Voiding cystography practices and preferences of North American pediatric urologists

Update on imaging recommendations in paediatric uroradiology: the European Society of Paediatric Radiology workgroup session on voiding cystourethrography

Voiding cystourethrography (VCUG) is a fluoroscopic technique that allows the assessment of the urinary tract, including the urethra, bladder, and-if vesicoureteral reflux (VUR) is present-the ureters and the pelvicalyceal systems. The technique also allows for the assessment of bladder filling and emptying, providing information on anatomical and functional aspects. VCUG is, together with contrast-enhanced voiding urosonography (VUS), still the gold standard test to diagnose VUR and it is one of the most performed fluoroscopic examinations in pediatric radiology departments. VCUG is also considered a follow-up examination after urinary tract surgery, and one of the most sensitive techniques for studying anatomy of the lower genitourinary tract in suspected anatomical malformations. The international reflux study in 1985 published the first reflux-protocol and graded VUR into five classes; over the following years, other papers have been published on this topic. In 2008, the European Society of Paediatric Radiology (ESPR) Uroradiology Task Force published the first proposed VCUG Guidelines with internal scientific society agreement. The purpose of our work is to create a detailed overview of VCUG indications, procedural recommendations, and to provide a structured final report, with the aim of updating the 2008 VCUG paper proposed by the European Society of Paediatric Radiology (ESPR). We have also compared VCUG with contrast-enhanced VUS as an emergent alternative. As a result of this work, the ESPR Urogenital Task Force strongly recommends the use of contrast-enhanced VUS as a non-radiating imaging technique whenever indicated and possible.

Intussusception reduction methods in daily practice-a survey by the European Society of Paediatric Radiology Abdominal Imaging Taskforce

BACKGROUND

Image-guided intussusception reduction has been practised internationally for many decades. The use of different modalities, delayed repeat attempts, and sedation/anaesthesia are unknown.

OBJECTIVE

To survey the practice of image-guided intussusception reduction.

MATERIALS AND METHODS

A 20-point questionnaire created by the European Society of Paediatric Radiology (ESPR) Abdominal Imaging Taskforce was distributed via the ESPR members' mailing list and shared on social media between 28 March and 1 May 2023.

RESULTS

There were 69 responses from 65 worldwide institutions, with a mean of 18 intussusception reductions performed per year: 55/69 (80%) from 52 European institutions and 14/69 (20%) from 13 institutions outside of Europe. European centres reported using 19/52 (37%) fluoroscopy, 18/52 (35%) ultrasound, and 15/52 (28%) a mixture of both, with 30/52 (58%) offering a delayed repeat at 15 min to 24 h. Non-European centres reported using 5/13 (39%) fluoroscopy, 6/13 ultrasound (46%), and 2/13 (15%) a mixture of both, with 9/13 (69%) offering a delayed repeat attempt. Sedation or analgesia was used in 35/52 (67%) of European and 2/13 (15%) non-European institutions.

CONCLUSION

There is wide variation in how image-guided intussusception reduction is performed, and in the use of sedation/anaesthesia.

The accuracy of cystography under general anesthesia in children with vesicoureteral reflux

PURPOSE

To examine the accuracy of cystography under general anesthesia in children with vesicoureteral reflux (VUR).

MATERIALS AND METHODS

A prospective study of children who had VUR on cystography without general anesthesia (i.e., the gold-standard), and who are candidates for endoscopic VUR repair surgery. All children subsequently underwent a cystography under general anesthesia before injection using standardized method, which was compared to the gold-standard cystography. χ² and Mann-Whitney U tests were used to compare proportions and medians between groups.

RESULTS

Between 2017 and 2021, 126 renal units in 13 boys and 50 girls were included. Median age was 3.4 years (interquartile range [IQR] 1.5-6.5). Median time from cystography without to cystography with general anesthesia was 3.8 months (IQR 2.7-6). Of the 126 renal units, 96 had VUR on cystography without general anesthesia. On dichotomous analysis (no VUR vs. any VUR) sensitivity, specificity, negative and positive predictive values of cystography under general anesthesia were 47% (45/96), 87% (26/30), 34% (26/77) and 92% (45/49), respectively. Accuracy was 56.3%; Cohen's Kappa coefficient was 0.22, indicating poor agreement. In subgroup analysis, the sensitivity of cystography under general anesthesia was significantly lower in primary VUR (20% vs. 55% in secondary VUR, p = 0.01) and active VUR (14% vs. 52% in passive VUR, p = 0.008).

