Predicting Renal Outcomes in Children With Anterior Urethral Valves: A Systematic Review

Robot-assisted laparoscopic anterior urethral diverticulectomy

INTRODUCTION AND HYPOTHESIS

A 31-year-old patient with a history of fetal sacrococcygeal teratoma requiring tumor resection and pelvic reconstruction in infancy presented with a 3-year history of recurrent vulvar abscesses and voiding dysfunction. Magnetic resonance imaging demonstrated a fluid collection posterior to the pubic bone and inferior to the bladder. The objective was to demonstrate the key steps in the resection and repair of an anterior urethral diverticulum via robot-assisted laparoscopic approach.

METHODS

Cystoscopy followed by robot-assisted laparoscopic retropubic dissection was used for resection of an anterior urethral diverticulum followed by urethral reconstruction.

RESULTS

Cystoscopy revealed a large anterior cavity at the midpoint of the urethra consistent with an anterior urethral diverticulum. This likely tracked inferiorly toward her vulva during repeated episodes of infection expressing through her recurrent abscesses. Retropubic space exploration revealed dense fibrotic tissue adherent to the underside of the pubic tubercule contiguous with the anterior urethral diverticulum, which was successfully resected.

CONCLUSIONS

Female anterior urethral diverticulum is a rare entity. A robot-assisted laparoscopic approach can be safely utilized to identify and resect an anterior urethral diverticulum. Key points include optimization of port placement, use of a council-tip catheter to facilitate bladder drainage in the setting of distorted pelvic anatomy, and multi-layered tension-free urethral closure with flap placement.

Congenital anterior urethral valves and diverticulum: A case series and association with posterior urethral valves

INTRODUCTION

There is limited data regarding long-term results and associated complications in patients with anterior urethral valve (AUV) and diverticulum (AUD). We retrospectively reviewed AUV/AUD cases managed by us between the year 2002-2020.

MATERIAL AND METHODS

Presentation, investigations, management, concomitant posterior urethral valves (PUV) and pre-operative characteristics predisposing to long-term poor renal outcome were assessed.

RESULTS

There were 27 patients [AUV (n = 11); AUD (n = 16)] with 5 having concomitant PUV. All presented with poor urinary stream and dribbling at a median age of 1-year (5 days-12 years). More patients with AUD (9 of 16, 56.3%) especially with concomitant PUV presented at ≤1-year-age as compared to those with AUV (4 of 11, 36.4%). Concomitant PUV and AUD cases (n = 3) had characteristic micturating cystourethrography (MCUG) features. (Fig. 1A) Retrograde urethrography delineated the valve and distal urethra dimensions better (Fig. 1B, C). Urethral hypoplasia distal to the valve (n = 4) urethral duplication (n = 1) were associated (Fig. 1D). Syringocele was ruled out in proximal AUD by absence of filling defect on MCUG and appearance of urethral walls on urethrocystoscopy. Serum creatinine > 1 mg/dL (n = 5), trabeculated bladder (n = 12), and vesicoureteral reflux (VUR) (n = 12) was noted at presentation. Diverticulum/valve excision (n = 13, 48.2%), fulguration alone (n = 12, 44.4%) and primary urinary diversion (n = 2, 7.4%) were performed. Follow up (range:3 mo-19 years), showed deranged renal function tests (n = 6), VUR (n = 4), impaired renal function on scans (n = 8), and lower urinary tract dysfunction (n = 7). Outcome with and without associated PUV was similar. Long term results were better in AUV compared to AUD. Pre-operative raised serum creatinine (>1 mg/dL), trabeculated bladder, non-dilated posterior urethra on MCUG and bilateral impaired renal function on scans had significant association with follow up eGFR less than 60 ml/kg/min.

CONCLUSIONS

Co-existing PUV and AUD present earlier and have specific imaging findings. In proximal AUD, possibility of syringocele should be kept in mind, as they have similar presentation and imaging. Concomitant PUV did not alter prognosis. Secondary effects on bladder and renal function were more with AUD. Follow up eGFR less than 60 ml/kg/min was associated with pre-operative elevated serum creatinine, trabeculated bladder, non-dilated posterior urethra, and bilateral impaired renal function on scans.

Case Report: Neonatal Urinary Ascites Without Hydronephrosis: A Rare Case of Anterior Urethral Valve and Diverticulum in Preterm Newborn

The deformation of congenital obstruction of the anterior urethra is rare in male infants. The anterior urethral valve (AUV) and diverticulum are not common causes of distal urethral obstruction, which may be significant but difficult to diagnose in time. We describe a premature infant who was diagnosed with AUV as part of a diverticulum in the anterior urethra and was presented as massive urinary ascites without hydroureters and hydronephrosis. After indwelling abdominal tube and urinary catheterization, the infant's massive ascites were resolved, while urethral obstruction had successful treatment by Holmium laser. We suggest that the presence of urinary ascites in fetuses and neonates should be considered as a warning against urinary malformations.

