Patient dose reduction during voiding cystourethrography

Voiding cystourethrography (VCUG) is a commonly performed examination in a pediatric uroradiology practice. This article contains suggestions on how the radiation dose to a child from VCUG can be made "as low as reasonably achievable" (ALARA). The pediatric radiologist should consider the appropriateness of the clinical indication before performing VCUG and utilize radiation exposure techniques and parameters during VCUG to reduce radiation exposure to a child. The medical physicist and fluoroscope manufacturer can also work together to optimize a pulsed-fluoroscopy unit and further reduce the radiation exposure. Laboratory and clinical research is necessary to investigate methods that reduce radiation exposures during VCUG, and current research is presented here.     

Intranasal fentanyl versus placebo for pain in children during catheterization for voiding cystourethrography

Background

Voiding cystourethrogram (VCUG) is a common procedure at pediatric tertiary care centres that can be painful as it involves a urinary catheter. Currently there are no widely utilized protocols for non-topical medications to decrease pain that children feel during catheterization.

Objective

To determine if intranasal (IN) fentanyl is effective at decreasing pain that children feel during catheterization of VCUG when compared with sterile water.

Materials and methods

We performed a double-blind randomized controlled trial, using IN fentanyl (2 μg/kg) compared to placebo (sterile water,) in children 4–8 years of age scheduled for elective VCUG in one urban pediatric tertiary center.

Results

Using the Face Pain Score-Revised, children receiving IN fentanyl scored 2.58 (1.93–3.25 95% CI) while those receiving sterile water scored 2.86 (2.20–3.51 95% CI) showing no statistically significant difference. There were no adverse events.

Conclusions

Although we were unable to show a statistically significant difference between our study and control groups, we believe that this may be due to technique (positioning, delivery device) and timing of administration of IN fentanyl as well as multi-factorial causes of distress during VCUG. Future studies investigating alternative delivery techniques of IN fentanyl for analgesia during VCUG may yield more promising results.     

Suprapubic voiding cystourethrography in the evaluation of lower urinary tract

Suprapubic micturating cystourethrography is a technique of great value in evaluating lower urinary tract in infants and children. It has been employed in 28 patients of age group ranging from newborn to 12 years, without any serious complication. The minor complication of extravasation of contrast media into the perivesical and peritoneum was observed in three patients. The method is easy, safe, reliable and time saving.     

Simultaneous voiding cystourethrography and voiding urosonography reveals utility of sonographic diagnosis of vesicoureteral reflux in children

AIM: To evaluate the diagnostic potential of voiding urosonography (VUS) compared with fluoroscopic voiding cystourethrography (VCUG) under identical conditions and to evaluate potential reasons for false-negative VUS results, particularly regarding bladder concentrations of the US contrast agent, Levovist. METHODS: Fifty-six paediatric patients (M/F 34/22, mean age 2.3 y, age range 1 mo-14 y) underwent simultaneous VUS and VCUG under identical conditions. The bladder was filled by simultaneous administration of Levovist and the X-ray contrast medium, DIP Conray. Levovist concentrations in bladders were calculated using amounts of Levovist injected and total DIP Conray infused when reflux was first observed in either procedure. RESULTS: Sensitivities of VUS and VCUG for detection of vesicoureteral reflux (VUR) were both 86%, assuming that VUR detected by either method represented a true-positive, and no reflux by either method represented a true-negative. Patients under 24-mo of age displayed a better VUS sensitivity, of 94%. Levovist concentrations in bladders ranged from 1.8% to 23%, with older children tending to demonstrate increased bladder capacity and lower concentration. All VUS false-negative units displayed Levovist bladder concentrations of less than 5%. CONCLUSION: The present simultaneous study suggests that: 1) the two techniques demonstrate similar sensitivity for detection of reflux; 2) sustained Levovist bladder concentrations of below 5% may not allow detection of reflux on VUS; and 3) VUS represents a suitable technique, particularly for small children whose bladder capacity is not so large.     

