Posterior urethral valves (PUV) are the most common form of lower urinary tract obstructions (LUTO). The valves can be surgically corrected postnatally; however, the impairment of kidney and bladder development is irreversible and has lifelong implications. Chronic kidney disease (CKD) and bladder dysfunction are frequent problems. Approximately 20% of PUV patients will reach end-stage kidney disease (ESKD). The subvesical obstruction in PUV leads to muscular hypertrophy and fibrotic remodelling in the bladder, which both impair its function. Kidney development is disturbed and results in dysplasia, hypoplasia, inflammation and renal fibrosis, which are hallmarks of CKD. The prognoses of PUV patients are based on prenatal and postnatal parameters. Prenatal parameters include signs of renal hypodysplasia in the analysis of fetal urine. Postnatally, the most robust predictor of PUV is the nadir serum creatinine after valve ablation. A value that is below 0.4 mg/dl implies a very low risk for ESKD, whereas a value above 0.85 mg/dl indicates a high risk for ESKD. In addition, bladder dysfunction and renal dysplasia point towards an unbeneficial kidney outcome. Experimental urinary markers such as MCP-1 and TGF-β, as well as microalbuminuria, indicate progression to CKD. Until now, prenatal intervention may improve survival but yields no renal benefit. The management of PUV patients includes control of bladder dysfunction and CKD treatment to slow down progression by controlling hypertension, proteinuria and infections. In kidney transplantation, aggressive bladder management is essential to ensure optimal graft survival.

(1) Background: The aim of this study was to compare perinatal outcomes and complication rates of vesicoamniotic shunting (VAS) before 17 + 0 weeks in isolated LUTO (lower urinary tract obstruction) with the Somatex® intrauterine shunt vs. the Harrison fetal bladder shunt. (2) Methods: This is a retrospective cohort study in two tertiary fetal medicine centers. From 2004−2014, the Harrison fetal bladder shunt was used, and from late 2014−2017, the Somatex shunt. Obstetrics and pediatric charts were reviewed for complications, course of pregnancy, perinatal outcome, and postnatal renal function. (3) Results: Twenty-four fetuses underwent VAS with a Harrison (H) shunt and 33 fetuses with a Somatex (S) shunt. Live birth rates and survival to last follow-up were significantly higher in the Somatex group, at 84.8% and 81.8%, respectively, vs. 50% and 33.3% in the Harrison group (p = 0.007 and p < 0.001). The dislocation rate in the Somatex group (36.4%) was significantly lower than in the Harrison group (87.5%) (p < 0.001). The median time to dislocation was significantly different, at 20.6 days (H) vs. 73.9 days (S) (p = 0.002), as was gestational age at dislocation (17 (H) vs. 25 (S) weeks, p < 0.001). Renal function was normal in early childhood in 51% (S) vs. 29% (H) (p = 0.11). (4) Conclusions: VAS before 17 + 0 weeks gestational age with a Somatex shunt improves perinatal survival significantly and might even have a positive effect on renal function, probably due to the lower dislocation rates. A normal amount of amniotic fluid in the third trimester was the best predictor of normal renal function in early childhood.

OBJECTIVE: Fetal megacystis (MC) can be severe and is mainly caused by fetal lower urinary tract obstruction (LUTO). Mortality of fetal LUTO can be high as a result of pulmonary hypoplasia and/or (chronic) renal insufficiency. Several technical procedures for vesicoamniotic shunting (VAS) were developed to improve fetal MC outcomes.
METHODS: We present the outcome of nine fetuses with MC who received VAS in the prenatal period (14 + 6 to 27 + 6 weeks GA) using the Somatex® intrauterine shunt system. MC was defined as an increased longitudinal measurement of the bladder >15 mm. The median follow-up time after birth was 18 months.
RESULTS: Eight Fetuses had uncomplicated VAS intervention. One case developed PPROM 24 h after VAS leading to abortion. Pregnancy was later terminated in further two cases. All six live-born infants received intensive care treatment. Invasive-mechanical ventilation was necessary in one case who died 24 h post-partum of severe cardiac depression. Five infants who survived the follow-up time developed chronic renal insufficiency (CRI), with one infant developing end-stage renal failure requiring peritoneal dialysis.
CONCLUSIONS: Overall, 5 of 9 LUTO fetuses (55%) undergoing VAS with the Somatex® intrauterine shunt system showed long-term survival beyond the neonatal period of 28 d (5/9; 55%) with varying morbidity.

