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

Palliative Care for Pediatric Urology

Palliative care in the field of urology has largely been limited to adult oncologic conditions. Although there is a plethora of established literature suggesting the advantageous impact of palliative care, there is limited integration of palliative care in adult urology. This underutilization is further exacerbated in pediatric urology, and palliative care in pediatric urology remains an underexplored area despite the prevalence of several life-limiting conditions in this patient population. This paper highlights the potential need for palliative care intervention in a variety of urologic conditions in the pediatric population, including congenital lower urinary tract obstruction, neurogenic bladder dysfunction, exstrophy-epispadias complex, and congenital bilateral renal agenesis. Each condition poses unique challenges that can be addressed with the inclusion of a palliative care team, including decision-making spanning prenatal-neonatal-pediatric periods, acute and chronic symptom management, family relations, body image issues, risk of recurrent hospitalizations and surgeries, and potentially fatal complications. Alongside standard urologic interventions, palliative care can serve as an additional means of addressing physical and psychosocial symptoms experienced by pediatric urology patients to enhance the quality of life of patients and their families.

Outcomes of fetal lower urinary tract obstruction based on timing of oligohydramnios onset

OBJECTIVE

Fetal Lower Urinary Tract Obstruction (LUTO) is associated with oligohydramnios and significant fetal morbidity, resulting in poor lung development and perinatal death. However, oligohydramnios may develop at different gestational periods, and the impact of timing on fetal outcomes remains unknown. Our objective was to characterize the impact onset of oligohydramnios had on prenatal outcomes.

METHODS

This study is a retrospective cohort study of all patients with a prenatal diagnosis of LUTO at our tertiary referral center from 2014 to 2023. All patients underwent detailed ultrasonography and interdisciplinary counseling and were subsequently delivered at our institution. Data were obtained from electronic medical records and complete extraction was required for final inclusion.

RESULTS

During the study time period, 93 patients met inclusion criteria of which 68 (73.1%) developed oligohydramnios during their pregnancy. 63 (93%) of these pregnancies resulted in livebirths with 28 (41.1%) perinatal deaths. Onset of oligohydramnios was earlier in pregnancies with perinatal death (23 vs. 28 weeks, p = 0.004) and associated with pulmonary hypoplasia.

CONCLUSIONS

Our data show the impact of oligohydramnios timing in pregnancy on pulmonary hypoplasia and ultimately perinatal death. This allows for detailed patient counseling on the impact oligohydramnios may have on pregnancies by the gestational age of onset.

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.

In Utero Treatment of Obstructive Ureterocele

Lower urinary tract obstruction consists of a heterogeneous group of conditions in which the normal urethral egress of urine from the fetal bladder is impaired. The most frequent diagnoses are posterior urethral valves, urethral atresia, and less common obstructive ureterocele. We report a case of a fetus with prenatal diagnosis of obstructive ureterocele who presented progressive bilateral hydronephrosis. A fetal cystoscopy with laser ablation was performed.

Fetal Megacystis in the first trimester: Comparing management and outcomes between longitudinal bladder length groups

Fetal megacystis is a sonographic sign, defined in first trimester as a longitudinal bladder length (LBD)>7 mm. Different causes may be associated with megacystis and outcomes vary with many factors. There are no international guidelines on how to manage megacystis cases, and invasive testing is controversial when no other abnormalities are found. The main objective of this study is to compare etiologies, management and outcomes of fetuses with first trimester megacystis, specifically between groups of LBD≤15 mm and >15 mm. This is a retrospective cohort study of megacystis cases managed in a Prenatal Diagnosis Center, between January 2009 and September 2020. Descriptive and bivariate analysis were performed. We studied 43 fetuses: 67.4% with LBD≤15 mm and 32.6% with LBD>15 mm. We found an association between LBD and isolated Low Urinary Tract Obstruction (LUTO) (3.4% vs 64.3%; p<0.001) and with isolated megacystis (44.8% vs 0.0%; p = 0.001). No differences were seen regarding the presence of aneuploidies (31.0% vs 14.3%; p = 0.213). Invasive testing was performed in 93.0% of cases. Overall, we report 41.9% of live births, 39.5% of pregnancy termination and 18.6% of intrauterine fetal demise. We found a higher rate of live births in fetuses with LBD≤15 mm (55.2% vs 14.3%; p = 0.011). For a mean follow-up time of 20.6 months, we report one neonatal death and one case of renal insufficiency. In conclusion, isolated LUTO is more frequent if LBD>15 mm whereas isolated megacystis is more frequently found if LBD≤15 mm. If LBD≤15 mm, live birth rates and long-term outcomes seem to be enhanced.

