Outcome of posterior urethral valves: to what extent is it improved by prenatal diagnosis?

Antenatal Determinants of Postnatal Renal Function in Fetal Megacystis: A Systematic Review

Introduction: To evaluate the clinical usefulness of demographic data, fetal imaging findings and urinary analytes were used for predicting poor postnatal renal function in children with congenital megacystis. Materials and methods: A systematic review was conducted in MEDLINE's electronic database from inception to December 2023 using various combinations of keywords such as "luto" [All Fields] OR "lower urinary tract obstruction" [All Fields] OR "urethral valves" [All Fields] OR "megacystis" [All Fields] OR "urethral atresia" [All Fields] OR "megalourethra" [All Fields] AND "prenatal ultrasound" [All Fields] OR "maternal ultrasound" [All Fields] OR "ob-stetric ultrasound" [All Fields] OR "anhydramnios" [All Fields] OR "oligohydramnios" [All Fields] OR "renal echogenicity" [All Fields] OR "biomarkers" [All Fields] OR "fetal urine" [All Fields] OR "amniotic fluid" [All Fields] OR "beta2 microglobulin" [All Fields] OR "osmolarity" [All Fields] OR "proteome" [All Fields] AND "outcomes" [All Fields] OR "prognosis" [All Fields] OR "staging" [All Fields] OR "prognostic factors" [All Fields] OR "predictors" [All Fields] OR "renal function" [All Fields] OR "kidney function" [All Fields] OR "renal failure" [All Fields]. Two reviewers independently selected the articles in which the accuracy of prenatal imaging findings and fetal urinary analytes were evaluated to predict postnatal renal function. Results: Out of the 727 articles analyzed, 20 met the selection criteria, including 1049 fetuses. Regarding fetal imaging findings, the predictive value of the amniotic fluid was investigated by 15 articles, the renal appearance by 11, bladder findings by 4, and ureteral dilatation by 2. The postnatal renal function showed a statistically significant relationship with the occurrence of oligo- or anhydramnion in four studies, with an abnormal echogenic/cystic renal cortical appearance in three studies. Single articles proved the statistical prognostic value of the amniotic fluid index, the renal parenchymal area, the apparent diffusion coefficient (ADC) measured on fetal diffusion-weighted MRI, and the lower urinary tract obstruction (LUTO) stage (based on bladder volume at referral and gestational age at the appearance of oligo- or anhydramnios). Regarding the predictive value of fetal urinary analytes, sodium and β2-microglobulin were the two most common urinary analytes investigated (n = 10 articles), followed by calcium (n = 6), chloride (n = 5), urinary osmolarity (n = 4), and total protein (n = 3). Phosphorus, glucose, creatinine, and urea were analyzed by two articles, and ammonium, potassium, N-Acetyl-l3-D-glucosaminidase, and microalbumin were investigated by one article. The majority of the studies (n = 8) failed to prove the prognostic value of fetal urinary analytes. However, two studies showed that a favorable urinary biochemistry profile (made up of sodium < 100 mg/dL; calcium < 8 mg/dL; osmolality < 200 mOsm/L; β2-microglobulin < 4 mg/L; total protein < 20 mg/dL) could predict good postnatal renal outcomes with statistical significance and urinary levels of β2-microglobulin were significantly higher in fetuses that developed an impaired renal function in childhood (10.9 ± 5.0 mg/L vs. 1.3 ± 0.2 mg/L, p-value < 0.05). Conclusions: Several demographic data, fetal imaging parameters, and urinary analytes have been shown to play a role in reliably triaging fetuses with megacystis for the risk of adverse postnatal renal outcomes. We believe that this systematic review can help clinicians for counseling parents on the prognoses of their infants and identifying the selected cases eligible for antenatal intervention.

Infantile versus childhood posterior urethral valve diagnosis: management patterns and clinical outcomes at opposite ends of the spectrum

BACKGROUND

Management patterns and outcomes are poorly defined in cases of late PUV diagnosis.

OBJECTIVE

To compare post-ablation management and clinical outcomes of patients with infantile (<1 year) versus childhood (>5 year) PUV diagnosis to gain insight into the pathologies at opposite ends of the PUV spectrum.

STUDY DESIGN

A multicenter retrospective cohort study was conducted using the TriNetX research network between 2006 and 2022. TriNetX synthesizes insurance claims and electronic medical record data for over 110 million patients from 92 healthcare organizations. We defined two cohorts: 1) The <1 year arm had an index diagnosis of PUV and cystoscopy with valve ablation within 1 year of life, 2) the >5 year arm had an index diagnosis of PUV and valve ablation after age 5. We report rates and time-to-first use of antispasmodics, alpha-blockers, CIC, bladder botox, enterocystoplasty or Mitrofanoff or secondary cutaneous vesicostomy, and CKD.

RESULTS

We identified 569 patients (323 <1 year; 246 >5 year). Median age at diagnosis was 1 month (median follow-up 8 years) and 9 years (median follow-up 10 years) for the <1 year and >5 year cohorts, respectively. Following ablation, both arms were primarily managed with antispasmodics, with no difference between groups. The >5 year arm was significantly more likely to receive alpha-blockers or bladder botox. The <1 year arm was significantly more likely to be started on CIC, undergo enterocystoplasty, Mitrofanoff or secondary cutaneous vesicostomy, or renal transplantation. The <1 year arm had significantly higher rates and shorter time-to-progression to all stages of CKD.

DISCUSSION

Despite higher utilization of conservative strategies among patients with a late PUV diagnosis, these patients had superior renal outcomes and low rates of progression to invasive treatments. Limitations include potential inaccuracies in medical coding as well as variations in thresholds to initiate CIC, perform surgical reconstruction, or proceed with renal transplantation at participating centers.

CONCLUSIONS

These findings provide evidence that a late PUV diagnosis reflects an overall milder disease process.

Comparison of outcomes of prenatal versus postnatal presentation of posterior urethral valves: a systematic review and meta-analysis

OBJECTIVE

To determine through a comprehensive systematic review and meta-analysis the differences in the outcomes of prenatally versus postnatally diagnosed posterior urethral valves (PUV) to ascertain if prenatal detection of PUV has superior outcomes.

