Long-term outcome in children after antenatal intervention for obstructive uropathies

Postnatal surgical complications in lower urinary tract obstruction following fetal vesico- amniotic shunting

PURPOSE

Fetal lower urinary tract obstruction (LUTO) is a rare congenital disease associated with high morbidity and mortality due to pulmonary hypoplasia and renal insufficiency. Fetal management includes early vesicoamniotic shunting (VAS), a technique that has evolved in recent years to preserve kidney function. Previous publications have focused on intrauterine shunt complications, such as dislocation and preterm premature rupture of membranes (PPROM). In our study we aimed to assess postnatal shunt related complications that became obvious after birth.

MATERIALS AND METHODS

We describe our preliminary experience with 25 fetuses who underwent VAS with a Somatex® shunt as well as postnatal shunt removal at two experienced centers for fetal medicine. The intrauterine course, underlying pathology, postnatal outcome and details on shunt explantation and related complications were assessed. The data were retrospectively analysed in relation to the intrauterine course, underlying pathology, further malformations, and perioperative characteristics with a focus on the complication spectrum and type of intervention.

RESULTS

Twenty-five fetuses underwent VAS at a median of 17 weeks. Two newborns were excluded because they died within the first 24 hours of life secondary to fulminant lung hypoplasia. In ten (43%) newborns, shunt removal was performed under local anaesthesia. In 13 (57%) neonates, the shunt was explanted surgically, and five (22%) of these operations were defined as complex.

CONCLUSION

Intrauterine VAS with a Somatex® shunt is feasible, and in the majority of cases, shunt explantation can be easily performed after birth. However, the umbrellas may cause intraabdominal tissue damage, peritoneal adhesions or skin defects, and early surgical management of VAS associated complications might be necessary.

A Neonatal Case of Lower Urinary Tract Obstruction and Imperforate Anus: Urethral Decompression Due to Rectourinary Fistula

Lower urinary tract obstruction (LUTO) is a rare fetal condition associated with significant perinatal morbidity and mortality. Herein, we report a neonatal case of LUTO with anal atresia complicated by anhydramnios and pulmonary hypoplasia. After treatment for severe postnatal respiratory distress, the neonate underwent vesicostomy and colostomy. Postoperatively, respiratory status and renal function improved. This case highlights a unique feature where a large rectovesical fistula channeled fetal urine into the colon, which minimized obstructive damage to the urinary tract and preserved renal morphology. Fetal colonic dilatation and numerous enteroliths indicate urine influx into the intestinal tract. Our case suggests the importance of recognizing such exceptions in complete LUTO to predict postnatal outcomes diagnosed in utero.

Kidney function and transplants in prune belly syndrome: a scoping review

BACKGROUND

Children with prune belly syndrome (PBS) are at higher risk of developing kidney dysfunction and requiring kidney replacement therapy (KRT). While studies have described surgical and survival outcomes in these populations, there has yet to be a focused synthesis of evidence regarding kidney outcomes in this population. Here, the focus of this scoping review was to highlight knowledge gaps and report standards on kidney outcomes in PBS of all ages.

METHODS

Following scoping review methodology, EMBASE, MEDLINE, and Scopus were searched for peer-reviewed literature that describe kidney outcomes in PBS. All studies with a broad set of kidney outcomes (such as kidney function measures, chronic kidney disease (CKD), KRT and associated outcomes) were included. Findings were summarized and qualitatively synthesized.

RESULTS

Of the 436 unique records identified, 25 were included for synthesis. A total of 17 studies (441 patients) reported on kidney insufficiency outcomes, with an estimated prevalence of CKD ranging from 8 to 66%. A total of 15 studies (314 patients) described KRT, primary kidney transplant, and outcomes. Of these, the age for KRT ranged from 4 to 21 years, and graft survival ranged from 22 to 87% by last follow-up (range 1.3-27 years).

CONCLUSIONS

There is significant variability in studies reporting kidney outcomes in PBS which limits meaningful synthesis. There is a need for future studies with comprehensive reporting of confounders and drivers for kidney insufficiency in PBS.

[In utero surgery for lower urinary tract obstruction]

Prenatal therapy for LUTO (Lower Urinary Tract Obstruction) is debated due to mixed results regarding postnatal renal function following fetal cystoscopy or vesicoamniotic shunting. Current literature is, however, limited by the inability to determine the cause of the obstruction using plain sonography and the lack of selection criteria for fetuses who may benefit from prenatal therapy. Fetal cystoscopy may serve as a diagnostic tool and would offer a more "physiologic" treatment for bladder outlet obstruction. However, it carries additional technical issues due to inappropriate instrumentation.

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.

Publication landscape of Posterior urethral valve- A scientometric study

To assess the global research landscape in the field of Posterior urethral valve (PUV), a scientometric study was conducted to determine the quantity and quality of the research output and get insight into the key research areas and pattern of collaboration in the research community.

METHODS

Primary data was acquired from the Scopus® database. Various parameters like the total research productivity, citations, citations per publication, citations per year, citations per publication per year, the scientific output of countries, institutions, authors, and journals were calculated. Key research areas were inferred by examining the top-cited articles (citations >150). Collaborative maps were generated by calculating co-authorship links amongst countries and authors using VOSviewer software.

RESULTS

One thousand seven hundred fourteen results were found published from 1913 to 2019, receiving a total of 27,253 citations, authored by 5138 authors from 125 countries. The top three countries were the United States of America (USA), India, and the United Kingdom (UK). The leading institutes were the Children's Hospital Boston, USA (n = 48), All India Institute of Medical Sciences (AIIMS, Delhi), India (n = 38), and Great Ormond Street Hospital, UK (n- = 27). The journals which published the most articles on PUV were the Journal of Urology (n = 278), Journal of Pediatric Urology (n = 121), followed by Urology (n = 86). Leading authors were Glassberg, K. L and Bajpai M (n = 17, each), Canning DA & Kajbafzadeh, AM (n = 16, each), followed by Peters CA with 14 manuscripts. The top-cited documents (n = 10) received 2104 citations and were published between 1986 and 2010. The key areas of interest found were "long-term outcomes" (n = 4) and "fetal surgery" (n = 2). The most productive countries were also the most collaborative countries (the USA and UK).

CONCLUSION

In the research landscape of PUV, the USA, Children's Hospital Boston, and Glassberg, K. L, along with Bajpai, M were the top contributors in terms of the country, organization, and authors, respectively. The "Journal of Urology" and "Pediatric Nephrology" stands out in terms of bibliometric parameters considered. The hotspot topics based on the number of citations received were "long-term outcomes" and "fetal surgery" in PUV. The most productive countries were also the most collaborative countries (the USA and UK).