A comparison of echo-enhanced voiding urosonography with X-ray voiding cystourethrography in the first year of life

Background: Second‐generation echo‐enhanced voiding urosonography (VUS) with improved contrast‐specific ultrasound (US) techniques is increasingly being used for vesicoureteric reflux (VUR) detection. Aim: To compare VUS with X‐ray voiding cystourethrography (VCUG) and to evaluate the predictive value of pelvicalyceal dilatation for detecting VUR in the first year of life. Materials and methods: Sixty‐six children younger than one were investigated by US, VUS and VCUG. VCUG represented the reference method for VUR detection. Results: According to VCUG, VUR was present in 16/132 (12%) renal units. VUS confirmed all these and additionally revealed VUR in 26 renal units (all together 42/132 (32%) renal units with VUR). It should be noted that all VUR detected only with VUS and missed by VCUG were of grades II and III. In 27/92 (29%) US normal and in 15/40 (37%) renal units with pelvicalyceal dilatation, VUR was detected by VUS. Conclusion: We believe that VUS could safely replace VCUG in VUR detection in infants, with no regard to the degree of abnormality of the upper urinary tract seen on US. VCUG should be limited only to cases where bladder and/or urethra pathology are suspected.     

Is there a benefit from routine voiding cystourethrography after ureterocystoneostomy?

Surgical repair such as ureterocystoneostomy (UCN) for vesicoureteral reflux (VUR) or primary obstructive megaureter (POM) is the treatment of choice after the failure of conservative therapy. To document the postoperative outcome, a voiding cystourethrography is routinely performed to exclude persisting reflux. Our aim was to evaluate the benefit of voiding cystoureterography (VCUG) in our patients with respect to radiation, discomfort to the child and costs. The medical records of all patients who underwent an ureterocystoneostomy at the Department of Paediatric Surgery in St. Gallen, Switzerland, between January 1, 1995 and December 31, 2000 were reviewed in terms of the pre- and postoperative clinical course, type of surgical procedure and radiographic examinations performed. During this period, 126 renal units were operated in 81 patients. The surgical technique employed was Cohen's procedure in 121 (96 %) renal units and a Leadbetter-Politano procedure in 5 (4 %) renal units. Mean postoperative follow-up was 42 months (6 - 84). All patients had an ultrasonographic follow-up. 77 (95 %) patients underwent a VCUG with normal results one year postoperatively. VUR was found in 4 patients, 3 of them were asymptomatic one year postoperatively, one had a complication of a fistula with reflux and required reoperation 2 months after operation. The VCUG was performed earlier because of clinical und ultrasonographic findings. None of the routinely performed VCUGs led to a change of procedure. All pathologies had already been detected by clinical or ultrasonographic findings. We recommend clinical and ultrasonographic follow-up after an UCN and performance of a VCUG only when problems appear to be present.     

Reflux into vagina,uterus, fallopian tubes and peritoneal cavity during voiding cystourethrography: Case report

A case of reflux of contrast medium into the peritoneal cavity via the vagina, uterus and Fallopian tubes during voiding cystourethrography is presented. This patient had abdominal symptoms which may have been related to intraperitoneal reflux of urine during voiding.     

Comparison of direct radionuclide cystography and voiding cystourethrography in detecting vesicoureteral reflux

