Integrated Ultrasound With Urodynamics Illustrates Effect of Bladder Volume on Upper Tract Dilation: Should we Trust Surveillance Ultrasounds?

OBJECTIVE: To evaluate if ultrasound during urodynamics (uUS) will show that traditional ultrasound (tUS) routinely underestimates the potential magnitude of upper tract dilation (UTD). METHODS: Prospective pilot study of 10 consecutive patients ≥ 5 years of age undergoing same day uUS and tUS. Using randomized images, the study pediatric radiologist determined anterior-posterior renal pelvic diameter (APD), bladder volume, vesicoureteral reflux (VUR) and UTD grades. A single pediatric urologist determined urodynamic bladder capacity and assigned either hostile, intermediate, abnormal but safe, or normal national spina bifida patient registry classification (NSBPR). RESULTS: Bladder volume on tUS was significantly smaller than final bladder volume on uUS (180 vs 363 ml: P<.001). On average, patient reported maximum catheterized/voided volumes were also 82 ml greater than final bladder capacity on uUS. UTD was upgraded in 25% of kidneys and APD increased by 0.6 cm on uUS over that seen on tUS (P=.001). Units with VUR had greater increases in APD (1.2 P=.007 vs. 0.3 cm P=0.06). Changes in APD stratified by NSBPR revealed average increases of up to 1.3 cm. CONCLUSION: Despite instructions to the contrary, patients come for tUS with a relatively empty bladder as compared to either their urodynamic or patient-reported capacity. This translates to a significant underestimation of UTD with tUS, most notably in those with VUR. Alternatives to traditional protocols include insisting patients wait until their bladder is truly full for tUS, retrograde filling their bladder, or performing uUS. Accurate assessment of UTD severity may help guide long term management.

Predicting oxygen tension along the ureter.

Continuous measurement of bladder urine oxygen tension (Po2) is a method to potentially detect renal medullary hypoxia in patients at risk of acute kidney injury (AKI). To assess its practicality, we developed a computational model of the peristaltic movement of a urine bolus along the ureter and the oxygen exchange between the bolus and ureter wall. This model quantifies the changes in urine Po2 as urine transits from the renal pelvis to the bladder. The model parameters were calibrated using experimental data in rabbits, such that most of the model predictions are within ±1 SE of the reported mean in the experiment, with the average percent difference being 7.0%. Based on parametric experiments performed using a model scaled to the geometric dimensions of a human ureter, we found that bladder urine Po2 is strongly dependent on the bolus volume (i.e., bolus volume-to-surface area ratio), especially at a volume less than its physiological (baseline) volume (<0.2 mL). For the model assumptions, changes in peristaltic frequency resulted in a minimal change in bladder urine Po2 (<1 mmHg). The model also predicted that there exists a family of linear relationships between the bladder-urine Po2 and pelvic urine Po2 for different input conditions. We conclude that it may technically be possible to predict renal medullary Po2 based on the measurement of bladder urine Po2, provided that there are accurate real-time measurements of model input parameters.NEW & NOTEWORTHY Measurement of bladder urine oxygen tension has been proposed as a new method to potentially detect the risk of acute kidney injury in patients. A computational model of oxygen exchange between urine bolus and ureteral tissue shows that it may be technically possible to determine the risk of acute kidney injury based on the measurement of bladder urine oxygen tension, provided that the measurement data are properly interpreted via a computational model.

The effectiveness and safety of Sun tip-flexible ureterorenoscope for the management of kidney stones: A protocol for systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Kidney stone is one of the urinary system diseases with a high incidence. In this study, we will evaluate the effectiveness and safety of Sun tip-flexible ureterorenoscope treating patients with kidney stone. METHODS AND ANALYSIS: English and Chinese literature about Sun tip-flexible ureterorenoscope treatment for kidney stones published before October 31, 2020 will be systematic searched in PubMed, Embase, Web of Science, Cochrane Library, Open Grey, Clinicaltrials.gov, Chinese Clinical Trial Registry, WANFANG, VIP Chinese Science and Technology Journal Database, CNKI, Chinese biomedical document service system (SinoMed). Only randomized controlled trials (RCTs) of patients with kidney stones will be included. Literature screening, data extraction, and the assessment of risk of bias will be independently conducted by 2 reviewers, and the 3rd reviewer will be consulted if any different opinions existed. Systematic review and meta-analysis will be produced by RevMan 5.3 and Stata 14.0. This protocol reported in accordance with the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) statement, and we will report the systematic review by following the PRISMA statement. RESULTS: The current study is a protocol for systematic review and meta-analysis without results, and data analysis will be carried out after the protocol. We will share our findings in the fourth quarter of 2021. CONCLUSION: This study will provide recommendations for the effectiveness and safety of Sun tip-flexible ureterorenoscope for patients with kidney stones (KS), which may help to guide clinician. ETHICS AND DISSEMINATION: Ethical approval is not required as the review is a secondary study based on published literature. The results of the study will be published in peer-reviewed publications and disseminated electronically or in print. PROTOCOL REGISTRATION NUMBER: INPLASY2020110099.