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.

Fetal interventions for congenital renal anomalies

Congenital abnormalities of the kidney and urinary tract (CAKUT) represent 20% of prenatally diagnosed congenital abnormalities. Although the majority of these abnormalities do not require intervention either pre or postnatally, there is a subset of patients whose disease is so severe that it may warrant intervention prior to delivery to prevent morbidity and mortality. These cases consist of patients with moderate lower urinary tract obstruction (LUTO) in which vesicocentesis, shunting or cystoscopy are options and patients with early pregnancy renal anhydramnios (EPRA) in whom amnioinfusion therapy may be an option. The main causes of EPRA are congenital bilateral renal agenesis (CoBRA), cystic kidney disease (CKD) and severe LUTO. Untreated, EPRA is universally fatal secondary to anhydramnios induced pulmonary hypoplasia. The evidence regarding therapy for LUTO is limited and the stopped early PLUTO (Percutaneous Shunting in Lower Urinary Tract Obstruction) trial was unable to provide definitive answers about patient selection. Evidence for EPRA therapy is also scant. Serial amnioinfusions have shown promise in cases of EPRA due to CoBRA or renal failure and this treatment modality forms the basis of the ongoing NIH funded RAFT (Renal Anhydramnios Fetal Therapy) trial. At present, there is consensus that treatment for EPRA should only occur in the setting of a clinical trial.

Prediction of kidney failure in children with chronic kidney disease and obstructive uropathy

BACKGROUND

Obstructive uropathy (OU) is a leading cause of pediatric kidney injury. Accurate prediction of kidney disease progression may improve clinical outcomes. We aimed to examine discrimination and accuracy of a validated kidney failure risk equation (KFRE), previously developed in adults, in children with OU.

METHODS

We identified 118 children with OU and an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 in the Chronic Kidney Disease in Children study, a national, longitudinal, observational cohort. Each patient's 5-year risk of kidney failure was estimated using baseline data and published parameters for the 4- and 8-variable KFREs. Discriminative ability of the KFRE was estimated using the C statistic for time-to-event analysis. Sensitivity and specificity were evaluated across varying risk thresholds.

RESULTS

Among the 118 children, 100 (85%) were boys, with median baseline age of 10 years (interquartile range, 6-14). Median eGFR was 42 mL/min/1.73m 2 (32-53), with a median follow-up duration of 4.5 years (2.7-7.2); 23 patients (19.5%) developed kidney failure within 5 years. The 4-variable KFRE discriminated kidney failure risk with a C statistic of 0.75 (95% CI, 0.68-0.82). A 4-variable risk threshold of ≥ 30% yielded 82.6% sensitivity and 75.0% specificity. Results were similar using the 8-variable KFRE.

CONCLUSIONS

In children with OU, the KFRE discriminated the 5-year risk of kidney failure at C statistic values lower than previously published in adults but comparable with suboptimal values reported in the overall CKiD population. The 8-variable equation did not improve model discrimination or accuracy, suggesting the need for continued research into additional, disease-specific markers.

Urethroplasty with balloon catheterization in fetal lower urinary tract obstruction: observational study of 10 fetuses

OBJECTIVE

To present the preliminary outcomes of fetal urethroplasty using a coronary angioplasty balloon catheter in lower urinary tract obstruction (LUTO).

METHODS

We included 10 consecutive male fetuses diagnosed with LUTO caused by presumed isolated posterior urethral valves (PUVs), who underwent urethroplasty with a balloon catheter in our center between 2015 and 2018. During urethroplasty, the fetal urethra was dilated using a balloon catheter (diameter, 0.014 inches; balloon size, 2 × 9 mm) inserted under ultrasonographic guidance via an 18-gauge needle introduced into the fetal bladder.

RESULTS

Mean gestational age at the time of urethroplasty was 17.8 (range, 16.5-20.4) weeks. All fetuses survived the procedure without any complications and there was no case of preterm prelabor rupture of the membranes. The procedure was successful in 5/10 (50%) fetuses, while in the other five (50%), we were unable to insert the balloon catheter into the urethra. In the five successfully treated cases, mean gestational age at delivery was 38 (range, 36-40) weeks and presence of PUVs was confirmed after birth. All five neonates micturated spontaneously and presented with normal urine output after birth. During the follow-up period, the parameters of kidney function were within normal limits in two neonates, whereas signs of impaired renal function were seen in another two. The other was diagnosed with renal insufficiency and required kidney transplant with bladder sparing at 2 years of age.

CONCLUSIONS

Urethroplasty with a balloon catheter is a new prenatal treatment option for fetuses with PUVs. By restoring fetal micturition, the procedure can preserve normal urinary bladder and kidney function. Although data on its efficacy and potential to differentiate the etiology of LUTO are sparse, a significant advantage of this method is its safety for the fetus and the mother. Even if the neonates develop renal insufficiency, they may be eligible for kidney transplant with connection to their own bladder, without the need for urostomy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Current perspective and scope of fetal therapy: part 1

Fetal therapy term has been described for any therapeutic intervention either invasive or noninvasive for the purpose of correcting or treating any fetal malformation or condition. Fetal therapy is a rapidly evolving specialty and has gained pace in last two decades and now fetal intervention is being tried in many malformations with rate of success varying with the type of different fetal conditions. The advances in imaging techniques have allowed fetal medicine persons to make earlier and accurate diagnosis of numerous fetal anomalies. Still many fetal anomalies are managed postnatally because the fetal outcomes have not changed significantly with the use of fetal therapy and this approach avoids unnecessary maternal risk secondary to inutero intervention. The short-term maternal risk associated with fetal surgery includes preterm labor, premature rupture of membranes, uterine wall bleeding, chorioamniotic separation, placental abruption, chorioamnionitis, and anesthesia risk. Whereas, maternal long-term complications include risk of infertility, uterine rupture, and need for cesarean section in future pregnancies. The decision for invasive fetal therapy should be taken after discussion with parents about the various aspects like postnatal fetal outcome without fetal intervention, possible outcome if the fetal intervention is done, available postnatal intervention for the fetal condition, and possible short-term and long-term maternal complications. The center where fetal intervention is done should have facility of multi-disciplinary team to manage both maternal and fetal complications. The major issues in the development of fetal surgery include selection of patient for intervention, crafting effective fetal surgical skills, requirement of regular fetal and uterine monitoring, effective tocolysis, and minimizing fetal and maternal fetal risks. This review will cover the surgical or invasive aspect of fetal therapy with available evidence and will highlight the progress made in the management of fetal malformations in last two decades.

