Fetal bladder morphology as a predictor of outcome in fetal lower urinary tract obstruction.

OBJECTIVE: We evaluate survival of fetuses with severe Lower Urinary Tract Obstruction (LUTO) based on bladder morphology. We hypothesize that fetuses with a "floppy" appearing bladder on initial prenatal ultrasound will have worse infant outcomes than fetuses with full/rounded bladders. METHOD: We retrospectively reviewed all cases of LUTO evaluated in our fetal center between January 2013 and December 2021. Ultrasonographic assessment, renal biochemistry, and bladder refilling contributed to a "favorable" or "unfavorable" evaluation. Bladder morphology on initial ultrasound was classified as "floppy" or "full/rounded." Vesicoamniotic shunting was offered for favorably evaluated fetuses. Baseline demographics, ultrasound parameters, prenatal evaluations of fetal renal function, and infant outcomes were collected. Fetuses diagnosed with severe LUTO were included in analysis using descriptive statistics. The primary outcome measured was survival at 6 months of life. RESULTS: 104 LUTO patients were evaluated; 24 were included in analysis. Infant survival rate at 6 months was 60% for rounded bladders and 0% for floppy bladders (p = 0.003). Bladder refill adequacy was lower in fetuses with floppy bladders compared with rounded bladders (p value < 0.00001). CONCLUSION: We propose that bladder morphology in fetuses with severe LUTO may be a prognostication factor for predicting infant outcomes and provides a valuable, noninvasive assessment tool.

The utility of gene sequencing in identifying an underlying genetic disorder in prenatally suspected lower urinary tract obstruction.

OBJECTIVE: Fetal megacystis generally presents as suspected lower urinary tract obstruction (LUTO), which is associated with severe perinatal morbidity. Genetic etiologies underlying LUTO or a LUTO-like initial presentation are poorly understood. Our objectives are to describe single gene etiologies in fetuses initially ascertained to have suspected LUTO and to elucidate genotype-phenotype correlations. METHODS: A retrospective case series of suspected fetal LUTO positive for a molecular diagnosis was collected from five centers in the Fetal Sequencing Consortium. Demographics, sonograms, genetic testing including variant classification, and delivery outcomes were abstracted. RESULTS: Seven cases of initially prenatally suspected LUTO-positive for a molecular diagnosis were identified. In no case was the final diagnosis established as urethral obstruction that is, LUTO. All variants were classified as likely pathogenic or pathogenic. Smooth muscle deficiencies involving the bladder wall and interfering with bladder emptying were identified in five cases: MYOCD (2), ACTG2 (2), and MYH11 (1). Other genitourinary and/or non-genitourinary malformations were seen in two cases involving KMT2D (1) and BBS10 (1). CONCLUSION: Our series illustrates the value of molecular diagnostics in the workup of fetuses who present with prenatally suspected LUTO but who may have a non-LUTO explanation for their prenatal ultrasound findings.

External validation and reliability assessment of posterior urethral morphology on initial voiding cystourethrogram as a predictor for infants with posterior urethral valves.

