Voiding cystourethrography in boys: does the presence of the catheter obscure the diagnosis of posterior urethral valves?

Contrast-enhanced voiding urosonography part 2: urethral imaging

Ultrasound (US) has been increasingly used as an important imaging tool to assess the urethra in children. The earliest reports of pediatric urethral sonography involved imaging the urethra in a non-voiding state, during physiological voiding of urine, and after instillation of saline. The introduction of US contrast agents has continued to improve visualization of urethral anatomy. Contrast-enhanced US of the urethra can be performed during the voiding phase of a standard contrast-enhanced voiding urosonography (ceVUS) exam or with retrograde instillation of a contrast agent, depending on the exam indication. Both techniques are well tolerated by children and provide accurate information about urethral pathology and periurethral soft tissues. This article reviews the technical aspects and imaging findings of urethral pathologies in children using contrast-enhanced US, both by the voiding and retrograde instillation techniques.

ACR Appropriateness Criteria® Antenatal Hydronephrosis-Infant

Antenatal hydronephrosis is the most frequent urinary tract anomaly detected on prenatal ultrasonography. It occurs approximately twice as often in males as in females. Most antenatal hydronephrosis is transient with little long-term significance, and few children with antenatal hydronephrosis will have significant obstruction, develop symptoms or complications, and require surgery. Some children will be diagnosed with more serious conditions, such as posterior urethral valves. Early detection of obstructive uropathy is necessary to mitigate the potential morbidity from loss of renal function. Imaging is an integral part of screening, diagnosis, and monitoring of children with antenatal hydronephrosis. Optimal timing and appropriate use of imaging can reduce the incidence of late diagnoses and prevent renal scarring and other complications. In general, follow-up neonatal ultrasound is recommended for all cases of antenatal hydronephrosis, while further imaging, including voiding cystourethrography and nuclear scintigraphy, is recommended for moderate or severe cases, or when renal parenchymal or bladder wall abnormalities are suspected. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Insight into Posterior Urethral Valve from Our Experience: Paradigm Appended to Abate Renal Failure

Objective:

The objective of the study was to share our experience of management of posterior urethral valve (PUV) and to suggest a paradigm to impede upstaging of chronic kidney disease (CKD) and prevent end-stage renal failure (ESRF).

Patients and Methods:

We have treated 332 patient of PUV from March 2005 to April 2016, Of which 272 case records had adequate data to be analyzed. The mean age was 2.48 years (range: 1 day–18 years). We did primary fulguration in 231 patients, of which five patients needed bilateral ureterostomy for obstinate high creatinine level. The remaining 36 patients had primary fulguration done elsewhere.

Results:

The mean duration of follow-up was 7.8 years (range 3–14 years). In the end of this study, 10 patients had down staging in CKD, 36 patients had up staging in CKD, and 9 patients ended in ESRF (3.8%).

Conclusions:

Detection of deterioration of renal function with creatinine clearance along with identifying the causes of deterioration and necessary interventions would help to arrest upstaging of CKD otherwise that might end in ESRF. From this study and reviewing the literature, we presume that the rhabdosphincter spasm underneath actually renders bladder outlet obstruction, and cusps of PUV, particularly in neonates, amplify the obstruction, following that bladder outlet obstruction cascades detrusor hypertrophy, bladder neck hypertrophy/obstructions, and ureterovesical junction obstruction/reflux, causing gradual damage to the bladder and upper tract and deterioration of renal function as a consequence.

Comparison of diagnostic accuracy for fistulae at ultrasound and voiding cystourethrogram in neonates with anorectal malformation

BACKGROUND

Recently, it has been reported that anorectal malformation with rectourethral fistula in male neonates can be managed by primary neonatal reconstruction without colostomy. To prevent urethral injury during anorectoplasty, the fistula's location is important. To date, the use of voiding cystourethrograms to determine the presence and location of fistulas in neonates with anorectal malformations has not been studied.

OBJECTIVE

To compare the accuracy of ultrasound (US) and voiding cystourethrogram for determining the presence and location of fistulas in neonates with anorectal malformation.

MATERIALS AND METHODS

We included 21 male neonates with anorectal malformation with rectourethral fistula (n=16), rectovesical fistula (n=1) or no fistula (n=4) who underwent US and voiding cystourethrogram preoperatively on the day of surgery. Fistula imaging was classified into three grades (0-2), and grades 1-2 were considered fistula positive. We compared the imaging-based location of the fistula with surgical findings.

RESULTS

US performed significantly better than voiding cystourethrogram for determining the presence of fistulas (area under the receiver operating characteristic curve, 0.90 vs. 0.71, respectively; P=0.044) (diagnostic accuracy 85.7%, 95% confidence interval [95% CI] 63.7-97.0% and 52.4%, 95% CI 29.8-74.3%, respectively). In cases with fistulas detected by either modality, the accuracy of locating the fistula by US was 50.0% (95% CI 24.7-75.3%) and by voiding cystourethrogram was 100% (95% CI: 59.0-100%).

