Posterior urethral valves: does young age at diagnosis correlate with poor renal function?

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.

Short-Term Outcomes of Treatment of Boys with Posterior Urethral Valves

Background:

Posterior urethral valve (PUV) is a significant cause of morbidity and mortality among male children resulting in renal failure in 25%–30% before adolescence irrespective of initial treatment. This study aimed at evaluating the early outcomes of children managed for PUV.

Materials and Methods:

This was a prospective study of all children who were treated for PUV between 2012 and 2016 at a single referral institution. Information reviewed included demographic and clinical data, imaging findings, pre- and post-operative serum electrolytes, and postoperative renal outcomes.

Results:

Twenty-nine male children were managed for PUV at a median age of 6 months including 7 (24.1%) neonates. Two (6.9%) patients had antenatal diagnosis. Micturating cystourethrogram confirmed PUV in all patients. Fourteen (48.3%) patients had impaired renal function (IRF) at presentation and 8 (57%) had improved renal function (RF) after initial catheter drainage. The mean creatinine at presentation was 1.86 ± 1.69 mg/dl and the mean serum creatinine following initial catheter drainage was 0. 93 ± 0.49 mg/dl (P = 0.003). For those patients with normal RF, the mean creatinine at presentation was 0.81 ± 0.22 mg/dl versus 0.74 ± 0.21 mg/dl (P = 0.012), following initial catheter drainage. Children with IRF on admission had mean creatinine at presentation of 2.61 ± 2.00 mg/dl compared to 1.17 ± 0.53 mg/dl (P = 0.002) after initial catheter drainage. Valve ablation was achieved with Mohan's valvotome in 26 (96.3%) patients. All patients had good urine stream at a median follow-up of 5 months. Four (13.8%) patients developed IRF at follow-up. Renal outcomes of patients presenting before 1 year and those presenting after 1 year were similar. Two children died preoperative of urosepsis and one out of hospital death given an overall mortality of 10.3% (n = 3).

Conclusion:

There was significant improvement in RF after initial catheter drainage. The incidence of IRF at follow-up was 13.8%. Long-term follow-up is necessary to identify patients at risk of end-stage renal disease.

Outcome of posterior urethral valve in 64 children: a single center's 22-year experience

BACKGROUND

Posterior urethral valve (PUV) is the most serious form of congenital anomalies of kidney and urinary tract (CAKUT) in boys with significant risk of progression to chronic kidney disease (CKD). We present our long-term results in children with PUV.

METHODS

Retrospective chart review of 113 children with PUV followed within the years of 1996-2018 was performed. Clinical, laboratory and epidemiologic parameters were analyzed for their impact on renal outcome.

RESULTS

The median age of diagnosis was 1.00 month (1.00-132.00) and the median follow-up period was 70 months (60.00-216.00). Antenatal diagnosis was present in 33 patients (51.5%) mainly with bilateral hydronephrosis and oligohydramnios. The most common postnatal presentation was recurrent urinary tract infection (UTI) in 14 cases (21.9%) and incontinence in three cases (4.7%). Vesicoureteral-reflux (VUR) was present in 31 cases (48.4%). All patients had surgery and urinary diversion was needed in 18 (28.2%). Varying stages of chronic kidney disease (CKD) developed in 23 cases (35.9%) and rise in serum creatinine was especially prominent after the 4th year of follow-up. Of 23 CKD patients, seven (10.9%) were in ESRD and on dialysis. Mortality occurred in one (1.5%) patient. Hypertension, proteinuria and high initial serum creatinine (>1.28 mg/dL) were statistically significant risk factors for CKD, as expected. Surprisingly VUR and UTI did not show such a significant impact on CKD development. Antenatal detection was with significantly less risk for CKD.

CONCLUSIONS

Our results confirm that PUV has a considerable risk for CKD development. Antenatal diagnosis, management of proteinuria and hypertension may modify this progression. But already injured kidneys still have a potential risk. The need for further research to evaluate the impact of any intervention on long term renal outcome is obvious.

Predicting and Modifying Risk for Development of Renal Failure in Boys with Posterior Urethral Valves

PURPOSE OF REVIEW

The purpose of this review is to bring the reader up to date on the current risk factors for the development of renal deterioration in the boys with posterior urethral valves (PUV) and approaches to modify this risk.