Are anterior urethral valve and anterior urethral diverticulum two separate entities: A radiological and endoscopic review

BACKGROUND

Anterior urethral valve (AUV) and anterior urethral diverticulum (AUD) are two rare causes of anterior urethral obstruction with variable presentation and anatomy. Their existence as the same or different entity is still debatable, and management has not yet been standardized.

OBJECTIVE

This study is a retrospective review of cases diagnosed with anterior urethral obstruction and correlation of radiological and endoscopic anatomy of AUV and AUD.

STUDY DESIGN

A retrospective review of cases diagnosed with AUV and AUD, between May 2013 and February 2020 is presented. The presentation, laboratory, radiological and endoscopic anatomy along with the management required was reviewed. A special emphasis has been given on the correlation of radiological and endoscopic anatomy and an attempt has been made to standardize the management.

RESULTS

A total of 8 patients with age ranging from 2 months to 9 years were reviewed. Poor urinary stream and recurrent UTI was the commonest presentation. The anatomy of the anterior urethra on VCUG (voiding cystourethrogram) and Urethrocystoscopy was correlated. Two sets of patients were identified. In the first set, five cases on endoscopy had findings of the classical valve-like fold in the anterior urethra with immediate proximal dilation of the urethra giving the appearance of a 'pseudodiverticula' without any definite opening. In three of these cases, endoscopic findings correlated well with radiological findings of 'pseudodiverticula' in which dilated proximal urethra formed an obtuse angle with the ventral floor of the urethra. The other set of four patients had a 'true diverticula' on endoscopy with a well-defined mouth and prominent distal lip, correlating well with radiological findings of a 'true diverticula' forming an acute angle with the ventral floor of the urethra. One case on endoscopy had both an anterior urethral valve with a proximal 'pseudodiverticula and a large wide-mouthed bulbar 'true diverticula'. All the patients with classical valves were successfully treated using a resectoscope while two patients with 'true diverticula' were successfully managed by incising the distal lip. One of the patients previously managed for the posterior urethral valve (PUV) had both classical valves in the anterior urethra with proximal 'pseudodiverticula' and a bulbar 'true diverticula'. The AUV was ablated with a resectoscope while 'true diverticula' required diverticulectomy. All the patients after follow up of 3 months-8 years, were asymptomatic except the one with 'true diverticulum' who remained symptomatic after TUR (Trans-urethral resection) and required vesicostomy.

DISCUSSION

AUV and AUD both can cause obstructive uropathy. The proximal dilatation related to AUV cannot be labeled as a 'true diverticula', which lacks a classical orifice. The distal obstructing lip of 'true diverticula' should not be confused with a classical mucosal valve-like fold seen in AUV. While AUV and small AUD can be treated with endoscopic ablation, large diverticula as a result of wide spongiosal defects require surgical excision. A good understanding of their radiological and endoscopic anatomy is required to differentiate them and decide for appropriate management.

CONCLUSION

Based on our experience, AUV and AUD should be differentiated and should be considered as two separate entities.

Anterior urethral valves - A rare but challenging congenital pathology

BACKGROUND

Anterior urethral valves (AUV) and associated anterior urethral diverticula (AUD) are a rare cause of congenital lower urinary tract obstruction. They occur 25-30 times less frequently than posterior urethral valves (PUV) and historically tend to have a less aggressive presentation and outcome. However, due to the low incidence, little is known about management and long-term prognosis.

OBJECTIVE

We aim to evaluate the outcomes after AUV valve ablation and compare this group to a previously studied PUV cohort.

STUDY DESIGN

In this IRB-approved study, we retrospectively identified all patients from 2002 to 2017 undergoing valve ablation using CPT code 52400. Charts were manually reviewed to identify AUV patients, their presenting symptoms, timing of diagnosis, pre and postnatal imaging findings, age at presentation and valve ablation, creatinine, recurrences, additional surgeries and follow-up. The AUV group was then compared to a previously studied PUV cohort of 104 patients from our institution.

