Effectiveness of vesicoamniotic shunt in fetuses with congenital lower urinary tract obstruction: an updated systematic review and meta-analysis

Advancement of 3D printing technology for the development of a training model in US-guided vesicoamniotic shunting for early LUTO therapy

INTRODUCTION

Prenatal lower urinary tract obstruction (LUTO) is a rare and challenging condition with potential severe morbidity and mortality. Prenatal shunting methods, specifically vesicoamniotic shunting (VAS) and fetal cystoscopy, aim to manage this condition. However, comprehensive education and training are hindered by the rarity of LUTO. To address this gap, we present a low-cost 3D-printed ultrasound training model for VAS in LUTO fetuses. The aim of the study was to evaluate ultrasound and haptic fidelity of the model.

MATERIAL AND METHODS

Ultrasound images of three LUTO fetuses at 12-14 weeks were utilized to create detailed 3D-printed models. Fusion360TM software generated stereo-lithography files, and the Formlabs Form3® printer, using Flexible 80A resin, produced the models. A simulation box mimicking uterine conditions and fetal anatomy was developed for testing. Ultrasound assessments determined model accuracy, and expert evaluations gauged fidelity for VAS placement.

RESULTS

The 3D-printed model accurately replicated LUTO fetal anatomy, demonstrating structural integrity and realistic sonographic and haptic feedback during 20 punctures. Macroscopic visualization confirmed the model's durability and authenticity.

DISCUSSION

This innovative 3D-printed model addresses the scarcity of LUTO cases and the lack of realistic training tools. Simulation models enhance skills, providing a controlled learning environment that bridges theoretical knowledge and clinical application, potentially improving patient outcomes.

CONCLUSIONS

The 3D-printed training model for VAS in LUTO represents a significant advancement in surgical education, offering realistic anatomical simulation and tactile feedback. Future studies should assess its effectiveness in enhancing surgical skills and impacting patient outcomes in clinical practice.

Severe Fetal CAKUT (Congenital Anomalies of the Kidneys and Urinary Tract), Prenatal Consultations, and Initiation of Neonatal Dialysis

INTRODUCTION

 Pediatric nephrology prenatal consultations for congenital anomalies of the kidney and urinary tract (CAKUT) and criteria for kidney replacement therapy initiation in neonatal end-stage kidney disease (ESKD) are not well described. We evaluated pediatric nephrology approaches to prenatal CAKUT counseling and neonatal dialysis initiation.

METHODS

 A 35-question Qualtrics survey was distributed via the North American Pediatric Renal Trials and Collaborative Studies email list between January and March 2021. Thirty-nine pediatric nephrology centers completed the survey.

RESULTS

 All but one responding center (n = 38) provide prenatal CAKUT consultations and neonatal dialysis, with wide variability in reported multispecialty involvement. Nearly half (47%) of centers utilize written/unwritten criteria for offering neonatal dialysis. The most common contraindications to neonatal dialysis were parental refusal (61%), contraindication to access placement by surgeons (55%), and birth weight (BW) contraindication (55%, with < 1,500 g being the most common BW contraindication). Overall, 79% of centers reported caring for < 5 neonates with ESKD in the past year, 61% use hemodialysis therapies prior to peritoneal dialysis in neonates requiring dialysis, and 100% transition to peritoneal dialysis by hospital discharge.

CONCLUSION

 Many pediatric nephrology programs provide prenatal CAKUT consultations and neonatal dialysis, but with variability in practice approach. Further multicenter research regarding prenatal consultations and neonatal dialysis outcomes is necessary to further improve care delivery to this population.

Congenital anomalies of the kidney and urinary tract: antenatal diagnosis, management and counselling of families

Congenital anomalies of the kidney and urinary tract are collectively one of the most commonly diagnosed antenatal conditions. Clinicians have several tools available to diagnose anomalies, including imaging, biomarkers, family history and genetic studies. In certain cases, antenatal interventions such as vesico-amniotic shunting may be considered to improve postnatal outcomes.Congenital kidney anomalies detected antenatally can vary in clinical significance from almost no impact postnatally to significant morbidity and perinatal mortality. Prognosis broadly depends on kidney size, structure and amount of amniotic fluid, alongside genetics and family history, and progression on subsequent scans. It is important to counsel parents appropriately using a parent-focused and personalised approach. The use of a multidisciplinary team should always be considered.

Post-obstructive diuresis after posterior urethral valve treatment in neonates: a retrospective cohort study

BACKGROUND

The management of posterior urethral valve (PUV) in neonates requires close monitoring in the intensive care unit because of the risk of post-obstructive diuresis (POD). Our aim was to describe the incidence and factors associated with POD in newborns treated for PUV.

METHODS

Retrospective analysis of the medical records of all neonates who underwent surgical intervention for PUV in our neonatal intensive care unit between January 2014 and April 2021.

RESULTS

Of the 40 patients included, 15 (37.5%) had POD defined by urine output > 6 ml.kg-1.h-1 during the first 24 h following urinary tract obstruction relief. At prenatal ultrasound examinations, oligohydramnios was more common in the group with POD than in the group without (53.3% vs. 8%, p = 0.002). Preterm birth was more frequent in neonates with POD (66.7% vs. 8%; p < 0.001). Median serum creatinine (212 [137-246] vs. 95 [77-125] µmol.l-1; p < 0.001) and urea (8.5 [5.2-12.2] vs. 4.1 [3.5-4.7] mmol.l-1; p < 0.001) concentrations on the day of obstruction relief were significantly higher in the group with POD than in the group without. After adjustment for prematurity, logistic regression models confirmed correlation between the occurrence of POD and the severity of the consequences of urethral obstruction (i.e., oligohydramnios and serum creatinine levels; ß = 2.90 [0.88; 5.36], p = 0.013 and ß = 0.014 [0.003; 0.031], p = 0.034, respectively).

CONCLUSIONS

In neonates, POD is common after the relief of PUV-related obstruction. Our findings may help to identify patients at highest risk. A higher resolution version of the Graphical abstract is available as Supplementary information.

Fetal urinary tract dilation: What to tell the parents

Urinary tract dilation (UTD), which refers to the abnormal dilation of the urinary collection system, is the most common finding on prenatal ultrasound and presents with varying severity, presentation, etiology, and prognosis. Prenatal classification and risk stratification aim to prevent postnatal complications, such as urinary tract infections and further kidney dysfunction. Parents expecting a child with UTD should be counseled by a multidisciplinary team consisting of maternal-fetal medicine specialists, and pediatric urology and nephrology providers. This review summarizes the key points in the diagnostic evaluation and management during the prenatal and initial postnatal period, focusing on the information that should be provided to future parents. We address frequently asked parental questions and concerns that our multidisciplinary clinical practice faces.