BACKGROUND: Fluoroscopic voiding cystourethrography (VCUG) is a widely used imaging test for the diagnosis of vesicoureteral reflux (VUR). However, high gonadal radiation and intermittent imaging are the main disadvantages of VCUG. Direct radionuclide cystography (DRC) has been advocated for the detection of VUR with increased sensitivity and low radiation doses, however, having the disadvantage of providing less anatomical details for urethral evaluation. In this study, DRC has been compared with standard fluoroscopic VCUG for detection of VUR. METHODS: A total of 41 children (82 kidney ureter units, KUU) aged 1 month-126 months (median, 15 months) were studied sequentially using DRC and VCUG. The indications of VUR studied were urinary tract infection in 29 children, VUR follow up in eight children and antenatal dilatation history in four children. RESULTS: A total of 18 refluxing ureters were detected by DRC, 22 refluxing ureters by VCUG and 14 refluxing ureters by both methods. The two methods were concordant for the detection and exclusion of VUR in 85% of KUU. VUR was missed by VCUG in four KUU (three severe, one mild) whereas VUR was missed by DRC in eight KUU (four grade I, four grade III). CONCLUSIONS: There was a good correlation between DRC and VCUG in the evaluation of VUR. DRC provides continuous monitoring and low gonadal radiation exposure. DRC can be used in the diagnosis of VUR as an alternative to VCUG in selected cases.     

Predictors for abnormal voiding cystourethrography in pediatric patients undergoing renal transplant evaluation

The role of pretransplant voiding cystourethrography (VCUG) in adults has been questioned owing to the low prevalence of abnormal findings. As there are no studies evaluating the relevance of VCUG in children and because vesicoureteral reflux (VUR) occurs with higher prevalence in children, we performed a retrospective cohort study to identify any predictors for abnormal VCUG. We reviewed 271 consecutive renal transplants performed between 1980 and 1997. By logistic regression, the etiology of end-stage renal disease (ESRD) and age at transplantation (Tx) were strong predictors of abnormal pretransplant VCUG findings in children. On multi-variate analysis, children with urologic etiologies of renal disease had an odds ratio (OR) of 16.5 (p < 0.0001) for abnormal VCUG as compared to children with non-urologic or acquired causes of ESRD. Similarly, children transplanted when younger than 8 yr of age had an OR of 3.0 (p = 0.0043) for having an abnormal VCUG when compared with older children. Finally, our analysis suggests that children with abnormal pretransplant VCUG findings, whether or not pretransplant surgical correction was performed, were over three-fold more likely to require post-transplant urologic surgery when compared to children with normal pretransplant VCUG. We conclude that urologic causes of ESRD and age under 8 yr are strong independent predictors of abnormal pretransplant VCUG findings, and that these findings are of clinical relevance both in deciding whether to pursue pretransplant VCUG and in the post-transplant course of the patient.     

Results of systematic voiding cystourethrography in infants with antenatally diagnosed renal pelvis dilation

OBJECTIVES: To assess the yield of neonatal renal ultrasonography as a predictor of abnormalities on voiding cystourethrography (VCUG). STUDY DESIGN: We prospectively followed 264 infants with antenatal renal pelvis dilation. Two successive neonatal renal ultrasound examinations were performed at day 5 and 1 month after birth. VCUG was performed in all infants. RESULTS: Neonatal ultrasound findings were abnormal in 190 infants (72% of total). Among them, 63 (33%) had an abnormal VCUG. The most common abnormalities were primary vesico-ureteral reflux (VUR) in 30 infants, VUR into the lower pole of a duplex kidney in 14, refluxing megaureter in 9, posterior urethral valves in 5, and ureterocele in 5. When both neonatal ultrasound findings were normal (74 infants), the VCUG showed abnormalities in only 5 (6.7%) patients (4 low-grade primary VUR and 1 posterior urethral valve). The sensitivity, specificity, positive predictive value, and negative predictive value of 2 successive ultrasound scans in the neonatal period to predict an abnormality on VCUG were 93%, 35%, 33%, and 93%, respectively. CONCLUSIONS: A normal-appearing urinary tract on 2 successive neonatal ultrasound scans rarely coexists with abnormal findings at VCUG. Therefore, in such patients, VCUG does not seem justified.     

