Contrast-enhanced voiding urosonography with intravesical administration of a second-generation ultrasound contrast agent for diagnosis of vesicoureteral reflux: prospective evaluation of contrast safety in 1,010 children

To evaluate the safety of intravesical administration of a second-generation ultrasound (US) contrast agent for the diagnosis of vesicoureteral reflux in children. One thousand and ten children (563 girls, 447 boys; mean age: 2.9 years, range: 15 days-17.6 years) with 2,043 pelvi-ureter-units underwent contrast-enhanced voiding urosonography (ce-VUS) to rule out vesicoureteral reflux. A second-generation US contrast agent (SonoVueA (R), Bracco, Milan) was administered intravesically through transurethral bladder catheterization at a dose of 0.5 ml/bladder filling. Possible adverse events were monitored during the examination and followed up for 7 days after ce-VUS by phone calls. Urine analysis and culture were performed 3-5 days before ce-VUS in all children and 24-48 h in any patient who reported with adverse events. No case of serious adverse event was recorded. Minor events were reported in 37 children (3.66% of the study population). These included dysuria (n = 26, 2.57%), urinary retention (n = 2, 0.2%), abdominal pain (n = 2, 0.2%), anxiety (n = 1, 0.1%) and crying (n = 1, 0.1%) during micturition, blood and mucous discharge (n = 1, 0.1%), increased frequency of micturition (n = 1, 0.1%), vomiting (n = 1, 0.1%), perineal irritation (n = 1, 0.1%), and an episode of urinary tract infection 10 days after ce-VUS (n = 1, 0.1%). Of these adverse events, 91.9% were subacute in onset and 8.1% were delayed. All events were self-limited and none required hospitalization. There were no serious adverse events. Only a few minor events were reported, most likely due to the catheterization process. Thus, ce-VUS with intravesical administration of the second-generation US contrast agent (SonoVueA (R)) for vesicoureteral reflux detection or exclusion had a favorable safety profile in our study group.