Obstructive uropathy in the context of ureteroinguinal hernia: experience of challenges in surgical management of an unwell patient.

This case exemplifies an unusual anatomical variation of a common presentation and highlights the importance of perioperative diagnosis and planning in complex surgical patients. A 72-year-old comorbid man presented to the emergency department with an infected obstructed right kidney secondary to an obstructing 12 mm vesicoureteric junction calculi. However, imaging also showed concurrent ureteroinguinal hernia associated with a 130 cm-long ureter, too long for conventional treatment with a ureteric stent. Acutely, the patient's collecting system was decompressed via nephrostomy, but due to the rarity of this anatomical variation, definitive treatment had to be rethought to help reduce the risk of iatrogenic damage and the associated long-term complications.

Spontaneous subepithelial hemorrhage of renal pelvis and ureter (Antopol-Goldman lesion) in hemophilia A patient with inhibitor: Case report and review of the literature.

INTRODUCTION: The Antopol-Goldman lesion (AGL), which expresses subepithelial hemorrhage in the renal pelvis, was first defined by Antopol and Goldman in 1948. The objective of this study is to report the first case of AGL in patients with congenital hemophilia and review the relevant literature. PATIENT CONCERNS: A 32-year-old male patient diagnosed with congenital hemophilia A (FVIII = %4) with high responding inhibitors (7.4 BU) was admitted to our emergency department with gross hematuria and sudden onset flank pain. DIAGNOSIS: Abdominal computed tomography (CT-scan) presented a hyperdense lesion in the left ureteropelvic junction with Hounsfield Units of 56 compatibles with hemorrhage. INTERVENTIONS: The patient was given 4500 IU of factor eight inhibitor bypass activity (FEIBA) intravenously twice daily for 5 days. Subsequently, 4500 IU of FEIBA was administrated once a day for 2 days. OUTCOMES: The patient's complaints disappeared on the fourth day of treatment. Macroscopic and microscopic hematuria was not seen in the following days. Follow-up CT was done 3 months after discharge and showed normal left renal pelvis without hyperdenosis. Follow-up CT was performed 3 months after discharge and presented normal left renal pelvis with no hyperdense lesion. CONCLUSION: Although very rare, AGL should be kept in mind in the differential diagnosis of renal pelvic hemorrhage. In the patient who has an underlying history of coagulopathy nephrectomy can be avoided when there is awareness of AGL.

The course of alterations in ureteral jet dynamics following kidney transplantation: a prospective observational cohort study.

OBJECTIVES: To prospectively investigate the alterations and normal ranges of ureteral jet dynamics after double-J-stent (DJS) removal in patients who underwent renal transplantation (RTx). METHODS: Patients who underwent RTx were prospectively evaluated between November 2017 and June 2018. After RTx, Doppler ultrasonography (D-US) was performed on all patients after DJS removal. Renal artery resistive index (RA-Ri), renal pelvis anterior-posterior diameter (RP-APD), pelvicalyceal system dilation (PCSD), and ureteral jet flow dynamics (maximum and average velocity; JETmax and JETave) were measured by D-US. Also, patients' demographics, estimated glomerular filtration rate (eGFR) levels, and acute rejection were investigated in the study. Patients were assessed two different times by D-US, about 6 and 12 weeks after DJS removal, and the two different measurements were compared with the Wilcoxon test and Chi-square test. RESULTS: A total of 25 patients were evaluated in the study. Nonobstructive PCSD rate (12% vs 8%), JETave (18.8 vs 12.9 cm/sec), and JETmax (29.2 vs 20 cm/sec) levels were significantly decreased (p values are 0.01, 0.010 and 0.014, respectively). In addition, monophasic and square pattern rates were significantly observed to increase over time (p=0.035); however, ureteral jet patterns were correlated between the two different D-US measurements (R=0.225, p=0.032). CONCLUSION: After RTx, dilation rate and ureteral jet flow velocities were significantly decreased, and monophasic and square JETpattern rates were significantly increased over time. Ureteral jet dynamics can provide useful information about the follow-up of peristaltic activity in the pelvic-ureteric system.

