Long-term Status of Patients with Posterior Urethral Valves

Surrogate imaging markers of Urodynamic proven bladder dysfunction in posterior urethral valves: A comprehensive evaluation

INTRODUCTION

Although urodynamic evaluation forms the cornerstone of diagnosis and management of bladder dysfunction in posterior urethral valves (PUV), yet it could be helpful to learn if there are any non-invasive surrogate imaging markers for the same.

AIM

To study the diagnostic accuracy of various imaging surrogate markers of urodynamic proven bladder dysfunction in PUV.

METHOD

This cross-sectional study over two years included 38 children of endoscopically proven PUV. Based on bladder function on Urodynamics the patients were divided into 2 groups: Group 1: PUV with normal bladder function (n: 17, 44.7%); Group 2: PUV with impaired bladder function (n: 21, 55.3%). Voiding dysfunction, incidence of recurrent urinary tract infection (UTI), polyuria, grade of hydronephrosis, retrovesical ureteric diameter (mm) and detrusor wall thickness (DWT mm) was compared in the two groups. MCU at initial presentation and post definitive treatment was studied and a bladder hostility score (BHS) was assigned to each patient and compared in the two groups. Correlation between impaired bladder function and clinical and radiological variables was performed by using Spearman Rank correlation and data receiver operating curves (ROC) were plotted to identify the critical values predicting the probability of bladder dysfunction in PUV.

RESULTS

Mean age at evaluation was 6.1 ± 4.2 years with a mean follow-up of 5 ± 3.9 years (median: 3.5 years). Voiding dysfunction, persistent or worsening grade III and IV hydroureteronephrosis, retrovesical ureter diameter ≥13.1 mm (diagnostic accuracy: 68.4%, AUC: 0.738), DWT on full bladder ≥1.85 mm (diagnostic accuracy: 81.6%, AUC: 0.846) and pretreatment BHS ≥5.5 (diagnostic accuracy: 71.4%, AUC: 0.763) were the clinical and imaging predictors of impaired bladder function. Comparative analysis of the two groups is as shown in table.

CONCLUSION

Clinical and imaging parameters are unable to convincingly identify the type of bladder dysfunction which is often required to manage PUV patients appropriately. Increased detrusor wall thickness suggests underlying bladder dysfunction and while those with small capacity hypertonic bladders have higher mean detrusor wall thickness than those with myogenic failure, the difference was not statistically significant (p: 0.41). Attempts to predict underlying bladder dysfunction by MCU imaging may be erroneous in nearly one-third of the patients. Thus, these imaging parameters are complementary and sequential to urodynamic, which certainly continues to be the gold standard investigation to assess bladder dysfunction in PUV.

Collateral Damage From Fetal Interventions: Increasing the Complexity of Complex Patients

Fetal interventions are often key to fetal survival and growth; however, they can often have complications causing significant morbidity and mortality. This case highlights not only a complication of fetal surgery, but also a very unusual diagnosis. We present the case of a male fetus who was diagnosed with urethral atresia and subsequently underwent 2 vesicoamniotic shunt placements. At birth, he was diagnosed with Megacystis Microcolon Intestinal Hypoperistalsis Syndrome and was noted to have rectovesical and vesicocutaneous fistulae likely iatrogenically created from shunt placement. While fetal interventions are often required, a multidisciplinary team approach is often necessary as complications occur.

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.

Long-term outcomes of kidney and bladder function in patients with a posterior urethral valve

We investigated long-term functional changes in the kidney and bladder of patients with posterior urethral valve (PUV) who underwent fetal intervention or postnatal surgery.We retrospectively reviewed the medical records of 28 consecutive patients treated for PUV at our institution. Detailed data on medical and surgical histories, particularly on pre- and postnatal treatment modality, including fetal vesicoamniotic shunt, endoscopic valve ablation, and vesicostomy, were collected and analyzed. Long-term renal function was evaluated based on serum levels of creatinine (sCr), estimated glomerular filtration rate (eGFR), and renal scans. Voiding function was evaluated in urodynamic tests.Vesicoamniotic shunting was performed in 12 (42.8%) patients. Although the mean initial sCr was significantly higher in patients in whom a fetal shunt was placed than in others (2.04 vs 1.17 mg/L, P = .038), the sCr at long-term follow-up was not significantly different between them (0.64 vs 0.40 mg/L, P = .186). The mean maximum detrusor pressure was significantly lower in patients with a fetal shunt than in others (37.7 vs 73.0 cm H2O, P = .019). Postnatal vesicostomy was performed in 14 patients, and primary valve ablation was performed in 13 patients. The mean initial sCr was higher in patients in the vesicostomy group than in the primary valve ablation group (2.08 vs 0.86 mg/L, P = .014). However, no significant differences were found in sCr (0.9 vs 0.3 mg/L, P = .252) or GFR (59.1 vs 68.5 mL/min/1.73 m, P = .338) at long-term follow-up. Bladder capacity was greater and residual urine volume was less in the vesicostomy group than in the primary valve ablation group, but without statistical significance.Vesicostomy is more beneficial in the recovery of renal function and is not inferior in terms of bladder function, even in patients with severe PUV disorder. It is a reliable surgical option that can spare renal function and guarantee adequate bladder function in the long term.