INTRODUCTION: The morphology of the bladder and posterior urethra on initial voiding cystourethrogram (VCUG) in posterior urethral valve (PUV) has been proposed as a meaningful early metric for short- and long-term kidney outcomes. Here, we seek to externally validate the proposed association and assess the reliability of PUV morphology characteristics. MATERIALS AND METHODS: We reviewed our institutional database for patients managed for PUV between 2000 and 2022 and included those treated with primary ablation with at least 1 year of follow-up for kidney function. Each VCUG was evaluated by three independent raters for the height-width ratio of the bladder (HW-B), height-width ratio of the posterior urethra (HW-PU), and posterior-anterior urethral ratio (PA-UR), and trabeculation (none, fine, or coarse). We assessed the reliability in these with intra-class coefficient and Fleiss kappa for continuous and categorical data, respectively. We performed univariate analysis with nadir creatinine and five-year follow-up glomerular filtration rate (GFR). RESULTS: In total, 98 patients met inclusion criteria. The median age at diagnosis and ablation was 10 and 21 days, respectively. Patients with nadir creatinine <0.8 mg/dL had higher follow-up GFR (101 vs. 20 ml/min/1.73 m2, p = 0.04), and lower risk of CKD (odds ratio 14.7, p = 0.002). The median value for HW-B was 1.4, median HW-PU was 2.1, and median PA-U was 4.7, There was significant inter-class agreement between all three measures of 0.80, 0.51, and 0.70 (p < 0.001). The inter-rater agreement for bladder trabeculation was fair (Fleiss K = 0.40, p < 0.001). There was no statistically significant correlation between HW-B, HW-PU, PU-A with nadir creatinine (p = 0.07, 0.33, 0.91) or 5-year GFR (0.27, 0.45, 0.62), respectively. DISCUSSION: There is significant interest in determining prognostic factors and metrics in PUV. The morphological characteristics on VCUG are reliable and is available information for all boys diagnosed with PUV, resulting in an attractive metric. While we do not demonstrate correlation with kidney outcomes, VCUG features warrant further attention as prognostic factors in PUV. CONCLUSIONS: PUV morphology on initial VCUG is a reliable metric of lower urinary tract deformity but is not associated with 5-year kidney outcomes.

Congenital lower urinary tract obstruction with spontaneous fetal bladder rupture due to posterior urethral valves: a case report.

BACKGROUND: Congenital lower urinary tract obstruction (LUTO) is a rare but significant condition affecting fetal urinary tract development. LUTO has a range of etiologies, with posterior urethral valves (PUV) being the most common cause. The prenatal diagnosis of LUTO plays a crucial role in recognizing the condition and guiding management decisions. Prenatal ultrasound serves as the primary tool for identifying LUTO, with key findings including megacystis, bladder wall thickening, oligohydramnios, hydronephrosis, and the 'keyhole sign' indicating dilatation of the posterior urethra. We present a case of congenital LUTO with a rare complication of spontaneous fetal bladder rupture and urinary ascites, treated by peritoneo-amniotic shunt placement. CASE PRESENTATION: A 27-year-old pregnant Caucasian women was referred at 28 weeks of pregnancy due to the presence of megacystis and bilateral hydronephrosis on routine ultrasound and suspicion of LUTO. Repeat ultrasound at 29 weeks showed significant fetal ascites, oligohydramnios and resolution of megacystis and hydronephrosis, after which diagnosis of spontaneous bladder rupture was made. Despite ascites aspiration and amnio-infusion, there was persistent ascites and oligohydramnios. A peritoneo-amniotic shunt was placed with resolution of ascites and normalization of the amniotic fluid volume. At 35 weeks, relapse of the megacystis was observed with bilateral pyelectasis and oligohydramnios, possibly due to healing of the bladder rupture, after which elective cesarean section was planned. Cystography confirmed spontaneous healing of the bladder rupture and the presence of posterior urethral valves, which were resected in the neonatal period with cold knife incision. Total follow-up of 8 years continued to show positive ultrasonographic results and good renal function, but the child suffers from bladder dysfunction, manifesting as overactive bladder disease. CONCLUSIONS: LUTO might lead to important renal dysfunction and pulmonary hypoplasia in case of increasing disease severity. Spontaneous bladder rupture might improve renal prognosis, acting as a pop-off mechanism by decompression of the urinary tract. However, fetal bladder rupture is rare and only few cases have been reported. Prenatal intervention can be considered for moderate or severe LUTO, but the benefit for long-term outcome remains uncertain and further studies are needed.

Urethral obstruction from Cobb's collar in association with VACTERL.

SUMMARY: Cobb's collar is a rare intraluminal congenital cause of bulbar urethral obstruction that is commonly mislabelled congenital obstructive posterior urethral membrane (COPUM) but may be distinguished from this endoscopically as it has no connecting folds to the verumontanum. In this report, Cobb's collar is described for the first time in association with the VACTERL syndrome. The abnormality was diagnosed and treated by diathermy and dilatation at the time of endoscopic evaluation, with improvement of vesicoureteric reflux on micturating cystourethrogram and renal ultrasound.