Comparative Proteome Analyses of Ureteropelvic Junction Obstruction and Surrounding Ureteral Tissue.

Ureteropelvic junction (UPJ) obstruction is a common problem in children, but its etiology remains unclear. In this study, the proteome profiles of the obstructed segment and its surrounding distal and proximal parts were comparatively evaluated. Twelve children younger than 2 years of age with unilateral intrinsic UPJ obstruction were included. The excised operational tissue was divided into three parts immediately after resection: the obstructed part (Obst), the distal normal ureteral part (Dist), and the proximal part of the obstructed segment (Prox). Proteins extracted from the tissue samples were subjected to two-dimensional gel electrophoresis analysis to identify differentially regulated proteins. Spot analysis revealed that four proteins, namely tropomyosin beta and alpha-1 chains, actin and desmin, were upregulated in Obst in comparison to Dist. A similar analysis between Obst and Prox showed that heat shock protein beta-1 and carbonic anhydrase-1 were upregulated in Obst, while tropomyosin alpha 3 chain and ATP synthase beta were upregulated in Prox. The last comparative analysis between Dist and Prox revealed upregulation of annexin-A5 and annexin-A1 in Dist and vimentin, mitochondrial ATP synthase subunit-beta, peroxiredoxin-2, and apolipoprotein-A1 in Prox. Bioinformatics analysis using the STRING server indicated that the differentially regulated proteins, altogether, point to the changes occurring in muscle filament sliding pathway. When regulations occurring in each group were mutually compared, a change in lipase inhibition activity was detected by STRING. This is the first study scrutinizing changes occurring in protein profiles in UPJ.

The course of alterations in ureteral jet dynamics following kidney transplantation: a prospective observational cohort study

SUMMARY OBJECTIVES To prospectively investigate the alterations and normal ranges of ureteral jet dynamics after double-J-stent (DJS) removal in patients who underwent renal transplantation (RTx). METHODS Patients who underwent RTx were prospectively evaluated between November 2017 and June 2018. After RTx, Doppler ultrasonography (D-US) was performed on all patients after DJS removal. Renal artery resistive index (RA-Ri), renal pelvis anterior-posterior diameter (RP-APD), pelvicalyceal system dilation (PCSD), and ureteral jet flow dynamics (maximum and average velocity; JETmax and JETave) were measured by D-US. Also, patients' demographics, estimated glomerular filtration rate (eGFR) levels, and acute rejection were investigated in the study. Patients were assessed two different times by D-US, about 6 and 12 weeks after DJS removal, and the two different measurements were compared with the Wilcoxon test and Chi-square test. RESULTS A total of 25 patients were evaluated in the study. Nonobstructive PCSD rate (12% vs 8%), JETave (18.8 vs 12.9 cm/sec), and JETmax (29.2 vs 20 cm/sec) levels were significantly decreased (p values are 0.01, 0.010 and 0.014, respectively). In addition, monophasic and square pattern rates were significantly observed to increase over time (p=0.035); however, ureteral jet patterns were correlated between the two different D-US measurements (R=0.225, p=0.032). CONCLUSION After RTx, dilation rate and ureteral jet flow velocities were significantly decreased, and monophasic and square JETpattern rates were significantly increased over time. Ureteral jet dynamics can provide useful information about the follow-up of peristaltic activity in the pelvic-ureteric system.