Comparison of biochemical analysis of fetal serum and fetal urine in the prediction of postnatal renal outcome in lower urinary tract obstruction

OBJECTIVES

To compare the prognostic value of fetal serum biochemistry and fetal urine biochemistry in predicting renal outcome in lower urinary tract obstruction (LUTO).

METHODS

We retrospectively studied renal outcome following a prenatal diagnosis of LUTO in cases for which both fetal blood and fetal urine were sampled. We classified the renal outcome as either "favorable," when postnatal renal function was normal, or "adverse," in the case of postnatal chronic renal failure or when renal histological lesions were present at autopsy in the case of termination of pregnancy. A prognostic model was constructed for urine and serum separately. β2-Microglobulin was the only remaining independent predictor in fetal urine. β2-Microglobulin in serum and urine were compared by using receiver operating characteristic curves.

RESULTS

In the 50 cases included, the rate of adverse outcome was 34 of 50(68%): autopsy confirmed severity of renal disease in all 27 cases who underwent termination of pregnancy, and among the 23 live born children, 7 developed renal failure. Fetal serum and urine markers were all significantly associated with renal outcome (P < .01). The receiver operating characteristic curves for fetal serum and fetal urinary β2-microglobulin were similar (area under the curve = 0.908 versus 0.909, P = .96).

CONCLUSION

Fetal serum biochemistry and fetal urine biochemistry are of similar prognostic value in predicting postnatal renal outcome in fetuses with LUTO.

Cystometrogram appearance in PUV is reliably quantified by the shape,wall, reflux and diverticuli (SWRD) score, and presages the need for intervention

OBJECTIVE

Radiological bladder abnormalities in boys with posterior urethral valves (PUV) are well recognised; however, the assessment is subjective. The shape, wall, reflux and diverticuli (SWRD) score objectively assesses shape, wall, reflux and diverticuli in a simple way. This study was undertaken to demonstrate that the SWRD score is reliable, reproducible and correlates with bladder outcome and videourodynamic (VUD) assessment in boys with PUV.

MATERIALS AND METHODS

Three blinded assessors determined the SWRD scores of PUV bladders from cystometrograms taken during VUD from September 2012 to October 2013. The scores were correlated with clinical outcome and VUD pressure measurements. Data were given as median (interquartile range), non-parametric tests used as appropriate (Mann-Whitney U test, or Kruskall-Wallis) and P < 0.05 was taken as significant.

RESULTS

A total of 55 boys with PUV underwent VUD assessment, for which 52 cystometrograms were available. The SWRD score for non-operative management was 1.0 (0.1-1.9) vs 2.0 (1.0-3.3) for operative intervention, P = 0.018 (Summary Figure). The SWRD score for compliant bladders was 1.1 (0.6-2.0) vs hypercompliant 1.7 (0.5-2.8) vs non-compliant 3.3 (2.8-5.0), Kruskall-Wallis P = 0.011. The hostile detrusor overactivity (DO) bladders (Pdet >40 cmH₂O) had a SWRD score of 2.0 (1.3-3.7) vs 1.0 (0.5-2.5) for low-pressure DO bladders, P < 0.05.

DISCUSSION

In this series of patients, increasingly distorted bladder shape was seen to be associated with poor bladder dynamics on VUD. Patients with poorly compliant bladders had a significantly higher SWRD score than normal or megacystis patients. Severe DO was also significantly associated with a high SWRD score. Therefore, the radiological appearance of a hostile bladder represented a marker for high intravesical pressure. VUR and bladder diverticuli may lead to spurious pressure measurements during VUD; however, the SWRD score provided an independent mechanism with which to objectively assess these patients, even in the presence of gross VUR.

CONCLUSIONS

The SWRD score is a simple and objective scoring system for the radiological abnormalities of PUV bladders. It correlates with clinical outcome and VUD assessment of compliance and DO, but is independent of pressure measurements and so not confounded by VUR acting as a 'pop-off' mechanism.

Sequential fetal serum β2-microglobulin to predict postnatal renal function in bilateral or low urinary tract obstruction

OBJECTIVE

Fetal serum β2-microglobulin has been shown to predict postnatal renal outcome in cases of fetal obstructive uropathy. We assessed the value of serial measurements of fetal serum β2-microglobulin in the prediction of postnatal renal outcome.

METHODS

We retrospectively studied renal outcome in 42 fetuses with bilateral or low urinary tract obstruction that had fetal blood sampling on at least two occasions to assay serum levels of β2-microglobulin. Amniotic fluid volume at the time of each sampling was recorded. We classified renal outcome as either favorable (when postnatal renal function was normal) or adverse (when postnatal chronic renal failure occurred or when renal dysplasia at autopsy was noted). A β2-microglobulin cut-off of 5 mg/L and amniotic fluid index of 5 cm were used to predict postnatal renal outcome.