METHODS

We conducted a systematic review and meta-analysis in March 2022 (PROSPERO ID - CRD42021243546) and included all studies that reported outcomes of prenatally and postnatally diagnosed PUV. However, for meta-analysis, only those studies that described both groups were included. The main outcomes of interest included progression of chronic kidney disease (CKD), need for renal replacement therapy (RRT) and renal transplant, and bladder dysfunction as determined by initiation of clean intermittent catheterization (CIC). Time to event analyses were completed when possible.

RESULTS

The systematic review included 49 studies (3820 patients). The pooled effect estimates for progression to CKD (OR 0.75 [95% CI 0.43, 1.31]), need for RRT (OR 1.39 [95% CI 0.64, 2.99]) and need for renal transplant (OR 1.64 [95% CI 0.61, 4.42]) between prenatal and postnatal groups was not different. CICs rates were as high as 32% in the prenatal group and 22% in the postnatal group. Most studies had a moderate or serious risk of bias.

CONCLUSION

The existing comparative literature on prenatal versus postnatal presentation of PUV is very heterogeneous. The diagnostic and treatment protocols have not been reported in majority of the studies. The outcome variables are also reported inconsistently. Based on the current evidence, prenatal diagnosis of PUV does not appear to improve the long-term outcomes of these patients.

Pre-natal vs Post-natal Presentation of PUV: A Multi-institutional Experience

OBJECTIVE

To compare the outcomes of prenatally versus postnatally diagnosed posterior urethral valves (PUV) at two large pediatric centres in North America to ascertain if the prenatal diagnosis of PUV is associated with better outcomes.

MATERIALS AND METHODS

All patients with PUV were identified at 2 large pediatric institutions in North America between 2000-2020 (The Hospital for Sick Children [SK] and Children's Hospital of Philadelphia [CHOP]). Baseline characteristics and outcome measures were compared between those diagnosed prenatally vs. postnatally. Main outcomes of interest included progression of chronic kidney disease (CKD), the need for renal replacement therapy (RRT) and bladder function compromise as determined by need for clean intermittent catheterization (CIC). Time-to-event analyses were completed when possible.

RESULTS

During the study period, 152 patients with PUV were treated at SK (39% prenatal) and 216 patients with PUV were treated at CHOP (71% prenatal). At SK, there was no difference between prenatal and postnatal groups in the proportion of patients who required RRT, progressed to CKD stage 3 and above, or who were managed with CIC when comparing the timing of diagnosis. The time to event for RRT and CIC was significantly younger for prenatally detected PUV. At CHOP, significantly more prenatal patients required RRT, however there was no significant difference in the age this outcome was reached. The proportion of children managed with CIC was not different but the time to event was significantly earlier in the prenatal group.

CONCLUSION

This study represents the largest multi-institutional series of patients with PUV and failed to identify any difference in the outcomes of prenatal versus postnatal detection of PUV. A multidisciplinary approach with standardization of the treatment pathways will help in understanding the true impact of prenatal/ early detection on outcomes of PUV.

Bladder function in children with posterior urethral valves: impact of antenatal versus postnatal diagnosis

Purpose:

Posterior urethral valves (PUVs) are the most common cause of congenital bladder obstruction in boys. Our aim was to assess the impact of early diagnosis and fulguration of PUVs on bladder function and compare their functional and urodynamic outcome with children who underwent delayed intervention.

Materials and Methods:

We retrospectively evaluated 153 patients who underwent primary valve ablation from two tertiary hospitals between 2001 and 2018. Patients have been divided into 2 groups, group 1 included 69 patients who were detected antenatally and underwent early fulguration of PUVs while group 2 included 84 children presented postnatally and underwent delayed valve ablation. The recorded data throughout follow-up in renal function tests, urodynamics and changes in the upper urinary tracts were evaluated and compared.

Results:

Median age at time of valve ablation was 10 days in group 1 and 7 months in group 2. The median follow-up period was 6.5 and 7 years in group 1 and 2, respectively. Chronic kidney disease (CKD) developed in 15 (22%) boys in group 1 while in group 2 it was observed in 31 (37%), p=0.04. While Q-max, mean bladder capacity and post-void residual (PVR) volumes were comparable in both groups, percent PVR was significantly higher in group 2 (3.27 vs. 1.44, p=0.002). Detrusor overactivity was slightly different in both groups (p = 0.07).

Conclusions:

Compared to delayed intervention, primary ablation of PUVs during the early neonatal life possibly provides the optimum chance to have optimum renal function without impact on bladder function.

Serum creatinine levels in cases of posterior urethral valve: 29 years experience of a pediatric urology reference center

OBJECTIVES

The aim of this retrospective study is to describe the importance of serum creatinine levels for the long-term renal outcome in cases of posterior urethral valve.

METHODS

Records of 94 patients who underwent cystoscopic valve ablation were evaluated retrospectively. Demographic variables, radiologic findings, and serum creatinine levels were recorded. Patients were grouped according to the serum creatinine levels in the first month of life. Twenty-four patients' serum creatinine levels were found to be above 1 mg/dL in group 1 and ≤1 mg/dL in 70 patients in group 2.

RESULTS

The initial findings of 74 patients were as follows: pyelonephritis in 24 (32.43%) patients, hydronephrosis in 20 (27.02%), and inability to urinate in 18 (24.32%). Prenatal hydronephrosis was present in 36 cases (38.29%). Of the 92 voiding cystograms, 53.26% had findings that included vesicoureteral reflux. The mean serum creatinine levels of the patients in group 1 increased above 1 mg/dL in the 2nd year, the significant difference between the two groups lasted up to 7 years of age, and no significant difference was observed at the age of 7. The mean serum creatinine levels of the patients in group 2 were observed to increase above 1 mg/dL by the 10th year.

CONCLUSIONS

In patients with posterior urethral valves, nadir creatinine, especially higher than 1 mg/dL, should be considered as high risk for end-stage renal disease. Therefore, clinicians should improve awareness about early detection and treatment of posterior urethral valves, and these patients should be monitored as early as possible for the risk of chronic kidney disease.