Case report laparoscopy-assisted pre-pubic urethrostomy as a palliative procedure for resection of distal urethral tumor in a female dog.

BACKGROUND: This paper presents the first described case of laparoscopy-assisted prepubic urethrostomy and laparoscopic resection of a tumor of the distal part of the urethra in a female dog as a palliative treatment. CASE PRESENTATION: An intact, 11 -year-old, mixed breed female dog, weighing 15 kg, was admitted with signs of urinary obstruction and difficulty with catheterization. Vaginal, rectal, and endoscopic examinations revealed a firm mass in the pelvic cavity at the level of the pelvic urethra. Ultrasound and computed tomography examination showed enlargement of the urethral wall (5.5 cm width and 3 cm thick), which was significantly restricting the patency of the urethra. The lesion affected only the distal part of the urethra without the presence of local or distant metastatic changes. The affected portion of the urethra was laparoscopically removed while performing pre-pubic urethrostomy with laparoscopy. The patient regained full consciousness immediately after the end of anesthesia, without signs of urinary incontinence. Histopathological examination of the removed urethra revealed an oncological margin only from the side of the bladder. In the period of 2.5 months after the procedure, the owner did not notice any symptoms that could indicate a postoperative recurrence, which was diagnosed three months after the procedure. CONCLUSIONS: Pre-pubic urethrostomy can be successfully performed with the assistance of laparoscopy. The use of minimally invasive surgery will allow, in selected cases, removal of the urethral tumor, and in inoperable cases, to perform a minimally invasive palliative pre-pubic urethrostomy.

Predictive accuracy of prenatal ultrasound findings for lower urinary tract obstruction: A systematic review and Bayesian meta-analysis.

BACKGROUND: Lower urinary tract obstruction (LUTO) is a rare but critical fetal diagnosis. Different ultrasound markers have been reported with varying sensitivity and specificity. AIMS: The objective of this systematic review and meta-analysis was to identify the diagnostic accuracy of ultrasound markers for LUTO. MATERIALS AND METHODS: We performed a systematic literature review of studies reporting on fetuses with hydronephrosis or a prenatally suspected and/or postnatally confirmed diagnosis of LUTO. Bayesian bivariate random effects meta-analytic models were fitted, and we calculated posterior means and 95% credible intervals for the pooled diagnostic odds ratio (DOR). RESULTS: A total of 36,189 studies were identified; 636 studies were available for full text review and a total of 42 studies were included in the Bayesian meta-analysis. Among the ultrasound signs assessed, megacystis (DOR 49.15, [15.28, 177.44]), bilateral hydroureteronephrosis (DOR 41.33, [13.36,164.83]), bladder thickening (DOR 13.73, [1.23, 115.20]), bilateral hydronephrosis (DOR 8.36 [3.17, 21.91]), male sex (DOR 8.08 [3.05, 22.82]), oligo- or anhydramnios (DOR 7.75 [4.23, 14.46]), and urinoma (DOR 7.47 [1.14, 33.18]) were found to be predictive of LUTO (Table 1). The predictive sensitivities and specificities however are low and wide study heterogeneity existed. DISCUSSION: Classically, LUTO is suspected in the presence of prenatally detected megacystis with a dilated posterior urethra (i.e., the keyhole sign), and bilateral hydroureteronephrosis. However, keyhole sign has been found to have modest diagnostic performance in predicting the presence of LUTO in the literature which we confirmed in our analysis. The surprisingly low specificity may be influenced by several factors, including the degree of obstruction, and the diligence of the sonographer at searching for and documenting it during the scan. As a result, providers should consider this when establishing the differential for a fetus with hydronephrosis as the presence or absence of keyhole sign does not reliably rule in or rule out LUTO. CONCLUSIONS: Megacystis, bilateral hydroureteronephrosis and bladder wall thickening are the most accurate predictors of LUTO. Given the significant consequences of a missed LUTO diagnosis, clinicians providing counselling for prenatal hydronephrosis should maintain a low threshold for considering LUTO as part of the differential diagnosis.