CONCLUSION

Cystography under general anesthesia was poorly correlated to cystography performed while the child was awake or lightly sedated. Clinical decision relying on this cystography is questionable.

Contrast-enhanced voiding urosonography in the assessment of vesical-ureteral reflux: the time has come

Vesicoureteral reflux (VUR) is a pathological condition contradistinguished by monolateral or bilateral retrograde flow of urine from the bladder to the ureter and to the kidney. If not properly recognized and treated, VUR can potentially be associated to several complications such as recurrent infections and possible secondary scars with Chronic Kidney Disease (CKD). Furthermore, it represents an important risk factor for nephrovascular hypertension. During the last 20 years, the diagnostic approach to this entity has passed through several, drastic changes: indeed, since its introduction in 1994 contrast-enhanced voiding urosonography (ceVUS) has gradually accompanied the voiding cystourethrography (VCUG) as alternative imaging technique for the diagnosis and staging of VUR. Despite a large number of papers has strongly encouraged its use in clinical practice, due to the lack of ionizing radiations and its high sensitivity rate, to date almost all the guidelines only include the VCUG for VUR diagnosis. The introduction of technologically advanced US software and the approval of the intravesical administration of ultrasound contrast agents by the Food and Drug Administration (FDA) and by the European Medicine Agency (EMA) have to induce the Scientific Community to a deep revaluation of the role of ceVUS in the diagnosis and follow-up of VUR: urosonography might extensively replace VCUG as the reference method, reserving to cystourethrography a role in the most complex anatomic settings for pre-surgical evaluation.

The learning curve of contrast-enhanced 'microbubble' voiding urosonography-validation study

INTRODUCTION

Vesicoureteral reflux (VUR) is a common pediatric urologic condition associated with urinary tract infection and pyelonephritis. It can be diagnosed via fluoroscopic voiding cystourethrogram (VCUG) and, more recently, contrast-enhanced voiding ultrasonography (ceVUS), which does not expose the patient to ionizing radiation. Voiding urosonography contrast agents used for the diagnosis of VUR have been widely available in Europe but were approved by the Food and Drug Administration for use in the United States only in 2016.

OBJECTIVE

The objective was to optimize a protocol and compare the diagnostic performance of ceVUS to fluoroscopic VCUG in an academic medical center naïve to previous use of contrast-enhanced voiding urosonography.

STUDY DESIGN

Thirty-nine patients referred for clinically indicated evaluation of VUR were enrolled between September 2016 and March 2017. Patients underwent contrast-enhanced ultrasonography with prediluted Lumason and under the same catheterization underwent fluoroscopic VCUG. Comparative grading was performed by pediatric radiologists on-site at the time of examination.

RESULTS

Reflux was observed in 16 of 39 patients (20 of 64 renal units) ranging from grades 1 through 5. VCUG and ceVUS were concordant for detecting reflux in 10 of 39 patients (14 of 84 renal units) and excluding reflux in 23 of 39 patients (64 of 84 renal units) (Fig. 1). Using contrast enhanced voiding urosonography, 1 of 20 renal units had high-grade and 2 of 20 renal units had low-grade reflux that was not found on fluoroscopy. Using fluoroscopy, 1 of 20 renal units had high-grade and 2 of 20 renal units had low-grade reflux that had not been found on ceVUS. Two of 20 renal units were upgraded from low-grade on ceVUS to high-grade on fluoroscopy. This corresponds to a Cohen's kappa of 0.72 (confidence interval [CI] 0.54-0.91) or 'moderate.'

DISCUSSION

During our investigation, we noted that there was a technical learning curve related to poor contrast mixing and the need to titrate the concentration of Lumason. However, over the course of the study, we were able to correct the technical aspects. Ultimately, our results showed good correlation between VCUG and Lumason ceVUS and only slightly less correlation than published studies by experienced centers. Future studies with voiding should allow for improved urethral visualization.

CONCLUSION

While there is a considerable learning curve to the implementation of ceVUS for the diagnosis of pediatric VUR, these technical aspects can be corrected. Even a center previously naïve to contrast-enhanced ultrasound technology can, over a short period of time, demonstrate good correlation between VCUG and ceVUS in the diagnosis of VUR. Translation of ceVUS into clinical practice is an alternative to VCUG for diagnosis of reflux, is feasible, and can eliminate the radiation exposure associated with a VCUG.