Common clinical markers predict end-stage renal disease in children with obstructive uropathy

BACKGROUND

Obstructive uropathy (OU) is a common cause of end-stage renal disease (ESRD) in children. Children who escape the newborn period with mild-to-moderate chronic kidney disease (CKD) continue to be at increased risk. The predictive ability of clinically available markers throughout childhood is poorly defined.

METHODS

Patients with OU were identified in the Chronic Kidney Disease in Children Study. The primary outcome of interest was renal replacement therapy (RRT) (cases). Controls were age matched and defined as patients within the OU cohort who did not require RRT during study follow-up.

RESULTS

In total, 27 cases and 41 age-matched controls were identified. Median age at baseline and age at outcome measurement were 10 vs. 16 years, respectively. First available glomerular filtration rate (GFR) (36.9 vs. 53.5 mL/min per 1.73 m²), urine protein/creatinine (Cr) (0.40 vs. 0.22 mg/mg) and microalbumin/Cr (0.58 vs. 0.03 mg/mg), and serum CO₂ (20 vs. 22 mmol/L) and hemoglobin (12.4 vs. 13.2 g/dL) differed significantly between cases and controls, respectively. GFR declined 3.07 mL/min per 1.73 m²/year faster in cases compared to that in controls (p < 0.0001). Urine protein/Cr and microalbumin/Cr increased by 0.16 and 0.11 per year more in cases compared to those in controls, respectively (p ≤ 0.001 for both). Serum phosphate increased by 0.11 mg/dL and serum albumin and hemoglobin decreased by 0.04 (g/dL) and 0.14 (g/dL) per year more for cases compared to those for controls, respectively (p < 0.05 for all).

CONCLUSIONS

Age-specific baseline and longitudinal measures of readily available clinical measures predict progression to ESRD in children with mild-to-moderate CKD from OU.

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.

Posterior urethral valves: Risk factors for progression to renal failure

INTRODUCTION

Posterior urethral valves (PUVs) are the most common etiology for congenital urethral obstruction and congenital bilateral renal obstruction. PUVs produce a spectrum of urologic and renal sequelae. Our aims were to assess outcomes of PUV patients, to determine whether vesicoureteral reflux (VUR) is a risk factor for progression to renal failure, and to identify other risk factors for poor outcomes.

MATERIALS AND METHODS

We conducted a retrospective analysis of PUV patients from 2006 to 2014. Data collected included demographics, initial renal ultrasound (RUS) findings, creatinine at presentation and nadir, pre- and postoperative VUR status, presence or absence of recurrent urinary tract infections (UTIs), and surgical intervention(s). Univariate and multivariate analyses were used to determine risk factors for renal failure.

RESULTS

Of 104 patients, 42.3% (44/104) were diagnosed prenatally, 31.8% (14/44) of whom underwent prenatal intervention. Postnatally, 90.4% (94/104) initially underwent transurethral resection of PUVs (TUR-PUVs). Vesicostomy was the next most common index surgery (4.8%). Forty-two percent (44/104) required >1 surgery. The predominant second surgery was repeat TUR-PUV in 16 patients. At last follow-up (mean 28.8 months after initial surgery), 20.2% had chronic kidney disease (CKD) of at least stage IIIA, and 8.6% had progressed to end-stage renal disease (ESRD). Antenatal diagnosis, prematurity, abnormal renal cortex, and loss of corticomedullary differentiation (CMD) on initial RUS were associated with CKD and ESRD on univariate analysis, as were elevated creatinine on presentation and at nadir. Presence of pre- or postoperative VUR and recurrent UTIs were associated with the need for multiple surgeries, but not with poor renal outcomes. On multivariate analysis, nadir creatinine was the only independent predictor of final renal function.

CONCLUSIONS

Our finding that creatinine is the only independent risk factor for poor renal outcomes in PUV patients is consistent with the literature. The effect of VUR has been controversial, and our finding that VUR is associated with need for multiple surgeries but not with CKD or ESRD is novel. Limitations include biases inherent to retrospective studies and relatively small sample size. The majority of patients with PUVs (56.7%) required one surgery and maintained renal function with CKD II or better (79.8%) up to 2 years after initial surgery. While multiple factors were associated with poor renal outcomes, nadir creatinine was the only independent predictor. VUR and recurrent UTIs were not associated with poor renal outcomes. Longer follow-up is necessary to identify risk factors for delayed progression of renal disease.

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.

Antenatal Determinants of Long-Term Kidney Outcome in Boys with Posterior Urethral Valves

Background: Posterior urethral valves (PUV) are the most important cause of end-stage renal disease (ESRD) in young boys. The objective of this report was to define the antenatal determinants of long-term postnatal renal outcome in this condition. Design: This was a retrospective cohort analysis. The primary outcome was the development of ESRD defined as starting dialysis or receiving a preemptive kidney transplant. Results: Eighty-two cases of PUV were identified, with 17 (21%) developing ESRD at 6.1 ± 7.1 years. Cases developing ESRD were more likely diagnosed antenatally (41 vs. 19%, p = 0.05), had a younger gestational age (35.5 ± 3.4 weeks vs. 37.3 ± 2.1 weeks, p = 0.02), and on antenatal ultrasound scan were more likely to have oligohydramnios (60 vs. 26%, p = 0.02), renal cortical cysts (47 vs. 17%, p = 0.02), and the combination of oligohydramnios, renal cortical cysts, and increased renal echogenicity (47 vs. 9%, p = 0.002). Conclusions: In boys with PUV, decreased gestational age, oligohydramnios, renal cysts, and the combination of oligohydramnios, cortical cysts, and echogenic kidneys were associated with ESRD, while the combination was an independent predictor of poor long-term postnatal kidney function.

Posterior urethral valves: Metabolic consequences in a cohort of patients

BACKGROUND

Despite the improvements in diagnosis and management of posterior urethral valves (PUVs), about one third of patients develop chronic kidney disease (CKD). Children with PUVs might have abnormal calcium, phosphorus, vitamin D and parathyroid hormone levels, which could affect their bone growth and overall health.

OBJECTIVE

The aim was to determine the relationship between kidney function, vitamin D deficiency and secondary hyperparathyroidism in children with PUVs.