Z-scores of fetal bladder size for antenatal differential diagnosis between posterior urethral valves and urethral atresia.

OBJECTIVE: To construct reference values for fetal urinary bladder distension in pregnancy and use Z-scores as a diagnostic tool to differentiate posterior urethral valves (PUV) from urethral atresia (UA). METHODS: This was a prospective cross-sectional study in healthy singleton pregnancies aimed at constructing nomograms of fetal urinary bladder diameter and volume between 15 and 35 weeks' gestation. Z-scores of longitudinal bladder diameter (LBD) were calculated and validated in a cohort of fetuses with megacystis with ascertained postnatal or postmortem diagnosis, collected from a retrospective, multicenter study. Correlations between anatomopathological findings, based on medical examination of the infant or postmortem examination, and fetal megacystis were established. The accuracy of the Z-scores was evaluated by receiver-operating-characteristics (ROC)-curve analysis. RESULTS: Nomograms of fetal urinary bladder diameter and volume were produced from three-dimensional ultrasound volumes in 225 pregnant women between 15 and 35 weeks of gestation. A total of 1238 urinary bladder measurements were obtained. Z-scores, derived from the fetal nomograms, were calculated in 106 cases with suspected lower urinary tract obstruction (LUTO), including 76 (72%) cases with PUV, 22 (21%) cases with UA, four (4%) cases with urethral stenosis and four (4%) cases with megacystis-microcolon-intestinal hypoperistalsis syndrome. Fetuses with PUV showed a significantly lower LBD Z-score compared to those with UA (3.95 vs 8.83, P < 0.01). On ROC-curve analysis, we identified 5.2 as the optimal Z-score cut-off to differentiate fetuses with PUV from the rest of the study population (area under the curve, 0.84 (95% CI, 0.748-0.936); P < 0.01; sensitivity, 74%; specificity, 86%). CONCLUSIONS: Z-scores of LBD can distinguish reliably fetuses with LUTO caused by PUV from those with other subtypes of LUTO, with an optimal cut-off of 5.2. This information should be useful for prenatal counseling and management of LUTO. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Evaluation of Sequential Urine Analysis when Selecting Candidates for Vesicoamniotic Shunting in Lower Urinary Tract Obstruction.

OBJECTIVE: The objective of our study was to assess the utility of sequential fetal urine analysis in severe lower urinary tract obstruction (LUTO) when selecting cases suitable for vesicoamniotic shunting. MATERIAL AND METHODS: This was a retrospective cohort study of cases of severe LUTO treated in our fetal medicine center from 1994 to 2013. Two fetal bladder samples were taken 24-48 h apart to assess renal function. A vesicoamniotic shunt was inserted in case of improvement in urinary biochemistry between the 2 samples. We assessed perinatal morbidity and mortality and renal function at 5 years. RESULTS: Among a total of 26 LUTO cases with sequential urine analysis, 5 showed normal urinary biochemistry, 13 were abnormal, and 8 improved between the 2 samples. These 8 cases underwent vesicoamniotic shunt placement, leading to the birth of 6/8 (75%) live infants, 5/6 (83%) of whom had normal renal function at 5 years. The 5 cases with normal biochemistry occasioned 2 neonatal deaths and 3 children with normal renal function at 5 years. Elective termination of pregnancy was requested by parents for the fetuses exhibiting abnormal biochemistry. CONCLUSION: An improvement in urinary biochemistry between 2 sequential fetal bladder punctures in severe LUTO could be an effective criterion in the selection of candidates for vesicoamniotic shunting. However, the benefit of a shunt in fetuses with normal amniotic fluid remains to be evaluated in clinical trials.

Check cystoscopy in the management of anterior urethral valves in a cohort of pediatric patients.