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.

Development and validation of a novel fetal vesico-amniotic shunt, the vortex shunt

Fetal lower urinary tract obstruction (LUTO) is a severe malformation associated with an up to 80% mortality risk as well as significant renal and pulmonary morbidity in survivors. Fetal vesico-amniotic shunts (VAS) bypass the bladder obstruction, improve amniotic fluid volume and enhance in-utero pulmonary development. VAS has been shown to reduce respiratory morbidity and mortality in the neonatal period without proven benefit on long-term renal and bladder function. Clinically available shunts are associated with an up to 80% dislodgement rate, leading to repeat invasive procedures which increase fetal and maternal risks. We developed a novel "Vortex" shunt, which incorporates enhanced fixation to reduce dislodgement, a one-way valve to optimize in-utero bladder function, and enhanced sonographic echogenicity that optimizes the accurate deployment. Following the validation of these characteristics in initial benchtop experiments we have moved to feasibility studies in the fetal lamb model. We hope that the Vortex shunt may ultimately facilitate shunt deployment, reduce dislodgement risk, improve neonatal morbidity and mortality, and decrease the significant healthcare expenditures associated with long-term morbidity in LUTO survivors. In this manuscript, we review the natural history of LUTO, the risks and benefits of clinically available fetal shunts, and our development and early validation experiments.

Single-center outcome analysis of 46 fetuses with megacystis after intrauterine vesico-amniotic shunting with the Somatex®intrauterine shunt

OBJECTIVES

To assess the spectrum of underlying pathologies, the intrauterine course and postnatal outcome of 46 fetuses with megacystis that underwent intrauterine vesico-amniotic shunting (VAS) with the Somatex® shunt in a single center.

METHODS

Retrospective analysis of 46 fetuses with megacystis that underwent VAS either up to 14 + 0 weeks (early VAS), between 14 + 1 and 17 + 0 weeks (intermediate VAS) or after 17 + 0 weeks of gestation (late VAS) in a single tertiary referral center. Intrauterine course, underlying pathology and postnatal outcome were assessed and correlated with the underlying pathology and gestational age at first VAS.

RESULTS

46 fetuses underwent VAS, 41 (89%) were male and 5 (11%) were female. 28 (61%) fetuses had isolated and 18 (39%) had complex megacystis with either aneuploidy (n = 1), anorectal malformations (n = 6), cloacal malformations (n = 3), congenital anomalies overlapping with VACTER association (n = 6) or Megacystis-Microcolon Intestinal-Hypoperistalsis Syndrome (MMIHS) (n = 2). The sonographic 'keyhole sign' significantly predicted isolated megacystis (p < 0.001). 7 pregnancies were terminated, 4 babies died in the neonatal period, 1 baby died at the age of 2.5 months and 34 (74%) infants survived until last follow-up. After exclusion of the terminated pregnancies, intention-to-treat survival rate was 87%. Mean follow-up period was 24 months (range 1-72). The underlying pathology was highly variable and included posterior urethral valve (46%), hypoplastic or atretic urethra (35%), MMIHS or prune belly syndrome (10%) and primary vesico-ureteral reflux (2%). In 7% no pathology could be detected postnatally. No sonographic marker was identified to predict the underlying pathology prenatally. 14 fetuses underwent early, 24 intermediate and 8 late VAS. In the early VAS subgroup, amnion infusion prior to VAS was significantly less often necessary (7%), shunt complications were significantly less common (29%) and immediate kidney replacement therapy postnatally became less often necessary (0%). In contrast, preterm delivery ≤ 32 + 0 weeks was more common (30%) and survival rate was lower (70%) after early VAS compared to intermediate or late VAS. Overall, 90% of liveborn babies had sufficient kidney function without need for kidney replacement therapy until last follow-up, and 95% had sufficient pulmonary function without need for mechanical respiratory support. 18% of babies with complex megacystis suffered from additional health restrictions due to their major concomitant malformations.

CONCLUSIONS

Our data suggest that VAS is feasible from the first trimester onward. Early intervention has the potential to preserve neonatal kidney function in the majority of cases and enables neonatal survival in up to 87% of cases. Despite successful fetal intervention, parents should be aware of the potential of mid- or long-term kidney failure and of additional health impairments due to concomitant extra-renal anomalies that cannot be excluded at time of intervention.

Observed to expected lung area to head circumference ratio (O/E LHR) in fetuses with congenital anomalies of the kidney and urinary tract (CAKUT): assessment and evaluation as predictive factor for acute postnatal outcome-a single center study

Introduction

To assess the observed to expected lung area to head circumference ratio (O/E LHR) in fetuses with congenital anomalies of the kidney and urinary tract (CAKUT) and to explore its value as a potential predictive factor for postnatal outcome.

Methods

A retrospective single-center study was conducted on pregnancies complicated by CAKUT between 2007 and 2018. The lung-to-head ratio (LHR) was calculated for each fetus by two independent observers. Correlations between O/E LHR and various perinatal outcome factors were assessed with Spearman's rank correlation. Furthermore, nominal logistic regression was performed to assess O/E LHR as predictive factor for respiratory distress in newborn.

Results

Of 64 pregnancies complicated by CAKUT, 23 were terminated. In the 41 cases of continuation of pregnancy, newborn presenting respiratory distress with need for respiratory support in the delivery room showed earlier gestational age at onset of amniotic fluid abnormalities and at birth. Although median O/E LHR and median single deepest pocket (SDP) of amniotic fluid were significantly smaller in newborn that did develop respiratory distress with need of respiratory support in the delivery room, neither O/E LHR nor SDP were accurate predictors for the development of respiratory distress.

Conclusions

Our data show that O/E LHR alone cannot serve as a predictive marker for fetal outcome in pregnancies complicated by CAKUT, though it might still be a helpful parameter together with detailed renal ultrasound evaluation, onset of amniotic fluid abnormality and SDP, particularly in its extreme values.

Urodynamic changes before and after endoscopic valve ablation in boys diagnosed with the posterior urethral valve without chronic renal failure

INTRODUCTION

Current research on the posterior urethral valve (PUV) mainly focuses on the follow-up of bladder function after valve ablation. However, few studies exist on the changes in bladder function before and after valve ablation.

OBJECTIVES

To investigate the urodynamic changes before and after PUV ablation and determine the effect of operation on bladder function, in patients.