PATIENTS AND METHODS

Sixty-four children with PUVs were followed for a period of 3.64 ± 2.50 years after their initial presentation and management. Their laboratory parameters were compared with 20 age-, gender- and race-matched children in a control group, including: serum calcium, phosphorus, intact parathyroid hormone (iPTH), 25-hydroxyvitamin D levels, and kidney function.

RESULTS

Children with PUVs had significantly lower estimated kidney function (P = 0.006) and vitamin D levels (P < 0.001) and higher iPTH levels (P = 0.042). There were no significant between-group differences in serum calcium, phosphorus, alkaline phosphatase, sodium, potassium, and bicarbonate levels. There was a strong correlation between the degree of vitamin D deficiency and hyperparathyroidism and the degree of kidney dysfunction (r = 0.52 and -0.52, respectively) in the PUV group. On a multivariate analysis, the kidney dysfunction was the only independent predictor of vitamin D deficiency (ρ = 0.271, P < 0.001), while kidney dysfunction, serum calcium and alkaline phosphatase were independent predictors for hyperparathyroidism (ρ = 0.925, P<0.001, ρ = 0.933, P<0.001 and ρ = 0.913, P < 0.001, respectively).

DISCUSSION

The prevalence of CKD in children with PUVs ranges from 30 to 60%. Patients with CKD are more likely to have vitamin D deficiency and display more-prominent hyperparathyroidism. Compared with a control group with normal kidney function, the present cohort had lower 25-hydroxyvitamin D and higher iPTH serum levels. Abnormal kidney function was a major predictor for both serum levels. In this cohort, there were no significant differences in serum calcium and phosphorus between children with PUVs and the control group, and also between those with and without CKD. On the contrary, vitamin D level decreased early in the disease and progressively declined thereafter, while iPTH was the opposite. These findings were comparable to previous studies. This study had some limitations because it was a single center cross-sectional non-randomized study. However, the findings in this study can be extrapolated to children with PUVs and CKD from other origins because the unit is considered as a referral center in the Middle East region.

CONCLUSION

Abnormal kidney function, vitamin D deficiency, and secondary hyperparathyroidism are prevalent in children with PUVs. Kidney function is the main determinant of vitamin D and parathyroid hormone levels. Efforts should be directed toward managing CKD, and controlling vitamin D deficiency and hyperparathyroidism in children after ablation of PUV.

Study of prognostic significance of antenatal ultrasonography and renin angiotensin system activation in predicting disease severity in posterior urethral valves

Aims:

Study on prognostic significance of antenatal ultrasonography and renin angiotensin system activation in predicting disease severity in posterior urethral valves.

Materials and Methods:

Antenatally diagnosed hydronephrosis patients were included. Postnatally, they were divided into two groups, posterior urethral valve (PUV) and non-PUV. The studied parameters were: Gestational age at detection, surgical intervention, ultrasound findings, cord blood and follow up plasma renin activity (PRA) values, vesico-ureteric reflux (VUR), renal scars, and glomerular filtration rate (GFR).

Results:

A total of 25 patients were included, 10 PUV and 15 non-PUV. All infants with PUV underwent primary valve incision. GFR was less than 60 ml/min/1.73 m² body surface area in 4 patients at last follow-up. Keyhole sign, oligoamnios, absent bladder cycling, and cortical cysts were not consistent findings on antenatal ultrasound in PUV. Cord blood PRA was significantly higher (P < 0.0001) in PUV compared to non-PUV patients. Gestational age at detection of hydronephrosis, cortical cysts, bladder wall thickness, and amniotic fluid index were not significantly correlated with GFR while PRA could differentiate between poor and better prognosis cases with PUV.

Conclusions:

Ultrasound was neither uniformly useful in diagnosing PUV antenatally, nor differentiating it from cases with non-PUV hydronephrosis. In congenital hydronephrosis, cord blood PRA was significantly higher in cases with PUV compared to non-PUV cases and fell significantly after valve ablation. Cord blood PRA could distinguish between poor and better prognosis cases with PUV.

Posterior urethral valve: Prognostic factors and renal outcome

OBJECTIVE

The aim was to study the outcome of posterior urethral valve (PUV) cases treated by stepladder protocol and the prognostic factors affecting the outcome.

MATERIALS AND METHODS

Hospital records of all PUV patients treated by stepladder protocol between January 1992 and December 2013 were reviewed. The studied parameters were: Age at presentation, serum creatinine, types of surgical intervention, vesicoureteral reflux (VUR) on initial voiding cystourethrogram (VCUG), renal cortical scars, plasma renin activity (PRA), and glomerular filtration rate (GFR).

RESULTS

Of 396 PUV patients treated during the study period, 152 satisfied study criteria. The age at presentation ranged from 2 days to 15 years (mean 31.3 months). The mean follow-up period was 5 years (range: 2-18 years). Primary endoscopic valve ablation was the most common initial procedure. Chronic renal failure was seen in 42.7% patients at the last follow-up. Serum creatinine at presentation, initial PRA levels, initial GFR, and PRA levels at last follow-up were significant predictors of final renal outcome. Age at presentation (<1 vs. >1 year), presence/absence of VUR on initial VCUG and renal cortical scars had no significant correlation with ultimate renal function.

CONCLUSION

Our study confirms the high prognostic significance of initial serum creatinine, PRA levels and GFR in cases with PUV. PRA also holds promise in long-term follow-up of these patients as a marker of progressive renal damage.

Fetal lower urinary tract obstruction and its management

INTRODUCTION

Prenatal counselling in case of fetal obstructive uropathies still represents a clinical dilemma, despite ultrasound detection of lower urinary tract obstruction has greatly advanced during recent years as well as fetal intervention techniques.

MATERIALS AND METHODS

A systematic review of the relevant literature on the topic was performed, with a special focus on the role of antenatal ultrasound, in utero treatment and prognosis.

CONCLUSIONS

A clinico-diagnostic flow chart was developed, with the specific aim of aiding health care givers in the clinical management and the parental decision-making process.

Outcome of prenatally detected bilateral higher urinary tract obstruction or megacystis: sex-related study on a series of 709 cases

OBJECTIVE

To compare the sex specific outcome of fetuses with prenatally detected urinary tract dilatation, with the exclusion of pyelectasia.

