URODYNAMIC FINDINGS IN BOYS WITH POSTERIOR URETHRAL VALVES AFTER TREATMENT WITH PRIMARY VALVE ABLATION OR VESICOSTOMY AND DELAYED ABLATION

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.

Primary ablation versus urinary diversion in posterior urethral valve: Systematic review and meta-analysis

PURPOSE

To determine differences in long-term kidney and bladder outcomes in boys with posterior urethral valves (PUV) managed by a primary valve ablation or primary urinary diversion.

MATERIALS AND METHODS

A systematic search was performed in March 2021. Comparative studies were evaluated according to Cochrane collaboration recommendations. Assessed measures included kidney outcomes (chronic kidney disease, end-stage renal disease, kidney function) and bladder outcomes. Odds ratios (OR) and mean difference (MD) with 95% confidence interval (CI) were extrapolated from available data for quantitative synthesis. Random-effects meta-analysis and meta-regression were performed according to study design, and potential covariates were assessed with subgroup analysis. The systematic review was prospectively registered on PROSPERO (CRD42021243967).

RESULTS

Thirty unique studies describing 1547 boys with PUV were included in this synthesis. Overall effect estimates demonstrate that patients undergoing primary diversion have significantly increased odds of developing renal insufficiency [OR 0.60, 95% CI 0.44, 0.80; p < 0.001]. However, when adjusting for baseline kidney function between intervention groups, there was no significant difference in long term kidney outcomes [p = 0.09, 0.35], or the development of bladder dysfunction or requiring clean-intermittent catheterization with primary ablation rather than diversion [OR 0.89, 95% CI 0.49, 1.59; p = 0.68].

CONCLUSIONS

Current low-quality evidence suggests that medium-term kidney outcomes in children are similar between primary ablation and primary diversion after adjusting for baseline kidney function, while bladder outcomes are highly heterogenous. Further research with covariate control is warranted to investigate sources of heterogeneity.

LEVEL OF EVIDENCE

Level III.

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.

Are pressure pop-offs beneficial to the bladder in boys with posterior urethral valves?

BACKGROUND

Pressure pop-offs, such as high-grade vesicoureteral reflux with renal dysplasia, have historically been considered beneficial for renal and bladder outcomes in boys with posterior urethral valves (PUV). Recent longer-term studies have called into question the beneficial effects of pop-offs on renal function.

OBJECTIVE

To evaluate how pop-offs affect bladder outcomes in boys with PUV.

STUDY DESIGN

At a single-center, the electronic medical records of boys with PUV who underwent valve ablation from 2000 to 2014 were retrospectively reviewed for bladder and continence outcomes. Patients were excluded due to presentation after one year of age, age at last follow-up <1 year, lack of urodynamic study (UDS), lack of voiding cystourethrogram, or concomitant prune belly syndrome. Between patients with and without pop-offs, the following outcomes were compared: prevalence of significant hydronephrosis (Society for Fetal Urology grade 3 or 4) prior to valve ablation and at last follow-up, nadir creatinine level, classification of initial UDS, type of medical and/or surgical interventions, dryness during the day and toilet-training status at last follow-up (among patients ≥4 years), and age at toilet-training. For patients with multiple UDS, initial and latest UDS were compared.

RESULTS

48 patients met inclusion criteria, of whom 31 (65%) had pop-offs and 17 (35%) did not. Median age at last follow-up was 5.9 years (range: 1.0-12.2 years). Patients with pop-offs were more likely to have unsafe initial UDS (26% vs. 12%, p = 0.15) but less likely to have high voiding pressures at their latest UDS (15% vs. 50%, p = 0.03). Patients with pop-offs were more likely to have used clean intermittent catheterization (26% vs. 0%, p = 0.04) and were less likely to be toilet-trained by age 4 (76% vs. 100%, p = 0.15) or dry during the day at last follow-up (56% vs. 92%, p = 0.06). Toilet-trained patients with pop-offs were toilet-trained by an earlier age than patients without pop-offs (3 vs 4 years, p = 0.04).

DISCUSSION

The results of the present retrospective study show that patients with pop-offs required more extensive interventions to achieve continence, and achieved continence and toilet-training less frequently than patients without pop-offs. Additionally, our results demonstrated that patients with pop-offs had worse bladder dynamics initially, which may suggest that pop-offs are a manifestation of more excessive pressure build-up prior to valve ablation.