RESULTS

Renal outcome was adverse in 28 cases and favorable in 14. In 12 (28.6%) cases, fetal serum β2-microglobulin concentration differed between the first and last measurement. Prediction of postnatal renal outcome was correct in 11 of these cases based on the last β2-microglobulin measurement. The sensitivity of β2-microglobulin in predicting renal outcome was significantly higher (P = 0.005) when using the last rather than the first measurement (96.4% vs 64.3%), with similar specificity for both measurements (85.7% vs 78.6%, non-significant). The sensitivity of amniotic fluid volume was also significantly higher (P = 0.005) when using the last rather than the first measurement (75.0% vs 35.7%), with similar specificity for both measurements (64.3% vs 71.4%, non-significant).

CONCLUSION

Sequential measurement of serum β2-microglobulin, performed for adverse ultrasound findings, such as renal parenchymal abnormality or decreasing amniotic fluid volume, predicts postnatal renal outcome more accurately than does a single assay. This may be due to possible worsening of renal injury with increasing duration of urinary tract obstruction. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Nadir creatinine in posterior urethral valves: How high is low enough?

INTRODUCTION

Large retrospective studies of people with posterior urethral valves (PUV) have reported chronic renal insufficiency (CRI) in up to one third of the participants and end-stage renal failure in up to one quarter of them. Nadir creatinine (lowest creatinine during the first year following diagnosis) is the recognised prognostic indicator for renal outcome in PUV, the most commonly used cut-off being 1 mg/dl (88.4 umol/l).

OBJECTIVE

To conduct a statistical analysis of nadir creatinine in PUV patients in order to identify the optimal cut-off level as a prognostic indicator for CRI.

STUDY DESIGN

Patients treated by endoscopic valve ablation at the present institution between 1993 and 2004 were reviewed. Chronic renal insufficiency was defined as CKD2 or higher. Statistical methods included receiver operating characteristic (ROC) curve analysis, Fisher exact test and diagnostic utility tests. Statistical significance was defined as P < 0.05.

RESULTS AND DISCUSSION

Nadir creatinine was identified in 96 patients. The median follow-up was 9.4 (IQR 7.0, 13.4) years. A total of 29 (30.2%) patients developed CRI, with nine (9.4%) reaching end-stage renal failure. On ROC analysis, Nadir creatinine was highly prognostic for future CRI, with an Area Under the Curve of 0.887 (P < 0.001). Renal insufficiency occurred in all 10 (100%) patients with nadir creatinine >88.4 umol/l compared with 19 of 86 (22.2%) patients with lower nadir creatinine (P < 0.001). As a test for future CRI, a nadir creatinine cut-off of 88.4 umol/l gave a specificity of 100%, but poor sensitivity of 34.5%. Lowering the cut-off to 75 umol/l resulted in improvement in all diagnostic utility tests (Table). All 14 (100%) patients with nadir creatinine >75 umol/l developed CRI, compared with 15 of 82 (18.3%) patients with lower nadir creatinine (P < 0.001). Sensitivity only approached 95% at 35 umol/l, at which level specificity was low (Table). Two out of 36 (5.6%) patients with nadir creatinine <35 umol/l developed CRI. Multivariate analysis found recurrent UTI (OR 4.733; CI 1.297-17.280) and nadir creatinine >75 umol/l (OR 48.988; CI 4.9-490.11) to be independent risk factors for progression to CRI. Using cut-off values of 35 umol/l and 75 umol/l, patients can be stratified into low-, intermediate- and high-risk groups, with development of CRI in 5.3%, 28.3% and 100%, respectively (P <0.001). The stage of CKD was higher in higher risk groups.

CONCLUSION

Patients with nadir creatinine >75 umol/l (0.85 mg/dl) should be considered at high risk for CRI, while patients with nadir creatinine ≤35 umol/l (0.4 mg/dl) should be considered low risk. Patients with nadir creatinine between these two values have an intermediate risk of CRI.

[Urodynamic profile of voiding disorders persisting after treatment of posterior urethral valve]

PURPOSE

Posterior urethral valves (PUV) are the most common cause of bladder outlet obstruction in infancy that impairs renal and bladder function.

MATERIAL AND METHODS

We realize a retrospective study and examined 35 boys with urinary disorders post-treatment of PUV, seen at the urodynamic consultation.

RESULTS

The mean age: 7.56 years, urinary problems are dominated by recurrent urinary tract infections and urinary leakage, morphological assessment is marked by the constant expansion of the urinary tract and bladder, 18 children have end-stage renal disease of which 8 are candidates for transplantation. About urodynamic, the uroflowmetry with measure of post-void urine residue: dysuria with significant residual urine in 14 children; for cystometry, 20 children with bladder hyperactivity, 9 bladders are hypotonic hypoactive with high capacity, 6 explorations are normal.

CONCLUSION

Urodynamic explorations are all interest when voiding symptoms persist after endoscopic section valves and despite a good radiological result.

The experience of pregnant women with a diagnosis of fetal lower urinary tract obstruction (LUTO)

OBJECTIVE

to gain insight into the experiences and perspectives of pregnant women diagnosed antenatally with fetal lower urinary tract obstruction (LUTO) participating in an interventional fetal medicine randomised controlled trial (RCT).

DESIGN

a qualitative study using semi-structured interviews. Interviews were analysed using Riessman's narrative analysis.