METHOD

Included in the study were 709 cases of major dilatation of the fetal urinary tract, diagnosed at routine ultrasound scan. For each sex group, cases were divided into two subgroups depending on the level of dilatation. Final diagnosis was based on postnatal evaluation or on fetal autopsy. Postnatal renal function was evaluated using serum creatinine at two years of age.

RESULTS

Bilateral higher urinary tract dilatation was prenatally observed in 148 (20.8%) and lower urinary tract obstruction or bladder dilatation in 561 (79.1%) of the 709 cases (121 female and 588 male fetuses) (P <0.001). Bladder dilatation was less frequent in female fetuses (62%) than in males (82.6%) (P <0.001). At final diagnosis, associated malformations were observed in 53.7% of female fetuses versus 11% in males (P <0.001). The survival rate was 42.7%. Postnatal renal function, evaluated in 289/303 live infants, was impaired in 29.7% of cases and depended on the level of obstruction, but not on the sex.

CONCLUSION

Prenatally detected urinary tract dilatation has a poor prognosis both in male and female fetuses. Associated malformations are observed more frequently in female than in male fetuses.

Neonatal ascites and oligohydramnios: the role of kidney

Posterior urethral valve pathologies are the most frequent childhood obstructive uropathy reported, and we infer their presence on diagnosing foetal ascites and oligohydramnios. Early action is vital to determine the long-term development and the degree of impairment of renal function. We report a newborn male 34 weeks of gestation with a prenatal diagnosis of foetal ascites, fluid on the loose in renal fossa and oligohydramnios. Subsequent studies have shown the presence of posterior urethral valves with associated significant vesicoureteral reflux. There was no secondary renal damage. Intrauterine decompression of the urinary tract seems to have exerted a protective role against kidney damage. This finding supports the role of foetal decompression surgery in early and severely obstructive forms to improve the prognosis of renal function in the long term.

Quantitative analysis of renal vascularization in fetuses with urinary tract obstruction by three-dimensional power-Doppler

OBJECTIVE

To evaluate the applicability of 3-dimensional evaluation of renal vascularization for predicting postnatal renal function in fetuses with suspected urinary obstruction.

STUDY DESIGN

Fetuses were evaluated by 3-dimensional power-Doppler histogram, and vascular indices were estimated. Depth between the probe and the renal cortex was also evaluated. Postnatal follow-up was obtained in all cases and the main outcome was renal impairment.

RESULTS

Twenty-three fetuses with urinary dilatation (cases) and 73 with normal renal morphology (controls) were included in the current study. Five (21.7%) cases developed renal impairment. Vascularization index and vascularization and flow index were significantly lower in fetuses that developed renal impairment compared with those with normal renal function (P = .009 and P = .036, respectively). The 3 vascular indexes correlated with depth. Percentage of depth-corrected vascularization index and vascularization flow index were lower in fetuses developing postnatal renal failure.

CONCLUSION

Fetal renal vascularity (vascularization index and vascularization and flow index) was significantly lower in fetuses that developed renal impairment.

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.

Ultrasound evaluation of prognosis in fetuses with posterior urethral valves

PURPOSE

The aim of this study was to evaluate the ability of prenatal ultrasound markers to predict postnatal renal prognosis in fetuses with posterior urethral valves.

METHODS

Medical files on fetuses with prenatal diagnosis of posterior urethral valves from 2000 to 2006 were reviewed retrospectively. Data from prenatal follow-up included gestational age at diagnosis, ultrasound renal parenchyma evaluation, and presence and time of oligohydramnios onset. Prenatal parameters studied were correlated to postnatal renal function.

RESULTS

Thirty-one male fetuses were included. Six pregnancies were terminated. Of the remaining 25 pregnancies that were continued, 4 children had abnormal creatine and 21 normal creatinine levels at follow-up. Presence and time of oligohydramnios onset did not differ between groups (P = .43). Ultrasound detected bilateral renal abnormalities in 3 fetuses (75%) with altered renal function, and 10 fetuses (55%) with normal creatinine, at follow-up.

CONCLUSIONS

None of the ultrasound parameters evaluated were able to reliably predict postnatal renal function.

Posterior urethral valves: multivariate analysis of factors affecting the final renal outcome

PURPOSE

Posterior urethral valves represent the most common obstructive uropathy in children with a broad spectrum of clinical severity. We evaluated prognostic variables affecting the outcome of renal function in such children.

MATERIALS AND METHODS

Between 1987 and 2004, 120 patients with a mean age of 2 years with posterior urethral valves were treated initially with valve ablation at our center. We studied certain parameters, including age at presentation, serum creatinine (initial and nadir), initial creatinine clearance, renal ultrasound findings (hydronephrosis and renal parenchymal echogenicity), vesicoureteral reflux on initial voiding cystourethrogram, bladder dysfunction and popoff mechanisms such as the syndrome of large vesical diverticulum, urinoma and ascites. Long-term renal outcome was assessed.

RESULTS

Followup was 2 to 16 years (median 3.6). Renal insufficiency developed at the end of followup in 44 patients (36.5%). Serum creatinine at hospital admission, nadir serum creatinine, initial creatinine clearance and renal parenchymal echogenicity were significant predictors of the final renal outcome (p < 0.05). Patient age at diagnosis (2 or less vs greater than 2 years), upper tract dilatation, the presence or absence of vesicoureteral reflux, popoff mechanisms and bladder dysfunction had no significant impact on future renal function. On multivariate analysis nadir serum creatinine was the only independent prognostic factor.

CONCLUSIONS

Our data confirm the high prognostic value of nadir creatinine after primary valve ablation. Also, initial serum creatinine, creatinine clearance and renal parenchymal echogenicity on initial renal ultrasound correlate significantly with long-term renal function in children with posterior urethral valves.

Prenatal ultrasonography: implications for pediatric urology

Prenatal ultrasonography has become a critical and integral component of the obstetric care of women worldwide. As a result, a number of congenital anomalies are now routinely being detected prior to birth. Anomalies affecting the genitourinary system are among those most commonly detected, and thus pediatric urologists are increasingly being asked to provide parental counseling in such situations. However, much of the data needed to enhance these discussions and provide informed consent are absent from the literature. In this review, we hope to address the published literature describing the rapidly expanding role of ultrasound in prenatal care. More importantly, however, we hope to provide some insight into the manner in which prenatal ultrasound and subsequent urologic anomaly diagnosis has affected the practice of pediatric urology.