INTRODUCTION: Anterior urethral valves (AUV) are a rare cause of lower urinary tract obstruction which could progress to renal damage, Clinical presentation varies according with patient's age and severity of obstruction, but, in most cases, diagnosis is based on voiding cysto-urethrogram (VCUG). To date, the treatment of choice is endoscopic ablation even if approved guidelines about the overall management of AUVs, including the recognition and treatment of residual valves, are not available. OBJECTIVE: We describe our protocol for AUV treatment based on primary endoscopic valve ablation followed by check cystoscopy 15 days later. STUDY DESIGN: Medical records of 5 patients with AUVs admitted from 2008 to 2018 to our Pediatric Urology Unit were retrospectively reviewed. Blood tests, urinalysis, renal US and VCUG were performed in all children, while urodynamic evaluation was performed in the 3/5 patients who could void spontaneously. All patients underwent endoscopic valves ablation and after 15 days after a second look cystoscopy was performed. Follow up was based on clinical and radiological evaluation with US, urinalysis and blood tests. Postoperative non-invasive urodynamic studies were performed in the 3/5 patient toilet-trained patients and VCUG was performed in 1/5 patient. RESULTS: and Discussion: At primary endoscopic ablation cystoscopy revealed AUVs in the penile urethra in three patients, in the penoscrotal urethra in one case, in the bulbar urethra in another case. In 3/5 patients check cystoscopy found residual valves and a second endoscopic ablation was performed. All patients achieved symptoms release and improved urodynamic parameters. No intra or post-operative complication were reported. The assessment of residual valves is variable in literature and it is usually described for posterior urethral valves (PUVs). Few series report the use of VCUG within the first week after valve ablation, our experience instead suggests that performing a second look cystoscopy, is very effective to evaluate the presence of residual AUVs and eventually proceed with further ablation. CONCLUSION: Endoscopic ablation is the gold standard treatment for AUV, but residual valves management is not clearly defined. According to our experience, a check cystoscopy 15 days after primary ablation allows to identify and treat possible residual valves showing good results in terms of safety and efficacy.

Radiographic diagnoses in 80 cats before and 73 cats after unobstructing the urethra.

OBJECTIVE: The aim of this study was to investigate causes for feline urethral obstruction and determine whether the frequency of radiographic diagnoses differs between cats radiographed before or after unobstruction of the urethra. MATERIALS AND METHODS: A retrospective cross-sectional study of cats with naturally occurring urethral obstruction was performed. Only cats presenting for their first urethral obstruction in which radiography was integrated in the initial evaluation were included. The diagnosis frequency (overall and for each disease type) was compared between cats radiographed before or after unobstruction of the urethra. RESULTS: Eighty cats (52%) had radiographs obtained before unobstructing the urethra and 73 cats (48%) had radiographs taken after unobstructing the urethra. Cats radiographed before unobstruction had a greater frequency of radiographic diagnoses than those radiographed after unobstruction (61% versus 45%). This difference was largely due to a greater frequency of urethral plugs detected before unobstruction versus after unobstruction (45% versus 5.5%). CLINICAL SIGNIFICANCE: Radiographs obtained before unobstructing the urethra provided a diagnostic advantage for detecting a cause for urethral obstruction compared to radiographs obtained after unobstructing the urethra. Urethral plugs were the most common diagnosis.

Primary infertility secondary to a hidden posterior urethral valve representing a diagnostic challenge in the fifth decade.

Posterior urethral valves (PUVs) are frequently recognized during the perinatal period. Delayed diagnosis is reported usually within the first decade of life with diverse clinical presentations. In the current case report, we describe a 45 years old man patient who presented with aspermia and primary infertility for 8 years in whom his diagnostic workup revealed radiological imaging suggestive of PUVs. This phenomenon was confirmed by cystourethroscopy that showed obstructive valve. Endoscopic ablation resulted in significant improvement of his seminal parameter with successful conception.

Decreased biventricular myocardial deformation in fetuses with lower urinary tract obstruction.