OBJECTIVE: To examine the outcomes of prenatally diagnosed lower urinary tract obstruction (LUTO) with current management using vesicoamniotic shunting (VAS).
METHODS: A retrospective study of prenatally diagnosed LUTO before 26 weeks of gestation at two tertiary centers in Japan between March 2002 and September 2017. LUTO was diagnosed by ultrasound demonstration of an enlarged fetal bladder associated with hydronephrosis and/or hydroureters. VAS was offered for fetuses with LUTO at ≤26 weeks of gestational age, in the presence of oligohydramnios or decreasing amniotic fluid and a favorable fetal urinary analysis.
RESULTS: Among 87 fetuses with LUTO, 46 (53%) were terminated before 22 weeks of gestation. Eight cases (9%) underwent VAS and one underwent fetoscopic urethrotomy. The live birth rates in the VAS and expectant groups were 100% (8/8) and 56% (18/32), respectively (p = 0.034), and the survival rates at 6 months old with a normal renal function were 38% (3/8) and 16% (5/32), respectively (p = 0.608). The etiology varied with six cases of associated anomalies among 23 diagnosed cases. Among the nine cases of posterior urethral valve (PUV), only one fetus underwent VAS at 25 weeks of gestation, ultimately surviving with mild renal dysfunction. Among the other eight cases of PUV that were managed expectantly, two died, and only one of the six survivors showed a normal renal function.
CONCLUSIONS: More than half of the prenatally diagnosed LUTO cases were terminated. VAS seemed effective for achieving a perinatal survival, regardless of etiology. The outcomes were poor in cases of expectantly managed PUV.

The aim of this review article is to provide a practical and concise overview of diagnosis and management of pregnancy with fetal lower urinary tract obstruction.
Review of literature and current studies.
Proper diagnosis and management of isolated fetal lower urinary tract obstruction with oligohydramnios allows appropriate implementation of intrauterine treatment in indicated cases. The treatment is a prevention of pulmonary hypoplasia and also improves renal function; this  finally contributes to the improvement of overall perinatal morbidity and mortality.

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.
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.
CONCLUSIONS: 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.

BACKGROUND: In utero therapeutic approaches for lower urinary tract obstruction (LUTO) have been developed to salvage the fetal kidney function.
OBJECTIVE: The aim of this work was to report the long-term survival, nephrological, and urological outcome of children treated prenatally for LUTO using operative fetal cystoscopy (FC) and vesicoamniotic shunting (VAS) or both.
METHODS: A retrospective study of 48 procedures (23 FC, 25 VAS) was performed on 33 patients (between 2008 and 2018). Reviewed data included prenatal management and clinical follow-up by a pediatric nephrologist and a pediatric urologist. Both intention-to-treat and per-protocol analyses were conducted.
RESULTS: The median follow-up was 3.6 years (0.5-7) for FC and 2.5 years (1.1-5.1) for VAS. There was no difference between FC and VAS in terms of survival (92 vs. 83%, p = 1), complication rate (74 vs. 92%, p = 0.88), or chronic kidney disease (58 vs. 50%, p = 1). The number of procedures was higher in the VAS group: 1.7 (1-3) versus 1.1 (1-2), p = 0.01. With a 30% rate of technical failure, FC added diagnostic value in 3 out of 21 cases.
CONCLUSIONS: No difference was found between FC and VAS regarding survival, long-term kidney function, or urological outcome. Despite overly optimistic reports on FC, it lacks reproducibility due to posterior-urethra inadequate visualization and inappropriate instrumentation.

Vesicoamniotic shunting (VAS) and other bladder drainage techniques for fetal lower urinary tract obstruction (LUTO) have been proven to ameliorate pulmonary hypoplasia and increase survival in patients with an initial poor prognosis. Currently there are limited prognostic tools available during gestation to evaluate and predict postnatal renal function.
The aim was to describe the prenatal growth of the renal parenchymal area (RPA) in patients with LUTO and determine its application as a predictor of renal function at one year of life.
The study population comprised a retrospective cohort of all infants who survived the fetal VAS to birth. Renal growth and size were measured using imageJ software to calculate the RPA in sequential prenatal ultrasounds. The parenchymal area was measured from the image of each kidney with the greatest longitudinal length. These measurements were further correlated and analyzed as a predictor of end-stage renal disease (ESRD) within the first year of life.
Etiologies of LUTO in the 15 male fetuses included eight posterior urethral valves, four Eagle-Barrett/prune belly syndrome, two urethral atresia, and one megacystis microcolon intestinal hypoperistalsis syndrome. All patients had patent shunts, in place, at birth. Furthermore, ultrasonographic parameters such as oligohydramnios, keyhole sign, and bladder wall thickness showed no statistical difference between groups. Renal parenchymal growth correlated with postnatal renal function in both the ESRD (r = 0.409, p = 0.018) and the non-ESRD (r = 0.657, p < 0.001) groups. Most notably, RPA during the 3rd trimester predicted ESRD with the best cut-off point determined to be 8 cm2 (sensitivity, 0.714; specificity, 0.882; and positive likelihood ratio, 6.071) (Table).
Despite definitive VAS for LUTO, postnatal morbidity and mortality remain high, emphasizing the role of renal dysplasia in postnatal renal failure, in spite of urinary diversion. Renal growth statistically differs between groups in the 3rd trimester of gestation; RPA development appears stagnant in patients that developed ESRD within the first year of life. In contrast, patients that did not develop ESRD continued to have renal parenchymal growth in a linear fashion. This suggests that prenatal RPA may be predictive of postnatal ESRD.
RPA measurement during the prenatal period could play an important role as a non-invasive tool to predict postnatal renal function and to anticipate postnatal clinical interventions.