RECENT FINDINGS

Renal bladder ultrasound (RBUS) is routinely performed in boys with PUV and recent advancements allow imaging processing that can more accurately quantify renal parenchyma and correlate this with risk for renal loss. Refinement of urine studies may improve our ability to stratify patients into renal loss categories. Use of videourodynamics (VUDS) allows refined assessment of the valve bladder to identify those who might benefit from secondary procedures and/or the addition of targeted pharmacotherapy to improve bladder emptying or dangerous storage pressures. All boys with a history of PUV are at a significant long-term risk of renal deterioration. The literature suggests that several technical advances have improved our ability to predict this risk, although there needs to be further refinement and validation before widespread use. Utilization of close follow-up, VUDS, pharmacotherapy, and bladder drainage provide the best methods to improve care to this group of patients and if more studies confirm their utility, adoption of these as part of standard of care protocols may be warranted.

Late diagnosis of posterior urethral valves

CLINICAL PROBLEM

We diagnosed 8 patients with late-stage posterior urethral valves (PUV) between 1 and 14 years of age. Five patients complained of symptoms related to voiding dysfunction. The other 3 patients required urethrocystoscopy for other reasons (hypospadias fistulae, difficulty with catheterisation and high-grade vesicoureteral reflux [VUR]). A second review of the first 2 patients' medical history showed voiding dysfunction symptoms. All patients underwent preoperative ultrasonography: 3 patients had normal results and 5 had renal or vesical disorders. The diagnosis was reached through voiding cystourethrogram (VCUG), and 4 patients underwent urodynamic studies. The diagnosis was confirmed by urethrocystoscopy, performing valve electrofulguration. We performed urethrocystoscopy during the check-ups at 3-6 weeks and observed no stenosis. The symptoms disappeared for all patients after 20 months of follow-up. The patient with VUR was cured. The ultrasounds showed no progression of the renal involvement and showed improvement in the vesical involvement. The velocimetries during check-ups presented curves within normal ranges.

DISCUSSION

Most children with PUV are diagnosed through ultrasound during the neonatal period. Some patients present PUV at later ages with diverse symptoms, which impedes its diagnosis. We should suspect PUV in male patients with symptoms of voiding dysfunction, either when they have normal or pathological results from ultrasounds or VCUG. We recommend performing urethrocystoscopy to rule out urethral obstruction.

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.

Which patients are at higher risk for residual valves after posterior urethral valve ablation?

Purpose

To find patients at high risk of obstructive remnant leaflets after valve ablation among boys with posterior urethral valve (PUV), we evaluated any possible relationship between preoperative findings in our patients and residual obstructive leaflets after valve ablation.

Materials and Methods

We retrospectively reviewed the medical records of 55 patients with PUV that was treated by the same surgeon between 2008 and 2012. Of these, 37 patients (67.3%) had no obstructive remnant leaflets (group A) and 18 patients (32.7%) had obstructive remnant leaflets (group B) in follow-up cystoscopy. Preoperative clinical and radiological findings were evaluated and compared between the groups.

Results

Among all the preoperative data we examined, the analysis revealed that age at the time of surgery (median age: group A, 15 months; group B, 7 months; p=0.017), echogenicity of kidneys (p<0.05), presence of vesicoureteral reflux (p<0.05), and grade of reflux (p<0.05) were significantly different between the groups. Method of valve ablation, anterior-posterior diameters of the renal pelvis, renal cortical thickness, bladder wall thickening, and scarring on the dimercaptosuccinic acid scan showed no significant differences between the two groups.

Conclusions

In our patients, younger age at surgery time, hyperechogenicity of renal parenchyma, presence of vesicoureteral reflux, and grade 4 or 5 reflux before surgery had a significant relationship with residual valves. More studies may result in enhanced management of patients at high risk of residual valves after PUV ablation, because the sooner the obstruction is resolved entirely, the better the outcome.

[Is there an outcome difference between posterior urethral valves diagnosed prenatally and postnatally at the time of antenatal screening?]

PURPOSE

Posterior urethral valves (PUV) diagnosed during childhood have classically been associated with a better outcome than antenatally diagnosed PUV. The aim of our study was to compare long-term outcome of these two patients' groups.

MATERIAL AND METHODS

We retrospectively reviewed the medical records of boys with PUV managed between 1990 and 2010. Patient demographics, clinical background, radiographic data (including prenatal ultrasonography data when available), renal and bladder functional outcomes, surgical procedures and urinary tract infections (UTI) were abstracted. Impaired renal function (IRF) was defined as glomerular filtration rate less than 90 mL/min/1.73 m(2) at last follow-up.