Contemporary Outcomes of Patients with Isolated Bilateral Renal Agenesis with and without Fetal Intervention

INTRODUCTION

Bilateral renal agenesis (BRA) is a lethal diagnosis, specifically meaning that natural survival beyond birth is not expected secondary to pulmonary hypoplasia. Limited contemporary data are available about intervention and the impact of restoring amniotic fluid volume in relation to the risk for lethal pulmonary hypoplasia and other factors that might influence survival in cases of fetal BRA.

OBJECTIVE

We report the largest series of patients undergoing fetal intervention and postnatal care for BRA at a single comprehensive fetal center.

METHODS

All patients with fetal BRA were reviewed from January 2004 to November 2017. Maternal and neonatal data were collected in an institutional review board-approved retrospective review.

RESULTS

From 2014 to 2017, 20 singleton pregnancies with isolated fetal BRA were evaluated and 14 had amnioinfusion. Eight had serial infusions. Of those, there were 6 neonatal deaths. There were 2 neonatal survivors beyond 30 days; however, both died of sepsis on dialysis. One of these survivors received amnioinfusions by percutaneous approach and one via amnioport. There were no survivors to transplantation.

CONCLUSION

Fetal intervention via amnioinfusion may promote pulmonary survivorship after birth, but postnatal survival remains poor. Future studies must place an emphasis on standardizing the postnatal approach to this patient population.

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.

Surgical interventions and anesthesia in the 1st year of life for lower urinary tract obstruction

BACKGROUND

Patients with a prenatal diagnosis of lower urinary tract obstruction (LUTO) may undergo prenatal interventions, such as vesicoamniotic shunt (VAS) placement, as a temporary solution for relieving urinary tract obstruction. A recent FDA communication has raised awareness of the potential neurocognitive adverse effects of anesthesia in children. We hypothesized as to whether a prenatal LUTO staging system was predictive of the number of anesthesia events for prenatally diagnosed LUTO patients.

METHODS

We retrospectively reviewed the prenatal and postnatal clinical records for patients with prenatally diagnosed LUTO from 2012 to 2015. Patients were stratified by prenatal VAS status and by LUTO disease severity according to Ruano et al. (Ultrasound Obstet Gynecol. 2016).

RESULTS

31 patients were identified with a prenatal LUTO diagnosis, and postnatal records were available for 21 patients (seven patients in each stage). When combining prenatal and postnatal anesthesia, there was a significant difference in the number of anesthesia encounters by stage (1.6, 3.7, and 6.7 for Stage I, II, and III respectively, p = .034). Upon univariate analysis, higher gestational age (GA) at birth was associated with a decreased number of anesthesia events in the first year (p = .031).

CONCLUSIONS

The majority of infants with prenatally diagnosed LUTO will undergo postnatal procedures with general anesthesia exposure in the first year of life. Patients with higher prenatal LUTO severity experienced a higher number of both prenatal and postnatal anesthesia encounters. In addition, higher GA at birth was associated with fewer anesthesia encounters in the first year.

LEVEL OF EVIDENCE

This is a prognostic study with Level IV evidence.

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.

Consensus on the Management of Posterior Urethral Valves from Antenatal Period to Puberty

The need for successful management of posterior urethral valves always captivates the minds of pediatric surgeons. Its success, however, depends on several factors ranging from prenatal preservation of upper tracts to postoperative pharmacological compliance. Regardless of measures available, some cases do not respond and progress to end stage. The management depends on several issues ranging from age and severity at presentation to long-term follow-up and prevention of secondary renal damage and managing valve bladder syndrome. This article is based on a consensus to the set of questionnaires, prepared by research section of Indian Association of Paediatric Surgeons and discussed by experienced pediatric surgeons based in different institutions in the country. Standard operating procedures for conducting a voiding cystourethrogram and cystoscopy were formulated. Age-wise contrast dosage was calculated for ready reference. Current evidence from literature was also reviewed and included to complete the topic.

Early fetal megacystis: Is it possible to predict the prognosis in the first trimester?

OBJECTIVE

To evaluate the best management of fetal megacystis diagnosed in the first trimester and define the prognosis and the most appropriate follow-up as early as possible.

METHODS

This is a retrospective study of first-trimester fetal megacystis diagnosed in pregnant women who performed a combined screening for fetal aneuploidy. Megacystis was defined as a longitudinal bladder diameter (LBD) greater than 7 mm. All fetuses were divided into two groups according to the LBD: Group A with LBD > 15 mm and Group B with LBD < 15 mm. The fetal karyotype and associated anomalies were evaluated. Ultrasound monitoring was performed every 2 weeks (a second ultrasound scan after 2 weeks from diagnosis and a third ultrasound scan 2 weeks after the second one).

RESULTS

Twenty-six cases were identified between 2011 and 2016; three cases of aneuploidy were excluded from the study. Of the remaining 23 cases, 11 were included in Group A and 12 in Group B. All Group A fetuses had an adverse outcome. In Group B: five (41.7%) cases had an adverse outcome and seven (58.3%) had a spontaneous resolution of megacystis. The ultrasound findings of both the ultrasound scans, the second and the third, were 100% concordant.

CONCLUSION

An ultrasound scan performed 2 weeks after the megacystis diagnosis can predict the outcome in fetuses with an LBD < 15 mm as early as the end of the first trimester. The outcome of euploid fetuses with an LBD < 15 mm was favorable in 58.3% of the cases.

Prenatal Urinary Tract Dilatation

Urinary tract dilatation (UTD) is the most common congenital anomaly detected on prenatal ultrasonography (US), affecting 1% to 3% of all pregnancies. This article focuses on the prenatal detection of UTD and the postnatal evaluation and management based on the UTD grading system risk assessment. Prophylactic antibiotics and postnatal imaging are discussed. The recent management trend is for a more conservative approach to minimize unnecessary testing and exposures to the fetus and neonate while detecting those who may have clinically significant disorder. The renal bladder US remains a critical part of the evaluation and helps guide further investigations.

Long-term renal outcome in infants with congenital lower urinary tract obstruction

INTRODUCTION

Congenital Lower Urinary Tract Obstructions (LUTO) is a heterogeneous group of diseases in which urine elimination is obstructed at the level of bladder neck or urethra. The aim of the study is to evaluate the long-term renal outcome of patients suffering of congenital LUTO.

PATIENTS AND METHOD

We retrospectively reviewed patients with congenital LUTO. All patients had at least 1 year follow-up. Data on surgery, renal imaging and Schwartz estimate creatinine clearance were collected. Incidence of Chronic Renal Disease (CRD) is presented with Kaplan-Meier method.