RESUMO OBJETIVOS Investigar prospectivamente as alterações e as variações normais da dinâmica do jato ureteral após a remoção do J-stent duplo (DJS) em pacientes submetidos a transplante renal (RTx). MÉTODOS Pacientes submetidos a RTx foram avaliados prospectivamente entre novembro de 2017 e junho de 2018. Após o RTx, o D-US foi realizado em todos os pacientes após a remoção do DJS. Índice de resistência da artéria renal (RA-Ri), diâmetro ântero-posterior da pelve renal (AP-DPR), dilatação do sistema pelvicaliceal (PCSD) e dinâmica do jato ureteral (velocidade máxima e média; JETmax e JETave) foram medidos por D-US. Além disso, a demografia dos pacientes, os níveis estimados de taxa de filtração glomerular (eGFR) e a rejeição aguda foram investigados no estudo. Os pacientes foram avaliados em dois momentos diferentes pelo D-US, cerca de 6 e 12 semanas após a remoção do DJS, e as duas medidas diferentes foram comparadas com o teste de Wilcoxon e o teste do qui-quadrado. RESULTADOS Um total de 25 pacientes foi avaliado no estudo. Taxa de PCSD não obstrutiva (12% vs. 8%), JETave (18,8 vs. 12,9 cm/seg) e JETmax (29,2 vs. 20 cm/seg), os níveis foram significativamente diminuídos (valores de p são 0,01, 0,010 e 0,014, respectivamente). Além disso, as taxas de padrão monofásico e quadrado foram significativamente observadas para aumentar ao longo do tempo (p=0,035); no entanto, padrões de jato ureteral foram correlacionados entre as duas diferentes medidas D-US (R=0,225, p=0,032). CONCLUSÃO Após o RTx, a velocidade de dilatação e as velocidades de fluxo do jato ureteral foram significativamente diminuídas e as taxas de JET padrão monofásico e quadrado foram significativamente aumentadas ao longo do tempo. A dinâmica do jato ureteral pode fornecer informações úteis sobre o acompanhamento da atividade peristáltica no sistema pélvico-ureteral.

[Primary megaureter in the newborn period: making the case for a temporary splint-free cutaneous ureterostomy]. / Primärer Megaureter beim Neugeborenen ­ die passagere externe Harnableitung ­ ein Plädoyer.

The term "megaureter" is used to describe a markedly dilated ureter, irrespective of its underlying anatomic abnormality. Primary megaureters categorised as type I and II according to the Pfister-Hendren classification resolve spontaneously during the first years of life, whereas severely dilated type III megaureters have no potential to resolve on conservative management. Regarding this small group of very severely dilated type III megaureters, we recommend a two-step surgical approach: in a first step, we place a temporary splint-free ureterocutaneostomy for early disobstruction. In a second step, we perform the actual corrective surgery with closure of the incontinent urinary diversion when the patient is approximately one year old, a point in time when bladder function is more mature. With this strategy, ultrasound imaging provides all important information until the corrective surgery is performed. A voiding cystourethrogram (VCUG) to rule out reflux and a MAG-3 diuretic renography can supplement the diagnostic work-up before the ureterocutaneostomy is closed.

The Impact of Ureteral Deformation and External Ureteral Pressure on Stent Failure in Extrinsic Ureteral Obstruction: An In Vitro Experimental Study.

Background and Purpose: Extrinsic ureteral obstruction is caused frequently by pelvic malignancies or metastatic lymphadenopathy, necessitating renal drainage with ureteral stents to prevent renal failure and kidney damage. Understanding the nature of stent behavior under deformation and realistic external pressures may assist in evaluation of stent performance. Few published studies have investigated the flow and mechanical properties of stents within ureters, and none has considered the effects of deformation and compression on flow in realistic, in vitro, ureter-stent systems. The purpose of this work was to determine whether or not stent failure is due only to stent compression and deformation in the presence of extrinsic obstruction. Methods: We developed an in vitro ureter-stent experimental setup, using latex tubing to simulate a flexible ureter connecting a renal unit and a bladder side. We examined flow behavior in three stents (4.8F, 6F, 7F). The ureter-stent configuration was varied, simulating four levels of deformation (0°, 20°, 40°, 60°) and then simulating different external compressive forces on a stented ureter with 40° deformation. A constant, realistic fluid flow was applied through the ureter-stent configurations, and pressure fluctuations in the renal unit were monitored. Results: Deformation alone on four different levels (0°, 20°, 40°, 60°) has essentially no influence on fluid flow and renal pressure variation. Under increasing external compressive forces of 500, 1000, 2000, and up to 5000 g at 40° deformation, no effect on fluid flow and pressure within the renal unit was noted for the 6F and 7F stents. The only exception was for the 4.8F stent, which demonstrated complete failure at compressive forces near 4000 g. Conclusions: Neither realistic extrinsic ureteral compression forces nor ureteral deformation explain the high frequency of stent failure in extrinsic ureteral obstruction. Other factors such as urine composition may be a major contributor to stent failure.

[Primary obstructive megaureter: a domain of conservative treatment]. / Der Primär Obstruktive Megaureter (POM) ­ Eine Domäne konservativer Therapie.