Respiratory and general outcome in neonates with renal oligohydramnios--a single-centre experience

BACKGROUND

Renal oligohydramnion (ROH) is predominantly caused by congenital abnormalities of the kidney and urogenital tract (CAKUT). Although the number of neonates born with chronic renal failure is small, they provide many challenges, and among the most problematic are respiratory management and long-term treatment of chronic renal failure. We studied the value of prenatal and perinatal variables to predict survival and the general long-term outcome of our ROH population. Method. A single-centre retrospective chart review was conducted in 36 neonates with ROH treated between 1996 and 2007. Respiratory data sets including minimum inspiratory oxygen concentration (FiO(2), 1d), best oxygenation index (BOI, 1d) and minimum arterial partial carbon dioxide (pCO(2), 1d) at the first day of life were available in 23 children requiring intubation.

RESULTS

ROH causes were obstructive uropathy (n = 19), polycystic kidney disease [autosomal recessive polycystic kidney disease (ARPKD) n = 5 and autosomal dominant polycystic kidney disease n = 1], renal agenesis/dysplasia (n = 10) and bilateral renal vein thrombosis (n = 1). Survival until discharge was 64% (23/36), and overall survival was 58% (21/36). Seven patients died within 48 h from respiratory failure. Non-survivors had a higher minimum FiO(2) and pCO(2) (1d) compared to survivors (P < 0.001). Mean BOI (1d) was 6.2 in survivors versus 43.9 in the non-surviving group (P < 0.001). Logistic regression showed that BOI (</≥ 9.6) and first diagnosis of ROH (≤/>28 gestational weeks) retained significance in predicting survival until discharge.

CONCLUSIONS

The attitude toward initiating dialysis in neonates is changing and long-term outcome in the absence of severe comorbidity is promising. Prenatal prediction concerning respiratory and renal outcome in fetuses with ROH is difficult. Our data suggest that BOI (1d) and onset of ROH may be reliable predictors of respiratory prognosis in children born with ROH.

Long-term upper and lower urinary tract functions in children with posterior urethral valves

OBJECTIVE

Several factors have been identified as predictive of future renal function in children with posterior urethral valves (PUV). Our aim was to analyse upper and lower urinary tract outcome in patients with PUV, and determine any factors from the period of early management that were predictive of future renal function.

METHODS

The charts of 67 boys (mean age 2.4 years) diagnosed with PUV were reviewed. The most common presenting symptom was dribbling in 43.2% and UTI in 28.3%. Twenty-three (34.8%) patients developed end-stage renal disease aged 1-15 years. The mean time of renal survival was calculated as 7.8 (SEM=0.73) years.

RESULTS

Incontinence in patients over 5 years old, lower urinary tract dysfunction, serum creatinine level in first year or at the time of diagnosis, and presence of vesicoureteral reflux and high-grade bilateral reflux were significant risk factors for occurrence of renal failure in the future. Lower tract dysfunction was seen in 58.6% of patients. Postnatal diagnosis and presence of high-grade reflux were significant risk factors for the future occurrence of lower urinary tract dysfunction.

CONCLUSION

It is important to recognize that PUV have consequences not only during childhood or before treatment, but also during or after the treatment period. Long-term assessment and follow-up of upper and lower urinary tract functions after valve ablation is necessary.

Abnormal antenatal sonogram: an indicator of disease severity in children with posterior urethral valves

PURPOSE

To review the association of an abnormal prenatal sonogram with most recent serum creatinine in patients with proven posterior urethral valves (PUV).

METHODS

Since 1992, all live-born patients between 1992-2004 with clinically proven PUV, with postnatally proven PUV, from 2 pediatric tertiary care centers, were reviewed for age at diagnosis, most recent serum creatinine, presence of chronic renal failure (CRF) (serum creatinine >2 standard deviations above normal for age), or end stage renal disease (dialysis or transplant). Available antenatal reports from the 2 centres and surrounding community hospitals were reviewed for gestational age (GA) at the time of ultrasound, volume of amniotic fluid, and urinary-tract abnormality.

RESULTS

Thirty-four patients with proven PUV and prenatal sonograms were identified (1992-2004). Eighteen patients had abnormalities on their prenatal sonogram, with poor outcome in 5 (mean follow-up, 8 years [1-13 y]). No specific features were identified on prenatal sonogram. Sixteen patients had normal prenatal sonograms, with poor outcomes in 2 (mean follow-up, 8 years [3-13y]). There is an increased risk of an abnormal serum creatinine among those patients with an abnormal prenatal study, odds ratio (OR) 2.6 (95% confidence interval, 0.35-32).

CONCLUSIONS

PUV represents a spectrum of disease severity. A normal prenatal ultrasound does not preclude PUV. The majority of patients with a normal prenatal examination have good outcomes. The OR suggests that there may be increased risk for poor outcome in those with an abnormal prenatal examination. A multicenter study is necessary to obtain a larger sample size and more precise ORs.

Postnatal evaluation of infants with an abnormal antenatal renal sonogram

PURPOSE OF REVIEW

Antenatally detected renal abnormalities are frequently encountered. Recommended postnatal evaluation of these infants has evolved to minimize invasive testing while maximizing detection of significant abnormalities.

RECENT FINDINGS

There is a low rate of detectable renal abnormalities in infants with a normal postnatal sonogram at 4-6 weeks of age. Routine prophylactic antibiotics are not indicated in infants with isolated antenatal hydronephrosis. Infants with a multicystic dysplastic kidney and a normal contralateral kidney on renal ultrasound do not require further evaluation. Parents of these children should be counseled on symptoms of urinary tract infections to allow prompt diagnosis.

SUMMARY

All infants with abnormalities on antenatal sonogram should undergo postnatal evaluation with a sonogram after birth and at 4-6 weeks of age. Further evaluation can be safely limited when the postnatal sonogram is normal at 6 weeks of age.