RESULTS

40 patients were included, 23 patients with Posterior Urethral Valve (PUVs) and 17 patients with other aetiologies: anterior urethral valve (2), urethral atresia (2), urethral stenosis (2), cloacal malformations (2), obstructive ureterocele (1), bladder trigone malformation (1) and neonatal bladder-sphincter dysfunction without neurological abnormalities (7). Incidence of CRD at age 10 years was 37% in congenital LUTO, 42% in PUVs and 30% in other aetiologies, and was significantly higher in PUVs (P=0.032). Renal prognosis was significantly worsened by discover of retentional bladder wall changes in initial cystoscopy, and by loss of parenchymal differentiation or cortical microcysts in first ultrasonography. The use of urinary diversion was significantly higher in LUTO of other aetiologies.

CONCLUSION

A high incidence of CRD is observed in patients with congenital LUTO, significantly higher in patients with PUV. LUTO of other aetiologies require step by step surgical management and higher use of urinary diversion. Precise initial evaluation in cystoscopy and ultrasonography is required and participate to evaluate future renal outcome.

LEVEL OF INCIDENCE

4.

Lower urinary tract obstruction: fetal intervention based on prenatal staging

The authors present an overview of lower urinary tract obstruction (LUTO) in the fetus with a particular focus on the insult to the developing renal system. Diagnostic criteria along with the challenges in estimating long-term prognosis are reviewed. A proposed prenatal LUTO disease severity classification to guide management decisions with fetal intervention to maintain or salvage in utero and neonatal pulmonary and renal function is also discussed. Stage I LUTO (mild form) is characterized by normal amniotic fluid index after 18 weeks, normal kidney echogenicity, no renal cortical cysts, no evidence of renal dysplasia, and favorable urinary biochemistries when sampled between 18 and 30 weeks; prenatal surveillance is recommended. Stage II LUTO is characterized by oligohydramnios/anhydramnios, hyperechogenic kidneys but absent renal cortical cysts or apparent signs of renal dysplasia and favorable fetal urinary biochemistry; fetal vesicoamniotic shunting (VAS) or fetal cystoscopy is indicated to prevent pulmonary hypoplasia and renal failure. Stage III LUTO is oligohydramnios/anhydramnios, hyperechogenic kidneys with cortical cysts and renal dysplasia and unfavorable fetal urinary biochemistry after serial evaluation; fetal vesicoamniotic shunt may prevent severe pulmonary hypoplasia but not renal failure. Stage IV is characterized by intrauterine fetal renal failure, defined by anhydramnios and ultrasound (US) findings suggestive of severe renal dysplasia, and is associated with death in 24 h of life or end-stage renal disease (ESRD) within the first week of life; fetal vesicoamniotic shunt and fetal cystoscopy are not indicated.

Fetal surgery: a critical review

Therapeutic fetal surgical procedures are predicated upon the ability to make an accurate fetal diagnosis. The earliest open fetal surgical procedures were introduced in the 1960s to treat Rh isoimmunisation. They were introduced when it became possible to predict impending fetal demise. Open procedures were abandoned when percutaneous approaches proved superior. The introduction of fetal ultrasound allowed the diagnosis of other congenital anomalies, some being amenable to fetal interventions. Open fetal surgical procedures were initially utilised, with significant maternal morbidity. For some anomalies, percutaneous approaches became favoured. In general, all of these procedures involved significant risks to the mother, to save a baby that was likely to die before or shortly after birth without fetal intervention. Fetal repair for myelomeningocele was a "sea change" in approach. The same maternal risks were taken to improve the quality of life of the affected fetus, not save its life. The completion of the "MOMs Trial" has occasioned a "tsunami" of centres in North America applying this approach. Others are attempting percutaneous repairs, with mixed results. This paper reviews the history of fetal surgery, focusing on the themes of the tension between accurate diagnosis and prognosis and open versus "minimally invasive" approaches.

Posterior urethral valves: Impact of low birth weight and preterm delivery on the final renal outcome

Objective

To investigate the relationship between low birth weight (LBW; <2.5 kg) and preterm delivery (<37 weeks gestational age) and final renal outcome in infants with posterior urethral valves (PUVs), emphasising the risk factors for the development of chronic kidney disease (CKD).

Patients and methods

A retrospective review was performed for all infants with PUVs who were treated between 1990 and 2010. In all, 52 infants were identified to have LBW and/or delivered preterm (Group 1). Infants in Group 1 were compared with a matching group (Group 2) of 60 full-term normal birth weight (NBW) infants with PUVs managed during the same period. The outcome of both groups was analysed.

Results

During follow-up, CKD developed in 17 (32.5%) and 22 patients (36.5%) in Groups 1 and 2, respectively (P = 0.812). Patients with LBW or delivered preterm had significantly higher incidence of oligohydramnios (P = 0.009), increased risk of vesicostomy (P < 0.001), longer hospital stay (P < 0.001), and higher incidence of vesico-ureteric reflux (VUR, P = 0.024). In the LBW patients, initial serum creatinine, nadir serum creatinine, oligohydramnios and Neonatal Intensive Care Unit (NICU) length of stay were significant predictors of final renal outcome (P < 0.001, P = 0.002, P = 0.004 and P = 0.012, respectively).

Conclusion

In our cohort of LBW and preterm delivery infants with PUVs, outcomes were similar to those of NBW full-term infants with PUVs but with an increased risk of vesicostomy, longer hospital stay, and higher incidence of VUR. LBW was associated with oligohydramnios, longer NICU admission, high initial and nadir serum creatinine, which were associated with a poor prognosis.

Advances in Fetal Surgery

Advances in prenatal screening and diagnosis, combined with an understanding of the pathophysiology of congenital anomalies, have brought incredible impetus to the field of fetal surgery. Identification of fetal anomalies can lead to counseling of the affected family so that informed decisions can be made on how to proceed with the pregnancy. Counseling may lead to pregnancy termination, changes in the timing or mode of delivery, and, in select cases, prenatal intervention. Open fetal surgery may be considered in severe cases of congenital diaphragmatic hernia, congenital chest lesions, sacrococcygeal teratoma, urinary tract obstruction, and myelomeningocele. The ex utero intrapartum treatment procedure may be lifesaving for fetuses with giant neck masses. Finally, fetoscopic surgery may be offered for select cases of twin-twin transfusion syndrome and twin reversed arterial perfusion sequence. Fetal intervention in all of these cases depends on a team approach to the patient and on the objective comparison of outcomes with and without fetal therapy. In the future, further understanding of the genetic basis of congenital diseases may enable minimally invasive treatments such as stem cell transplantation or gene therapy.