MATERIALS AND METHODS

The clinical records of 38 boys diagnosed with PUV and undergone urodynamic exams before and after valve ablation were retrospectively reviewed. In addition, differences in patients' radiographic studies and urodynamic characteristics between pre- and post-operation were evaluated. Moreover, the urodynamic data was compared using the paired t-test and all the data was expressed as means ± SEM. Additionally, p values less than 0.05 were considered to be statistically significant.

RESULTS

All the patients were diagnosed with PUV and the follow-up period after operation ranged between 9 and 114 months. The urodynamic exams were performed about 6 months after operation. The results revealed that bladder compliance improved from 8.49 ± 4.73 to 13.31 ± 6.78 ml/cmH₂O while the maximum detrusor pressure decreased from 95.18 ± 37.59 to 50.71 ± 21.71 cmH₂O, after valve ablation. Additionally, there were significant differences in the pre- and post-operation values of bladder compliance and maximum detrusor pressure (p < 0.05). However, there were no significant differences in the pre- and post-operation values with regard to the residual urine volume, maximum bladder volume and maximum urinary flow rate (p > 0.05).

CONCLUSIONS

The adequacy of the COPUM incision is necessary. But the study showed that endoscopic valve ablation couldn't by itself completely improve the bladder function of patients diagnosed with PUV. However, it was able to improve bladder compliance and decrease maximum detrusor pressure to a certain extent. However, bladder compliance still couldn't reach the normal level.

GRADE Use in Evidence Syntheses Published in High-Impact-Factor Gynecology and Obstetrics Journals: A Methodological Survey

Objective: To identify and describe the certainty of evidence of gynecology and obstetrics systematic reviews (SRs) using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Method: Database searches of SRs using GRADE, published between 1 January 2016 to 31 December 2020, in the 10 "gynecology and obstetrics" journals with the highest impact factor, according to the Journal Citation Report 2019. Selected studies included those SRs using the GRADE approach, used to determine the certainty of evidence. Results: Out of 952 SRs, ninety-six SRs of randomized control trials (RCTs) and/or nonrandomized studies (NRSs) used GRADE. Sixty-seven SRs (7.04%) rated the certainty of evidence for specific outcomes. In total, we identified 946 certainty of evidence outcome ratings (n = 614 RCT ratings), ranging from very-low (42.28%) to low (28.44%), moderate (17.65%), and high (11.63%). High and very low certainty of evidence ratings accounted for 2.16% and 71.60% in the SRs of NRSs, respectively, compared with 16.78% and 26.55% in the SRs of RCTs. In the SRs of RCTs and NRSs, certainty of evidence was mainly downgraded due to imprecision and bias risks. Conclusions: More attention needs to be paid to strengthening GRADE acceptance and building knowledge of GRADE methods in gynecology and obstetrics evidence synthesis.

Fetal Therapy for Renal Anhydramnios

The most severe forms of congenital anomalies of the kidney and urinary tract present in fetal life with early pregnancy renal anhydramnios and are considered lethal due to pulmonary hypoplasia without fetal therapy. Due to the high rate of additional structural anomalies, genetic abnormalities, and associated syndromes, detailed anatomic survey and genetic testing are imperative when stratifying which pregnancies are appropriate for fetal intervention. Restoring amniotic fluid around the fetus is the principal goal of prenatal treatment. The ongoing multi-center Renal Anhydramnios Fetal Therapy (RAFT) trial is assessing the safety and efficacy of serial amnioinfusions to prevent pulmonary hypoplasia so that the underlying renal disease can be addressed.

Chronic Kidney Disease in Boys with Posterior Urethral Valves-Pathogenesis, Prognosis and Management

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.

Prenatally diagnosed posterior urethral valves: ethical dilemmas of fetal intervention

Although anhydramnios due to in utero renal failure has traditionally been considered lethal, in utero interventions offer the potential for pulmonary survival. As fetal interventions become more common, questions arise about how to identify and counsel eligible candidates.  In this report we describe the presentation and management of a 17-year-old pregnant female who presented from out-of-state with severe lower urinary tract obstruction (LUTO) with associated anhydramnios, focusing on the ethical questions that this case raised.

Urologic Considerations in Pediatric Chronic Kidney Disease

Common causes of pediatric ESRD are distinct from those seen in the adult population. In the pediatric population, the most common are congenital anomalies of the kidney and urinary tract (CAKUT), affecting approximately 30% of children with CKD. These structural anomalies often require coordinated care with the pediatric urology team to address voiding issues, bladder involvement, and the potential need for surgical intervention. For pediatric nephrologists and urologists, common CAKUT that are encountered include antenatal hydronephrosis, obstructive uropathies (eg, posterior urethral valves), and vesicoureteral reflux. As more pediatric patients with CAKUT, CKD, and ESRD transition to adult care, it is important for receiving adult nephrologists to understand the clinical presentation, natural history, and prognosis for these diagnoses. This review outlines the diagnosis and potential interventions for these conditions, including strategies to address bladder dysfunction that is often seen in children with CAKUT. A discussion of these management decisions (including surgical intervention) for CAKUT, which are quite common to pediatric nephrology and urology practices, may provide unique learning opportunities for adult nephrologists who lack familiarity with these pediatric conditions.

Vesicoamniotic Shunting before 17 + 0 Weeks in Fetuses with Lower Urinary Tract Obstruction (LUTO): Comparison of Somatex vs. Harrison Shunt Systems

(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.

Vesico-amniotic shunt insertion prior to the completion of 16 weeks results in improved preservation of renal function in surviving fetuses with isolated severe lower urinary tract obstruction (LUTO)

PURPOSE

The purpose of this retrospective cohort study was to compare the outcome of human fetuses with isolated severe lower urinary tract obstructions (LUTO) that were first treated before the completion of 16 weeks of gestation to fetuses first treated later in gestation.

PATIENTS AND METHODS

Vesicoamniotic shunt insertion (VAS) was performed in 63 subsequent fetuses with LUTO between 12 + 5 and 30 + 3 weeks. The fetuses were analyzed in three groups: Group-I-fetuses underwent their first intervention until the completion of 16 weeks, Group-II-fetuses were first treated between 16 + 1 and 24 + 0 weeks and Group-III-fetuses beyond 24 + 1 weeks. Renal and pulmonary outcome parameters and complicating factors were assessed.

RESULTS

- All mothers tolerated the procedures well. Overall fetal survival was 47 of 63 (75%). The mean age at delivery of survivors was 35 weeks. 68% of Group-I-fetuses, 77% of group-II-fetuses, and 100% of group-III-fetuses survived beyond postnatal hospital discharge. Amongst the survivors the chance for normal renal function was higher for group I with 79% (15/19) compared to first fetal intervention after the completion of 16 weeks with 32% (9/28, p = 0.003, OR = 7.9 [2.0, 30.8] 95% CI). Clinically relevant pulmonary hypoplasia was observed in 11% of Group-I-, 27% of Group-II-, and 20% of Group-III-fetuses.