Urodynamic assessment in the management of the child's posterior urethral valves

BACKGROUND

Bladder dysfunction may be associated with valves of the posterior urethra. Their evaluation by urodynamic assessment is an important parameter for the therapeutic management. The objective of our study was to study the contribution of urodynamic assessment in the management of valves of the posterior urethra of the child.

METHODS

Our study was descriptive, retrospective, involving 43 children with posterior urethral valves (PUV), followed at the pediatric ward at Charles Nicolle Hospital in Tunis from January 1995 to December 2015. All the children had an urodynamic assessment after valves of the posterior urethra treatment.

RESULTS

The mean age was 15.8 months. Preoperatively, creatinine clearance was below 60 ml / min in 32 patients (74%). The worsening of renal function was noted in 32 (74%). A significant post-voiding residue proved in 34 patients (79%). Cystometry revealed a hypo compliant bladder in 24 (56%), low bladder capacity in 42% of cases; a hypertonic detrusor in 37% of cases. Bladder sphincter dyssynergia was diagnosed in 6 patients. Like urodynamic assessment data, bladder enlargement associated with a Mitrofanoff-type shunt was indicated and performed in 3 patients (7%).

CONCLUSION

Through our study, the urodynamic profile made it possible to specify the type of vesico-sphincter dysfunctions persistent in patients operated for PUV, and subsequently to adapt the therapeutic conduct in these patients. Given the lack of management and the consequences on the health of the child as well as on his quality of life, reflections on the preventive and therapeutic approach after PUV treatment are necessary.

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.

Genome-Wide Survey for Microdeletions or -Duplications in 155 Patients with Lower Urinary Tract Obstructions (LUTO)

Lower urinary tract obstruction (LUTO) is, in most cases, caused by anatomical blockage of the bladder outlet. The most common form are posterior urethral valves (PUVs), a male-limited phenotype. Here, we surveyed the genome of 155 LUTO patients to identify disease-causing CNVs. Raw intensity data were collected for CNVs detected in LUTO patients and 4.392 healthy controls using CNVPartition, QuantiSNP and PennCNV. Overlapping CNVs between patients and controls were discarded. Additional filtering implicated CNV frequency in the database of genomic variants, gene content and final visual inspection detecting 37 ultra-rare CNVs. After, prioritization qPCR analysis confirmed 3 microduplications, all detected in PUV patients. One microduplication (5q23.2) occurred de novo in the two remaining microduplications found on chromosome 1p36.21 and 10q23.31. Parental DNA was not available for segregation analysis. All three duplications comprised 11 coding genes: four human specific lncRNA and one microRNA. Three coding genes (FBLIM1, SLC16A12, SNCAIP) and the microRNA MIR107 have previously been shown to be expressed in the developing urinary tract of mouse embryos. We propose that duplications, rare or de novo, contribute to PUV formation, a male-limited phenotype.

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.

Prenatal exposure to isolated amniotic fluid disorders and the risk for long-term endocrine morbidity of the offspring

BACKGROUND

Amniotic fluid abnormalities may be associated with adverse perinatal outcomes, some of which are endocrine related.

OBJECTIVE

To evaluate whether in utero exposure to amniotic fluid abnormalities is associated with long-term endocrine morbidity in the offspring.

STUDY DESIGN

In this cohort study, the incidence of long-term endocrine disorders was compared between singletons exposed and non-exposed to oligohydramnios or polyhydramnios.

RESULTS

During the study period, 195 943 newborns were included in the study, of them 2.0% (n = 4072) and 2.9% (n = 5684) were exposed to oligohydramnios and polyhydramnios, respectively. Long-term endocrine morbidity was higher among children exposed to isolated amniotic fluid disorders, as was also noted in the Kaplan-Meier survival curve (log-rank test p < 0.001). Abnormal amniotic fluid volume was found to be independently associated with long-term endocrine morbidity of the offspring according to a Cox regression model controlled for clinically related confounders.

CONCLUSION

In utero exposure to isolated amniotic fluid abnormalities is independently associated with long-term endocrine morbidity in the offspring.

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

OBJECTIVE

To determine postnatal neurodevelopmental (ND) outcomes for children with congenital lower urinary tract obstruction (LUTO) based on disease severity.