Fetal bladder outlet obstruction: Embryopathology, in utero intervention and outcome

Fetal bladder outlet obstruction (BOO), most commonly caused by posterior urethral valves (PUV), remains a challenging and multi-faceted condition. Evolving techniques, and refinement in ultrasound, optics and instrumentation, have increased our rate of prenatal diagnosis, and enabled valve ablation not only in smaller newborns, but also in fetuses. Long-term outcome studies have raised our awareness of the silent damage caused by bladder dysfunction and polyuria and encouraged their proactive management. In spite of our best efforts, the proportion of boys with PUV who progress to chronic and end-stage renal disease (ESRD) has not changed in the last 25 years. Evidence suggests a reduction in perinatal mortality following prenatal intervention, probably resulting from amelioration of oligohydramnios at the crucial time of lung development between 16 and 28 weeks' gestation, but no improvement in postnatal renal outcome. There are no bladder functional outcome studies in patients who have undergone prenatal intervention and hence the long-term effect of in utero defunctionalisation of the bladder is not known. This aim of this review is to revisit the embryopathology of fetal BOO, in particular the renal and bladder structural and functional changes that occur with in utero obstruction. The effect of earlier prenatal diagnosis, and therapy, on postnatal outcome is also explored and compared with outcomes published for traditional postnatal treatment.

Use of an Amnioport to Maintain Amniotic Fluid Volume in Fetuses with Oligohydramnios Secondary to Lower Urinary Tract Obstruction or Fetal Renal Anomalies

OBJECTIVE

We describe a technique to maintain amniotic fluid in fetuses with severe oligo-/anhydramnios secondary to lower urinary tract obstruction or fetal renal disease when urine production is inadequate to maintain a normal amniotic fluid volume (AFV).

METHODS

An amnioport was inserted into the amniotic space. The catheter was secured to prevent dislodgment and tunneled to a subcutaneous reservoir. The reservoir was accessed as necessary, infusing normal saline to maintain AFV. Pregnancy continued until term or indicated delivery.

RESULTS

Since 2010, 15 patients in this category were considered for an amnioport. Six chose comfort care and one elected percutaneous amnioinfusions. Nine amnioport procedures were performed in eight patients. There were no fetal deaths. All eight had successful restoration and maintenance of amniotic fluid. Delivery ranged from 9 to 96 days after placement (mean 63.7 days). One died due to unrecognized laryngeal web and another one died of pulmonary hypoplasia after preterm premature rupture of membranes. None of the remaining six had pulmonary hypoplasia. Three remain alive.

DISCUSSION

Severe oligo-/anhydramnios in the second trimester secondary to fetal anomalies is almost uniformly lethal due to pulmonary hypoplasia without restoration of amniotic fluid. The amnioport procedure may allow pulmonary survival but commits families to postnatal care decisions regarding pulmonary and renal complications.

Severe antenatally diagnosed renal disorders: background, prognosis and practical approach

Nowadays most renal disorders, especially urinary tract malformations and renal cystic disease, are diagnosed antenatally. In cases of severe bilateral disease, intrauterine renal dysfunction may lead to renal oligohydramnios (ROH), resulting in pulmonary hypoplasia which affects perinatal mortality and morbidity as well as the long-term outcome. However, some infants may only have mild pulmonary and renal disease, and advances in postnatal and dialysis treatment have resulted in improved short- and long-term outcome even in those infants with severe ROH. Here, we review the current state of knowledge and clinical experience of patients presenting antenatally with severe bilateral renal disorders and ROH. By addressing underlying mechanisms, intrauterine tools of diagnosis and treatment as well as published outcome data, we hope to improve antenatal counselling and postnatal care. KEY SUMMARY POINTS: 1. Nowadays most renal disorders are diagnosed antenatally, especially urinary tract malformations and renal cystic disease. 2. Severe kidney dysfunction may lead to renal oligohydramnios, which can cause pulmonary hypoplasia and is a risk factor of perinatal mortality and postnatal renal outcome. However, as considerable clinical heterogeneity is present, outcome predictions need to be treated with caution. 3. Advances in postnatal and dialysis treatment have resulted in improved short- and long-term outcomes even in infants with severe renal oligohydramnios. 4. A multidisciplinary approach with specialist input is required when counselling a family with an ROH-affected fetus as the decision-making process is very challenging.

Current applications of in utero intervention for lower urinary tract obstruction

PURPOSE

Since the early 1980s with the inception of fetal intervention for obstructive uropathy, there have been creative attempts to improve both perinatal and long-term outcomes. Despite advances in technology and an improved understanding of lower urinary tract obstruction (LUTO) in the fetus, the results for these therapeutic interventions remain guarded and the long-term renal morbidity among survivors remains problematic.

RECENT FINDINGS

Fetal LUTO represents a range of disorders but the most common of these is posterior urethral valves (PUVs). Selection criteria for candidates of possible intervention have improved with our understanding of fetal renal physiology. Serial urinalysis has marginally improved our ability to predict those that may ultimately respond to treatment [1,2], but the potential in the development of biomarkers for renal development or maldevelopment holds greater promise [3]. Advancements in fetal surgery may result in less fetal and maternal morbidity, but limited long-term improvement in outcomes highlights the controversial nature of the various interventions [4-10]. We must counsel families that fetal surgery offers hope but we cannot allow them to hold unrealistic expectations for cure.

SUMMARY

In appropriately selected fetuses, intervention may improve perinatal survival but not without risk to mother and fetus. Long-term renal outcomes remain problematic amongst survivors. In the case of PUV, postnatal primary valve ablation remains the cornerstone of treatment for nephron preservation; however, our ability to mimic these results in the prenatal population remains poor [11]. Disease severity has likely predetermined those that will survive through the perinatal period with or without intervention. Nonetheless, our drive to assess and manage fetal obstructive uropathy perseveres so that we may ultimately relieve obstruction and preserve renal and lung function. We must maintain optimism that continued advances will ultimately improve outcomes, but also be realistic with our current expectations. This paper reviews the status of current in utero interventions and outcomes.

Pressure limited vesico-amniotic shunt allows normal lung growth in a fetal lamb model of obstructive uropathy

BACKGROUND

In our fetal lamb model of lower urinary tract obstruction, a pressure limited shunt preserves bladder function and renal development. This study investigates the effects on pulmonary histology.

METHODS

We created obstructive uropathy (OU) in 60-day gestation fetal lambs, ligating the urethra and urachus, and delivering them at term (130-145days). We compared pulmonary histology in 4 groups: group A, OU without shunt; group B, pressure limited shunt; group C, non-valved shunt. Shunts were inserted 3weeks post-obstruction. Group D were normal controls.

