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

Implementation of a standardized clinical pathway in a dedicated posterior urethral valves clinic: short-term outcomes

BACKGROUND

To determine if the implementation of a posterior urethral valves (PUV) clinic and standardized management pathway improves the short-term kidney outcomes of infants with PUV.

METHODS

From 2016-2022, 50 consecutive patients were divided into groups after the implementation of the clinic (APUV, n = 29) and before (BPUV, n = 21) during a comparable timeframe. Assessed data included age at initial visit, timing and type of surgery, frequency of follow-up visits, medications, nadir creatinine, and development of CKD/kidney failure. Data are shown as median with interquartile range (IQR) and odds ratios (OR) with 95% confidence interval (CI).

RESULTS

APUV had higher rates of prenatal diagnoses (12/29 vs. 1/21; p = 0.0037), earlier initial surgical intervention (8 days; IQR 0, 105 vs. 33 days; IQR 4, 603; p < 0.0001), and higher rates of primary diversions (10/29 vs. 0/21; p = 0.0028). Standardized management led to earlier initiation of alpha blockers (326 days; IQR 6, 860 vs. 991; IQR 149, 1634; p = 0.0019) and anticholinergics (57 days; IQR 3, 860 vs. 1283 days; IQR 477, 1718; p < 0.0001). Nadir creatinine was reached at earlier ages in APUV (105 days; IQR 2, 303 vs. 164 days; IQR 21, 447; p = 0.0192 BPUV). One patient progressed to CKD5 in APUV compared to CKD3, CKD5 and one transplant in BPUV.

CONCLUSION

Implementing the PUV clinic with standardized treatment expedited postnatal management and resulted in a higher number of cases detected prenatally, a shift in primary treatment, younger ages at initial treatment, reduced time to nadir creatinine, and timely initiation of supportive medications. A higher resolution version of the Graphical abstract is available as Supplementary information.

Bladder height width ratio on voiding cystourethrogram as a predictor of future valve bladder in children with posterior urethral valve

BACKGROUND/AIMS

Prompt and early treatment of valve bladder is known to improve renal outcome in patients with PUV. We hypothesized that bladder height width ratio (HWR) measurement on voiding cystourethrogram (VCUG) could predict development of valve bladder.

METHODS

All patients who underwent primary PUV ablation and evaluated later with urodynamics were included. Valve bladder was suspected when there were daytime wetting, persistent hydroureteronephrosis, and elevated detrusor pressures on urodynamics. VCUGs were analysed for HWR: maximum height/width of bladder. ROC curve analysis was performed to identify HWR that could predict development of urodynamic abnormality.

RESULTS

Between 2012 and 2017, 102 patients were studied: median age at valve ablation 25 days (3-125 days); follow-up 5 years (3-7 years). The ROC curve comparing post-ablation HWR with occurrence of valve bladder showed a cut-off of 1.45 (AUC 0.93). HWR cut-off of 1.45 had a sensitivity of 89% and specificity of 84% in predicting future valve bladder. Detrusor overactivity was noticed on urodynamics in 41/55 (74%) of those with HWR > 1.45 compared 5/47 (11%) in those with HWR < 1.45 (p = 0.001).

CONCLUSION

Bladder height width ratio on VCUG is a useful parameter to predict development of future valve bladder in children with PUV.

Paediatric nephrology in under-resourced areas

BACKGROUND

Nearly 50% of the world population and 60% of children aged 0 to 14 years live in low- or lower-middle-income countries. Paediatric nephrology (PN) in these countries is not a priority for allocation of limited health resources. This article explores advancements made and persisting limitations in providing optimal PN services to children in such under-resourced areas (URA).

METHODS

Medline, PubMed and Google Scholar online databases were searched for articles pertaining to PN disease epidemiology, outcome, availability of services and infrastructure in URA. The ISN and IPNA offices were contacted for data, and two online questionnaire surveys of IPNA membership performed. Regional IPNA members were contacted for further detailed information.

RESULTS

There is a scarcity of published data from URA; where available, prevalence of PN diseases, managements and outcomes are often reported to be different from high income regions. Deficiencies in human resources, fluoroscopy, nuclear imaging, immunofluorescence, electron microscopy and genetic studies were identified. Several drugs and maintenance kidney replacement therapy are inaccessible to the majority of patients. Despite these issues, regional efforts with support from international bodies have led to significant advances in PN services and infrastructure in many URA.

CONCLUSIONS

Equitable distribution and affordability of PN services remain major challenges in URA. The drive towards acquisition of regional data, advocacy to local government and non-government agencies and partnership with international support bodies needs to be continued. The aim is to optimise and achieve global parity in PN training, investigations and treatments, initially focusing on preventable and reversible conditions.

Is Vesicostomy Still a Contemporary Method of Managing Posterior Urethral Valves?

In boys with posterior urethral valves (PUVs) the main treatment aim is to preserve long-term bladder and renal function. To determine the effectiveness of secondary vesicostomy in boys with PUVs, the medical records of 21 patients with PUV (2010–2019), divided into two groups (group I: valve ablation; group II: secondary vesicostomy), were reviewed regarding the course of serum creatinine, renal ultrasound, voiding cystourethrogram, urodynamics, postoperative complications, need of further surgery, and long-term solution. The median age of all patients at first follow-up was 11 (9–13) months and at last follow-up 64.5 (39.5–102.5) months. Despite a significant difference of the SWDR score (shape, wall, reflux, and diverticula) (p = 0.014), both groups showed no significant differences preoperatively. Postoperatively, serum creatinine (p = 0.024), grade of vesicoureteral reflux (p = 0.003), side of upper tract dilatation (p = 0.006), side of megaureter (p = 0.004), and SWDR score (p = 0.002) were significantly decreased in group II. Postoperative urodynamic measurements showed comparable results in both groups. Stoma complications were found in three (20%) patients (group II). Eight (53.3%) patients already received a closure of the vesicostomy. Seven out of eight (87.5%) patients were able to micturate spontaneously. Vesicostomy remains a reliable treatment option for boys with PUV to improve bladder function and avoid further damage to the urinary tract.