METHODS

Twenty male infants with LUTO were classified prenatally as Stage 1 (normal amniotic fluid and renal function; n = 5), Stage 2 (signs of obstruction with preserved renal function; n = 13), and Stage 3 (signs of severe renal damage; n = 2). ND status was assessed using the Developmental Profile-3 test in 5 developmental domains (physical, adaptive behavior, social-emotional, cognitive, and communication). Each domain was considered to be delayed if standard scores were 2 or more SD below the mean. ND outcomes were compared between cases with an expected normal renal function (LUTO Stage 1) and those with impaired renal function (LUTO Stages 2 and 3). Results from cases with Stage 2 were also compared to those from Stage 3. ORs were calculated to predict risk for adverse ND outcome for each domain considering prenatal and postnatal factors.

RESULTS

Gestational age (GA) at the diagnosis of LUTO was similar between both groups (Stage 1: 24.85 ± 7.87 vs. Stages 2 and 3: 21.4 ± 4.31 weeks; p = 0.24). Twelve of 15 cases with Stage 2 or 3 underwent vesicoamniotic shunt placement compared to none of Stage 1 fetuses (p < 0.01). No differences in GA at delivery were detected between the groups (37.9 ± 1.6 vs. 35.1 ± 3.6 weeks; p = 0.1). One of the infants in the Stage 2 and 3 groups received a kidney transplant during follow-up. One case (20%) from Stage 1 group required dialysis during the first 6 months of life, and 1 case from Stage 2 to 3 group required it during the first 6 months (p = 1.0), whereas 3 additional cases needed dialysis from 6 to 24 months (p = 0.6). Mean age at Developmental Profile 3 (DP-3) testing was 20.3 ± 12.3 months (Stage 1: 11.2 ± 8.6 vs. Stages 2 and 3: 23.4 ± 13.4 months; p = 0.07). Fifteen of the 20 patients (75%) had no ND delays. Of the 5 patients with ND delays, 4 received dialysis. No differences in ND outcomes between infants with LUTO Stage 1 and those with Stages 2 and 3 were detected except for a trend toward better physical development in Stage 1 (102.6 ± 11.6 vs. 80.7 ± 34.9; p = 0.05). Infants diagnosed with LUTO Stage 3 showed significantly lower adaptive scores than those diagnosed with Stage 2 (Stage 2: 101.9 ± 22.3 vs. Stage 3: 41.5 ± 30.4; p = 0.04) and a nonsignificant trend for lower results in physical (85.8 ± 33.0 vs. 47.5 ± 38.9; p = 0.1) and socio-emotional (94.7 ±17.9 vs. 73.5 ± 13.4; p = 0.1) domains. Infants who received dialysis showed 15-fold increased risk (95% CI 0.89-251) for delayed socio-emotional development (p = 0.06). Diagnosis of fetal renal failure increased the risk for delays in the adaptive domain 30-fold (95% CI 1.29-93.1; p = 0.03). Infants with abnormal renal function had 19 times (95% CI 1.95-292) increased risk for delays in the physical domain (p = 0.03).

CONCLUSIONS

While most patients with LUTO do not exhibiting ND delays, our results support the importance of ND monitoring, especially in severe forms of LUTO, as increased severity of this condition may be associated with poorer ND outcomes.

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

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

Anhydramnios in the Setting of Renal Malformations: The National Institutes of Health Workshop Summary

Anhydramnios in the setting of severe malformations of the fetal kidney and urinary tract is associated with a high incidence of stillbirths and life-threatening complications, including severe pulmonary hypoplasia, umbilical cord compression, and perinatal asphyxia. To prevent such adverse outcomes, some centers in the United States and elsewhere are offering amniotic fluid restoration for women diagnosed with anhydramnios in the setting of fetal renal malformations. The procedures include infusions of amniotic fluid substitutes (normal saline), percutaneously or through an amnioport-an implanted system for serial or continuous infusion of normal saline to maintain the desired amniotic fluid volume. The procedures are intended to prevent pulmonary hypoplasia and allow the pregnancy to progress closer to term gestation, enabling postnatal renal management, including long-term dialysis and renal transplantation. However, these procedures have not been recommended as standard of care by the professional societies because there are many knowledge gaps, including few data on short-term and long-term renal outcomes. The available diagnostic methods do not provide reliable prognostic information, and the current maternal and fetal interventions have not been standardized. To address these unresolved issues and to propose a research agenda, the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Institute of Diabetes and Digestive and Kidney Diseases invited a panel of experts to a workshop in August 2016. This report provides a summary of that meeting.