RESULTS

We compared 27 fetuses: 7 fetuses in group A, 4 fetuses in group B, 2 fetuses in group C, and 14 fetuses in group D. There was no significant difference in lung volume in any group. In group A, there were some areas of atelectasis and incomplete alveolar formation histologically. The alveoli in group A lambs lungs had a predominance of type II cells, whereas group B lambs lungs were lined by type I epithelial cells and were essentially indistinguishable from controls.

CONCLUSIONS

This study suggests that using a pressure-limited vesico-amniotic shunt in OU may preserve the renal tract and the lungs.

Sequential Amniotic Fluid Thyroid Hormone Changes Correlate with Goiter Shrinkage following in utero Thyroxine Therapy

Several isolated reports of fetal goiter treatment have shown limited generalizability of approaches and provide no real guidance for optimal timing, dosages, and treatment strategies. Graves' disease accounts for >60% of these cases. Maternal treatments of hyperthyroidism include antithyroid medications such as methimazole and more commonly propylthiouracil (PTU). Here, our management of a patient with a fetal thyroid goiter from maternal exposure to PTU diagnosed at 23.6 weeks' gestation and the management of other cases allow us propose a general strategy for treatment. Intrauterine therapy with 200 and then 400 μg of levothyroxine (3 weeks apart) showed an 85% reduction in fetal thyroid goiter volume. We collected amniotic fluid samples at the time of treatments and assayed thyroid hormones and associated antibodies which closely reflected the changes in thyroid goiter mass volume. Our observations suggest a weekly or biweekly therapeutic intervention schedule. Utilizing both goiter size as well as a novel approach in using amniotic fluid hormone levels to monitor therapy efficacy might improve the quality of treatments. Only with a standardized approach and collection of amniotic fluid thyroid panels do we have the opportunity to develop the database required to determine the number and timing of treatments needed.

Long-term neurologic outcomes after common fetal interventions

OBJECTIVE

Fetal interventions have clearly decreased mortality, but the neurological outcomes of survivors are of critical concern. Here we consolidated available data on long-term neurological outcomes after common fetal interventions to guide counseling, management, and future research.

STUDY DESIGN

Published studies assessing long-term neurological outcomes after common fetal interventions from 1990 through 2014 were collected. We included all studies with a cohort of more than 5 patients and with follow-up of 1 year or longer. We divided procedures into those performed for singletons and for multiples. Singleton procedures included amnioinfusion for preterm premature rupture of membranes, intrauterine transfusion for red cell alloimmunization-associated anemia, intrauterine transfusion for parvovirus-associated anemia, vesicoamniotic shunts, thoracoamniotic shunts, ventriculoamniotic shunts, fetal endoscopic tracheal occlusion for congenital diaphragmatic hernia, and open fetal cases by myelomeningocele and others. Multiple procedures included those done for monochorionic twins including serial amnioreduction, selective fetoscopic laser photocoagulation, and selective termination.

RESULTS

Of 1341 studies identified, 28 met the inclusion criteria. We combined available literature for all procedures. Studies varied in their length of follow-up and method of assessing neurological status. Neurological outcome after intervention varied by procedure but was normal in 40-93%, mildly impaired in 3-33%, and severely impaired in 1-40%. Follow-up to school age was rare with the exception of procedures for monochorionic twins.

CONCLUSION

Fetal treatments have been successful in achieving survival in previously hopeless cases, but success should also be determined by the outcomes of survivors. Except for monochorionic twins, there is a dearth of reported long-term outcomes. Standardized reporting of long-term neurological sequelae is imperative so that meaningful analysis and study comparisons can be made.

Can a pressure-limited V-A shunt for obstructive uropathy really protect the kidney?

BACKGROUND

In our fetal lamb model of lower urinary tract obstruction, a valved shunt preserves bladder function. This study investigates the effects on renal histology.

METHODS

We created obstructive uropathy (OU) in 60-day gestation fetal lambs, ligating the urethra and urachus, and delivering them at term (130-145days). We compared renal histology in 4 groups: group A-OU without shunt, group B-low-pressure shunt (15-54mmH2O), group C-high-pressure shunt (95-150mmH2O). Shunts were inserted 3weeks post-obstruction. Group D were normal controls.

RESULTS

We delivered 32 fetuses from 23 ewes: 13 fetuses in group A (9 survived), 6 fetuses in group B (5 survived), 7 fetuses in group C (5 survived), and 6 fetuses in group D. Histologically, we found renal tubular distention, vacuolated degeneration of tubular epithelial cells in 7 lambs, and cyst formation in 4 lambs in group A. There was renal tubular distention in two lambs, and cyst formation in one lamb in both groups B and C, with vacuolated degeneration of tubular epithelial cells observed in all but 1 lamb in each group.

CONCLUSIONS

V-A shunting prevents multicystic dysplastic kidney (MCDK). Some lambs have renal tubular distention and vacuolated degeneration of renal tubular epithelial cells.

Hydronephrosis: prenatal and postnatal evaluation and management

Antenatal hydronephrosis (ANH) is one of the most frequently detected abnormalities found on routine prenatal ultrasounds, affecting 1% to 4.5% of all pregnancies. Despite its prevalence, there continues to be uncertainty regarding the clinical impact after birth. Prognosis depends on the severity of the dilation. Expectant prenatal management is the rule with fetal intervention rarely needed in a few select cases. Ureteropelvic junction obstruction and vesicoureteral reflux are the most common postnatal diagnoses. A renal and bladder ultrasound is essential in the follow-up of patients with ANH and helps dictate further investigation with voiding cystourethrography and/or diuretic renography.