SETTING

fetal medicine clinics within the United Kingdom National Health Service (NHS).

PARTICIPANTS

five pregnant women who were recruited as part of an RCT and two additional women who were recruited after the trial was terminated before completion.

FINDINGS

three themes were identified and form the basis of this article: the use of technology in pregnancy, the loss of a normal pregnancy, and decision making in uncertainty.

IMPLICATIONS AND CONCLUSIONS

undertaking qualitative research within an RCT can illuminate the experience of the condition being studied. Women's experience of a pregnancy where LUTO was diagnosed in the fetus entailed an emotional journey following the visualisation of the abnormality through the use of routine ultrasound screening. Women tried to make sense of the diagnosis in order to make the best, albeit less than ideal, decisions for themselves, their baby, and their family. Midwives are in a good position to support women through the emotional distress of diagnosis and to help them negotiate the uncertain terrain in which they make decisions.

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.

Mini-vesicostomy in the management of PUV after valve ablation

AIM

To determine the usefulness of infra-umbilical mini-vesicostomy in infants with posterior urethral valves (PUV), in developing countries. This new technique facilitates clean intermittent catheterization (CIC) and overnight bladder drainage, which have been effectively used for the treatment of valve bladders in the developed world.

METHODS

A retrospective analysis of the records of three infants who underwent a mini-vesicostomy between 2005-2009 was done. All were put on CIC in the neonatal period. Monitoring of renal parameters, bladder function and structural changes in the bladder was done before and after 4 years of CIC.

RESULTS

All three showed a decrease in upper tract dilatation, improvement in cortical function and improvement of bladder compliance at the end of 4 years. Two patients are on CIC through vesicostomy and can pass a good stream of urine per urethraly, and in one the vesicostomy has been closed.

CONCLUSION

Mini-vesicostomy is a useful option to allow CIC on a long-term basis in children with PUV. There were no complications with this technique in this small group of patients, and it has been well accepted by their families.

CKD and bladder problems in children

Approximately 35% of children with CKD who require renal replacement therapy have a significant urological abnormality, including posterior urethral valves, a neuropathic bladder, prune belly syndrome, Hinman syndrome, or severe vesicoureteral reflux. In such children, abnormal bladder function can have a significant deleterious effect on the renal function. In children with bladder outlet obstruction, bladder compliance and capacity often are abnormal, and a sustained intravesical pressure of >40 cm H(2)O impedes drainage from the upper urinary tract. Consequently, in these conditions, regular evaluation with renal sonography, urodynamics, urine culture, and serum chemistry needs to be performed. Pediatric urological care needs to be coordinated with pediatric nephrologists. Many boys with posterior urethral valves have severe polyuria, resulting in chronic bladder overdistension, which is termed as valve bladder. In addition to behavioral modification during the day, such patients may benefit from overnight continuous bladder drainage, which has been shown to reduce hydronephrosis and stabilize or improve renal function in most cases. In children with a neuropathic bladder, detrusor-sphincter-dyssynergia is the most likely cause for upper tract deterioration due to secondary vesicoureteral reflux, hydronephrosis, and recurrent urinary tract infection (UTI). Pharmacologic bladder management and frequent intermittent catheterization are necessary. In some cases, augmentation cystoplasty is recommended; however, this procedure has many long-term risks, including UTI, metabolic acidosis, bladder calculi, spontaneous perforation, and malignancy. Nearly half of children with prune belly syndrome require renal replacement therapy. Hinman syndrome is a rare condition with severe detrusor-sphincter discoordination that results in urinary incontinence, encopresis, poor bladder emptying, and UTI, often resulting in renal impairment. Children undergoing evaluation for renal transplantation need a thorough evaluation of the lower urinary tract, mostly including a voiding cystourethrogram and urodynamic studies.

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.

Clinical and radiological characteristics of Nigerian boys with posterior urethral valves

Posterior urethral valve (PUV) obstruction is the most common cause of bladder outlet obstruction in boys. Currently, the diagnosis of PUV is commonly made prenatally. In our environment, however, prenatal diagnosis is rare and the diagnosis is usually made postnatally from the clinical and radiological features. This study therefore examines the clinical and radiological spectrum of boys with PUV in our environment. We examined the clinical presentations, ultrasonographic and the micturating cystourethrographic (MCUG) features of boys with PUV in our institution over a 22-month period from June 2006. There were 28 patients with PUV over this period. The age at presentation ranged from 11 days to 11 years (mean age = 2.7 years). Although prenatal ultrasound scan was done in 23 (82.1%) patients, no prenatal diagnosis was made in any of the patients. The diagnosis was made after infancy in 16 (57.1%) patients. Recurrent urinary tract infection (UTI) was the most common mode of presentation occurring in 14 (50.0%) patients with 7 (50.0%) of the patients with UTI presenting with septicaemia. Voiding dysfunctions, which occurred in all the patients, were the primary mode of presentation in 12 (42.9%) patients. Three (10.7%) patients presented with renal insufficiency, which was significantly associated with the age at presentation (P = 0.026). Ultrasound scan done in the postnatal period strongly suggested the diagnosis of posterior urethral valves in 22 (78.6%) patients in whom the posterior urethra was found to be dilated, associated with thick-walled urinary bladder and bilateral hydronephrosis. Trabeculations of the bladder was a constant feature on MCUG. Other features on MCUG included dilatation of the posterior urethra in 26 (92.8%), bladder diverticuli in 15 (53.6%) and unilateral and bilateral vesicoureteric reflux in 3 (10.7%) and 1 (3.6%) patient(s), respectively. The diagnosis of PUV obstruction which is often made late in our environment, is mainly by clinical, sonographic and MCUG features in the postnatal period. A majority of patients present late, with recurrent UTI.