RESULTS

Nine AUV patients were identified. Only four (44%) patients were diagnosed prenatally. Three (33%) patients were diagnosed neonatally, one for weak stream/dribbling and two for febrile UTIs. The remaining two patients were diagnosed at ages 3 and 4 due to dysuria and penile swelling with micturition. Patients presenting later in life had no evidence of renal dysfunction or VUR. All patients underwent primary TUR-AUV (1 laser, 4 cold knife, 4 cautery), but 55% had residual valves and/or diverticula identified on routine postoperative imaging in two patients and due to development of clinic symptoms in three patients. All five patients with recurrences underwent repeat endoscopic evaluation, and thereafter two patients required urethral reconstruction. In contrast, only 15% (16/104) of PUV patients required re-TUR (p = 0.01). At an average follow-up time of 4.24 years (range 0.6-11.4 years), 44% of patients had no evidence of CKD, and two patients (22%) had progressed to CKD of at least stage IIIA, compared to 21.4% in the PUV cohort at a mean follow-up of 2.3 years.

DISCUSSION

The overall incidence of AUV is low, making it difficult to characterize these patients definitively. However, despite a milder phenotype and later presentation in most AUV patients, they do require more aggressive surgical treatment for complete resolution of the AUV. Furthermore, the long-term renal outcomes appear more severe than previously reported.

CONCLUSIONS

The poorer outcomes of AUV patients both with respect to recurrence and long-term CKD indicate that close urologic follow-up is essential in this group.

Prenatal diagnosis and postnatal outcome of anterior urethral anomalies

OBJECTIVES

Anterior urethral anomalies (AUA) which present as anterior urethral valve, stenosis or atresia, are a rare cause for congenital urinary tract obstruction. We present our AUA prenatal diagnosis case series.

METHODS

Fetuses presenting with prenatal findings suggestive for AUA according to postnatal reported clinical and imaging signs (urinary tract dilatation, dilated bladder, enlarged edematous fetal penis, dilatation of the fetal urethra and diverticula) were followed prospectively.

RESULTS

Six fetuses were diagnosed with AUA. Diagnosis was confirmed upon examination of the neonate or the abortus. All cases presented with variable degrees of urinary tract dilatation. Four fetuses who presented with additional congenital anomalies of the kidneys and urinary tract (CAKUT) developed intra-uterine or early postnatal renal failure, while two isolated AUA cases have a normal renal outcome.

CONCLUSIONS

AUA is a rare diagnosis. However, high index of suspicion and careful sonographic assessment of the male fetal urethra in cases referred for urinary tract dilatation may enable appropriate parent counseling, optimal prenatal surveillance and timed postnatal urological intervention. As in other lower urinary tract obstructions, future renal function seems to correlate with associated CAKUT, therefore close follow up throughout pregnancy and meticulous sonographic assessment is recommended.

A Convex Hull-Based New Metric for Quantification of Bladder Wall Irregularity in Pediatric Patients With Congenital Anomalies of the Kidney and Urinary Tract

OBJECTIVES

Early identification and quantification of bladder damage in pediatric patients with congenital anomalies of the kidney and urinary tract (CAKUT) is crucial to guiding effective treatment and may affect the eventual clinical outcome, including progression of renal disease. We have developed a novel approach based on the convex hull to calculate bladder wall trabecularity in pediatric patients with CAKUT. The objective of this study was to test whether our approach can accurately predict bladder wall irregularity.

METHODS

Twenty pediatric patients, half with renal compromise and CAKUT and half with normal renal function, were evaluated. We applied the convex hull approach to calculate T, a metric proposed to reflect the degree of trabeculation/bladder wall irregularity, in this set of patients.

RESULTS

The average T value was roughly 3 times higher for diseased than healthy patients (0.14 [95% confidence interval, 0.10-0.17] versus 0.05 [95% confidence interval, 0.03-0.07] for normal bladders). This disparity was statistically significant (P < .01).

CONCLUSIONS

We have demonstrated that a convex hull-based procedure can measure bladder wall irregularity. Because bladder damage is a reversible precursor to irreversible renal parenchymal damage, applying such a measure to at-risk pediatric patients can help guide prompt interventions to avert disease progression.

Impact of Adjuvant Urinary Diversion versus Valve Ablation Alone on Progression from Chronic to End Stage Renal Disease in Posterior Urethral Valves: A Single Institution 15-Year Time-to-Event Analysis

PURPOSE

Long-term progression to end stage renal disease of valve ablation alone vs ablation followed by additional urinary diversion were compared among children with stage 3 chronic kidney disease due to posterior urethral valves.