Rare Variants in BNC2 Are Implicated in Autosomal-Dominant Congenital Lower Urinary-Tract Obstruction

Congenital lower urinary-tract obstruction (LUTO) is caused by anatomical blockage of the bladder outflow tract or by functional impairment of urinary voiding. About three out of 10,000 pregnancies are affected. Although several monogenic causes of functional obstruction have been defined, it is unknown whether congenital LUTO caused by anatomical blockage has a monogenic cause. Exome sequencing in a family with four affected individuals with anatomical blockage of the urethra identified a rare nonsense variant (c.2557C>T [p.Arg853^∗]) in BNC2, encoding basonuclin 2, tracking with LUTO over three generations. Re-sequencing BNC2 in 697 individuals with LUTO revealed three further independent missense variants in three unrelated families. In human and mouse embryogenesis, basonuclin 2 was detected in lower urinary-tract rudiments. In zebrafish embryos, bnc2 was expressed in the pronephric duct and cloaca, analogs of the mammalian lower urinary tract. Experimental knockdown of Bnc2 in zebrafish caused pronephric-outlet obstruction and cloacal dilatation, phenocopying human congenital LUTO. Collectively, these results support the conclusion that variants in BNC2 are strongly implicated in LUTO etiology as a result of anatomical blockage.

A classic twin study of lower urinary tract obstruction: Report of 3 cases and literature review

OBJECTIVE

The aim of the present study was to investigate genetic effects in the formation of congenital lower urinary tract obstruction (LUTO) comprising posterior urethral valves (PUV), urethral atresia, and urethras with variable degrees of stenosis.

METHODS

A classic twin study was performed by assessing LUTO twin pairs from the literature. Furthermore, data regarding 3 previously unreported twin pairs with PUV from University of Bonn, Essen and Wrocławs own in-house databases were added. Both pair- and probandwise concordance rates were calculated and compared for monozygotic (MZ) and dizygotic (DZ) twin pairs.

RESULTS

The pairwise concordance rates for all LUTO were 53% (95% confidence interval [CI] 32%-73%) and 17% (95% CI 3%-56%) for MZ and DZ twin pairs, respectively (P = .180). The probandwise concordance rates were 69% (95% CI 51%-83%) and 29% (CI 95% 8%-64%) for MZ and DZ twin pairs respectively (P = .084). The MZ/DZ ratios of the pair- and probandwise concordance rates were 3.1 and 2.4, respectively.

CONCLUSION

The present study did not show significant differences in comparisons of concordance rates of MZ and DZ twin pairs, probably due to the small number of twin pairs reported. However, the more than 2-fold higher pair- and probandwise concordance rates for MZ versus DZ twin pairs are very suggestive of a contribution of genetic factors to the development of LUTO.

Shunt-based interventions: Why, how, and when to place a shunt

The broad categories of surgical fetal therapy can be separated into either open surgical techniques or minimally invasive endoscopic/ultrasound-guided techniques that require only puncture of the uterus with single or multiple small ports. Benefits of fetoscopic or ultrasound-guided fetal intervention include decreased uterine irritability, decreased incidence of preterm labor, and avoidance of risks associated with hysterotomy and commitment to cesarean delivery for future pregnancies. Fetal abnormalities potentially amenable to ultrasound-guided drainage techniques include thoracic fluid-filled lesions and lower urinary tract obstruction.

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.

Severe congenital anomalies of the kidney and urinary tract: epidemiology can inform ethical decision-making

OBJECTIVE

Decision-making for pregnancies complicated by severe congenital anomalies of the kidneys and urinary tract (CAKUT) are ethically challenging, partly because the outcomes are not well studied.

STUDY DESIGN

Retrospective cohort study of severe cases of CAKUT over 14 years.

RESULTS

Seventy-one of the 108 cases could be completely analyzed. Forty-six percent (n=33) infants were live-born; one-third (n=11) survived to 12 months. Twice as many non-surviving infants received a trial of therapy vs comfort care only. Two-thirds of non-survivors who received a trial of therapy died within the first 9 h of life. Live-born infants faced morbidities such as pneumothorax and neonatal dialysis.

CONCLUSIONS

Over half of pregnancies complicated by severe CAKUT ended in termination or stillbirth, but one-third of live-born infants survived to 12 months and the majority of non-survivors died within hours. This may allay concerns about prolonged and futile intensive care for parents considering a trial of therapy.

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.