BACKGROUND: To observe myocardial deformations in fetuses with isolated lower urinary tract obstruction (LUTO) and identify the correlation between myocardial deformation and the severity of obstruction. METHODS: The strain (S), strain rate in systole (SRs) and strain rate in diastole (SRd) of the left and right ventricles at the first examination were prospectively analyzed and compared between fetuses with isolated LUTO and gestational age (GA)-matched normal control fetuses. Multiple regression analyses were used to assess the obstructive factors for impaired strain and strain rate, and the independent variables included bladder volume, sum of the bilateral pelvic diameters, sum of the bilateral ureteral diameters, mean bilateral renal artery pulsatility index, and amniotic fluid index. RESULTS: Thirty-six fetuses with isolated LUTO and 36 normal controls were enrolled. Overall, decreased S, SRs and SRd of both ventricles were noted in fetuses with LUTO (p < 0.001). Moreover, S and SR were significantly negatively related to distended bladder volume (p < 0.001). CONCLUSIONS: Fetuses with LUTO demonstrated decreased left and right myocardial deformation, and this impaired cardiac dysfunction was correlated with the urinary bladder volume. Evaluating the myocardial deformation in fetal LUTO could provide information to aid in parental counselling and intervention monitoring.

Neurodevelopmental Outcome in Infants with Lower Urinary Tract Obstruction Based on Different Degrees of Severity.

OBJECTIVE: To determine postnatal neurodevelopmental (ND) outcomes for children with congenital lower urinary tract obstruction (LUTO) based on disease severity. METHODS: Twenty male infants with LUTO were classified prenatally as Stage 1 (normal amniotic fluid and renal function; n = 5), Stage 2 (signs of obstruction with preserved renal function; n = 13), and Stage 3 (signs of severe renal damage; n = 2). ND status was assessed using the Developmental Profile-3 test in 5 developmental domains (physical, adaptive behavior, social-emotional, cognitive, and communication). Each domain was considered to be delayed if standard scores were 2 or more SD below the mean. ND outcomes were compared between cases with an expected normal renal function (LUTO Stage 1) and those with impaired renal function (LUTO Stages 2 and 3). Results from cases with Stage 2 were also compared to those from Stage 3. ORs were calculated to predict risk for adverse ND outcome for each domain considering prenatal and postnatal factors. RESULTS: Gestational age (GA) at the diagnosis of LUTO was similar between both groups (Stage 1: 24.85 ± 7.87 vs. Stages 2 and 3: 21.4 ± 4.31 weeks; p = 0.24). Twelve of 15 cases with Stage 2 or 3 underwent vesicoamniotic shunt placement compared to none of Stage 1 fetuses (p < 0.01). No differences in GA at delivery were detected between the groups (37.9 ± 1.6 vs. 35.1 ± 3.6 weeks; p = 0.1). One of the infants in the Stage 2 and 3 groups received a kidney transplant during follow-up. One case (20%) from Stage 1 group required dialysis during the first 6 months of life, and 1 case from Stage 2 to 3 group required it during the first 6 months (p = 1.0), whereas 3 additional cases needed dialysis from 6 to 24 months (p = 0.6). Mean age at Developmental Profile 3 (DP-3) testing was 20.3 ± 12.3 months (Stage 1: 11.2 ± 8.6 vs. Stages 2 and 3: 23.4 ± 13.4 months; p = 0.07). Fifteen of the 20 patients (75%) had no ND delays. Of the 5 patients with ND delays, 4 received dialysis. No differences in ND outcomes between infants with LUTO Stage 1 and those with Stages 2 and 3 were detected except for a trend toward better physical development in Stage 1 (102.6 ± 11.6 vs. 80.7 ± 34.9; p = 0.05). Infants diagnosed with LUTO Stage 3 showed significantly lower adaptive scores than those diagnosed with Stage 2 (Stage 2: 101.9 ± 22.3 vs. Stage 3: 41.5 ± 30.4; p = 0.04) and a nonsignificant trend for lower results in physical (85.8 ± 33.0 vs. 47.5 ± 38.9; p = 0.1) and socio-emotional (94.7 ±17.9 vs. 73.5 ± 13.4; p = 0.1) domains. Infants who received dialysis showed 15-fold increased risk (95% CI 0.89-251) for delayed socio-emotional development (p = 0.06). Diagnosis of fetal renal failure increased the risk for delays in the adaptive domain 30-fold (95% CI 1.29-93.1; p = 0.03). Infants with abnormal renal function had 19 times (95% CI 1.95-292) increased risk for delays in the physical domain (p = 0.03). CONCLUSIONS: While most patients with LUTO do not exhibiting ND delays, our results support the importance of ND monitoring, especially in severe forms of LUTO, as increased severity of this condition may be associated with poorer ND outcomes.