CONCLUSION

US accurately detected, but did not accurately locate, fistulas in neonates with anorectal malformation. When planning primary neonatal reconstruction of anorectal malformation without colostomy, voiding cystourethrogram could provide additional information about fistula location.

Cystometrogram appearance in PUV is reliably quantified by the shape,wall, reflux and diverticuli (SWRD) score, and presages the need for intervention

OBJECTIVE

Radiological bladder abnormalities in boys with posterior urethral valves (PUV) are well recognised; however, the assessment is subjective. The shape, wall, reflux and diverticuli (SWRD) score objectively assesses shape, wall, reflux and diverticuli in a simple way. This study was undertaken to demonstrate that the SWRD score is reliable, reproducible and correlates with bladder outcome and videourodynamic (VUD) assessment in boys with PUV.

MATERIALS AND METHODS

Three blinded assessors determined the SWRD scores of PUV bladders from cystometrograms taken during VUD from September 2012 to October 2013. The scores were correlated with clinical outcome and VUD pressure measurements. Data were given as median (interquartile range), non-parametric tests used as appropriate (Mann-Whitney U test, or Kruskall-Wallis) and P < 0.05 was taken as significant.

RESULTS

A total of 55 boys with PUV underwent VUD assessment, for which 52 cystometrograms were available. The SWRD score for non-operative management was 1.0 (0.1-1.9) vs 2.0 (1.0-3.3) for operative intervention, P = 0.018 (Summary Figure). The SWRD score for compliant bladders was 1.1 (0.6-2.0) vs hypercompliant 1.7 (0.5-2.8) vs non-compliant 3.3 (2.8-5.0), Kruskall-Wallis P = 0.011. The hostile detrusor overactivity (DO) bladders (Pdet >40 cmH₂O) had a SWRD score of 2.0 (1.3-3.7) vs 1.0 (0.5-2.5) for low-pressure DO bladders, P < 0.05.

DISCUSSION

In this series of patients, increasingly distorted bladder shape was seen to be associated with poor bladder dynamics on VUD. Patients with poorly compliant bladders had a significantly higher SWRD score than normal or megacystis patients. Severe DO was also significantly associated with a high SWRD score. Therefore, the radiological appearance of a hostile bladder represented a marker for high intravesical pressure. VUR and bladder diverticuli may lead to spurious pressure measurements during VUD; however, the SWRD score provided an independent mechanism with which to objectively assess these patients, even in the presence of gross VUR.

CONCLUSIONS

The SWRD score is a simple and objective scoring system for the radiological abnormalities of PUV bladders. It correlates with clinical outcome and VUD assessment of compliance and DO, but is independent of pressure measurements and so not confounded by VUR acting as a 'pop-off' mechanism.

Posterior urethra: Anterior urethra ratio in the evaluation of success following PUV ablation

INTRODUCTION

There are conflicting reports on the criteria with which to determine success following posterior urethral valve (PUV) ablation. The aims of this study were to assess the value of the posterior urethra: anterior urethra ratio (PAR) in predicting successful PUV ablation.

MATERIALS AND METHODS

All neonates and infants with confirmed PUV on voiding cystourethrogram (VCUG) were included. Initial PAR was computed by dividing maximum posterior urethral diameter by anterior urethral diameter. Distances were measured by an on-screen distance measurement tool in the Radiology department, to avoid error. Only oblique images with good voiding phases were used for assessment. All patients underwent cystoscopy and PUV ablation using cold knife. Postoperative VCUG and cystoscopy were performed at 3 months follow-up. Success was defined as cystoscopic resolution of obstruction, in addition to biochemical and radiological improvement, and this was compared with PAR findings. An equal number of age-matched control patients who had a normal VCUG (as a part of evaluation of antenatal hydronephrosis) were also analyzed.

RESULTS

A total of 56 patients (median age 15 days, range 3-250 days) were analyzed between 2013 and 2016. The mean PAR was 1.5 (0.42) in controls and 3.42 (0.75) in those with PUV at diagnosis (P = 0.001). In those with successful PUV ablation (n = 51) the mean PAR was 1.8 (0.21), and in those with residual PUV/stricture (n = 5) the mean PAR was 3.16 (0.54). The difference between these two groups was statistically significant (P = 0.0001). Applying the value of mean + 2 SD of successful PUV ablation, an upper limit of PAR >2.2 was proposed to predict failure. Using this cut-off, 4/7 with PAR >2.2 had confirmed failure, while 48/49 with PAR <2.2 had successful resolution (P = 0.001) CONCLUSION: Whenever the posterior urethra is more than 2.2 times the diameter of the anterior urethra (PAR >2.2) on repeat VCUG following a PUV ablation, a cystoscopy check is essential to rule out residual PUV/stricture.