The term "megaureter" is an entirely descriptive designation for a number of different entities. It is crucial to distinguish between primary and secondary forms of megaureter and between obstructive and/or refluxive forms. In the majority of cases, there is a primary obstruction in the terminal ureterovesical segment. The treatment of primary obstructive megaureter has changed fundamentally over the last 3 decades. Whereas ureteral reimplantation was the treatment of choice in the past, conservative treatment is now preferred in 85 to 90 % of patients. With the advent of endoscopic balloon dilatation, a modern, minimally-invasive treatment option has become an alternative to ureteral reimplantation in selected patients. However, due to the possibility of postoperative VUR (vesicoureteral reflux), it is necessary to emphasize that this option should not weaken the generally strict indication for surgical treatment of primary obstructive megaureter.

The prevalence of vesicoureteral reflux in infants with first urinary tract infection following circumcision is similar to infants with UTI not following circumcision.

PURPOSE: Urinary tract infections (UTIs) are common serious bacterial infections in early infancy. Ritual circumcision in neonates may increase the risk of UTI within 2 weeks of the procedure. The aims of this study were to assess the prevalence and risk factors for vesicoureteral reflux (VUR) among young infants with first UTI following circumcision, and compare it with the prevalence of VUR among young infants with first UTI not related to circumcision. METHODS: In this retrospective cohort study, the medical records of all children aged 0-100 days who were diagnosed with UTI at Shaare Zedek Medical Center between 2005 and 2012 were reviewed for demographic, clinical and laboratory data and for the presence of VUR in voiding cystourethrography (VCUG). RESULTS: Four hundred and sixty eight cases of UTI were included. Infants with post-circumcision UTI in our study were more likely to have associated bacteremia and abnormal renal function tests. VCUG was done for 166 infants (35%). There was no statistically significant difference in the prevalence of abnormal VCUG between infants with UTI following circumcision, in comparison to infants with UTI not following circumcision (30% vs. 36%, p = NS). CONCLUSIONS: The decision regarding the need for radiographic evaluation and prophylactic antibiotic treatment following UTI should be made regardless if infection was related to circumcision.

Prognostic Significance of Murine Double Minute 2 Expression in Tumor Cells in Upper Tract Urothelial Carcinoma: An Analysis of 341 Cases in a Large Chinese Center.

Aims: The prognostic significance of murine double minute 2 (MDM2) expression remains unknown in patients with upper tract urothelial carcinoma (UTUC). This study was designed to evaluate MDM2 expression and its association with clinicopathological characteristics and tumor outcomes in UTUC patients. Materials and Methods: Expression levels of MDM2 and p53 were determined by immunohistochemistry in a cohort of 341 UTUC patients. Associations of MDM2 and p53 expression levels with clinicopathological characteristics, disease-free survival (DFS), cancer-specific survival (CSS), and intravesical recurrence-free survival (IVRFS) were analyzed. Results: Nuclear expression of MDM2 and p53 were detected in the tumor cells of 129 (37.8%) and 203 (59.5%) patients, respectively. Decreased p53 expression was associated with positive MDM2 staining in tumor cells (p = 0.002). MDM2 expression was correlated with the exposure to aristolochic acids (p = 0.020), better preoperative renal function (p = 0.016), ureter location (p = 0.002), higher pathological T stage (p = 0.006), high tumor grade (p < 0.001), presence of glandular differentiation (p = 0.036), and sarcoma differentiation (p = 0.020). Kaplan-Meier analysis showed that positive MDM2 staining was associated with shorter CSS (p < 0.001), DFS (p < 0.001), and IVRFS (p = 0.020); MDM2+/p53- was associated with shorter CSS (p < 0.001) and DFS (p < 0.001), but not IVRFS (p = 0.145); while CSS, DFS, and IVRFS did not differ significantly between the p53+ and p53- patients (p = 0.307, 0.089, and 0.198, respectively). Multivariate analyses revealed that MDM2 expression in tumor cells independently predicted shorter CSS (p < 0.001; hazard ratio [HR] = 2.600; 95% confidence interval [CI]: 1.625-4.161) and DFS (p < 0.001; HR = 1.863; 95% CI: 1.314-2.641), excepting IVRFS (p = 0.092; HR = 1.590; 95% CI: 0.928-2.726). Conclusions: UTUC patients with elevated MDM2 expression may exhibit more aggressive biological features of the tumor and tend to have shorter CSS and DFS.