Does Early Upper Tract Diversion and Delayed Undiversion in Megaureters Secondary to Severe Posterior Urethral Valves Lead to Better Renal Outcomes?

Background

There are conflicting reports for the management of severe posterior urethral valve (PUV) after ablation. The primary objective was to assess the renal outcomes using the estimated glomerular filtration rate (eGFR) and secondary outcomes in severe PUVs who underwent early partially diverting reduction ureterostomy (PDRU) and a delayed undiversion protocol.

Materials and Methods

This 10-year retrospective study reviewed the records of 1094 boys with PUV, where severe PUV cases were treated with early PDRU (324 surgeries). We then analyzed those patients who completed the early diversion and delayed undiversion protocol. The long-term renal outcomes using eGFR and antero-posterior diameter (APD) were compared at various time points using appropriate statistical methods.

Results

Of the 171 severe PUV patients who underwent PDRU, 31 completed undiversion and 26 (47 renal units) were analyzed after exclusions. The mean age (standard deviation) at presentation was 1.46 ± 4.1 months. Thirty-two units were refluxing and 15 were nonrefluxing megaureters. PDRU was closed at a mean age of 3.9 years and had a mean duration of follow-up of 6.4 years. The mean eGFR increased from a minimum of 10.78 ± 10.25 at baseline and remained stable at 28.69 ± 18.89 after closure of both stoma. Similarly, mean APD decreased from 12.07 ± 6.79 at the diagnosis to 7.00 ± 6.20. Three patients (3 renal units) required revision of the stoma for stenosis and 1 patient had a parastomal hernia that was repaired at the time of undiversion.

Conclusions

In severe PUVs, early PDRU with delayed undiversion is a reliable surgical option that may ensure better renal outcomes in the long-term. Nonrefluxing renal units recover better than the refluxing. APD measurements also are shown to improve favorably.

Evaluation of polyuria and polydipsia along with other established prognostic factors in posterior urethral valves for progression to kidney failure: experience from a developing country

BACKGROUND

Up to 50% of children with posterior urethral valves (PUV) progress to kidney failure. This study aimed to evaluate polyuria and polydipsia and other established variables with later development of kidney failure in children with PUV.

METHODS

Retrospective analysis of 297 children with PUV who underwent ablation of valves between January 1992 and January 2015 at our tertiary care center. Patients were divided into two groups: those who developed kidney failure (group 1) and those who did not (group 2). Specific prognostic factors for progression to kidney failure were analyzed including age at presentation < 1 year, nadir serum creatinine > 1.0 mg/dl, bilateral grade 3 or higher VUR at diagnosis, recurrent febrile UTIs, severe bladder dysfunction, polyuria, and polydipsia.

RESULTS

Thirty-eight (12.8%) patients progressed to kidney failure. Twenty-four and 64 patients were polyuric in group 1 and group 2 respectively (p < 0.001, Z-4.4666). Twenty-two and 61 patients were polydipsic in both groups respectively (p < 0.001). On univariate analysis, predicting variables were as follows: age at presentation < 1 year (p < 0.001), nadir serum creatinine > 1 mg/dl (p < 0.001), B/L high-grade VUR (p < 0.001), severe bladder dysfunction (p < 0.001), recurrent febrile UTIs (p = 0.002), polyuria (p < 0.001), and polydipsia (p < 0.001). On multivariate Cox regression analysis, severe bladder dysfunction, recurrent febrile UTIs, polyuria, and polydipsia were identified as significant prognostic factors predictive of ultimate progression to kidney failure.

CONCLUSION

Polyuria and polydipsia along with recurrent febrile UTI and bladder dysfunction are major prognostic factors affecting long-term kidney outcome in cases of PUV. Graphical abstract.

Correlation between the estimated GFR and SWRD score in patients with posterior urethral valves at King Abdul-Aziz University Hospital

Objective

The aim was to establish the reliability of the SWRD score as a predictor of both renal and bladder outcomes in posterior urethral valves. This retrospective study included 67 patients with PUVs at King Abdul-Aziz University Hospital. The score was calculated from voiding cystourethrogram before and after the relief of obstruction, and estimated glomerular filtration rates (eGFRs) were calculated as well.

Results

Based on Spearman correlations, both baseline eGFRs and SWRD scores can be possible predictors of long-term renal outcomes, as a significant positive correlation between the baseline eGFRs and the last eGFRs was found (p = 0.005). A significant negative correlation was also found between the SWRD score calculated before the intervention and the last eGFRs (p = 0.02). Additionally, the baseline SWRD scores can be possible predictors of short-term bladder outcomes, as the correlation analysis showed a positive relationship between the baseline SWRD scores and the SWRD scores calculated within 2 months after the intervention (p < 0.0001). A significant decrease in SWRD scores and eGFRs was found from before to after the intervention, regardless of the type of intervention. In conclusion, the SWRD scoring system proved to be a potentially promising tool in the anticipation of the clinical outcomes of PUVs.