CONCLUSIONS

Among boys with posterior urethral valves who present in the first year of life, pop-offs do not appear to impart significant benefit to bladder outcomes and may indicate more severe bladder dysfunction.

Bladder contractility index in posterior urethral valve: A new marker for early prediction of progression to renal failure

INTRODUCTION

Posterior urethral valve (PUV) is the most common cause of pediatric end stage renal disease (ESRD), imposing a major health burden on medical community caregivers and adversely affecting the quality of life of patients. Chronic kidney disease (CKD) stage III or estimated GFR of <60 mL/min/1.73 m² is known to be associated with more adverse renal, cardiovascular, and clinical outcomes. Thus, it is desirable to identify factors predicting the rapid and early progression of disease. In the present study, baseline characteristics and urodynamic study (UDS) parameters of boys with PUV are correlated with CKD progression to IIIB or more.

AIMS AND OBJECTIVES

To study the correlation of bladder contractility index (BCI) with development of CKD stage IIIB (eGFR of <45 mL/min/1.73 m²) or more in boys with PUV.

METHODOLOGY

Baseline characteristics and demographical variables of 270 boys with PUV who underwent valve fulguration at the hospital between 2000 and 2010 were recorded and certain UDS parameters in follow-up were noted such as bladder contractility index (BCI = PdetQmax + 5 Qmax), end filling pressure (EFP), compliance (ΔC), bladder outlet obstruction index (BOOI = Pdet Qmax - 2 Qmax), and bladder volume efficiency (BVE = Voided volume/total capacity). Fate of patients in follow-up was checked in December 2015.

RESULTS

Mean follow-up period was 8.5 years (range 5-15) and median age of patients at the time of evaluation was 5.8 years. At the end of the study, 21.8% (59/270) of patients had progressed to CKD stage IIIB or more (primary end point). Cox regression analysis was applied to risk factors predicting development of CKD stage IIIB. In the multivariate model, bladder contractility index (BCI) (HR 0.8; p = 0.004), end filling pressure (EFP) (HR 2.1; p = 0.010), and compliance (ΔC) (p = 0.020) were significantly associated with the event (i.e. an eGFR of <45 mL/min/1.73 m²), whereas BOOI (p = 0.053) and bladder BVE (p = 0.267) were not. ROC cut-off level for BCI predicting the primary end point was 75 (AUC ± SE, 0.73 ± 0.03, sensitivity of 78.2%, and specificity of 62.5%).

CONCLUSION

In a well performed UDS, BCI may be a useful tool for early detection of boys with PUV who are likely to progress to CKD stage IIIB or more.

Efficacy of bladder neck incision on urodynamic abnormalities in patients with posterior urethral valves

PURPOSE

This study aims to study the efficacy of simultaneous endoscopic bladder neck incision (BNI) and primary endoscopic valve incision (PEVI) in patients with posterior urethral valves (PUV).

MATERIALS AND METHODS

Nine PUV patients underwent PEVI and BNI over a year. They were compared to nine comparable historical controls that had undergone only PEVI. Trends in renal function tests, urodynamics and changes in the upper urinary tracts were evaluated after 3 months during which no pharmacotherapy was given.

RESULTS

The incidence of bladder dysfunction in the two groups was similar-55.5 % in case group and 66.6 % in control group. Hypocompliant, high-pressure bladder was the predominant cystometric finding in both groups. Three patients in the case group and two patients in the control group had high end infusion pressure (EIP) with poor compliance. Detrusor overactivity (DOA) was seen in 23.1 % patients in the case group as compared to 55.5 % patients in the control group (P = 0.3348). Five patients in both groups were later started on anticholinergics due to raised EIP, small capacity bladder and/or DOA.

CONCLUSION

Although BNI should theoretically improve the outcome of PUV patients, the current pilot study failed to demonstrate any significant difference. A larger sample size and longer follow-up are required to prove or disprove its efficacy.