Utilization of computer enhanced visual learning (CEVL) method improves endoscopic diagnosis of posterior urethral valves (PUV)

INTRODUCTION

Training in urology relies largely on the traditional methods of clinical immersion and the use of reference texts. Computer enhanced visual learning (CEVL) is an on-line learning tool that may effectively supplement these methods. We evaluate the role of CEVL in establishing the endoscopic diagnosis of posterior urethral valves (PUV).

MATERIAL AND METHODS

This study compares test scores of PUV diagnosis made by pediatric urologists and fellows in pediatric urology training programs while watching pediatric cystourethroscopy videos before and after viewing the CEVL learning module. The CEVL module used illustrations and video clips to highlight criteria important in diagnosing PUV. Data was analyzed for improvement in test scores (Chi square).

RESULTS

There were 112 study subjects enrolled. An improvement in the post-test scores was observed (p < 0.001). When independently analyzing cases with PUV, an improvement in diagnosis was also observed (p < 0.005). While a trend toward improvement was observed in correctly diagnosing normal urethras, this was not statistically significant.

CONCLUSION

Overall, there was an improvement observed after viewing the CEVL module. This was most notable in cases where PUV was present. The CEVL module is an effective supplement for enhancing the endoscopic diagnosis of PUV.

Residual valve and stricture after posterior urethral valve ablation: how to evaluate?

OBJECTIVE

To investigate the clinical and radiological parameters of posterior urethral valve (PUV) patients with residual valve or strictures after primary valve ablation.

PATIENTS AND METHODS

A total of 127 PUV patients were treated in our clinic between 1986 and 2009. We retrospectively reviewed the records of 101 patients, who had at least 1 year of follow-up data, regarding the presence of valve remnants or urethral strictures after PUV ablation.

RESULTS

A total of 21 patients (20.8%) underwent repeat-urethroscopy and, of these, residual valve leaflets or stricture were detected in 10 patients (10/101, 9.9%). In 2 of these 10 (20%), the urethra had been found to be normal on the first voiding cystourethrogram following ablation. However, these two boys underwent re-urethroscopy due to persistent vesicoureteral reflux in one and persistent hydroureteronephrosis in the other, and valve remnants were detected. The remaining 8 cases had radiological signs consistent with persistent infravesical obstruction in the early period. Obstruction was due to urethral stricture and residual valve remnants in 2 and 6 cases, respectively.

CONCLUSIONS

There was clinical suspicion of residual valve in about 20% of the cases and in half of these the urethra was found to be normal on urethroscopy. The possible presence of residual valve remnants after primary valve ablation should be confirmed by careful clinical, radiological and endoscopic evaluation.

The predictive value of a repeat micturating cystourethrogram for remnant leaflets after primary endoscopic ablation of posterior urethral valves

OBJECTIVE

We routinely perform a cystourethroscopy 3 months after initial ablation of posterior urethral valves. The aim of this study was to determine the predictive value of the urethral appearance on preoperative micturating cystourethrogram (MCUG) for further valve resection at check cystoscopy.

PATIENTS AND METHODS

We retrospectively reviewed 31 consecutive boys (aged 4-18 months) who underwent check cystoscopy and repeat MCUG between 2006 and 2008.

RESULTS

Repeat MCUG suggested remnant valves in 10, but no residual leaflets were identified cystoscopically in 4. In 20 boys, the valves appeared completely ablated on MCUG but valve leaflets received further resection in 10. One study was undiagnostic. Residual valves were resected in 83% (5/6) where valves and urethral dilatation were noted on MCUG. Where MCUG suggested either valves or persistent dilatation alone, further resection occurred in 40% (4/10). Remnant leaflets were also present in half of those (7/14) in whom the repeat MCUG had shown complete ablation and resolved/reduced posterior urethral dilatation.

CONCLUSIONS

The positive predictive value of valve leaflets and/or posterior urethral dilatation on repeat MCUG for subsequent resection of valve remnants was 56%; the negative predictive value was 50%. We found repeat MCUG alone imprecise in excluding residual valve tissue and recommend check cystoscopy in all.

Reliability of voiding cystourethrography to detect urethral obstruction in boys

OBJECTIVES

To evaluate the reliability of voiding cystourethrography (VCUG) to diagnose infravesical obstruction in boys.