Congenital urinary tract obstruction

Congenital urinary tract obstruction is a heterogenous condition with a varying natural history. Accurate diagnosis within the late-first and second trimesters allows for counselling of the parents and planning of multi-disciplinary care for the pregnancy and newborn. Antenatal investigations to predict postnatal renal function are of varying accuracy. However, some factors have been shown to be predictive of poor outcome in terms of renal function at birth and infancy. There is the possibility of in-utero intervention in these fetuses.

Fetal lower urinary tract obstruction

Fetal lower urinary tract obstruction affects 2.2 per 10,000 births. It is a consequence of a range of pathological processes, most commonly posterior urethral valves (64%) or urethral atresia (39%). It is a condition of high mortality and morbidity associated with progressive renal dysfunction and oligohydramnios, and hence fetal pulmonary hypoplasia. Accurate detection is possible via ultrasound, but the underlying pathology is often unknown. In future, magnetic resonance imaging (MRI) may be increasingly used alongside ultrasound in the diagnosis and assessment of fetuses with lower urinary tract obstruction. Fetal urine analysis may provide improvements in prenatal determination of renal prognosis, but the optimum criteria to be used remain unclear. It is now possible to decompress the obstruction in utero via percutaneous vesico-amniotic shunting or cystoscopic techniques. In appropriately selected fetuses intervention may improve perinatal survival, but long-term renal morbidity amongst survivors remains problematic.

Urodynamic investigation of valve bladder syndrome in children

OBJECTIVE

To investigate urodynamic manifestations and their relationship with the postoperative experience of children with valve bladder syndrome (VBS).

METHODS

Included were 16 children (mean age 3.2+/-1.8 years) with VBS, who were divided into two groups. The urodynamic study was performed less than 1 year in group 1 (seven boys, aged 1-1.9 years) and more than 1 year in group 2 (nine boys, aged 2.9-6.5 years) after urethral valve fulguration; at the time of operation patients were less than 2 years old. Standards of the International Children's Continence Society were respected, and results were compared between the two groups.

RESULTS

Compared to group 1, group 2 showed a significant decrease in maximum detrusor voiding pressure (Pdet.void.max) and bladder compliance (BC), and an increase in post-voiding residual (PVR) and maximum bladder capacity (MBC) (p<0.05), but the difference in detrusor instability was not significant (p>0.05), Pdet.void.max and PVR were 56.2+/-14.1 cmH(2)O and 96.6+/-52.4 ml, respectively, in group 2, and there were more intermittent detrusor contractions during voiding in this group.

CONCLUSION

Patients with VBS frequently present with multiple bladder dysfunctions that can be diagnosed accurately using urodynamics. Even after urethral valve fulguration Pdet.void.max and BC were inclined to decrease, while PVR and MBC increased with the growth of the children.

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.

Significance of age-specific creatinine levels at presentation in posterior urethral valve patients

OBJECTIVE

Determination of prognostic factors is of great importance in decision making on therapies and informing parents about the probable outcome of disease. The present study aims to evaluate and assess the prognostic factors in posterior urethral valve (PUV) patients.

MATERIALS AND METHODS

The data of 68 patients treated between 1996 and 2004 were evaluated retrospectively. The mean age at diagnosis was 36.4 months. The serum creatinine levels were standardized using the age-specific creatinine reference (ASCR) levels. The age at diagnosis, clinical presentation, initial serum creatinine, method of treatment, presence of vesicoureteral reflux (VUR) and hydroureteronephrosis (HUN), all of which may effect the prognosis, were evaluated.

RESULTS

The analysis revealed that, of the 36 patients whose initial serum creatinine levels were within ASCR, only one (2.8%) had a final serum creatinine higher than ASCR values. In contrast, of the 32 patients whose initial serum creatinine levels were not within ASCR, 19 (59.4%) had final serum creatinine levels higher than ASCR (P<0.001). The distribution of final serum creatinine according to treatment method, presence of UTI before treatment and age at diagnosis was not statistically significant; however, the difference in distribution for initial serum creatinine (P<0.001), mode of clinical presentation (0.016), presence of HUN (0.019) and state of VUR (0.037) before treatment was statistically significant.

CONCLUSION

Final outcome with regard to renal function in PUV patients is affected by bilateral VUR and most significantly by serum creatinine levels higher than ASCR.