Urodynamic testing in children: indications, technique, interpretation and significance

PURPOSE

Urodynamic studies in children have been performed with increasing frequency as the techniques, reproducibility and reliability of the testing have been refined in the last quarter century. Children of all ages and with a variety of comorbidities are now often referred for urodynamic testing to evaluate and understand the causes of incontinence and/or persistence of lower urinary tract symptoms, as well as to appropriately define and evaluate treatment regimens.

MATERIALS AND METHODS

We performed a MEDLINE® search for relevant articles on urinary tract dysfunction, neurogenic bladder and urodynamic studies in the pediatric population. We also included 3 major textbooks that addressed the subject matter.

RESULTS

We review the current indications for urodynamic studies in children with nonneurogenic and neurogenic bladder dysfunction. We summarize the components and techniques of the current practice of urodynamic studies in the pediatric population, and explain how to identify abnormal results.

CONCLUSIONS

The use of urodynamic studies in pediatrics has become almost mandatory for the effective management of severe or therapy resistant urinary tract abnormalities. This review may be used as a guideline for the appropriate application of urodynamics in this patient population.

[Botulinum toxin in the failure of high urinary diversion closure]

INTRODUCTION

The closure of urinary diversions performed on newly born infants has a notable failure percentage in patients with bladder disease. We present the use of botulinum toxin as a useful and minimally invasive alternative to treat these patients.

MATERIAL AND METHODS

We present two patients with a single kidney and with posterior urethral valves (PUV), in whom it was necessary to perform a ureterostomy due to chronic kidney disease. In both patients, the subsequent attempt to close the diversion failed. Aged 4 and 10 years respectively, they presented bladders commonly known as "dry bladders", with a low capacity (20 and 110 ml), bad adaptation (1.5 and 3.1 ml/ cm H(2)O) and high opening detrusor pressure. A 10 UI/Kg botulinum toxin A puncture was applied in the detrusor on one and two occasions respectively, prior to the closure of the diversion.

RESULTS

Neither of the patients suffered clinical or ecographic worsening after the closure of the diversion and their kidney function continued without change with respect to the first diversion after one and four years of follow-up respectively. One year after the surgical procedure, video urodynamics showed a significant improvement in bladder capacity (451 and 250 ml), in adaptation (20.4 and 81.9 ml/ cmH(2)O) and in the opening detrusor pressure.

CONCLUSIONS

The closure of high urinary diversions has a high failure percentage in infants with pathological high-pressure bladders. Botulinum toxin may be useful as bladder treatment prior to closure of the diversion, especially in patients with a single kidney.

Primary ablation of posterior urethral valves in low birth weight neonates by a visually guided fogarty embolectomy catheter

PURPOSE

In low birth weight neonates primary ablation of posterior urethral valves represents a particular difficulty. The tiny caliber of the urethra presents a challenge for even the smallest commercially available pediatric resectoscope. Transurethral ablation by wired electrodes is difficult due to the narrow field of neonatal scopes with slow irrigation and restricted maneuverability. A Fogarty embolectomy catheter under fluoroscopic control does not allow direct visual assessment, and can be a lengthy procedure with numerous manipulations at the radiology suite. We describe a hybrid technique for primary valve ablation in neonates using a Fogarty catheter working retrograde under direct visual guidance of a neonatal cystoscope.

MATERIALS AND METHODS

A total of 17 low birth weight newborns (median 2,100 gm, range 1,760 to 2,690) underwent primary valve ablation using a 2Fr Fogarty catheter working through a 7.5Fr neonatal cystoscope with an offset lens. Both components were withdrawn as a single unit to avulse the valve leaflets under vision. Vesicoureteral reflux was present in 13 patients (76%) involving 24 renal units. A voiding cystourethrogram was performed 8 to 10 weeks postoperatively to delineate adequate decompression of the posterior urethra and mark the end point of the study in evaluating the efficiency of the technique.

RESULTS

There were no immediate perioperative complications. Three patients died of causes unrelated to the procedure, leaving 14 boys (21 refluxing units) for evaluation. Voiding cystourethrogram revealed effective decompression of the posterior urethra with adequate drainage in all but 1 remaining patient (93%) due to a persistent left leaflet. Of 21 refluxing units reflux resolved in 6 (29%), was downgraded in 10 (48%) and remained unchanged in 5 (24%).