Transrenal Ureteral Occlusion for Palliation of Refractory Urine Leaks Using Vascular Plugs and Liquid Ethylene Vinyl Alcohol.

PURPOSE: To describe outcomes of transrenal embolization with vascular plugs and ethylene vinyl alcohol (EVOH) in a case series of patients with refractory urinary leak or fistula. MATERIALS AND METHODS: Fifteen ureteral occlusions performed over 53 months in 9 consecutive patients (56% female; mean age 61 y; range, 45-80 y) were reviewed retrospectively. The main indication was palliation for refractory fistula or leak in the setting of malignancy not responding to urine diversion by percutaneous nephrostomy tube or nephroureteral stent. Transrenal ureteral occlusion was performed using EVOH injected between vascular plugs placed distal and proximal to the leak or fistula. RESULTS: Technical success was 100%. Considerable reduction of urine leak or symptoms (clinical success) was achieved in 64% of ureters after mean follow-up of 105 days (range, 0-632 d). Complete ureteral occlusion on follow-up anterograde nephrostogram (imaging success) was achieved in 60% of ureters after mean follow-up of 139 days (range, 0-643 d). One patient with distal ureterovesical junction-perineal fistula had continued leak despite complete proximal occlusion of ureter owing to retrograde urine reflux from the bladder and was treated with endoscopic injection of intramural calcium hydroxyapatite to the ureteral segment distal to the fistula. Three ureters (33%) in 2 patients with vesicovaginal fistula had recanalization, requiring additional proximal embolization, yielding secondary success rates of 91% (clinical) and 90% (imaging) per ureter. One minor urinary tract infection and no major complications occurred. CONCLUSIONS: Transrenal anterograde ureteral occlusion using EVOH between vascular plugs could be considered a relatively safe and potentially valuable treatment option for refractory ureteral fistulae.

The Role of Antegrade Irrigation via Percutaneous Nephrostomy on Surgical Outcomes in Semirigid Ureteroscopy among Patients with Upper Ureteral Stones.

OBJECTIVE: We aimed to investigate the role of antegrade irrigation via percutaneous nephrostomy on surgical outcomes in retrograde ureteroscopy in patients with upper ureter stones. MATERIALS AND METHODS: In this retrospective study, we analyzed 134 patients who underwent retrograde semirigid ureteroscopy for upper ureter stones between August 2012 and December 2017. Patients were divided into two groups: retrograde irrigation group (conventional URS) and antegrade irrigation group (using percutaneous nephrostomy). Operation time, postoperative hospital stay, complications, and stone-free rate were measured for each patient after ureteroscopy. RESULTS: The mean age in the retrograde irrigation and antegrade irrigation groups was 53.3 and 60.7 years, respectively (p=0.007). The operation time was 60.8 min vs. 43.0 min (p=0.002), and stone-free rate was 82.0 % vs. 95.5 % (p=0.033). Stone size, laterality, the proportion of male patients, and urinary tract infection prevalence were comparable between the groups. In the subgroup analysis of stone size >10 mm, the antegrade irrigation group had a shorter operation time and a higher stone-free rate. For stone size of 5-10 mm, operation time in the antegrade irrigation group was shorter and the stone-free rate between the two groups was comparable. CONCLUSION: Antegrade irrigation via percutaneous nephrostomy during ureteroscopy has a higher stone-free rate with a shorter operation time without an increased urinary tract infection risk. Therefore, if percutaneous nephrostomy is necessary before ureteroscopy, antegrade irrigation of external fluid via percutaneous nephrostomy is strongly recommended.

Effect of forced diuresis during 18F-DCFPyL PET/CT in patients with prostate cancer: activity in ureters, kidneys and bladder and occurrence of halo artefacts around kidneys and bladder.