Management of the valve–bladder syndrome and congenital bladder obstruction: the role of nocturnal bladder drainage

Valve-bladder syndrome often develops after the resolution of posterior urethral valves, but is also found after the resolution of congenital bladder obstruction. The features of this syndrome include the persistent dilation of the upper urinary tracts, a thick-walled, noncompliant urinary bladder, urinary incontinence, and polyuria secondary to nephrogenic diabetes insipidus. Nocturnal bladder management, which involves timed emptying of the bladder or continuous drainage, has been recommended in conjunction with diurnal timed voiding therapy as an adjunct to the treatment of valve-bladder syndrome. This treatment is derived from the hypothesis that valve-bladder syndrome is caused by congenital obstruction, and that the resultant changes in detrusor muscle are associated with a persistent bladder dysfunction characterized by chronic overdistention of the urinary bladder. Such overdistention is exacerbated by polyuria, and can be a cause of secondary hydronephrosis. Bladder dysfunction and overdistention is usually treated during waking time, but occasionally this is not effective on its own, and nocturnal therapy is used as well. To date, there are a few sets of data that suggest overnight bladder drainage can bring about profound improvements in the degree of upper-tract hydronephrosis, renal function, or bladder function. Nocturnal bladder drainage seems, in these initial reports, to be a simple and safe therapeutic maneuver. This review discusses the etiology of valve-bladder syndrome and examines each of the studies which have investigated nocturnal bladder drainage in its treatment.

Urinary retention, erectile dysfunction and penile anaesthesia after circumcision: a mixed dissociative (conversion) disorder

We report on the long-term followup of a mixed dissociative (conversion) disorder after circumcision in childhood.

[Urodynamic investigations in children]

Performing urodynamic investigations in children presents some difficulty due to the lack of any normogram, and due to the results that vary with age. Such investigation is therefore carried out only when clinical examination and radiological assessment fail to explain a voiding dysfunction. The procedure should be performed in a urodynamic unit that has paediatric expertise. A specific paediatric procedure is to be respected when performing uroflowmetry and cystometry in children. Assessing the urethral pressure profile is very difficult since moving a catheter along the urethra causes a reflex activity of the pelvic floor muscles. Main indications are: neuropathic bladders, voiding dysfunctions, urinary infections, anorectal malformations and pelvic tumours. As in adults, urodynamic investigations are useful when selecting a therapeutic strategy.

PEDIATRIC UROLOGICAL CAUSES OF HYPERTENSION

PURPOSE

We reviewed the association of hypertension with several common pediatric urological conditions.

MATERIALS AND METHODS

We comprehensively reviewed the published literature linking hypertension with urinary tract infection, renal scarring, vesicoureteral reflux, multicystic dysplastic kidney, ureteropelvic junction obstruction and posterior urethral valves.

RESULTS

Hypertension is a recognized sequela of several common pediatric urological conditions. It is thought to be a direct consequence of renal damage or scarring often resulting from vesicoureteral reflux and/or febrile urinary tract infection. Multicystic dysplastic kidney has rarely been shown to cause hypertension when examined in large series rather than as isolated case reports. Ureteropelvic junction obstruction and posterior urethral valves have been linked to hypertension, although to our knowledge no series to date has specifically examined this relationship and smaller retrospective reviews seldom describe associated hypertension.

CONCLUSIONS

Several pediatric urological conditions are known to cause hypertension. However, methodological flaws in the literature, including a lack of standardized blood pressure followup, highly variable patient populations and poor control of concomitant urological abnormalities, greatly limit the ability to establish a causative link between any 1 specific condition and hypertension. Early diagnosis, the prevention of infection, close clinical followup and early intervention remain the primary means of preventing pediatric urological causes of hypertension.

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.

Outcome of valve ablation in late-presenting posterior urethral valves

OBJECTIVE

To explore the symptoms, radiological findings and outcome after valve ablation in patients who present late with posterior urethral valves (PUV) and who typically have mild forms of the disease with often minimal upper tract changes; these patients frequently escape detection by ultrasonography in utero and the diagnosis may be delayed to as late as adolescence.

PATIENTS AND METHODS

The charts of 70 boys (mean age 7.46 years, range 2-14) diagnosed late with PUV and treated with value ablation were retrospectively reviewed. Before ablation, history of voiding habits, voiding frequency, presence of enuresis, dysuria and the incidence of gross haematuria was recorded. Findings of a physical examination, laboratory testing (urine analysis and serum creatinine levels), ultrasonography and voiding cysto-urethrography (VCUG) were noted. After valve ablation, a review included a detailed voiding history and re-examination of abnormal variables including an assessment of enuresis, voiding frequency and ultrasonography. The mean (range) follow-up was 25 (1-78) months. One patient was lost after his first follow-up visit, but data were included to that time.

RESULTS

The most common presenting symptom was voiding dysfunction; 47 (67%) presented with nocturnal enuresis, 42 (60%) with urinary frequency and 12 (17%) with a history of urinary tract infection. On physical examination 12 (17%) had mild age-corrected hypertension. Microhaematuria was present in 21 (30%) but all patients had normal serum creatinine levels. Ultrasonography showed hydronephrosis in 33 (47%) and a postvoid residual volume in 57 (81%). On VCUG, 52 (79%) patients had clear evidence of PUV, 22 (31%) bladder trabeculation, 11 (16%) vesico-ureteric reflux and eight (11%) diverticula. On cystoscopy, 67 (96%) patients presented with the classic sail-shaped PUV and three a ring-shaped valve. After surgical ablation of the valve most patients dramatically improved; 31 of 42 (74%) had resolution of urinary frequency, 24 of 33 (73%) of diurnal enuresis and 17 of 47 (38%) nocturnal enuresis. Of 57 patients, 39 (68%) established good bladder emptying. Of 33 affected, 20 (60%) had some reduction of hydronephrosis but 63% continued to have some symptoms of voiding dysfunction.