CONCLUSIONS

Early intervention in fetal LUTO before the completion of 16 weeks may achieve a higher rate of normal renal and pulmonary function in survivors than treatment beyond that point in time. This observation is important for the future management of this challenging patient population.

Definition, diagnosis and management of fetal lower urinary tract obstruction: consensus of the ERKNet CAKUT-Obstructive Uropathy Work Group

Fetal lower urinary tract obstruction (LUTO) is associated with high mortality and postnatal morbidity caused by lung hypoplasia and impaired kidney function. Specific diagnostic features that can guide clinical approach and decisions are lacking; thus, the European Reference Network for Rare Kidney Diseases established a work group to develop recommendations regarding the clinical definition, diagnosis and management of prenatally detected LUTO. The work group recommends the use of antero-posterior diameter of renal pelvis as the most reliable parameter for suspecting obstructive uropathies and for suspecting prenatal LUTO in the presence of fetal megacystis. Regarding prenatal and postnatal prognosis of fetuses with LUTO, the risk of fetal and neonatal death depends on the presence of oligohydramnios or anhydramnios before 20 weeks' gestation, whereas the risk of kidney replacement therapy cannot be reliably foreseen before birth. Parents of fetuses with LUTO must be referred to a tertiary obstetric centre with multidisciplinary expertise in prenatal and postnatal management of obstructive uropathies, and vesico-amniotic shunt placement should be offered in selected instances, as it increases perinatal survival of fetuses with LUTO.

Development and in-vitro characterization of a novel fetal vesicoamniotic shunt - the Vortex Shunt

OBJECTIVES

To develop and test a novel vesicoamniotic shunt (VAS) to treat fetal lower urinary tract obstruction (LUTO), decrease dislodgement and optimize shunt deployment in-vitro.

METHODS

VAS design objectives included: 1) robust and atraumatic fixation elements, 2) kink resistant conduit to adjust to fetal movement and growth, 3) one-way pressure valve to facilitate bladder cycling, and 4) echogenic deployment visualization aids. The force to dislodge the novel Vortex shunt was compared with existing commercially available shunts in a bench-top porcine bladder model. Sonographic echogenicity was evaluated with ultrasound-guided deployment, and the shunt valve pressure measured.

RESULTS

A prototype novel Vortex shunt was developed using braided nitinol "umbrella-type" ends with a kink-resistant stem incorporating an internal one-way valve. The peak force required to dislodge the Vortex shunt was significantly higher than commercially available shunts (p<0.01). Shunt deployment in the bench-top model was easily confirmed with ultrasound guidance and the brisk decompression of the inflated porcine bladder thereafter. In-vitro valve gauge pressure testing mirrored bladder pressures in human LUTO cases.

CONCLUSION

In-vitro testing shows that the Vortex shunt may improve deployment, sonographic visualization, kink resistance, and dynamic size adjustment. Validation in preclinical animal models are warranted and currently underway. This article is protected by copyright. All rights reserved.

Predictors of advanced chronic kidney disease in infancy after definitive vesicoamniotic shunting for congenital lower urinary tract obstruction

BACKGROUND

Severe congenital lower urinary tract obstruction (cLUTO) is associated with poor postnatal outcomes, including chronic and end stage kidney disease, and high mortality. Studies of the impact of fetal intervention through vesicoamniotic shunting are marred by a device malfunction rate of up to 60%. In this study, we delineate the postnatal course and infant kidney function following definitive urinary diversion in utero.

MATERIALS AND METHODS

This is a retrospective, single-center cohort study of 16 male infants who survived the fetal intervention to birth, from 2010 to 2014 at a single center. All had patent shunts in place at birth. Perinatal and biochemical characteristics were collected with patients followed for one year, or until demise, with serial measures of serum creatinine (SCr) and serum cystatin C (CysC).

RESULTS

Of the 16 males, 81% were non-white (38% black, 43% Hispanic). Shunts were placed at a median of 20 weeks (IQR 19,23) gestation, with median fetal bladder volume of 39 cm³ (IQR 9.9,65). All neonates were born preterm [median 34 weeks (IQR 31,35)] and the majority with low birth weight [median 2340 grams (1,895, 2,600)]. 63% required positive pressure ventilation. Advanced chronic kidney disease stage 4-5 at 1 year of age was predicted by neonatal characteristics: peak SCr ≥2 mg/dl, time to peak SCr > 6 days, discharge SCr ≥1.0 mg/dl, CysC ≥2.5 mg/l, urine protein:creatinine ≥4.8 mg/mg, urine microalbumin:creatinine ≥2.2 mg/mg. In infancy, a nadir SCr ≥0.5 mg/dl occurring before 160 days (5.3 months) of age was also predictive of advanced chronic kidney disease stage 4-5 at 1 year. Three patients died in the neonatal period, with 1 receiving kidney replacement therapy (KRT). Three additional patients required KRT before 12 months of age.

CONCLUSIONS

Even with definitive vesicoamniotic shunting for cLUTO, postnatal morbidity and mortality remain high, emphasizing the role of renal dysplasia, in spite of urinary diversion, in postnatal kidney dysfunction. Neonatal and infant biochemical parameters exhibit distinct trends that offer families and physicians a better understanding of the prognosis of childhood kidney function.

Fetal therapy of LUTO (lower urinary tract obstruction) - a follow-up observational study

PURPOSE

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.

MATERIAL AND 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.

CONCLUSION

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.

[The ethics of fetal myelomeningocele surgery]

Fetal myelomeningocele surgery was introduced in France in 2014. Developments in prenatal diagnosis of neural tube defects have accompanied the development of prenatal diagnosis. This fetal surgery represents one of the three possible care paths for pregnant women faced with this prenatal diagnosis. The ethical issues of this fetal surgery are discussed and in particular regarding prenatal counselling and patient autonomy of choice.

Antenatal and postnatal management of posterior urethral valves: where do we stand?

Introduction

Posterior urethral valve (PUV) is the leading etiology of lower urinary tract obstruction (LUTO) in boys and is an important cause of end-stage renal disease (ESRD) in children. The aim of this article is to review the current status on antenatal intervention for PUV as well as postnatal medical and surgical management.