Forced diuresis may improve readability of 2-(3-(1-carboxy-5-[(6-[F]fluoro-pyridine-3-carbonyl)-amino]-pentyl)-ureido)-pentanedioic acid (F-DCFPyL) PET/computed tomography (CT) by reducing focal ureteral activity. A total of 40 patients received furosemide simultaneously with F-DCFPyL (cohort 1) and 40 patients received furosemide 85 min after F-DCFPyL administration (cohort 2). The frequency of occurrence of activity depositions in ureters and halo artefacts near the kidneys and bladder was measured, as well as intensity of F-DCFPyL uptake in kidneys and bladder. At 120 min after injection of F-DCFPyL, a significantly lower number of F-DCFPyL depositions in ureters was found in cohort 2. Moreover, F-DCFPyL uptake in kidneys and bladder was significantly lower in this cohort; however, the occurrence of halo artefacts was similar in both groups. Administration of furosemide may improve interpretation of F-DCFPyL PET/CT as it results in less activity depositions in ureters. However, the effect depends on the timing of furosemide administration in relation to F-DCFPyL administration and PET/CT acquisition time. Acquisition of PET-images 120 min after F-DCFPyL administration benefits from late furosemide administration (85 min after injection).

New trends in voiding cystourethrography and vesicoureteral reflux: Who, when and how?

Vesicoureteral reflux, retrograde flow of urine from the bladder into the upper urinary tract, is one of the most common urological diagnoses in the pediatric population. Diagnosis and subsequent management of urinary reflux have become increasingly debated in the past decade, with divergent opinions over which patients should be evaluated for reflux, and when detected, which children should receive intervention. Although some argue that vesicoureteral reflux is a "phenotype" that often resolves without intervention, others contest that untreated reflux has the potential to cause irreversible renal damage over time. Voiding cystourethrogram images the urethra and bladder during both bladder filling and emptying, as well as the ureters and kidneys when reflux is present, and is considered the gold standard for diagnosing vesicoureteral reflux. Once detected, therapeutic options for urinary reflux are diverse, ranging from observation with or without low-dose antibiotic prophylaxis to a variety of operative interventions. Management should be based on a multitude of factors including patient age, risk of subsequent urinary tract infections, risk of renal parenchymal injury, a given child's projected clinical course and parental preference. Over the past two decades, investigators have elucidated many crucial voiding cystourethrogram findings in addition to grade that provide significant prognostic information and are useful in determining the best course of action for a child on a more individualized basis.

Multifaceted Hoxa13 function in urogenital development underlies the Hand-Foot-Genital Syndrome.

Hand-Foot-Genital syndrome is a rare condition caused by mutations in the HOXA13 gene and characterized by limb malformations and urogenital defects. While the role of Hoxa13 in limb development has been extensively studied, its function during the development of the urogenital system remains elusive mostly due to the embryonic lethality of Hoxa13 homozygous mutant mice. Using a conditional inactivation strategy, we show that mouse fetuses lacking Hoxa13 function develop megaureters, hydronephrosis and malformations of the uterus, reminiscent of the defects characterizing patients with Hand-Foot-Genital syndrome. Our analysis reveals that Hoxa13 plays a critical role in Müllerian ducts fusion and in ureter remodeling by regulating the elimination of the caudal common nephric duct, eventually preventing the separation from the nephric duct. Our data also reveal a specific role for Hoxa13 in the urogenital sinus, which is in part mediated by Gata3, as well as Hoxa13 requirement for the proper organization of the ureter. Finally, we provide evidence that Hoxa13 provides positional and temporal cues during the development of the lower urogenital system, a sine qua non condition for the proper function of the urinary system.

Fluid-structure interaction simulation of ureter with vesicoureteral reflux and primary obstructed megaureter.

Two common abnormalities in ureters include primary refluxing megaureter (PRM) and primary obstructed megaureter (POM). The aim of this study was to represent the numerical simulation of the urine flow at the end of the ureter with vesicoureteral reflux (VUR) and POM during peristalsis. Methodologically, the peristalsis in the ureter wall was created using Gaussian distribution. Fluid-structure interaction (FSI) was applied to simulate urine-elastic wall interactions; and governing equations were solved using the arbitrary Lagrangian-Eulerian method. Theories such as wall elasticity, Newtonian fluid, and incompressible Navier-Stokes equations were used. Velocity fields, viscous stresses and volumetric outflow rate profiles were obtained through the simulation of the ureter with VUR and POM during peristalsis. In addition, the effect of urine viscosity on flow rate was investigated. When the bladder pressure increased, VUR occurred because of the ureterovesical junction (UVJ) dysfunction, leading to high stresses on the wall. In the POM, the outflow rate was ultimately zero, and stresses on the wall were severe in the obstructed section. Comparing the results demonstrated that the peristalsis leads to even further dilation of the prestenosis portion. It was also observed that the reflux occurs in the ureter with VUR when the bladder pressure is high. Additionally, the urine velocity during the peristalsis was higher than the non-peristaltic ureter.