Ultrasound diagnosis of fetal renal abnormalities

Development of the urogenital system in humans is a complex process; consequently, renal anomalies are among the most common congenital anomalies. The fetal urinary tract can be visualised ultrasonically from 11 weeks onwards, allowing recognition of megacystis at 11-14 weeks, which warrants comprehensive risk assessment of possible underlying chromosomal aneuploidy or obstructive uropathy. A mid-trimester anomaly scan enables detection of most renal anomalies with higher sensitivity. Bilateral renal agenesis can be confirmed ultrasonically, with empty renal fossae and absent bladder filling, along with severe oligohydramnios or anhydramnios. Dysplastic kidneys are recognised as they appear large, hyperechoic, and with or without cystic spaces, which occurs within the renal cortex. Presence of dilated ureters without obvious dilatation of the collecting system needs careful examination of the upper urinary tract to exclude duplex kidney system. Sonographically, it is also possible to differentiate between infantile type and adult type of polycystic kidney diseases, which are usually single gene disorders. Upper urinary tract dilatation is one of the most common abnormalities diagnosed prenatally. It is usually caused by transient urine flow impairment at the level of the pelvi-ureteric junction and vesico-ureteric junction, which improves with time in most cases. Fetal lower urinary tract obstruction is mainly caused by posterior urethral valves and urethral atresia. Thick bladder walls and a dilated posterior urethra (keyhole sign) are suggestive of posterior urethral valves. Prenatal ultrasounds cannot be used confidently to assess renal function. Liquor volume and echogenicity of renal parenchyma, however, can be used as a guide to indirectly assess the underlying renal reserve. Renal tract anomalies may be isolated but can also be associated with other congenital anomalies. Therefore, a thorough examination of the other systems is mandatory to exclude possible genetic disorders.

Development of an animal model to study congenital urinary obstruction

PURPOSE

We outline the development of a reliable model of obstructive uropathy in fetal lambs highlighting our understanding of the critical time points for interventions and the variability of any such model. We identify some discoveries that may have clinical implications.

METHODS

The model requires 60-day-gestation fetal lambs. In lambs, glomerulogenesis is complete by 90 days gestation. (Term is 145 days.) The ability to develop a reliable method of creating bladder outlet obstruction in females, ligating both the urethra and urachus was critical. The lambs are bred to an accuracy of ±24 h.

RESULTS

Creating the model at 50-60 days gestation, produces different expressions of renal dysplasia in groups of lambs undergoing identical interventions at the same stage of gestation. Early complete urethral obstruction can produce the Potter phenotype. An appropriately timed vesico-amniotic shunt preserves renal development, producing a shrunken, non-compliant bladder. Shunting the normal fetal bladder at 80 days gestation produces a similar bladder. Provision of a low-pressure valve in the shunt preserves bladder development and compliance. Using a high-pressure shunt produces results similar to non-shunted lambs.

DISCUSSION

We developed a reliable animal model for obstructive uropathy. Being alert to peripheral results can lead to new findings.

Outcomes of fetuses with lower urinary tract obstruction treated with vesicoamniotic shunt: a single-institution experience

PURPOSE

The purpose of this manuscript was to examine the outcomes of patients with lower urinary tract obstruction (LUTO) treated with vesicoamniotic shunt (VAS) to improve the quality of prenatal consultation and therapy.

METHODS

The medical records of all patients diagnosed with LUTO at our center between January 2004 and March 2012 were reviewed retrospectively.

RESULTS

Of 14 male fetuses with LUTO, all with characteristic ultrasound findings, 11 underwent intervention. One patient received vesicocentesis alone, while 10 had VAS. Two fetuses additionally underwent cystoscopy (one with attempted valve ablation), and two had peritoneoamniotic shunts. Of 16 total VAS, 13 were placed successfully, 8 dislodged (median 7 days), and 1 obstructed (84 days). Two fetuses suffered in utero demise, and two have unknown outcomes. LUTO was confirmed in six of eight live-born fetuses. One patient died in the neonatal period, while seven survived. All six available at follow-up (median 3.7 years), had significant genitourinary morbidity. Five patients had chronic kidney disease, but only one has required dialysis and transplant. Three had respiratory insufficiency, and one required a tracheostomy.

CONCLUSION

Despite significant perinatal and long-term morbidity, VAS offers patients faced with a poor prognosis an improved chance of survival. Our results underscore the need for further research into the diagnosis and treatment of LUTO.

Valved shunt as a treatment for obstructive uropathy: does pressure make a difference?

PURPOSE

A valved ventriculo-peritoneal shunt (V-P shunt) as a vesico-amniotic shunt (V-A shunt) preserves the filling/emptying cycle and normal bladder development in fetal lambs with bladder outlet obstruction. The optimal pressure for such shunts is unknown.

MATERIALS AND METHODS

We created obstructive uropathy in 60-day gestation fetal lambs. A V-A shunt was placed 3 weeks later, using a low-pressure (Group L: 15-54 mmH2O) or a high-pressure (Group H: 95-150 mmH2O) V-P shunt. We included non-shunted (obstructive uropathy, Group O) and control lambs (Group C). All were delivered at 130 days. Bladder volumes, bladder thickness, renal and bladder histology were compared.

RESULTS

Seventeen lambs had an obstructive uropathy created. Five Group L (four survived), four Group H (three survived) and five Group O survived. Body weight and crown-to-rump lengths of the three groups were not significantly different. Group H lambs had a dilated urachus, urinary ascites and severe ureteral dilatation similar to Group O lambs. There were four Group C lambs. Bladder volume was 10, 15 and 1,150 ml in Group H, 115 ± 67.9 ml in Group L, 128 ± 99.8 ml in Group O and 24.5 ± 3.84 ml in Group C. Unlike Group O lambs, Group L did not have urinary ascites, urinomas or renal dysplasia.

CONCLUSION

Low-pressure shunts preserved both bladder volume and renal development. High-pressure shunts did neither.

Urethral atresia and anhydramnios at 18 weeks of gestation can result in normal development

INTRODUCTION

Second-trimester anhydramnios is incompatible with survival unless amniotic fluid volume is restored. We describe the long-term outcome of a child with documented anhydramnios at 17 weeks.

CASE REPORT

A 28-year-old gravida II had anhydramnios at 17 weeks. At 19 weeks, the bladder measured 12 cm, and karyotype was XY. At 21 weeks, a fistula between the bladder and the amniotic space developed. At 36 weeks, a 2800 g boy with prune belly phenotype was delivered. The urachus was patent and drained urine. There was a completely obstructing membrane below the veru montanum and a hypoplastic urethra distal to it. The right kidney had no function and the left had grade V reflux. A P.A.D.U.A. (progressive augmentation by dilatating the urethra anterior) procedure was performed and the urachal fistula closed. At 6 months of age abdominoplasty, bilateral orchidopexy, right nephrectomy and left to right transuretero-ureterostomy were performed. At age 30 months he was toilet trained, with creatinine 0.5 mg/dl and normal growth. At 10 years of age he continues to be continent, with serum creatinine 0.9 mg/dl.

CONCLUSION

Resolution of anhydramnios at 21 weeks of gestation can result in normal pulmonary function and acceptable renal and bladder function in childhood. Efforts to develop effective methods of fetal bladder decompression should continue.