Main body

MEDLINE, EMBASE, Pubmed and Google Scholar search was conducted throughout December 2020 using the keywords: posterior urethral valves, congenital urinary obstruction, antenatal, valve bladder syndrome, medical, anticholinergics, alpha blocker, antibiotics, biofeedback, diversion, augmentation cystoplasty and renal transplantation. Only papers written in English were included. The relevant literature was summarized. Despite advances in antenatal intervention for fetal LUTO, it remains associated with considerable fetal and maternal morbidity. Patient selection criteria for antenatal intervention are greatly debated. Fetal intervention has resulted in improved perinatal survival in properly selected cases, with a questionable benefit to postnatal renal function. There is decent evidence supporting the use of anticholinergics in infants and young children following valve ablation, with less robust evidence advocating alpha blockers, overnight catheter drainage and biofeedback. The role of urinary diversion remains contentious. Optimizing bladder dynamics is crucial for successful renal transplantation outcomes.

Conclusion

While antenatal intervention has failed to improve renal function outcomes of PUV, patient-centered medical and sometimes surgical interventions can help delay the progression of chronic kidney disease. Lifelong monitoring and management of the associated bladder dysfunction is indispensable even after successful renal transplantation.

Prenatally diagnosed lower urinary tract obstruction: A 15-year experience at two tertiary centers in Japan

AIM

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.

Novel scoring system for determining fetal candidacy for prenatal intervention for severe congenital lower urinary tract obstruction

OBJECTIVES

To evaluate a novel scoring system that combines several prenatal parameters for selecting ideal candidates for fetal intervention, and for predicting postnatal survival in patients with severe fetal lower urinary tract obstruction (LUTO).

METHODS

We retrospectively reviewed all cases of severe LUTO evaluated for fetal intervention in a single large fetal center between January 2013 and December 2017. A scoring system for determining fetal candidacy for intervention was retrospectively developed based on postnatal outcomes. The proposed scoring system included fetal urinary biochemistry, renal ultrasound parameters, initial bladder volume, and degree of bladder refill. Relevant demographic characteristics, ultrasound reports and laboratory results were reviewed. Receiver operating characteristic (ROC) curves were used to select the cut-off values for initial bladder volume and degree of bladder refill and to evaluate the performance of the scoring system in predicting postnatal death.

RESULTS

Of the 79 LUTO patients evaluated, 31 were eligible for the study. The overall 6-month postnatal survival was 64.5 % (20/31). A scoring system (0-8) was suggested with 2 points for unfavorable biochemistry, 4 points for ultrasound evidence of dysplastic kidneys, 1 point for inadequate initial bladder volume and 1 point for inadequate bladder refill. Scores>3 (N = 7) were associated with 0 % 6-month survival. The ROC curve for predicting postnatal mortality showed area under curve (AUC) of 0.82 (95 % CI 0.65-0.99). Subgroup analysis within subjects who underwent fetal intervention (N = 22) also confirmed the significance of the distribution of the scoring system between groups who survived and those who did not after adjustment for GA at delivery (p = 0.01).

CONCLUSION

We propose a novel scoring system for antenatal evaluation of patients with severe LUTO which may be useful in selecting those candidates most appropriate for intervention and in counseling parents about predicted postnatal outcome.

Evaluation and fetal intervention in severe fetal hydronephrosis

PURPOSE OF REVIEW

Fetal hydronephrosis secondary to congenital anomalies of the kidney and urinary tract (CAKUT) can adversely affect neonates in the postnatal period with long-term consequences. A prenatal diagnosis of CAKUT can have an early fetal intervention to minimize these consequences. This review aims to provide an overview of the possible fetal intervention with severe hydronephrosis.

RECENT FINDINGS

Clinical course and outcomes of CAKUT are predicted based on biochemical markers and radiological findings. In spite of advancements and accurately diagnosing the severity of hydronephrosis, there are many controversies surround on selection of cases with antenatal hydronephrosis (ANH) that will benefit from fetal intervention. Despite better diagnosis and techniques fetal intervention is limited to mainly lower urinary tract obstruction patients to improve amniotic fluid volume and assist in lung development.

SUMMARY

ANH can potentially detect the severity of congenital renal anomalies but unable to recognize a specific disease. A multidisciplinary approach is required to diagnose and properly stage cases of severe CAKUT and potential surgical intervention can be considered.

Therapeutic intervention for fetal lower urinary tract obstruction: Current evidence and future strategies

In-utero vesica-amniotic shunting for fetal lower urinary obstruction (LUTO) is known to improve perinatal survival. More recently, studies including centres performing fetal cystoscopy, have suggested benefit on longer-term survival and renal outcome - within the limitations of small numbers and limited follow-up. These interventions carry significant risk, and therefore patient selection, and optimal timing, are key. The aim of this article is to explore ways of improving the accuracy of prenatal diagnosis, and of identifying risk factors for fetal and postnatal renal failure. The next step is that of using established staging and classification systems to select the patient group that may benefit from intervention, based on published outcomes. Several factors come into play when selecting the timing of intervention, especially if the aim is that of renal, and not only pulmonary, preservation. Lastly, current technologies and their shortfalls are discussed.

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.

Antenatal biological models in the characterization and research of congenital lower urinary tract disorders

Congenital lower urinary tract disorders are a family of diseases affecting both urinary storage and voiding as well as upstream kidney function. Current treatments include surgical reconstruction but many children still fail to achieve urethral continence or progress to chronic kidney disease. New therapies can only be achieved through undertaking research studies to enhance our understanding of congenital lower urinary tract disorders. Animal models form a critical component of this research, a corner of the triangle composed of human in-vitro studies and clinical research. We describe the current animal models for two rare congenital bladder disorders, posterior urethral valves (PUV) and bladder exstrophy (BE). We highlight important areas for researchers to consider when deciding which animal model to use to address particular research questions and outline the strengths and weaknesses of current models available for PUV and BE. Finally, we present ideas for refining animal models for PUV and BE in the future to stimulate future researchers and help them formulate their thinking when working in this field.

Selection of candidates for foetal intervention in congenital lower urinary tract obstruction

PURPOSE OF REVIEW

Congenital lower urinary tract obstruction (LUTO) is a rare group of conditions characterized by high perinatal morbidity and mortality if associated with oligohydramnios or anhydramnios in early pregnancy. Although foetal intervention has the potential to improve perinatal survival in a select group of foetuses with LUTO, the actual selection of those candidates most likely to benefit from intervention remains challenging.

