibility, generalizability, and wider impact of the scores generated by an assessment, respectively. When deciding the competency of a trainee, program directors and educators must have a clear understanding of how the validity is established and is determined in each assessment context. The contextual specificity of validity means that stakeholders must be prepared to defend the outcome of an assessment, particularly when making high-stake or summative decisions.

Basic Laparoscopic Skills Assessment Study: Validation and Standard Setting among Canadian Urology Trainees.

PURPOSE: As urology training programs move to a competency based medical education model, iterative assessments with objective standards will be required. To develop a valid set of technical skills standards we initiated a national skills assessment study focusing initially on laparoscopic skills. MATERIALS AND METHODS: Between February 2014 and March 2016 the basic laparoscopic skill of Canadian urology trainees and attending urologists was assessed using 4 standardized tasks from the AUA (American Urological Association) BLUS (Basic Laparoscopic Urological Surgery) curriculum, including peg transfer, pattern cutting, suturing and knot tying, and vascular clip applying. All performances were video recorded and assessed using 3 methods, including time and error based scoring, expert global rating scores and C-SATS (Crowd-Sourced Assessments of Technical Skill Global Rating Scale), a novel, crowd sourced assessment platform. Different methods of standard setting were used to develop pass-fail cut points. RESULTS: Six attending urologists and 99 trainees completed testing. Reported laparoscopic experience and training level correlated with performance (p <0.01). Attending urologists were significantly better than trainees (p <0.05), demonstrating construct validity evidence for the 4 AUA BLUS tasks. The C-SATS method of assessment correlated well with the traditional methods of time and error based scoring, and the global rating scale. We were able to use relative and absolute standard setting methods to define pass-fail cut points for all 4 AUA BLUS tasks. CONCLUSIONS: The 4 AUA BLUS tasks demonstrated good construct validity evidence for use in assessing basic laparoscopic skill. Performance scores using the novel C-SATS platform correlated well with traditional time-consuming methods of assessment. Various standard setting methods were used to develop pass-fail cut points for educators to use when making formative and summative assessments of basic laparoscopic skill.

Medical Expulsive Therapy: Worthwhile or Wishful Thinking.

PURPOSE OF REVIEW: We set out to provide an overview of the most recent evidence for medical expulsive therapy (MET). Conflicting level 1 evidence for and against the use of MET has been published. RECENT FINDINGS: The largest double-blind randomized control trial (1110 patients) comparing placebo, tamsulosin, and nifedipine found no benefit for MET in preventing the need for secondary intervention. A recent meta-analysis of 55 randomized trials using alpha-blockers suggests that no benefit is seen with smaller ureteric calculi, but patients with larger ureteric calculi experience shorter times to stone passage, fewer episodes of pain, require less surgical intervention, and fewer hospital admissions. All the major urological organizations (American Urological Association, European Association of Urology, Canadian Urological Association) suggest offering MET as part of conservative management for appropriate patients with ureteric calculi. MET is a reasonable option for conservative management of ureteric calculi that may avoid the need for surgical intervention. The greatest benefit is likely seen with alpha-blockers and calculi ≥5 mm in the distal ureter. Expanding indications for the use of MET include facilitating stone fragment clearance after SWL. MET appears to be safe for use in pregnant and pediatric patients.

The role of thrombectomy and diffusion-weighted imaging with MRI in post-transplant renal vein thrombosis: a case report.