CONCLUSIONS

In low birth weight neonates primary valve ablation by a visually guided Fogarty catheter ensures effective disruption of the valvular obstructive mechanism. The technique maintains the transurethral visual standard and avoids the difficult manipulation of wired electrodes in a restricted field. It is devoid of radiation exposure and its simplicity enables safe performance at the neonatal intensive care unit, where the support needs of this fragile subset of patients are optimally provided for.

The Effects of Bladder Neck Incision on Urodynamic Abnormalities of Children With Posterior Urethral Valves

PURPOSE

We evaluated the effects of simultaneous bladder neck incision and valve ablation on urodynamic abnormalities in patients with posterior urethral valves.

MATERIALS AND METHODS

A total of 46 patients with posterior urethral valves entered our prospective study between 1998 and 2003. Group 1 consisted of 22 patients who underwent simultaneous valve ablation and bladder neck incision at the 6 o'clock position. Group 2 consisted of 24 age matched patients with comparable prognostic factors who underwent simple valve ablation. Trends in renal function tests, urodynamics and changes in the upper urinary tracts were evaluated throughout followup.

RESULTS

Mean patient age at presentation was 1.6 years in group 1 and 1.8 years in group 2. Preoperatively, all patients in both groups had hypercontractile bladders and comparable high maximum voiding detrusor pressures. At the end of followup (mean 4.5 years) no patient in group 1 had bladder hypercontractility or detrusor overactivity, and the mean maximum voiding detrusor pressure was 53 +/- 15 cm H(2)O. In comparison, 9 patients in group 2 had bladder hypercontractility, 6 had detrusor overactivity and the mean maximum voiding detrusor pressure was 87 +/- 45 cm H(2)O (p <0.01). Myogenic bladder failure developed in 5 patients in group 2. The number of patients requiring anticholinergic medication and the duration of treatment were also significantly higher in group 2 compared to group 1.

CONCLUSIONS

Valve ablation with bladder neck incision may result in better bladder urodynamic function in comparison to simple valve ablation. However, long-term studies with followup through puberty are required to evaluate the final effects on renal function.

[Vesicostomy in children. Our experience with 43 patients]

INTRODUCTION AND OBJECTIVES

Cutaneous vesicostomy (CV) is a choice temporary urinary diversion technique for patients with upper urinary tract (URT) dilation, secondary to vesical o infravesical disease. The objective of this study is to share our experience in children undergoing such diversion, analysing its efficacy to prevent urinary infections, improve or resolve the ureterectasia, and stabilise or improve renal function; in short the functional and morphological recovery of URT.

MATERIAL AND METHODS

43 children, mean age 2.5 years (range: 1 month-14 years) with ureterohydronephrosis grade IV-V, persistent urinary infection and/or renal function impairment underwent cutaneous vesicostomy (Blocksom's technique in 36 and Lapides' procedure in the rest). Thirty subjects had neuropathic bladder (26 with secondary vesicoureteral reflux), 7 massive primary vesicoureteral reflux, and 6 posterior urethral valve.

RESULTS

All children (100%) with neurogenic bladder (30 cases), showed improvement of ureteral-pyelic-calyceal ectasia after the diversion, and 90% improved renal function with disappearance of vesiculoureteral reflux in 65%. Augmentation cystoplasty with gut was performed in 12 patients during vesicostomy closure, using Mitrofanoff's type diversion in 5 of them. The same continent diversion with cecal appendix was used in another 7 children as the only procedure. The remaining 11 children still retain their vesicostomy. In 5 of the 7 children with primary vesicoureteral reflux, the reflux disappeared and so the vesicostomy was closed. Reflux correction during the same surgical procedure was required for the other 2 children. Of the 6 children with posterior urethral valves, 2 received a renal transplant, one is in waiting list and the rest (50%) maintain an acceptable renal function. In the first year of follow-up, 4 patients developed symptomatic urinary infection that later disappeared. The rest had occasional asymptomatic bacteriuria that required no treatment. Complications included vesical prolapse due to ostomy in 4 patients, lithiasis in 3 and stomal stenosis in 2.

CONCLUSIONS

We consider vesicostomy to be the choice urinary diversion technique in cases of common section obstruction and/or non-obstructive ureterohydronephrosis in new-borns who do not improve with conservative treatment.