RECENT FINDINGS

Foetuses with LUTO who are potential candidates for prenatal intervention should undergo detailed multidisciplinary evaluation to ensure proper assessment and counselling. Using a combination of multiple ultrasound-based renal parameters, including measurement of foetal bladder volumes before and after vesicocentesis and kidney size and morphology, combined with repeated foetal urine biochemistry may allow for better selection than any single test.

SUMMARY

Foetal intervention should be offered to women carrying a foetus with LUTO only after appropriate evaluation and counselling. A combined approach utilizing ultrasound and biochemical measurements of foetal renal function appears best. Research focusing on the development of more accurate markers is needed.

Management of antenatal hydronephrosis

Antenatal hydronephrosis (AHN) is the most frequently detected abnormality by prenatal ultrasonography. Differential diagnosis of AHN includes a wide variety of congenital abnormalities of the kidney and urinary tract ranging from mild abnormalities such as transient or isolated AHN to more important ones as high-grade congenital vesicoureteral reflux or ureteropelvic junction obstruction. It is well known that the outcome depends on the underlying etiology. Various grading systems have been proposed for the classification of AHN on prenatal and postnatal ultrasonography. Mild isolated AHN represents up to 80% of cases, is considered to be benign, and majority of them resolve, stabilize, or improve during follow-up. Controversies exist regarding the diagnosis and management of some important and severe causes of AHN such as high-grade vesicoureteral reflux and ureteropelvic junction obstruction. Current approach is becoming increasingly conservative during diagnosis and follow-up of these patients with less imaging and close follow-up. However, there is still no consensus regarding the clinical significance, postnatal evaluation, and management of infants with AHN. The aim of this review is to discuss the controversies and provide an overview on the management of AHN.

Foetal therapies and their influence on preterm birth

Foetal therapy aims to improve perinatal survival or to prevent severe long-term handicap. Foetal medicine opens a new territory by treating the foetus as a patient. The mother has nothing to gain in terms of health benefits, yet she is inherently also undergoing treatment. In utero foetal interventions can be divided into ultrasound-guided minimally invasive procedures, fetoscopic procedures and open hysterotomy procedures, which carry an inherent risk of ruptured membranes and preterm birth. In this review, we summarise the conditions that may benefit from foetal therapy and review the current therapies on offer, each with their associated risk of ruptured membrane and preterm birth. We also look into some risk limiting and preventative strategies to mitigate these complications.

Clinical predictors of chronic kidney disease in congenital lower urinary tract obstruction

Congenital lower urinary tract obstruction is associated with oligohydramnios and significant perinatal mortality and long-term chronic kidney disease. The counseling of families facing this diagnosis, especially when prenatal intervention is proposed, is fraught with ambiguity. This review aims to equip the provider with the current evidence behind the conventional and novel biomarkers predictive of chronic kidney disease. The relevant clinical predictors are categorized by when they are identified, antenatally or postnatally, and as either anatomic or chemical. They are considered for their prognostic value and the challenges in obtaining them, specifically the risk to the fetus in the case of prenatal biomarkers. Serum creatinine in infancy is the traditional chemical biomarker of kidney function and continues to be a consistent predictor of future serum creatinine. β-2 microglobulin may provide earlier information regarding fetal glomerular and tubular function and is also predictive of long-term serum creatinine. Renal parenchymal area is an anatomic surrogate of nephron mass that is used in both prenatal and postnatal settings. Understanding the anatomic and chemical biomarkers is essential for future refinement of the staging algorithm used to distinguish which patients may benefit from early in utero intervention.

Prenatal regenerative fetoscopic interventions for congenital anomalies

Fetal intervention has progressed in the past two decades from experimental proof-of-concept to practice-adopted, life saving interventions in human fetuses with congenital anomalies. This progress is informed by advances in innovative research, prenatal diagnosis, and fetal surgical techniques. Invasive open hysterotomy, associated with notable maternal-fetal risks, is steadily replaced by less invasive fetoscopic alternatives. A better understanding of the natural history and pathophysiology of congenital diseases has advanced the prenatal regenerative paradigm. By altering the natural course of disease through regrowth or redevelopment of malformed fetal organs, prenatal regenerative medicine has transformed maternal-fetal care. This review discusses the uses of regenerative medicine in the prenatal diagnosis and management of three congenital diseases: congenital diaphragmatic hernia, lower urinary tract obstruction, and spina bifida.

Fetal anesthesia: intrauterine therapies and immediate postnatal anesthesia for noncardiac surgical interventions

PURPOSE OF REVIEW

This review describes maternal and fetal anesthetic management for noncardiac fetal surgical procedures, including the management of lower urinary tract obstruction, congenital diaphragmatic hernia (CDH), myelomeningocele, sacrococcygeal teratoma, prenatally anticipated difficult airway and congenital lung lesions.

RECENT FINDINGS

Fetal interventions range from minimally invasive fetoscopic procedures to mid-gestation open surgery, to ex-utero intrapartum treatment procedure. Anesthetic management depends on the fetal intervention and patient characteristics. Anesthesia for most minimally invasive procedures can consist of intravenous sedation and local anesthetic infiltration in clinically appropriate maternal patients. Open fetal and ex-utero intrapartum treatment procedures require maternal general anesthesia with volatile anesthetic and other medications to maintain uterine relaxation. Tracheal balloons are a promising therapy for CDH and can be inserted via minimally invasive techniques. Management of the prenatally anticipated difficult airway during delivery and removal of tracheal balloons from patients with CDH during delivery can be clinically dynamic and require flexibility, seamless communication and a high-functioning, multidisciplinary care team.

SUMMARY

Maternal and fetal anesthetic management is tailored to the fetal intervention and the underlying health of the fetus and mother.

Vesicoamniotic shunting for fetal megacystis in the first trimester with a Somatex® intrauterine shunt

Purpose

The objective was to evaluate the feasibility of vesicoamniotic shunting (VAS) in the first trimester with the Somatex^® intrauterine shunt and report on complications and neonatal outcome.

Methods

Retrospective cohort study of all VAS before 14 weeks at two tertiary fetal medicine centres from 2015 to 2018 using a Somatex^® intrauterine shunt. All patients with a first trimester diagnosis of megacystis in male fetuses with a longitudinal bladder diameter of at least 15 mm were offered VAS. All patients that opted for VAS after counselling by prenatal medicine specialists, neonatologists and pediatric nephrologists were included in the study. Charts were reviewed for complications, obstetric and neonatal outcomes.

Results

Ten VAS were performed during the study period in male fetuses at a median GA of 13.3 (12.6–13.9) weeks. There were two terminations of pregnancy (TOP) due to additional malformations and one IUFD. Overall there were four shunt dislocations (40%); three of those between 25–30 weeks GA.