Children’s anxious reactions to an invasive medical procedure: The role of medical and non-medical fears

This study investigated the relationship of medical and non-medical fears to children’s anxiety, pain, and distress during an invasive medical procedure, the voiding cystourethrogram. Parents of 34 children completed the Fear Survey Schedule-II prior to their child’s procedure. Child distress behaviors during the procedure were audiotaped and coded using the Child–Adult Medical Procedure Interaction Scale-Revised. Ratings of child procedural anxiety and pain were obtained from children, parents, and examining technologists within minutes following the procedure. Associations were observed between medical fears, procedural anxiety (parent and staff reports), and coded distress behaviors. Findings may inform preparation efforts to reduce anxiety around invasive medical procedures.

A systematic review of interventions for reducing pain and distress in children undergoing voiding cystourethrography

Voiding cystourethrography (VCUG) is commonly performed to screen for vesicoureteric reflux or other urological anomalies but has a potential to provoke distress in infants and children. We performed a systematic review of randomized controlled trials of interventions to reduce distress, pain or anxiety during VCUG. Eight trials (591 participants) met the inclusion criteria.

CONCLUSION

Conscious sedation with midazolam effectively alleviates the distress of VCUG in children older than 1 year of age. Psychological preparation and warmed contrast medium may also be effective. Nitrous oxide 50% may be an alternative to midazolam, but further evidence is needed.

Economic and radiation costs of initial imaging approaches after a child's first febrile urinary tract infection

BACKGROUND. The traditional initial imaging approach following pediatric urinary tract infection is the "bottom-up" approach (cystogram and renal ultrasound). Recently, the "top-down" approach (nuclear renal scan followed by cystogram for abnormal scans only) has gained increasing attention. The relative cost and radiation doses of these are unknown METHODS. The authors used a decision model to evaluate these imaging approaches. Cost and effective radiation dose estimates, including sensitivity analyses, were based on one-time imaging only. RESULTS. Comparing hypothetical cohorts of 100 000 children, the top-down imaging approach cost $82.9 million versus $59.2 million for the bottom-up approach. Per-capita effective radiation dose was 0.72 mSv for top-down compared with 0.06 mSv for bottom-up. CONCLUSIONS. Routine use of nuclear renal scans in children following initial urinary tract infection diagnosis would result in increased imaging costs and radiation doses as compared to initial cystogram and ultrasound. Further data are required to clarify the long-term clinical implications of this increase.

Costs and consequences of universal sibling screening for vesicoureteral reflux: decision analysis

OBJECTIVE

Our objective was to evaluate screening for vesicoureteral reflux (VUR) among siblings of patients with VUR, in terms of cost, radiation exposure, and number of febrile urinary tract infections (fUTIs) averted.

METHODS

We constructed a Markov model to evaluate 2 competing management options, that is, universal screening (cystographic evaluation of all siblings without symptoms) and usual care (cystographic evaluation of siblings only after fUTIs). Published data were used to inform all model inputs. Costs were estimated by using a societal perspective.

RESULTS

Universal screening yielded 2980 fUTIs, whereas usual care yielded 6330. Therefore, universal screening for VUR in a cohort of 100,000 siblings 1 year of age without symptoms resulted in the prevention of 1 initial fUTI per 3360 siblings, at an excess cost of $55,600 per averted fUTI, in comparison with usual care. These estimates were heavily dependent on screening age and the effectiveness of antibiotic prophylaxis; prevention of a single fUTI would require screening of 166 siblings 5 years of age and 694 siblings 10 years of age. Similarly, if prophylaxis was ineffective in preventing fUTIs, then up to 10,000 siblings would need to be screened for prevention of a single fUTI.

CONCLUSIONS

Prevention of a single fUTI would require screening of 30 to 430 siblings 1 year of age without symptoms, at an estimated excess cost of $56,000 to $820,000 per averted fUTI. These estimates are heavily dependent on screening age and the effectiveness of antibiotic prophylaxis.

Voiding urosonography with US contrast agent for the diagnosis of vesicoureteric reflux in children: an update

Voiding urosonography (VUS) entails the intravesical administration of US contrast agent (USCA) for the diagnosis of vesicoureteric reflux (VUR). VUS is now recognized as a practical, safe, radiation-free modality with comparable or higher sensitivity than direct radionuclide cystography (DRNC) and voiding cystourethrography (VCUG), respectively. An extensive review of the literature regarding both the procedural aspects and comparative diagnostic values of VUS has been published (Darge Pediatr Radiol 38:40-63, 2008a, b). The aim of this review is to provide an update on various facets of VUS that have taken place since the publication of the above-mentioned two reviews.