MATERIALS AND METHODS

We performed a retrospective study of children with posterior urethral valves and stage 3 chronic kidney disease treated at a single institution between 1986 and 2011. The 3 treatment groups were classified as group 1-valve ablation alone, group 2-ablation plus subsequent vesicostomy and group 3-ablation followed by ureterostomies and/or pyelostomies. Baseline demographic characteristics were analyzed. Statistical analyses compared the incidence of time to end stage renal disease among the intervention groups using the Fisher-Freeman-Halton exact test and Kaplan-Meier analysis with the log rank test. Cox regression was used to determine predictors of end stage renal disease progression.

RESULTS

A total of 40 eligible patients were included in the study (group 1-14 patients, group 2-13 patients, group 3-13 patients). Baseline characteristics and post-intervention estimated glomerular filtration rate revealed no significant between-group differences. A statistically significant difference in progression to end stage renal disease was noted within 1 year after diagnosis of stage 3 chronic kidney disease among the treatment groups (log rank test p=0.02). However, cumulative end stage renal disease incidence at 15-year followup showed no statistical difference (log rank test p=0.628). Cox regression analysis determined that bilateral renal dysplasia (HR 2.76, 95% CI 1.21-6.30) and estimated glomerular filtration rate 60 ml/minute/1.73 m² or greater after intervention (HR 0.23, 95% CI 0.09-0.61) were predictive of the likelihood of progression to end stage renal disease.

CONCLUSIONS

Urinary diversion following valve ablation in children with stage 3 chronic kidney disease associated with posterior urethral valves may temporarily delay progression to end stage renal disease. However, no long-term benefit was noted from diversion in the ultimate incidence of end stage renal disease, suggesting that these interventions should be seen as a temporizing measure. Bilateral renal dysplasia and post-intervention estimated glomerular filtration rate are independent variables predicting overall chronic kidney disease progression.

A systematic review of the quality of conduct and reporting of systematic reviews and meta-analyses in paediatric surgery

OBJECTIVE

Our objective was to evaluate quality of conduct and reporting of published systematic reviews and meta-analyses in paediatric surgery. We also aimed to identify characteristics predictive of review quality.

BACKGROUND

Systematic reviews summarise evidence by combining sources, but are potentially prone to bias. To counter this, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was published to aid in reporting. Similarly, the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) measurement tool was designed to appraise methodology. The paediatric surgical literature has seen an increasing number of reviews over the past decade, but quality has not been evaluated.

METHODS

Adhering to PRISMA guidelines, we performed a systematic review with a priori design to identify systematic reviews and meta-analyses of interventions in paediatric surgery. From 01/2010 to 06/2016, we searched: MEDLINE, EMBASE, Cochrane, Centre for Reviews and Dissemination, Web of Science, Google Scholar, reference lists and journals. Two reviewers independently selected studies and extracted data. We assessed conduct and reporting using AMSTAR and PRISMA. Scores were calculated as the sum of reported items. We also extracted author, journal and article characteristics, and used them in exploratory analysis to determine which variables predict quality.

RESULTS

112 articles fulfilled eligibility criteria (53 systematic reviews; 59 meta-analyses). Overall, 68% AMSTAR and 56.8% PRISMA items were reported adequately. Poorest scores were identified with regards a priori design, inclusion of structured summaries, including the grey literature, citing excluded articles and evaluating bias. 13 reviews were pre-registered and 6 in PRISMA-endorsing journals. The following predicted quality in univariate analysis:, word count, Cochrane review, journal h-index, impact factor, journal endorses PRISMA, PRISMA adherence suggested in author guidance, article mentions PRISMA, review includes comparison of interventions and review registration. The latter three variables were significant in multivariate regression.

CONCLUSIONS

There are gaps in the conduct and reporting of systematic reviews in paediatric surgery. More endorsement by journals of the PRISMA guideline may improve review quality, and the dissemination of reliable evidence to paediatric clinicians.

Scrotal pop off in a congenital anterior urethral diverticulum

INTRODUCTION AND OBJECTIVE

Congenital anterior urethral diverticulum is a rare entity. This teaching video shows the scrotal pop-off mechanism for an anterior urethral diverticulum and the unique voiding pattern of a boy who empties his bladder by compression of his scrotum. The findings during urethroscopy and open reconstruction are also demonstrated.

PATIENT AND METHODS

A four-year-old boy presented to the clinic with a poor urinary stream and scrotal swelling during voiding. Physical examination during voiding revealed a dumbbell-shaped anterior urethral diverticulum with scrotal pop off and preserved renal function.

RESULTS

Open excision of the scrotal part of diverticulum was performed. Urethroplasty was conducted using a de-epithelialised diverticular wall flap from the penobulbar urethra. On follow up the boy voided with a good flow and resolution of symptoms.