The Murine Bladder Supports a Population of Stromal Sca-1+/CD34+/lin- Mesenchymal Stem Cells

Bladder fibrosis is an undesired end point of injury of obstruction and often renders the smooth muscle layer noncompliant. In many cases, the long-term effect of bladder fibrosis is renal failure. Despite our understanding of the progression of this disease, little is known about the cellular mechanisms that lead to a remodeled bladder wall. Resident stem (progenitor) cells have been identified in various organs such as the brain, heart and lung. These cells function normally during organ homeostasis, but become dysregulated after organ injury. Here, we aimed to characterize a mesenchymal progenitor cell population as a first step in understanding its role in bladder fibrosis. Using fluorescence activated cell sorting (FACS), we identified a Sca-1⁺/ CD34⁺/ lin^- (PECAM^-: CD45^-: Ter119^-) population in the adult murine bladder. These cells were localized to the stromal layer of the adult bladder and appeared by postnatal day 1. Cultured Sca-1⁺/ CD34⁺/ lin^- bladder cells self-renewed, formed colonies and spontaneously differentiated into cells expressing smooth muscle genes. These cells differentiated into other mesenchymal lineages (chondrocytes, adipocytes and osteocytes) upon culture in induction medium. Both acute and partial obstruction of the bladder reduced expression of CD34 and changed localization of Sca-1 to the urothelium. Partial obstruction resulted in upregulation of fibrosis genes within the Sca-1⁺/CD34⁺/lin^- population. Our data indicate a resident, mesenchymal stem cell population in the bladder that is altered by bladder obstruction. These findings provide new information about the cellular changes in the bladder that may be associated with bladder fibrosis.

Expression of VEGF in neonatal urinary obstruction: does expression of VEGF predict hydronephrosis?

BACKGROUND

In animal studies, the inhibition of VEGF activity results in high mortality and impaired renal and glomerular development. Mechanical stimuli, like mechanical stretch in respiratory and circulatory systems, results in an elevated expression of VEGF. In animal models, the experimental urinary obstruction is associated with stretching of tubular cells and activations of the renin-angiotensin system. This results in the upregulation of vascular endothelial growth factor (VEGF) and TNF-alfa.

MATERIAL/METHODS

Tissue samples from urinary tract obstruction were collected and immunohistochemistry was performed in 14 patients (average age: 7.1±4.1 years). The control histology group consisted of ureteropelvic junction tissue from 10 fetuses after midtrimester artificial abortion. The fetuses did not have any failure at ultrasound screening and pathological examination. The mean gestational age was 20.6 weeks of gestation (±2.2SD). Expression of VEGF was detected with immunohistochemistry method.

RESULTS

Expression of VEGF was found in varying intensity in the submucosa and subserosa layers, but only in the test tissue (placental tissue). The tissue of the patients with urinary obstruction and the tissue of the fetal ureteropelvic junction without urinary obstruction were negative for expression of VEGF. The repeated examination showed negative cells and no color staining.

CONCLUSIONS

The pressure due to congenital urogenital obstruction resulting in mechanical stress in cells did not increase the expression of VEGF in young children in our study. To find a correlation between urogenital tract obstruction and increased expression of VEGF, we need to perform more examinations because the connection may be of therapeutic significance.

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.

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.

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.

Antenatal diagnosis and management of life-limiting conditions

Whereas structural fetal abnormalities are relatively frequent occurrences, many of these do not impact measurably on future life and/or are amenable to postnatal therapy. A small minority are considered to be potentially lethal or life-limiting. Examples include specific skeletal dysplasias, urinary tract abnormalities - typically those which lead to anhydramnios and pulmonary hypoplasia, some disorders of the central nervous system and trisomies 13 and 18. Without seeking to compile an exhaustive list of such conditions, we discuss the principles and new considerations in relation to antenatal diagnosis and perinatal management of such disorders.

Application of high-intensity focused ultrasound for fetal therapy: experimental study using an animal model of lower urinary tract obstruction

OBJECTIVE

The purpose of this study is to investigate whether high-intensity focused ultrasound (HIFU) exposure is able to produce a fistula between the bladder and abdominal wall of a fetus with lower urinary tract obstruction (LUTO).

MATERIALS AND METHODS

We constructed a prototype HIFU transducer in combination with an imaging probe. HIFU was applied to the lower abdomen of a rabbit neonate that was complicated by LUTO as an experimental model to produce a fistula; HIFU was applied in a tank filled with degassed water. Exposed lesions were assessed by histological analysis at necropsy.

RESULTS

When HIFU was applied at 5.5 kW/cm(2) of spatial-peak temporal average intensity (SPTA), a fistula was created between the lower abdominal wall and the urinary bladder; urine gushed out from the bladder through the fistula within 60 s after HIFU exposure.

CONCLUSION

The findings suggest that fetal diseases such as LUTO can be non-invasively treated using HIFU exposure from even outside the maternal body, though this study was performed in a water tank.

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.