CONCLUSION

PUV should be considered in boys presenting with voiding dysfunction. After valve ablation most patients improve dramatically. Despite surgery, enuresis, urinary frequency and poor bladder emptying persisted in some and required further treatment. The continued bladder dysfunction suggested that irreversible urinary tract damage may have occurred. Even in this apparently mildly affected group, long-term follow-up is essential.

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.

LONG-TERM BLADDER DYSFUNCTION AND RENAL FUNCTION IN BOYS WITH POSTERIOR URETHRAL VALVES BASED ON URODYNAMIC FINDINGS

PURPOSE

Posterior urethral valves are the most common cause of congenital obstructive uropathy leading to renal failure in childhood. We investigate the influence of bladder dysfunction on renal function impairment.

MATERIALS AND METHODS

We retrospectively reviewed the records of 116 patients with posterior urethral valves. After valve ablation urodynamic studies were performed in all patients. The presence of vesicoureteral reflux (VUR), renal dysplasia, serum creatinine during followup as well as urodynamic abnormalities were recorded. Mean followup was 10.3 years after valve ablation.

RESULTS

All patients underwent endoscopic valve ablation and urinary diversion was performed in 32. Renal dysplasia was found in 9 patients. Renal function impairment at the end of followup was present in 35 patients. Urodynamic studies showed poor compliance in 30 boys, detrusor overactivity in 44, and poor compliance and detrusor overactivity in 17. Bilateral VUR was found in 17 boys at the time of diagnosis. Urodynamic studies were normal in 23 (20%) patients, of whom 4 had renal failure. Univariate analysis showed that poor compliance and detrusor overactivity had a significant correlation to renal function impairment in addition to bilateral VUR and renal dysplasia. In a multivariate analysis bilateral VUR was an independent prognostic factor for poor prognosis.

CONCLUSIONS

Bladder dysfunction may contribute to renal function impairment eventually but normal urodynamic findings do not preclude renal deterioration. It is likely that loss of compliance and detrusor overactivity would actually result in a valve bladder reaching its end point function.

Vesicoureteral Reflux in Patients With Posterior Urethral Valves

PURPOSE

We reviewed our experience with posterior urethral valves to analyze the influence of reflux.

MATERIALS AND METHODS

We retrospectively analyzed the records of 73 consecutive patients with posterior urethral valves. Of the patients 35 boys had reflux at presentation, which was unilateral in 18 (severe in 17) and bilateral in 17 patients (severe unilateral reflux and low grade contralateral reflux to a better functioning kidney in 5). Followup ranged from 1 to 17 years (mean 5.6).

RESULTS

Reflux resolved after relief of obstruction in 11 of 44 (25%) evaluated renal units but only 5 of 35 (14%) units with high grade reflux. The reflux more often resolved in the bilateral than unilateral group (35% of units versus 11%) and usually did so on the initial study after obstruction relief. Neither the presence, grade, pattern of reflux nor type of initial treatment impacted the outcome in terms of overall renal function. The function of the involved kidney did affect the likelihood of resolution in that unit. Resolution occurred in 10% of refluxing units that provided less than 20% function versus 39% in units with better function.

CONCLUSIONS

Vesicoureteral reflux is common with posterior urethral valves and often persists, particularly to a poorly functioning kidney. Resolution, if it occurs, usually does so early after relief of obstruction. Reflux, no matter what the pattern, has not been a significant prognostic factor for renal function in this series.

Does Treatment With Clean Intermittent Catheterization in Boys With Posterior Urethral Valves Affect Bladder and Renal Function?

PURPOSE

In boys with resected posterior urethral valves (PUV) deterioration of renal function is seen during childhood and adolescence, which may partly be caused by bladder dysfunction. We present data on renal and bladder function initially and at followup of boys with PUV in whom the bladder dysfunction has been treated since infancy.

MATERIALS AND METHODS

The study included 35 boys with PUV. Bladder regimen, including early toilet training from the age of 1.5 years and detrusor relaxant drugs for the treatment of incontinence from ages 4 to 6 years, was introduced to all patients. A total of 19 boys were started on clean intermittent catheterization (CIC) at a median age of 8 months due to pronounced bladder dysfunction with poor emptying, unsafe pressure levels, high grade reflux and renal impairment.