Seven neonates were born alive at a median GA of 35.1 weeks (31.0–38.9). There was one neonatal death due to pulmonary hypoplasia. Neonatal kidney function was normal in the six neonates surviving the neonatal period. After exclusion of TOP, perinatal survival was 75%, and 85.7% if only live-born children were considered.

Conclusion

VAS in the first trimester is feasible with the Somatex^® Intrauterine shunt with low fetal and maternal complication rates. Neonatal survival rates are high due to a reduction in pulmonary hypoplasia and the rate of renal failure at birth is very low. VAS can be safely offered from the late first trimester using the Somatex^® intrauterine shunt.

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.

A single-center study to evaluate the efficacy of a fetal urine peptide signature predicting postnatal renal outcome in fetuses with posterior urethral valves

BACKGROUND

Posterior urethral valves (PUVs) account for 17% of pediatric renal failure. The management of pregnancies involving fetuses with PUV is hampered by the fact that current clinical parameters obtained from fetal ultrasound and/or fetal urine biochemistry are insufficient to predict postnatal renal function. We previously have developed a fetal urine peptide signature (12PUV) that predicted with high precision postnatal renal failure at 2 years of age in fetuses with PUV. Here, we evaluated the accuracy of this signature to predict postnatal renal outcome in fetuses with PUV in an independent single-center study.

METHODS

Thirty-three women carrying fetuses with suspected PUV were included. Twenty-five fetuses received vesicoamniotic shunts during pregnancy. PUV was confirmed postnatally in 23 patients. Of those 23 fetuses, 2 were lost in follow-up. Four and 3 patients died in the pre- and perinatal periods, respectively. Follow-up renal function at 6 months of age was obtained for the remaining 14 patients. The primary outcome was early renal failure, defined by an eGFR < 60 mL/min/1.73 m² before 6 months of age or pre- or perinatal death.

RESULTS

The peptide signature predicted postnatal renal outcome in postnatally confirmed PUV fetuses with an AUC of 0.94 (95%CI 0.74-1.0) and an accuracy of 90% (95%CI 78-100). The signature predicted postnatal renal outcome for the suspected PUV cases with an AUC of 0.89 (95%CI 0.72-0.97) and an accuracy of 84% (95%CI 71-97).

CONCLUSIONS

This single-center study confirms the predictive power of the previously identified 12PUV fetal urinary peptide signature.

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.

Antenatal hydronephrosis and fetal urine sampling

The aim of this study is to evaluate the significance of renal pelvis aspiration (RPA) in the management of antenatal hydronephrosis (AHN). This study enrolled 15 AHN cases (one twin pregnancy) that necessitated RPA for AHN. Chromosomal abnormalities, gene disorders, and additional life-threatening congenital abnormalities were eliminated prior to intrauterine interventions. Urine analysis were performed for the evaluation of renal function. Normal renal function was observed in six neonates/infants (40%) (group 1), whereas impaired renal function and various type of urinary system anomalies were observed in 9 neonates/infants (60%) (group 2) during the short-term and longitudinal follow-up periods. There were statistically significant differences in the oligohydroamniosis rate, mean fetal urine sodium value, mean fetal urine β2-microglobulin, mean gestational week at birth, and mean birthweight values between the groups (P = 0.007, P < 0.001, P = 0.035, P < 0.001, and P = 0.001, respectively). Renal pelvis aspiration and urine analysis were substantial for the management of AHN in necessary cases. β2-microglobulin and sodium are clinically useful markers to detect the presence of severe renal damage due to obstructive uropathy and thus, important adjuvants in the proper selection of fetuses for further antenatal interventions.

Prediction model of postnatal renal function in fetuses with lower urinary tract obstruction (LUTO)-Development and internal validation

OBJECTIVE

To develop a prediction model of postnatal renal function in fetuses with lower urinary tract obstruction (LUTO) based on fetal ultrasound parameters and amniotic fluid volume.

METHODS

Retrospective nationwide cohort study of fetuses with postnatally confirmed LUTO and known eGFR. Fetuses treated with fetal interventions such as vesico-amniotic shunting or cystoscopy were excluded. Logistic regression analysis was used to identify prognostic ultrasound variables with respect to renal outcome following multiple imputation of missing data. On the basis of these fetal renal parameters and amniotic fluid volume, a model was developed to predict postnatal renal function in fetuses with LUTO. The main study outcome was an eGFR less than 60 mL/min * 1.73 m² based on the creatinine nadir during the first year following diagnosis. Model performance was evaluated by receiver operator characteristic (ROC) curve analysis, calibration plots, and bootstrapping.

RESULTS

Hundred one fetuses with a confirmed diagnosis of LUTO were included, eGFR less than 60 was observed in 40 (39.6%) of them. Variables predicting an eGFR less than 60 mL/min * 1.73m² included the following sonographic parameters: hyperechogenicity of the renal cortex and abnormal amniotic fluid volume. The model showed fair discrimination, with an area under the ROC curve of 0.70 (95% confidence interval, 0.59-0.81, 0.66 after bootstrapping) and was overall well-calibrated.

CONCLUSION

This study shows that a prediction model incorporating ultrasound parameters such as cortical appearance and abnormal amniotic fluid volume can fairly discriminate an eGFR above or below 60 mL/min * 1.73m² . This clinical information can be used in identifying fetuses eligible for prenatal interventions and improve counseling of parents.

Outcome of fetuses with lower urinary tract obstruction and normal amniotic fluid volume in second trimester of pregnancy

OBJECTIVE

Congenital lower urinary tract obstruction (LUTO) is a rare condition with high perinatal mortality and morbidity when associated with severe oligohydramnios or anhydramnios in the second trimester of pregnancy. Severe pulmonary hypoplasia and end-stage renal disease are the underlying causes of poor neonatal outcome in these cases. However, little is known about the subset of fetal LUTO that is associated with a normal volume of amniotic fluid at midgestation. The objective of the current study was to describe the natural history, underlying causes, survival and postnatal renal function outcomes in pregnancies with fetal LUTO and normal amniotic fluid volume during the second trimester of pregnancy.

METHODS

This was a retrospective study of all pregnancies with fetal LUTO and normal amniotic fluid volume in the second trimester that received prenatal and postnatal care at our quaternary care institution between 2013 and 2017. Data on demographic characteristics, fetal interventions, perinatal survival, need for neonatal respiratory support, postnatal renal function and need for dialysis at the age of 1 and 24 months were analyzed.