CONCLUSION

Scrotal pop off with completion of voiding by manual compression of the diverticulum may preserve bladder and renal function. The preferred treatment of anterior urethral diverticulum is open excision of the diverticulum and reconstruction. The wall of the diverticulum may be used to reinforce the repair ventrally, where the corpus spongiosum is deficient.

Lower urinary tract development and disease

Congenital anomalies of the lower urinary tract (CALUT) are a family of birth defects of the ureter, the bladder, and the urethra. CALUT includes ureteral anomaliesc such as congenital abnormalities of the ureteropelvic junction (UPJ) and ureterovesical junction (UVJ), and birth defects of the bladder and the urethra such as bladder-exstrophy-epispadias complex (BEEC), prune belly syndrome (PBS), and posterior urethral valves (PUVs). CALUT is one of the most common birth defects and is often associated with antenatal hydronephrosis, vesicoureteral reflux (VUR), urinary tract obstruction, urinary tract infections (UTI), chronic kidney disease, and renal failure in children. Here, we discuss the current genetic and molecular knowledge about lower urinary tract development and genetic basis of CALUT in both human and mouse models. We provide an overview of the developmental processes leading to the formation of the ureter, the bladder, and the urethra, and different genes and signaling pathways controlling these developmental processes. Human genetic disorders that affect the ureter, the bladder and the urethra and associated gene mutations are also presented. As we are entering the postgenomic era of personalized medicine, information in this article may provide useful interpretation for the genetic and genomic test results collected from patients with lower urinary tract birth defects. With evidence-based interpretations, clinicians may provide more effective personalized therapies to patients and genetic counseling for their families.

Anterior urethral valves: not such a benign condition…

PURPOSE

Anterior urethral valves (AUVs) is an unusual cause of congenital obstruction of the male urethra, being 15-30 times less common than posterior urethral valves (PUVs). It has been suggested that patients with congenital anterior urethral obstruction have a better prognosis than those with PUV, with less hydronephrosis, and a lower incidence of chronic renal insufficiency (5 vs. 30%). The long-term prognosis of AUVs is not clear in the literature. In this report we describe our experience and long-term follow up of patients with anterior urethral valve.

MATERIALS AND METHODS

We retrospectively identified 13 patients who presented with the diagnosis of AUVs in our institutions between January 1994 and June 2012. Two patients were excluded: one patient had no follow up after intervention; the other had a follow up <1 year. From the 11 patients included, we evaluated the gestational age, prenatal and postnatal ultrasound findings, voiding cystourethrogram findings, age upon valve ablation, micturition pattern, creatinine, and clinical follow up.

RESULTS

Between 1994 and 2012 we evaluated 150 patients with the diagnosis of urethral valves. Of this group, 11 patients (7.3%) had AUVs and an adequate follow up. Mean follow up is 6.3 years (2.5-12 years). Five (45.4%) patients had prenatal diagnosis of AUV. The most common prenatal ultrasonographic finding was bilateral hydronephrosis and distended bladder. One patient showed a large perineal cystic mass, which was confirmed to be a dilated anterior urethra. The mean gestational age was 37.6 weeks (27-40 WGA). Postnatally, 90% had trabeculated bladder, 80% hydronephrosis, and 40% renal dysplasia. The most common clinical presentation was urinary tract infection in five patients (45.4%), followed by weak urinary stream found in four patients (36.3%). The age at initial surgical intervention ranged between 7 days and 13 years. Seven (63.6%) patients had primary transurethral valve resection or laser ablation and three patients (27.2%) had primary vesicostomies. One boy (9.1%) had penile urethrostomy with excision of urethral diverticulum. Two (18.2%) patients developed end-stage renal disease.

CONCLUSION

Anterior urethral valve is a rare congenital entity affecting the genitourinary system in males. Early urinary tract obstruction resulted in end-stage renal disease in 18% of our patient population. In our series, the complication rate and the evolution to renal failure are high and similar to patients with PUV. In patients with AUVs we recommend long-term follow up and close evaluation of patient's bladder and renal function.

Genitourinary imaging: part 1, congenital urinary anomalies and their management

OBJECTIVE

Congenital urinary anomalies may be symptomatic or encountered during imaging for other clinical indications. The array of abnormalities is related to the embryologic stage at the time of the developmental insult, and these abnormalities result in a spectrum of conditions ranging from insignificant to incompatible with life.

CONCLUSION

Understanding the implications of common congenital urinary anomalies is the key to detecting associated anomalies, initiating therapy, and avoiding both complications and unnecessary intervention.