Sedation with midazolam for voiding cystourethrography in children: a randomised double-blind study

BACKGROUND: Sedation with midazolam facilitates the performance of diagnostic procedures in children, including voiding cystourethrography (VCUG). However, the influence of sedation on voiding and imaging results have not been adequately evaluated. OBJECTIVE: Midazolam and placebo were compared to assess discomfort during VCUG and to evaluate if sedation influenced the outcome of the examination. MATERIALS AND METHODS: The study was prospective, randomised and double-blind, and included 95 children, 48 in the midazolam group (median age 2.2 years) and 47 in the placebo group (median age 3.2 years). The evaluation included the child's/parent's experience of the VCUG, as well as the examination results. RESULTS: The children/parents in the midazolam group experienced the VCUG as less distressing compared to those in the placebo group ( P<0.001). Forty-six of 48 children sedated with midazolam could void during the imaging procedure compared to 38 of 47 children given placebo ( NS). There was no difference in frequency or grade of vesicoureteric reflux or bladder emptying between the groups. CONCLUSIONS: When sedation is required to perform VCUG in children, midazolam can be used without negative effect on the outcome of the examination.     

Routine voiding cystourethrography is of no value in neonates with unilateral multicystic dysplastic kidney

OBJECTIVES: To determine if two successive ultrasound examinations could rule out the presence of clinically significant contralateral anomalies in neonates with multicystic dysplastic kidney (MCDK), thereby avoiding unnecessary voiding cystourethrography (VCUG). STUDY DESIGN: We followed 76 newborn infants with antenatally discovered MCDK. Two successive neonatal renal ultrasound examinations were performed, one within the first week and one at around 1 month of life. VCUG and isotopic studies were performed in all infants. RESULTS: Urologic anomalies of the contralateral kidney were present in 19 of 76 children (25%): vesicoureteral reflux (VUR) in 16 (21%), ureteropelvic junction obstruction in 2 (3%), and renal duplex kidney in 1 (1%). Sixty-one infants (80% of total) had normal contralateral urinary tract on the 2 successive neonatal renal ultrasound scans. Among them, 4 of 61 (7%) infants presented with low-grade VUR on VCUG that had resolved spontaneously before 2 years of age. The sensitivity, specificity, positive predictive value, and negative predictive value of two successive ultrasound scans in the neonatal period to predict contralateral urological anomalies on VCUG were 75%, 95%, 80%, and 93%, respectively. CONCLUSIONS: In infants with antenatally diagnosed MCDK, two successive normal neonatal renal ultrasound scans will rule out clinically significant contralateral anomalies, thereby rendering the need for a neonatal VCUG unnecessary.     

Neonatal bladder rupture

Neonatal bladder rupture is rare as a complication of bladder obstruction due to abnormal anatomy or iatrogenic cause such as umbilical catheterization. The present study describes the case of a 27-day old infant with ascites due to bladder perforation secondary to bladder wall necrosis as a result of severe urinary tract infection. The baby was treated aggressively with antibiotics and underwent successful surgical repair of the perforation.     

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.     

Spontaneous bladder rupture in non-augmented bladder exstrophy

Childhood spontaneous bladder rupture is an uncommon event, usually associated with bladder augmentation. Occasionally it occurs in normal bladders or non-augmented bladders with a predisposing factor. We present a unique case of misdiagnosed spontaneous bladder rupture in a non-augmented bladder exstrophy patient without evidence of lower urinary outlet obstruction. His acute abdomen mimicked appendicitis and was managed with laparoscopic exploration, intraperitoneal fluid drainage, appendectomy and bladder drainage. This case highlights the need for pediatric urological consultation by surgeons in the case of an acute abdomen with free fluid in a patient with an abnormal bladder.     

Urinary ascites with uremia and electrolyte imbalance: a delayed presentation of intraperitoneal bladder rupture in infancy

We report two infants with increasing abdominal distension, anuria, uremia, and electrolyte imbalance 4 and 8 days following intraperitoneal rupture of the urinary bladder. Awareness and early diagnosis by means of a urethrocystogram followed by surgical repair of the bladder may minimize the complication of this rare and easily missed injury in infants and small children.