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

Can the posterior:anterior urethral ratio on voiding cystourethrogram be used as a reliable predictor of successful posterior urethral valve ablation in male children?

Background

The role of the voiding cystourethrogram (VCUG) in the follow-up of children with posterior urethral valves (PUVs) post-ablation has been considered a standard practice. The urethral ratio and gradient of change have proven to be useful.

Objectives

We aimed to review the role of the ‘ideal’ ratio on predicting residual PUV post-ablation.

Methods

A systematic review of the PubMed, SCOPUS and Web of Science databases was performed (April 2019). The search terms included ‘Urethral Ratio and Posterior urethral valve ablation’. All cited reference lists were further evaluated for additional inclusive studies.

Results

Eleven studies were identified, of which nine were relevant to the topic. Case reports, comments and adult and animal studies were excluded, leaving four studies for critical review. In total, 338 patients were assessed. The control group consisted of 167 age-matched, male children. Study regions included India and Australia. The ages ranged from 15 days to 3.4 years. Ablation methods included the use of a resectoscope with cutting diathermy, cold knife or Bugbee electrode. The mean urethral ratios in the control group ranged from 1.04 to 1.73. The suggested predictive urethral cut-off ratios recommended include 2.2 (p = 0.001), 2.5–3 and 3.5.

Conclusion

Although the precise cut-off ratio could not be clearly defined in this review, a urethral ratio less than a range of 2.2–3.5 has proven to be a beneficial predictor of ablation success and should thus be incorporated into standard VCUG reporting templates in the follow-up of PUVs in male children in resource-limited settings.

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.

Posterior Urethral Valves in Children: Pattern of Presentation and Outcome of Initial Treatment in Ile-Ife, Nigeria

Background:

The management of posterior urethral valves (PUV) and its sequelae is still a challenge to most pediatric surgeons in our environment due to late presentation and inadequate facilities for long-term evaluation and treatment. Despite initial successful treatment about 40% would develop chronic renal failure. The aim is to describe the presentation, management and outcome of the initial treatment in boys with PUV.

Materials and Methods:

It is a retrospective analysis of PUV in boys 8 years and below over a 17 years period. Demographic characteristics, clinical features, investigations, and treatment outcome were reviewed.

Results:

Thirty-seven cases were analyzed. The median age was 5 months (range from birth to 8 years). Three (8.1%) patients had prenatal ultrasound diagnosis. The most common presentation was voiding dysfunction 37 (100%). Part of the preoperative investigation included micturating cystourethrogram (n = 31: 83.8%) and abdomino-pelvic ultrasonography (n = 37:(100%). The mean serum creatinine value of those who presented within the first 30 days of life and those who presented afterwards were 325 (±251) µmol/L and 141 (±100) µmol/L respectively, P = 0.003. Surgical interventions included trans-vesical excision of valves (n = 9: 28.1%), valvotomy (n = 10: 31.3%), balloon avulsion (n = 8: 25.0%), vesicostomy (n = 4: 12.5%) and endoscopic valve avulsion (n = 1: 3.1%). Seventeen (56.7%) patients had serum creatinine >70.4 µmol/L after 1-month of valve excision. Five (13.5%) patients had postrelief complications and 5 (13.5%) died on admission. Ninety percentage (27/30) of patients had poor prognostic indices.

Conclusions:

The initial treatment outcome was good but most had poor prognostic factors.