RESULTS

We identified 69 patients with confirmed PUV. Thirty-eight were diagnosed prenatally (group 1) at 30.5 weeks of gestation and 31 had a delayed diagnosis (group 2) at a median age of 6.31 years. At diagnosis, 20 patients in group 1 had renal insufficiency versus two in group 2 (P<0.05). At the end of mean follow-up of 7.2 ± 0.5 years, in group 1, 26.3% developed IRF versus 6.3% in group 2 (mean follow-up 2.3 years). Mean age at last follow-up was 7.3 years in group 1 versus 8.3 in group 2 (P>0.05). In group 1, 27% had voiding dysfunction versus 30% in group 2 (NS). In group 1, 35% had UTI during follow-up versus 10% (P=0.01).

CONCLUSION

During the follow-up, the patients with delayed diagnosis VUP have developed fewer complications related to the initial obstruction than the population who was detected antenatally and managed from the early hours of life. However, the rate of IRF and voiding disorders in our study, associated with the data of the literature, highlights the potential persistence and worsening of these conditions. That is why, whatever the age at diagnosis, VUP patients require a close monitoring.

Outcome of late presentation of posterior urethral valves in a resource-limited economy: challenges in management

Delayed presentation of patients with posterior urethral valve with complications like severe urosepsis, uremia, and anemia are seen in our setting. Renal replacement therapy which should have been offered to these patients is not readily available for children in our country. The aim of this study is to determine the pattern of late presentation and outcome of management of posterior urethral valve in a resource-limited setting. A descriptive retrospective study (1997–2009) was conducted. Data including pattern of presentation, duration of symptoms, complications, and outcome of initial management were analyzed. Twenty-one patients were seen. The median age was 3 years (2 days–13 years). The mean duration of symptoms before presentation was 2.6 years. Nineteen patients (91%) presented with urosepsis while 8 patients (36%) presented with significant renal insufficiency. Laboratory findings varied from-mild-to marked elevation in serum creatinine. Radiological findings confirmed the diagnosis of posterior urethral valve. We concluded that late presentation is common in our setting. This is associated with high morbidity and mortality rates. Efforts at improving awareness and early diagnosis among the health team should be made to stem the tide.

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.

Risk factors associated with chronic kidney disease in patients with posterior urethral valves without prenatal hydronephrosis

PURPOSE

Postnatal diagnosis of posterior urethral valves continues despite the prevalence of prenatal ultrasound. We identified risk factors associated with chronic kidney disease in these children.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of boys with posterior urethral valves with clinical presentations other than prenatal hydronephrosis. We recorded presenting symptoms, age at presentation, and preoperative hydronephrosis and/or vesicoureteral reflux. Chronic kidney disease was defined as previous renal transplantation, dialysis dependence or glomerular filtration rate less than 60 ml per minute/1.73 m(2) at last followup. We used univariate survival analysis with the log rank test of equality for categorical variables and Cox proportional hazard regression for continuous variables to identify risk factors associated with progression to chronic kidney disease.

RESULTS

We identified 141 boys with posterior urethral valves with a postnatal presentation. Median age at presentation was 46 months (range 0.3 to 174). Febrile urinary tract infection in 28% of patients and voiding complaints in 50% were the most common presentations. A total of 12 patients (9%) progressed to chronic kidney disease up to 23 years after initial presentation. Preoperative bilateral hydronephrosis, increased hydronephrosis severity and bilateral vesicoureteral reflux were associated with progression to chronic kidney disease.

CONCLUSIONS

Approximately 10% of cases with postnatal presentation of posterior urethral valves progress to chronic kidney disease, sometimes decades after the initial presentations. Although all patients with posterior urethral valves should be counseled on the potential loss of renal function, children with risk factors warrant close followup into adulthood.

Risk factors for progression to end-stage renal disease in children with posterior urethral valves

OBJECTIVE

To identify the variables which affect long-term renal outcome in children with posterior urethral valves (PUV).

MATERIALS AND METHODS

Retrospective analysis of 260 children with PUV who underwent ablation of valves in 1992-2008 at our tertiary care center. The following risk factors for progression to end-stage renal disease (ESRD) were analyzed: nadir serum creatinine greater than 1.0mg/dl, bilateral grade 3 or higher VUR at diagnosis, recurrent febrile UTIs, and severe bladder dysfunction. Patients were divided into two groups: those who developed ESRD (group 1) and those who did not (group 2).