Congenital anomalies of the male urethra

The spectrum of congenital anomalies of the male urethra is presented. The embryologic basis of each anomaly, when known, is discussed. Clinical and imaging features of each entity are presented.

Prune belly syndrome. A focused physical assessment

Prune belly syndrome, a rare congenital anomaly, exists almost exclusively in males and consists of genital and urinary abnormalities with partial or complete absence of abdominal wall musculature. The syndrome, caused by urethral obstruction early in development, is the result of massive bladder distention and urinary ascites, leading to degeneration of the abdominal wall musculature and failure of testicular descent. The impaired elimination of urine from the bladder leads to oligohydramnios, pulmonary hypoplasia, and Potter's facies. The syndrome has a broad spectrum of affected anatomy with different levels of severity. The exact etiology of prune belly syndrome is unknown, although several embryologic theories attempt to explain the anomaly. With advances in prenatal screening techniques, the diagnosis and possible treatment of prune belly syndrome can occur before birth, although controversy exists on the proper management of prune belly syndrome. This article explores the theories behind the pathophysiology and embryology of prune belly syndrome and its multisystemic effects on the newborn infant. Specific attention is paid to presentation, clinical features, head-to-toe physical assessment, family support, and nursing care of infants with prune belly syndrome.

Prognosis of antenatally diagnosed oligohydramnios of renal origin

Although clinical outcome data on fetuses with oligohydramnios of renal origin are scarce, prognosis is regarded as poor due to a high risk of renal dysfunction and pulmonary hypoplasia. This review aims to summarize the current knowledge and clinical experience with patients presenting antenatally with renal oligohydramnios. By reviewing the underlying mechanisms, complications, and outcome data, we hope to further improve antenatal counseling and postnatal care. We conclude that prognosis of ROH has changed in recent years. While early data before the introduction of sophisticated neonatal intensive care and renal replacement therapy indicated a poor prognosis, nowadays, a much more optimistic prognosis of children after renal oligohydramnios can be expected from the recent publications in the literature.

Current diagnosis and management of fetal genitourinary abnormalities

Prenatal assessment with ultrasonography provides excellent imaging of fluid-filled structures (eg, hydronephrosis, renal cysts, and dilated bladder) and renal parenchyma. This information allows for the generation of a differential diagnosis, identification of associated anomalies, and assessment of the prenatal and postnatal risks of a given anomaly. This enhances parental education and prenatal and postnatal planning. This article discusses the current methods of diagnosis and management of fetal genitourinary anomalies, and also the postnatal evaluation and treatment of these conditions.

Systematic review of accuracy of fetal urine analysis to predict poor postnatal renal function in cases of congenital urinary tract obstruction

OBJECTIVE

To evaluate the clinical usefulness of analysis of fetal urine in the prediction of poor postnatal renal function in cases of congenital urinary tract obstruction.

METHODS

A systematic review was performed. We conducted extensive electronic searches (database inception-2006). The reference lists of articles obtained were searched for any further articles. Two reviewers independently selected the articles in which the accuracy of fetal urinalysis was evaluated to predict poor postnatal renal function. There were no language restrictions. Data were extracted on study characteristics, quality and results, to construct 2 x 2 tables. Likelihood ratios for positive (LR+) and negative (LR-) test results were generated for the different fetal urinary analytes at various thresholds.

RESULTS

There were 23 articles that met the selection criteria, including a total of 572 women and 63 2 x 2 tables. The two most accurate tests were calcium > 95th centile for gestation (LR + 6.65, 0.23-190.96; LR - 0.19, 0.05-0.74) and sodium > 95th centile for gestation (LR + 4.46, 1.71-11.6; LR - 0.39, 0.17-0.88). beta(2)-microglobulin was found to be less accurate (LR + 2.92, 1.28-6.69; LR - 0.53, 0.24-1.17).

CONCLUSION

The current evidence demonstrates that none of the analytes of fetal urine investigated so far can be shown to yield clinically significant accuracy to predict poor postnatal renal function.

Prenatal hydronephrosis

Hydronephrosis is the most common genitourinary tract anomaly identified on prenatal ultrasound studies. Ureteropelvic junction obstruction accounts for approximately 50% of the cases of prenatally detected hydronephrosis. Postnatal evaluation allows for the identification of the cause and further management. Rarely, in utero intervention may be performed for severe oligohydramnios associated with hydronephrosis. Prenatal consultation with a pediatric urologist is useful in decreasing parental anxiety and facilitating postnatal management.

Obstructive uropathy

Routine second trimester ultrasound screening has resulted in more infants diagnosed with antenatal hydronephrosis. Current recommendations suggest postnatal evaluation of all infants with a renal pelvic diameter >5 mm with ultrasound and voiding cystourethrogram (VCUG.) There are many etiologies of obstructive uropathy including ureteropelvic junction (UPJ) obstruction, ureterovesical junction (UVJ) obstruction, posterior urethral valves (PUV), prune belly syndrome, and vesicoureteral reflux (VUR). Obstructive uropathy can result in tubular damage and decreased nephron number. Tubular damage can result in sodium wasting, hyperkalemic acidosis, and nephrogenic diabetes insipidus. Most patients do not require renal replacement therapy in the neonatal period; however, chronic renal insufficiency can occur if the neonate has a significant reduction in nephron number or progressive renal damage from obstruction or infection.

Diagnosis and outcome of fetal lower urinary tract obstruction in the northern region of England

OBJECTIVE

We reviewed the prenatal and postnatal management of fetal lower urinary tract obstruction (LUTO) in a large geographically defined population.

METHODS

The records of 113 cases of LUTO seen over a 14-year period were examined. The predictive accuracy of prenatal findings for chronic renal failure (CRF) and a comparison of prenatal-suspected and non-suspected cases were made.

RESULTS

The incidence of LUTO was 2.2 in 10 000 births. During the study period, prenatal detection improved from 33 to 62%. Sensitivity of prenatal ultrasound detection of renal dysplasia and fetal urinary sodium, calcium, and beta2-microglobulin for CRF or renal dysplasia on autopsy were 59, 33, 66, and 63% respectively. Compared to undetected cases, those detected prenatally had higher mortality and a higher rate of CRF at 24 months (17% vs 57%, p < 0.01).