RESULTS

Of the 18 fetuses that met the study criteria, 17 (94.4%) survived the perinatal period. Eleven (61.1%) pregnancies developed oligohydramnios in the third trimester, six of which were eligible for and underwent fetal intervention with vesicoamniotic shunt placement, which was performed successfully in all six cases. Two (11.1%) neonates required respiratory support owing to pulmonary hypoplasia. At the age of 2 years, 14 children had follow-up information available, two (14.3%) of whom had normal renal function, eight (57.1%) had developed some degree of chronic kidney disease (Stage 1-4) and four (28.6%) had developed end-stage renal disease (ESRD), including two who had already manifested ESRD in the neonatal period.

CONCLUSIONS

Most fetuses diagnosed prenatally with LUTO that is associated with a normal volume of amniotic fluid at midgestation will have a favorable outcome in terms of perinatal survival and few will need long-term respiratory support. However, these children are still at increased risk for chronic renal disease, ESRD and need for renal replacement therapy. Larger multicenter studies are needed to characterize the prenatal factors associated with postnatal renal function, and to investigate the role of fetal intervention in the group of fetuses that present with late-onset oligohydramnios and evidence of preserved fetal renal function. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Fetal Cystoscopy and Vesicoamniotic Shunting in Lower Urinary Tract Obstruction: Long-Term Outcome and Current Technical Limitations

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.

Antenatal staging of congenital lower urinary tract obstruction

OBJECTIVE

To propose a staging system for congenital lower urinary tract obstruction (LUTO) capable of predicting the severity of the condition and its prognosis.

METHODS

This was a national retrospective study carried out at the eight Academic Hospitals in The Netherlands. We collected prenatal and postnatal data of fetuses at high risk of isolated LUTO that were managed conservatively. Postnatal renal function was assessed by the estimated glomerular filtration rate (eGFR), calculated using the Schwartz formula, considering the length of the infant and the creatinine nadir in the first year after birth. Receiver-operating characteristics (ROC) curve analysis, univariate analysis and multivariate logistic regression analysis with stepwise backward elimination were performed in order to identify the best antenatal predictors of perinatal mortality and postnatal renal function.

RESULTS

In total, 261 fetuses suspected of having LUTO and managed conservatively were included in the study. The pregnancy was terminated in 110 cases and perinatal death occurred in 35 cases. Gestational age at appearance of oligohydramnios showed excellent accuracy in predicting the risk of perinatal mortality with an area under the ROC curve of 0.95 (P < 0.001) and an optimal cut-off at 26 weeks' gestation. Fetuses with normal amniotic fluid (AF) volume at 26 weeks' gestation presented with low risk of poor outcome and were therefore defined as cases with mild LUTO. In fetuses referred before the 26^th week of gestation, the urinary bladder volume (BV) was the best unique predictor of perinatal mortality. ROC curve analysis identified a BV of 5.4 cm³ and appearance of oligohydramnios at 20 weeks as the best threshold for predicting an adverse outcome. LUTO cases with a BV ≥ 5.4 cm³ or abnormal AF volume before 20 weeks' gestation were defined as severe and those with BV < 5.4 cm³ and normal AF volume at the 20 weeks' scan were defined as moderate. Risk of perinatal mortality significantly increased according to the stage of severity, from mild to moderate to severe stage, from 9% to 26% to 55%, respectively. Similarly, risk of severely impaired renal function increased from 11% to 31% to 44%, for mild, moderate and severe LUTO, respectively.

CONCLUSIONS

Gestational age at appearance of oligo- or anhydramnios and BV at diagnosis can accurately predict mortality and morbidity in fetuses with LUTO. Our proposed staging system can triage reliably fetuses with LUTO and predict the severity of the condition and its prognosis. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Congenital urinary tract obstruction

Congenital bladder neck obstruction (or lower urinary tract obstruction [LUTO]) describes a heterogeneous group of congenital anomalies presenting with similar prenatal ultrasonographic findings of dilated posterior urethra, megacystis, hydronephrosis, oligohydramnios and often with associated renal dysplasia. Untreated LUTO has high rate of perinatal morbidity and mortality from associated pulmonary hypoplasia and early-onset renal failure in infancy. Ultrasonographic features and prospective fetal urinalysis may help in predicting the overall prognosis of congenital LUTO. Currently, fetal vesicoamniotic shunt (of various designs), and fetal cystoscopy and fulguration of the obstruction are potential prenatal interventions. Retrospective and prospective cohort studies and a relatively small randomized controlled trial have demonstrated these treatments may possibly improve perinatal survival. Despite this, concerns remain as to the high rates of renal impairment observed in paediatric survivors. A clinical prospective scoring/staging system may improve prenatal diagnostic criteria and case selection for fetal therapy.

Antenatal intervention for congenital fetal lower urinary tract obstruction (LUTO): a systematic review and meta-analysis

Objective: To evaluate the effectiveness of antenatal intervention for the treatment of congenital lower urinary tract obstruction (LUTO) in improving perinatal survival and postnatal renal function.Methods: Electronic databases were searched from their inception until May 2018. Selection criteria included randomized controlled trials and nonrandomized studies including fetuses with ultrasound evidence of LUTO evaluating antenatal intervention for improving perinatal outcomes. Any type of antenatal bladder drainage technique was analyzed. The primary outcome was perinatal survival. The secondary outcome was postnatal survival with normal renal function. The summary measures were reported as summary odds ratio (OR) with 95% of confidence interval (CI).Results: Ten articles with a total of 355 fetuses were included in the meta-analysis. Inclusion criteria of the selected studies were singleton pregnancy with severe LUTO confirmed on detailed fetal ultrasound examination. Nine studies analyzed the efficacy of vesico-amniotic shunt performed in the second trimester. The overall estimate survival was higher in the vesico-amniotic shunt group compared to the conservative group (OR: 2.54, 95% CI: 1.14-5.67). 64/112 fetuses (57.1%) survived in the vesico-amniotic shunt group compared to 52/134 (38.8%) in the control group. Five studies reported on postnatal renal function between 6 months and 2 years. Rate of good postnatal renal function was higher in the vesico-amniotic shunt group compared to the conservative group (OR: 2.09, 95% CI: 0.74-5.9). Fetal cystoscopy was performed in only two included studies. Overall, 45 fetuses underwent fetal cystoscopy. The perinatal survival was higher in the cystoscopy group compared to the conservative management group (OR: 2.63, 95% CI: 1.07-6.47). Normal renal function was noted in 13/34 fetuses in the cystoscopy group versus 12/61 in the conservative management group at 6 months follow-up (OR: 1.75, 95% CI: 1.05-2.92)Conclusions: Antenatal bladder drainage appears to improve perinatal survival in cases of LUTO.