Long-term renal and neurodevelopmental outcome in infants with LUTO, with and without fetal intervention

Congenital lower urinary tract obstruction (LUTO) is a heterogeneous group of pathologies, the most common being posterior urethral valves (PUV) or urethral atresia. The bladder neck obstruction in utero leads to a spectrum of disease including mild oligohydramnios with normal renal function to a picture of severe oligohydramnios associated with chronic obstructive macro/microcystic renal parenchymal disease leading to chronic renal impairment. These anomalies may be isolated or complex; the latter being associated with other structural or chromosomal abnormalities. If isolated, the congenital bladder neck obstruction may be amenable to in-utero therapy. In a significant proportion of babies affected by LUTO there is severe oligohydramnios (occurring before 20 weeks gestation) and associated with pulmonary hypoplasia, a scenario almost always associated with perinatal death. For those babies that survive the perinatal period there is a significant risk of renal impairment, often necessitating renal dialysis or transplantation in childhood. In addition, there may be other morbidities such as chronic filling anomalies of the bladder that may require treatment.

Effectiveness of fetal cystoscopy as a diagnostic and therapeutic intervention for lower urinary tract obstruction: a systematic review

OBJECTIVE

To determine the effectiveness of fetal cystoscopy in the prenatal diagnosis of and intervention for congenital lower urinary tract obstruction.

METHODS

This study was a literature search using MEDLINE, Embase, Cochrane Library, MEDION, Web of Science reference lists and contact with experts. All studies reporting on fetal cystoscopy in lower urinary tract obstruction with data for a 2 × 2 table were selected for review. No language restrictions were applied. There was independent selection of studies, data extraction and quality assessment by two reviewers. Peto odds ratios were calculated as a summary measure of effect.

RESULTS

A total of 2071 citations were identified and 66 papers selected for detailed evaluation, from which four papers with a total of 63 patients were selected for inclusion. Two papers had results for the use of cystoscopy in diagnosis, showing that fetal cystoscopy altered the ultrasound diagnosis of the underlying pathology in 36.4 and 25.0% of fetuses, respectively. Compared to no treatment, fetal cystoscopic intervention demonstrated an odds ratio for improved perinatal survival of 20.51 (95% CI, 3.87-108.69). However, comparing vesicoamniotic shunt (VAS) with fetal cystoscopy there appeared to be no significant improvement in the perinatal survival odds ratio of 1.49 (95% CI, 0.13-16.97). These results had wide CIs and for cystoscopy vs. VAS, all results crossed the line of no effect.

CONCLUSION

There is little published evidence for the effectiveness of therapeutic fetal cystoscopy as an intervention for congenital lower urinary tract obstruction and the quality of this evidence is poor. It should thus be considered to be an 'experimental intervention' and subjected to further investigation.

Fetal surgery for severe lower urinary tract obstruction

Fetal interventions have been proposed for treatment of severe lower urinary tract obstruction (LUTO), as this condition is associated with high rates of perinatal mortality and postnatal renal impairment. The rationale for in utero treatment for those cases is based on the possibility of relieving the obstruction, improving the amniotic fluid volume, and preventing renal and bladder damage. Candidates for fetal intervention should be rigorously selected based on the confirmation of severe LUTO (dilated bladder and bilateral hydronephrosis), oligohydramnios or anyhydramnios and 'favorable' fetal urinalysis (dependent on gestational age). Nowadays there are two different therapeutic options with specific technical approaches. Vesico-amniotic shunting is an easier procedure, but with a higher frequency of related complications. Fetal cystoscopy can be used for diagnostic purpose and for treatment of posterior urethral valves, with suggestive advantage of allowing a more physiological release of the obstruction. According to the literature, estimated survival rates and postnatal normal renal function frequencies are approximately 40 and 50% after vesico-amniotic shunting and 75 and 65% after fetal cystoscopy, respectively.

Urethral hydrodistension for management of urethral hypoplasia in prune belly syndrome: long-term results

PURPOSE

The aim of the study was to evaluate the efficacy and safety of urethral hydrodistension for management of urethral hypoplasia in prune belly syndrome (PBS).

METHODS

During a 10-year period, 7 infants with PBS and urethral hypoplasia presented either with open urachus or surgically created urinary diversion referred to our hospital. Five milliliters of normal saline was pushed via a 22-gauge plastic angiocatheter into the urethra with simultaneous finger pressure on the perineum to occlude the proximal urethra that was repeated with higher volumes of the solution (up to 20 mL). The procedure was continued until a 6F or 8F feeding tube catheter confirmed the urethral patency. Hydrodistension was repeated in 3-month intervals till complete patency was confirmed by imaging.

RESULTS

Median age of the infants was 6 (1-8) months. All urethral hydrodistension were successful after 1 to 3 sessions. Follow-up imaging studies showed significant improvement in all patients except one. Natural and surgically created urinary diversions were closed in 6 infants.

CONCLUSIONS

The hydrodistension create an equal and constant pressure into the urethral wall without any urethral damage. This technique can be considered along with the other available methods for management of urethral hypoplasia in selected cases of PBS.

Megacystis with an anterior urethral valve: case report and review of literature

Fetal megacystis, an abnormally enlarged bladder identified at any gestational age, may be transient and resolve spontaneously or may be an early manifestation of bladder outlet obstruction. Anterior urethral valves are the most common cause of the rare condition of congenital obstruction of the anterior urethra. Herein is reported the prenatal observation and postnatal management of a case of megacystis with anterior urethral valves. The etiology is reviewed and strategies recommended for patients with these rare entities.

[Impact of fetal urinary ascites on serum beta2 microglobuline in obstructive uropathies: a case report]

We report a posterior urethral valves case diagnosed at 33 week's gestation on a fetus presenting with anamnios and urinary ascites. In this fetus, the serum beta2 microglobuline rate was high, suggesting a very poor renal prognosis. At 1-year-old, the creatinine rate is nearly normal. In case of urinary ascites, the serum beta2 microglobuline rate could be improved in relation with the transperitoneal reabsorption of this protein.

Prenatal management of urogenital disorders

Antenatal sonography has markedly increased the detection of urogenital anomalies, including those conditions that lead to significant morbidity and mortality. Prenatal intervention is feasible to arrest and sometimes reverse the sequelae of bladder outlet obstruction but not necessarily renal damage. Myelomeningoceles, the most severe form of spina bifida, can be corrected in utero, with improvements in hydrocephalus seen along with a decreased incidence of ventricular shunting postnatally. Medical therapy to prevent virilization associated with congenital adrenal hyperplasia has been successful, with improved ability to detect its presence prenatally now possible. As further techniques evolve to correct underlying disease processes, it becomes important to critically assess the therapies, particularly with long-term outcome data.