BACKGROUND: Surgical thrombectomy in the context of acute renal vein thrombosis (RVT) post-transplantation has had limited success, with considerable variation in the surgical techniques used. Unfortunately, it is usually followed by allograft nephrectomy within a few days if rapid allograft recovery does not ensue. We report a case of acute RVT in which nephrectomy was not performed despite a prolonged requirement for dialysis post-thrombectomy, but with recovery of renal function 2 weeks later. We also report the findings of serial MRI with diffusion-weighted imaging (DW-MRI) throughout the patient's recovery, which provided novel insights into allograft microvascular perfusion changes post-thrombectomy. CASE PRESENTATION: A 65-year old patient underwent living-unrelated kidney transplantation complicated by acute RVT. Surgical thrombectomy and irrigation led to a delayed, but significant, recovery of renal function. Serial non-contrast DW-MRI scanning was used to non-invasively assess microvascular renal blood flow post-operatively. Unlike standard Doppler ultrasonography, DW-MRI documented reduced microvascular perfusion initially, with gradual but incomplete recovery that mirrored the partial improvement in renal function. CONCLUSIONS: Our findings suggest that surgical thrombectomy may be more effective than previously described if followed by careful patient observation. Moreover, diffusion-weighted MRI appears to provide important insights into the pathophysiology of delayed graft function and deserves further investigation.

Low expression of miR-126 is a prognostic marker for metastatic clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) is an aggressive tumor with unpredictable behavior. Clinical parameters are not always accurate for predicting prognosis. miR-126 is differentially expressed in many cancers, including RCC, and is down-regulated in metastatic versus primary ccRCC. We assessed the prognostic significance of miR-126 in 264 primary ccRCCs. We also compared its expression in normal kidney, primary and metastatic ccRCC, and RCC subtypes. We validated our results on an independent set of 481 ccRCCs. miR-126 was down-regulated in metastatic versus primary tumors and in tumors of higher stage (P = 0.005) or higher grade (P = 0.002). miR-126 up-regulation was associated with significantly prolonged disease-free survival (P < 0.001) and overall survival (P = 0.015). For larger tumors (>4 cm), patients with higher miR-126 expression had significantly longer survival. Restoration of miR-126 expression decreased cellular migration and proliferation in RCC cell lines. The ccRCCs exhibited the highest miR-126 expression, and papillary RCCs exhibited the lowest expression. We identified a number of miR-126 targets and pathways that are involved in carcinogenesis, including the apoptosis signaling pathway. miR-126 is a promising prognostic marker in ccRCC that can distinguish between clear cell and papillary subtypes. In addition, miR-126 has potential therapeutic applications.

Robotic-assisted laparoscopic pyeloplasty for ureteropelvic junction obstruction A retrospective review of a high-volume Canadian center.

INTRODUCTION: At present, there is no literature on the outcomes of robotic-assisted laparoscopic pyeloplasty (RALPyelo) in a Canadian context. Our objective was to perform a retrospective review of RALPyelo cases at a high-volume Canadian center. METHODS: We performed a retrospective review of patients who underwent RALPyelo at St. Michael's Hospital, between January 2012 and May 2019. Demographics, operative details, and pre- and postoperative imaging results (ultrasounds, computed tomography [CT] scans, and diuretic renal scan [DRS ]) were recorded. Patients were excluded if at least one-year followup data was unavailable. Our primary outcome was clinical and radiologic improvement defined as 1) symptom improvement; 2) stable/improved split renal function on DRS ; and 3) either improvement in the degree of hydronephrosis on ultrasound or CT, or improved drainage time on DRS. Secondary outcomes included postoperative complications, need for diagnostic intervention, and reintervention for recurrent UPJO. RESULTS: A total of 156 patients underwent RALPyelo after exclusions. The median age was 42 and 66% were female. Mean followup was 2.5 years. For our primary outcome, 87% had clinical and radiologic improvement. Diagnostic investigation for possible recurrent/persistent obstruction, based on symptoms and/or imaging results, was required in 17% of cases, but only 3% required reintervention for recurrent UPJO. Accordingly, the overall treatment success was 97%. The most common postoperative complication was urinary tract infection (18%), and urine leak was seen in only 2% of patients. CONCLUSIONS: The results of our study compare favorably with currently reported outcomes in the literature and demonstrate the safety and high level of success of RALPyelo at a high-volume Canadian center.