CONCLUSION

Our observations confirm the poor prognosis associated with fetal LUTO. The value of serial fetal urine biochemistry, other prenatal predictors of postnatal renal function, and the benefits of vesicoamniotic shunting require larger series and longer follow-up.

Initial management of complex pediatric disorders: prunebelly syndrome, posterior urethral valves

Prunebelly syndrome and posterior urethral valves are conditions of detrusor dysfunction associated with antenatal urethral obstruction. The resultant severe hydroureteronephrosis and renal dysplasia initiate a sequence potentially leading to renal failure. This article reviews clinical features and explores neonatal evaluation and treatment for both conditions. A comprehensive approach to initial management aimed at optimal renal preservation and bladder rehabilitation is proposed.

Development of renal function after neonatal urinary ascites due to obstructive uropathy

PURPOSE

Neonatal urinary ascites is a rare complication of obstructive uropathy with possible lethal outcome if not treated adequately. We demonstrate that with adequate therapy the survival rate can be high and long-term survival, kidney function and lower urinary tract function of patients with urinary ascites can be good.

MATERIALS AND METHODS

The study included 4 females and 8 males born with urinary ascites. Followup ranged from 3 to 14 years. Blood analysis for renal function, electrolytes and blood gas was performed at hospitalization and during followup. Ultrasound, cystourethrograms or cystoscopy showed the site of obstruction and leakage of urine. All patients were initially treated with drainage of the ascites and decompression of the obstructed urinary tract. All patients underwent surgery to remove the obstruction and reconstruct the urinary tract. Bladder and kidney function was evaluated at long-term followup.

RESULTS

All patients had severe abdominal distention at presentation. Severe metabolic acidosis was present in cases that had not been detected prenatally or immediately after birth. Two patients died of causes related to pulmonary hypoplasia. Surprisingly urinary continence and renal function were good in 9 of 10 survivors.

CONCLUSIONS

Long-term outcome of bladder and kidney function is surprisingly good in cases of severe obstructive uropathy with ascites. Intrauterine pressure relief of the bladder through urinary extravasation protects renal function and this decompression of the urinary tract prevents severe secondary changes to bladder function. Although not proven we believe that high intrauterine pressures in the abdominal cavity are prevented by peritoneal absorption of the extravasated urine and consequent dialysis through the placenta.

Biochemical investigation of foetal and neonatal thyroid function using the ACS-180SE analyser: clinical application

Despite sonographic detection of foetal goitre, uncertainty persists in the initial diagnosis of thyrotoxicosis and hypothyroidism. The aim of this study was to establish foetal and neonatal iodothyronine and thyrotrophin reference values for the ACS-180SE analyser. From 22 to 36 weeks of gestation, median foetal serum free thyroxine (FT4) levels increased from 6.0 pmol/L to 143 pmol/L, while free tri-iodothyronine (FT3) levels increased from 0.7 pmol/L to 1.9 pmol/L and mean thyrotrophin (TSH) levels remained stable (10.2 +/- 3.8mU/L; n = 33). At birth, concentrations were independent of gender and gestational age. Among the 10 cases of sonographically detected foetal goitre, serum TSH and FT4 were measured in five, showing hypothyroidism (3/5) or hyperthyroidism (2/5). Cord blood TSH levels reflected the efficacy of prenatal therapy. Measurement of foetal FT4 and TSH can be used to confirm foetal thyroid dysfunction, whereas treatment efficacy can be assessed sonographically and confirmed by measurement of TSH assay at birth.

Fetal surgery for posterior urethral valves: long-term postnatal outcomes

OBJECTIVE

Fetal intervention for obstructive uropathy was first performed at the University of California, San Francisco in 1981. Indications for treatment were bilateral hydronephrosis with oligohydramnios. Preintervention criteria included fetal urinary electrolytes with beta-microglobulin levels, karyotyping, and detailed sonography specifically looking for renal cortical cysts. We reviewed the outcomes of children who underwent fetal intervention with specific long-term follow-up in patients who were found postnatally to have posterior urethral valves.

METHODS

A retrospective review of the University of California, San Francisco fetal surgery database was performed for patients with a prenatal diagnosis of obstructive uropathy. Medical records from 1981 to 1999 were reviewed. Long-term follow-up was documented if the cause of the urinary tract obstruction was posterior urethral valves. We collected data points, focusing on time and type of intervention, fetal urinary electrolytes, appearance of fetal kidneys, present renal function, length of follow-up, and present status of the urinary tract.

RESULTS

Forty patients were evaluated for fetal intervention; 36 fetuses underwent surgery during this time period. Postnatal confirmation of posterior urethral valves was demonstrated in 14 patients. All patients had favorable fetal urinary electrolytes. Mean gestational age at intervention was 22.5 weeks. The procedures performed included creation of cutaneous ureterostomies in 1, fetal bladder marsupialization in 2, in utero ablation of valves in 2, and placement of vesicoamniotic catheter in 9. Six deaths occurred before term delivery with premature labor and the newborns succumbing to respiratory failure. One pregnancy was terminated electively because of shunt failure and declining appearance of fetal lungs and kidney. The remaining 8 living patients had a mean follow-up of 11.6 years. Chronic renal disease with abnormal serum creatinine was present in 5 patients. Two patients have undergone renal transplantation, and 1 is awaiting organ donation. Five of the 8 living patients have had urinary diversion with vesicostomy, cutaneous ureterostomy, or augmentation cystoplasty with later reconstruction.

CONCLUSIONS

Fetal intervention for posterior urethral valves carries a considerable risk to the fetus with fetal mortality rate of 43%. The long-term outcomes indicate that intervention may not change the prognosis of renal function or be a predictor for possible urinary diversion. Despite all of these patients' having favorable urinary electrolytes, this did not seem to have any implication postnatally. When counseling families about fetal intervention, efforts should be focused on that intervention may assist in delivering the fetus to term and that the sequelae of posterior urethral valves may not be preventable. Fetal surgery for obstructive uropathy should be performed only for the carefully selected patient who has severe oligohydramnios and "normal"-appearing kidneys.