BACKGROUND: The Society for Fetal Urology panel section at the 2016 Fall Congress featured a multidisciplinary discussion on appropriate patient selection, the conservative versus surgical management, and postnatal renal outcome of fetuses with lower urinary tract obstruction (LUTO).
UNASSIGNED: Rodrigo Ruano shared his experience of prenatal intervention, presenting the outcome of 111 fetuses with severe LUTO treated with vesicoamniotic shunting (VAS) (n = 16), cystoscopy (n = 34) or no intervention (n = 61) in a non-randomized series. Multivariate analysis at the 6-month follow-up suggested a significantly higher probability of survival with fetal intervention versus no intervention. A clear trend for normal renal function was present in the fetal cystoscopy group, but not in the VAS group. In cases in which there was a postnatal diagnosis of posterior urethral valves (n = 57), fetal cystoscopy was effective in improving both the 6-month survival rate and renal function, while VAS was associated with an improvement in the 6-month survival rate. In an attempt to better define which fetuses would benefit from intervention, Michael Braun explained the proposed LUTO classification system that incorporates: (1) fetal urinary biomarkers of renal injury; (2) amniotic fluid levels as a surrogate for the severity of obstruction; and (3) imaging studies to identify signs of renal dysplastic or cystic changes. Intervention was not recommended in patients at low risk of either renal disease or pulmonary hypoplasia (Stage 1). Vesicoamniotic shunting was performed in patients at high risk of either progressive renal injury or pulmonary hypoplasia without evidence of severe pre-existing renal damage (Stage 2). For those patients, who at the time of evaluation had evidence of severe renal disease (Stage 3), fetal intervention was individualized and often based on bladder capacity and bladder refilling after vesicocentesis. He went on to present the nephrologic outcome of fetuses managed over the last 3 years utilizing the selection criteria. Craig Peters supported the concept of selective criteria and discussed the cautious viewpoint, namely: (1) the procedure may be unnecessary, as it is possible for patients to do well, in spite of severe prenatal obstruction; and (2) the risk of giving partial treatment by allowing the baby to survive to delivery with the daunting postnatal journey of renal and pulmonary insufficiency.
CONCLUSIONS: Standardized patient selection utilizing a staging system is undoubtedly the way forward and will enable comparable long-term renal and bladder functional outcome studies.

To examine the outcome of fetuses with megacystis treated with vesicoamniotic shunting (VAS) from 14 weeks onward.
Retrospective review of all fetuses that received VAS at two centres from 2004 to 2012.
53 fetuses with megacystis were included in the study. Mean gestational age at diagnosis was 16.4 weeks. Mean gestational age at first shunt placement was 17.8 weeks. The first shunt placement was performed before 16 weeks in 18 (34 %) cases. The mean number of shunts was 1.38. Dislocation occurred in 35 (66 %). TOP was performed in 21 (39.6 %), intrauterine death occurred in two (3.8 %) and spontaneous abortion in three cases (5.7 %). Of the 27 (50.9 %) live births, 17 (32.1 %) infants survived. Normal renal function was present in 10 cases, 4 have compensated renal failure and 3 infants had renal transplantation. Oligohydramnios was significantly associated with non-survival and renal insufficiency. The gestational age at VAS was neither correlated with renal function after birth nor with the survival in our cohort. Conversely, the interval between first shunt placement and delivery was positively correlated with survival and normal renal function. The gestational age at delivery was significantly higher in survivors and those born with normal renal function.
Despite intervention, the morbidity and mortality of megacystis is still high. We failed to demonstrate that early intervention is associated with an improved rate of normal renal function after birth. Oligohydramnios was the only parameter identifying fetuses with unfavourable outcome, while all other parameters were inconclusive.