METHODS

Hard copies of the VCUG findings of 72 boys were assessed by two pediatric radiologists and two pediatric urologists. The investigators were instructed to consider six items related to infravesical obstruction: vesicoureteral reflux, bladder wall thickness, bladder diverticulum, abnormal prostatic urethra, visible urethral obstruction, and obstruction in the sphincter area. Also, a scoring system was developed using these six items. Agreement among the four investigators for evaluation of the items on VCUG and for the scoring system was assessed using the kappa statistic. All boys underwent urethrocystoscopy, and the endoscopic findings were compared with VCUG results. Odds ratios were calculated for the results of VCUG for each investigator to predict the chance of cystoscopic infravesical obstruction.

RESULTS

Agreement among observers for vesicoureteral reflux and bladder diverticulum was good (kappa values for paired observers of 0.82 and 0.79). Agreement for bladder wall thickness, abnormal prostatic urethra, visible urethral obstruction, obstruction in the sphincter area, and the scoring system was poor (kappa values of 0.08, 0.35, 0.33, 0.26, and 0.33, respectively). Consequently, the results of VCUG could not predict for endoscopic infravesical obstruction accurately, although substantial differences occurred among investigators. Items on which investigators reached good agreement were negatively related to the risk of having infravesical obstruction.

CONCLUSIONS

Because agreement among investigators in the assessment of most items on VCUG was poor and because for the items with good agreement, the predictive power was poor, the current clinical use of VCUG for diagnosing infravesical obstruction needs reevaluation.

Voiding cystourethrography in boys. Does the presence of the catheter during voiding alter the evaluation of the urethra?

PURPOSE

We determined whether the presence of the catheter during the voiding phase of voiding cystourethrography alters the evaluation of the urethra concerning the normal structures as well as pathological findings, especially posterior urethral valves.

MATERIALS AND METHODS

A total of 123 males 3 days to 16 years old (median age 2.6 months) underwent voiding cystourethrography. Urethral catheterization was performed in all cases. Four views were taken during the voiding phase with and without the catheter in place. Only 80 patients had available results. These examinations were studied with special attention to the normal structures and pathological findings.

RESULTS

A total of 36 examinations (45%) were normal. Pathological findings were observed in 44 patients (55%), with abnormal vesical findings and/or vesicoureteral reflux in 33 (41.25%). In 11 patients (13.75%) 12 urethral abnormalities were found (posterior urethral valves 3, hypospadias 4, prostatic utricle 1, verumontanum polyp 1, prune belly syndrome with urethral dilatation 1, imperforate anus with urethral fistula 1 and urethral duplication 1). In all cases excluding those involving hypospadias there was no difference between the views with and without the catheter. However, concerning the normal structures, the verumontanum and fossa navicularis were better delineated without the catheter in 27% and 33% of cases, respectively.

CONCLUSIONS

Our study shows that a urethral catheter does not alter the diagnosis of abnormalities of the posterior urethra but may hamper the observation of normal structures or abnormalities of the anterior urethra.

Pediatric voiding cystourethrography: a pictorial guide

Voiding cystourethrography is commonly performed in children with prenatally diagnosed hydronephrosis, urinary tract infections, and voiding abnormalities. Voiding cystourethrography can be performed with many variations designed to optimize visualization of disease and minimize radiation exposure. The procedure should include assessment of the spine and pelvis; masses or opaque calculi; bladder capacity, contour, and emptying capability; presence and grade of reflux; and urethral appearance. Radiologists differ as to whether the patient should void prior to catheterization. Anteroposterior imaging of the bladder is performed during early filling; little or no imaging is necessary during intermediate filling. When bladder filling is complete, steep oblique images that are centered on the ureterovesical junction should be obtained. If reflux is observed, the ipsilateral renal fossa may be imaged prior to voiding. With a smaller than expected voiding volume, bladder refilling is recommended. Voiding around the catheter is also strongly recommended. In girls, one anteroposterior image of the urethra is usually sufficient; in boys, the entire urethra must be imaged. Steep oblique imaging is optimal. At the conclusion of voiding, each renal fossa should be imaged to detect reflux missed at fluoroscopy as well as other anomalies. Familiarity with these abnormalities and use of proper techniques will allow detection of most common pathologic conditions with very low radiation exposure.

Diagnosis of vesico-ureteric reflux

The demonstration and grading of reflux is crucial in examination and follow-up of any child with upper urinary tract infection. A variety of factors can influence the occurrence of reflux, e.g. race, genetics, state of maturation of the ureterovesical valve, diuresis, infection and bladder dysfunction, including obstruction and neurogenic disorders. Even when reflux is investigated under strictly standardized conditions, two consecutive bladder fillings frequently show different grades of reflux. Voiding cystourethrography is, to date, the only method with a generally accepted, well-defined grading of reflux. It also allows detection of intrarenal reflux and anatomical and functional information about the bladder and urethra that is unobtainable by other methods. It is therefore usually considered the method of choice. Radionuclide cystography and, possibly, contrast enhanced ultrasonography can be complementary to voiding cystourethrography, but mainly for postoperative follow-up and screening of siblings.