Fetal lower urinary tract obstruction: What should we tell the prospective parents?

Fetal lower urinary tract obstruction (LUTO), which often results in marked perinatal morbidity and mortality, is caused by a heterogeneous group of anatomical defects that lead to blockage of the urethra. The classic prenatal presentation of LUTO includes megacystis with hydronephrosis. While mild forms of the disease can be associated with favorable outcomes, more severe disease commonly leads to dysplastic changes in the fetal kidneys, and ultimately oligohydramnios, which can result in secondary pulmonary hypoplasia and renal failure at birth. The aim of this review is to provide practitioners with a general overview of the diagnosis and treatment of LUTO based on disease severity, along with some points to consider when counseling prospective parents of fetuses with this condition.

[Native kidney ultrasound in obstructive uropathy].

The term "obstructive uropathy" refers to the complex structural and functional changes following the interruption of normal urinary runoff, which can occur at every level of the urinary tract. Depending on its origin, duration and severity, urinary tract obstructions can be acute or chronic, mono or bilateral, partial or complete. The obstruction can be localized or extended to the entire pielo-caliceal system and/or homolateral urethra. The term "hydronephrosis" indicates the dilation of the pelvis detected through imaging techniques. Among these, ultrasound is considered the gold standard in the diagnosis of obstructive uropathy: it allows to distinguish three degrees of urinary tract dilation, depending on the extent of the dilation itself and the thickness of the parenchyma. Nephrologists are confronted daily with patients who experience kidney failure and must be able to quickly distinguish between chronic and acute and, in the latter case, to discern between issues of nephrological or urological competence. This short review aims at helping them deal with this very common scenario, through the use of ultrasound.

Etiology and management of early pregnancy renal anhydramnios: Is there a place for serial amnioinfusions?

Early pregnancy renal anhydramios (EPRA) comprises congenital renal disease that results in fetal anhydramnios by 22 weeks of gestation. It occurs in over 1 in 2000 pregnancies and affects 1500 families in the US annually. EPRA was historically considered universally fatal due to associated pulmonary hypoplasia and neonatal respiratory failure. There are several etiologies of fetal renal failure that result in EPRA including bilateral renal agenesis, cystic kidney disease, and lower urinary tract obstruction. Appropriate sonographic evaluation is required to arrive at the appropriate urogenital diagnosis and to identify additional anomalies that allude to a specific genetic diagnosis. Genetic evaluation variably includes karyotype, microarray, targeted gene testing, panels, or whole exome sequencing depending on presentation. Patients receiving a fetal diagnosis of EPRA should be offered management options of pregnancy termination or perinatal palliative care, with the option of serial amnioinfusion therapy offered on a research basis. Preliminary data from case reports demonstrate an association between serial amnioinfusion therapy and short-term postnatal survival of EPRA, with excellent respiratory function in the neonatal period. A multicenter trial, the renal anhydramnios fetal therapy (RAFT) trial, is underway. We sought to review the initial diagnosis ultrasound findings, genetic etiologies, and current management options for EPRA.

Urosonografía miccional seriada en el diagnóstico y manejo de las válvulas de uretra posterior en pacientes pediátricos / Serial voiding urosonography in posterior urethral valve diagnosis and management in pediatric patients