RESULTS

Forty (17.62%) patients had nadir serum creatinine >1mg/dl. At time of initial presentation, high-grade VUR was seen in 63.1% and 33.5% of groups 1 and 2, respectively (P=0.002). Overall, 77 (34%) of the boys developed breakthrough urinary tract infections: 37.03% and 33.5% in groups 1 and 2, respectively (P=1). Fifty-nine (26%) patients were found to have severe bladder dysfunction: 77.8% and 19% in groups 1 and 2, respectively (P<0.0001). Twenty-seven (11.89%) patients progressed to ESRD, at mean age of 11.21 years (5-16). On univariate analysis, the risk-predicting variables were: nadir serum creatinine value greater than 1mg/dl (P<0.0001), bilateral high-grade VUR (P=0.002) and severe bladder dysfunction (P<0.0001). On multivariate logistic regression analysis, nadir serum creatinine greater than 1mg/dl (OR 23.79; CI 8.20-69.05) and severe bladder dysfunction (OR 5.67; CI 1.90-16.93) were found to be independent risk factors predictive of ultimate progression to ESRD.

CONCLUSIONS

Nadir serum creatinine and bladder dysfunction are the main factors affecting long-term renal outcome in cases of PUV. Early identification and treatment of bladder dysfunction may thus be beneficial.

Validation of initial serum creatinine as a predictive factor for development of end stage renal disease in posterior urethral valves

OBJECTIVE

The aim of this study was to determine the value of initial serum creatinine in prediction of End-stage renal disease (ESRD) in children with posterior urethral valves PUV.

METHODS

In this retrospective study, patients diagnosed with PUV admitted in Aliasghar Children's Hospital in Tehran, Iran from 1991 through 2001 were studied. Based on the development of ESRD (need for dialysis) they were classified in two groups and their demographics, initial presentations, laboratory data, imaging findings and outcomes were reviewed and compared.

RESULTS

Thirty six male patients with PUV, treated with valve ablation (13), vesicostomy (13), or high ureterostomy (10) were followed for developing ESRD. Sixteen of the 36 patients developed ESRD at their last follow-up. There was no significant difference in age at initial presentation, presence of urinary tract infections, incidence of vesicoureteral reflux, renal dysplasia or type of primary surgical intervention between the patients with or without ESRD. Patients who progressed to ESRD had serum creatinine concentration > 1.0 mg/dl at diagnosis as compared to those without ESRD (P = 0.001).

CONCLUSION

Initial serum creatinine is a valuable factor for prediction of renal outcome in patients with PUV.

Demography of renal disease in childhood

The demography of renal failure in childhood is examined through an analysis of the UK Renal Registry data on patients in established renal failure (ERF) and studies of chronic kidney disease populations. The predominant cause is renal dysplasia and related conditions. Congenital obstructive uropathy is the third largest group overall and the second in early childhood. Males predominate in both these groups. Antenatal diagnoses are frequently not made despite routine scanning. Those children, who present to nephrology after the age of 3 months without an antenatal diagnosis, progress to ERF later than those diagnosed antenatally. Discrepancies exist between the demography of antenatal diagnoses and those seen postnatally. This is likely to represent the limitations of antenatal ultrasound as a diagnostic screening tool.

Does bladder augmentation stabilize serum creatinine in urethral valve disease? A series of 19 cases

OBJECTIVE

This study evaluates the results of bladder augmentation (BA) in 19 boys with posterior urethral valves, especially as regards its efficacy in stabilizing serum creatinine.

PATIENTS AND METHODS

In the period 1995-2005, 188 patients with urethral valves were surgically managed. Nineteen of these had undergone BA as a part of their surgical management after initial endoscopic valve ablation in 15 and diversion in four boys. The mean serum creatinine at the time of BA was 2.11 mg/dl.

RESULTS

BA stabilized the serum creatinine in 14 but failed to do so in five boys. A serum creatinine level of more than 2mg/dl at the time of BA was associated with a significantly worse rate of success. BA as part of an undiversion procedure in three boys was unsuccessful.

CONCLUSION

In an economic milieu where renal transplantation is not available for the majority of deserving children, careful selection is required before BA is considered as a surgical solution for the valve bladder. BA, when otherwise indicated, has been beneficial in children with pre-augmentation creatinine up to 2 mg/dl.