RESULTS

No serious complications of CIC have been seen during followup. Of the 19 boys 2 stopped performing CIC due to noncompliance of the parents at 1 and 3 years, respectively. Initial renal function, measured as median glomerular filtration rate (GFR) in percent of expected for age, was 60% in the CIC group and 90% in the nonCIC group. At followup at a median age of 8 years the CIC group (n = 14, 3 transplanted boys excluded) had an increase in median differential GFR (difference between followup and initial GFR) of 7% (p <0.01), which was similar increase to that of the nonCIC group. In the 2 boys who stopped performing CIC renal function deteriorated with a median differential GFR of -24%. In the CIC group detrusor instability decreased. Poor compliance was seen in 6 of the 19 boys initially and only one remained poorly compliant. In 1 of the boys who stopped performing catheterization a low compliant bladder developed. In all of the other cases bladder capacity increased more than expected for age.

CONCLUSIONS

The results suggest that treatment of bladder dysfunction in boys with PUV can counteract the deterioration in renal function seen during childhood but the number of patients in our study is limited.

Urinary outflow obstruction increases apoptosis and deregulates Bcl-2 and Bax expression in the fetal ovine bladder

During organogenesis, net growth of tissues is determined by a balance between proliferation, hypertrophy, and apoptotic death. Human fetal bladder outflow obstruction is a major cause of end-stage renal failure in children and is associated with complex pathology in the kidney and lower urinary tract. Experimental manipulation of the fetal sheep urinary tract has proved informative in understanding the pathobiology of congenital obstructive uropathy. In this study we used an ovine model of fetal bladder outflow obstruction to examine effects on apoptotic cell death in the developing urinary bladder. While 30 days of obstruction in utero between 75 and 105 days gestation resulted in overall growth of the fetal bladder as assessed by weight, protein, and DNA measurements, we found that apoptosis, as assessed by in situ end-labeling, was up-regulated in fetal bladder detrusor muscle and lamina propria cells and that this was accompanied by a down-regulation of the anti-death protein Bcl-2 and an up-regulation of the pro-death protein Bax. Moreover, activated caspase-3, an effector of apoptotic death, was increased in obstructed bladders. This is the first study to define altered death in an experimental fetal model of bladder dysmorphogenesis. We speculate that enhanced apoptosis in detrusor smooth muscle cells is part of a remodeling response during compensatory hyperplasia and hypertrophy. Conversely, in the lamina propria, an imbalance between death and proliferation leads to a relative depletion of cells.

Detrusor myotomy: a 5-year review in unstable and non-compliant bladders

OBJECTIVE

To identify urodynamic factors that might determine the clinical outcome of detrusor myotomy in incontinent children.

PATIENTS AND METHODS

Six girls and three boys (aged 5-14 years) underwent detrusor myotomy for severe urinary incontinence. Seven children had spina bifida, one had traumatic paraplegia and one had low bladder compliance. The patients were followed for a minimum of 5 years.

RESULTS

Urodynamic studies before surgery showed that three patients had normal compliance with grossly unstable detrusor contractions, and six had low bladder compliance with few phasic detrusor contractions. Detrusor leak-point pressures were > 40 cmH2O in five patients and < 40 cmH2O in four. Only two patients, both with grossly unstable detrusor contractions and leak-point pressures of > 40 cmH2O, had a successful 5-year outcome. The other seven patients remained incontinent; six underwent further surgery and one died from unrelated causes.

CONCLUSION

Detrusor myotomy appears to have the best outcome in those patients with marked phasic unstable detrusor contractions with a competent urethral sphincter. In this group it may have distinct advantages over more commonly used procedures.

The valve bladder syndrome: pathophysiology and treatment with nocturnal bladder emptying

PURPOSE

We determine the etiology and treat the specific pathophysiology of the valve bladder syndrome.

MATERIALS AND METHODS

Defined as persisting or progressive severe hydroureteronephrosis without residual or recurrent obstruction, the valve bladder syndrome developed in 18 boys who underwent successful ablation of the posterior urethral valve. Serial radiographic, renal function, renographic, urodynamic and perfusion studies were performed for a mean time of 11 years.

RESULTS

The cause of the valve bladder syndrome proved to be sustained bladder over distention due to a combination of polyuria with 24-hour urine volume greater than 2 l. in 10 boys, impaired bladder sensation in 18 and residual urine volume in 14. Treatment of over distention during the daytime alone was unsuccessful. Nocturnal bladder emptying was performed with an indwelling nighttime catheter, intermittent nocturnal catheterization and/or frequent nocturnal double voiding. Hydronephrosis markedly improved once nocturnal bladder emptying was started and was comparable to the results after urinary diversion.

CONCLUSIONS

The valve bladder syndrome is not due to a permanent prenatal alteration in bladder anatomy and function. Instead, it appears to result from sustained postnatal bladder over distention due to a combination of polyuria, impaired bladder sensation and residual urine volume, which represent sequelae of prenatal valve injury. These factors synergize to prevent bladder normalization after valve ablation and progressively reduce functional bladder capacity to maintain bladder over distention. Bladder decompensation, upper tract dilation, and renal injury develop and characterize the valve bladder syndrome. Because current therapy, including intermittent catheterization, leaves the bladder full throughout the night, it remains markedly over distended. Nocturnal bladder emptying is the specific antidote for this pathophysiological situation, and results in prompt and impressive improvement or elimination of hydronephrosis in these and similar groups of patients. This response to nocturnal bladder emptying suggests that the bladder is not the primary cause for the valve bladder syndrome.