Objetivos: Comunicar nuestra experiencia con la utilización de la urosonografía miccional seriada (UMS) para el diagnóstico y manejo de pacientes con válvulas de uretra posterior (VUP). Material y método: Estudio retrospectivo descriptivo en pacientes entre 0 a 14 años con sospecha de VUP en UMS realizada como primera prueba contrastada de la vía urinaria y con estudio cistoscópico posterior. Las variables se analizaron utilizando SPSSv22. Resultados: Fueron estudiados 18 pacientes (edad mediana de 6 meses). La mayoría de los pacientes (15) presentaban dilatación de la uretra posterior (diámetro medio de 9,56 mm) y diferencia entre uretra proximal y distal mayor de 2 mm. Trece casos tenían engrosamiento vesical y 9 RVU. Se diagnosticaron 15 casos de VUP, 1 caso de mucocele de uretra distal y 1 divertículo vesical que obstruía uretra. Se consiguió resección completa de las VUP en 10 pacientes (66,6%) en la primera cistoscopia. La UMS de control detectó un caso de resección incompleta por persistencia de dilatación de uretra posterior. Este caso y los 5 conocidos con resección incompleta se sometieron a una segunda cistoscopia y resección. El menor de los pacientes requirió una tercera resección y dilatación con balón de corte por estenosis residual. La creatinina media al diagnóstico fue 0,28 mg/dl. Conclusiones: La urosonografía miccional seriada (UMS) es una prueba complementaria útil en pacientes pediátricos con válvulas de uretra posterior. Su carácter dinámico y ventajas: ausencia de irradiación, seguridad y alta sensibilidad; la convierten en una prueba de imagen ideal para el diagnóstico y seguimiento de VUP

Objectives: Report our experience with the use of contrast-enhanced serial voiding urosonography (SVU) for posterior urethral valve (PUV) patient diagnosis and management. Materials and Methods: Descriptive retrospective study in 0- to 14-year-old patients with suspected PUV at SVU performed as a first contrast-enhanced urinary tract test with subsequent cystoscopic study. Variables were analyzed using SPSSv22. Results: 18 patients were studied (median age: 6 months). Most patients (15) presented posterior urethral dilatation (mean diameter: 9.56 mm) and a >2 mm gap between proximal and distal urethra. 13 cases had bladder thickening and 9 had VUR. 15 PUV cases, 1 case of distal urethral mucocele, and 1 case of bladder diverticulum obstructing the urethra were diagnosed. Complete PUV resection was performed in 10 patients (66.6%) at the first cystoscopy. The control SVU detected one case of recurrence due to persistence of posterior urethral dilatation. The recurrence case and the 5 incomplete resection cases were treated with a second cystoscopy and resection. The youngest patients required a third resection and cutting balloon dilatation due to residual stenosis. Mean creatinine levels at diagnosis were 0.28 mg/dl. Conclusions: Serial voiding urosonography (SVU) is a useful complementary test in pediatric patients with posterior urethral valve. Its dynamic nature and its advantages - absence of irradiation, safety, and high sens efitivity - make it an ideal imaging test for PUV diagnosis and follow-up

Prenatal diagnosis and postnatal outcome of anterior urethral anomalies.

OBJECTIVES: Anterior urethral anomalies (AUA) which present as anterior urethral valve, stenosis or atresia, are a rare cause for congenital urinary tract obstruction. We present our AUA prenatal diagnosis case series. METHODS: Fetuses presenting with prenatal findings suggestive for AUA according to postnatal reported clinical and imaging signs (urinary tract dilatation, dilated bladder, enlarged edematous fetal penis, dilatation of the fetal urethra and diverticula) were followed prospectively. RESULTS: Six fetuses were diagnosed with AUA. Diagnosis was confirmed upon examination of the neonate or the abortus. All cases presented with variable degrees of urinary tract dilatation. Four fetuses who presented with additional congenital anomalies of the kidneys and urinary tract (CAKUT) developed intra-uterine or early postnatal renal failure, while two isolated AUA cases have a normal renal outcome. CONCLUSIONS: AUA is a rare diagnosis. However, high index of suspicion and careful sonographic assessment of the male fetal urethra in cases referred for urinary tract dilatation may enable appropriate parent counseling, optimal prenatal surveillance and timed postnatal urological intervention. As in other lower urinary tract obstructions, future renal function seems to correlate with associated CAKUT, therefore close follow up throughout pregnancy and meticulous sonographic assessment is recommended.