VCUG is a radiologic procedure for the evaluation of the bladder and urethra, which is valuable for examining and following-up on a VUR and for helping the prevention of renal damage. Iatrogenic complications associated with VCUG are rare events, but some complications include UTI, allergic reaction after procedure, contact dermatitis, knotting of the urethral catheter, and bladder rupture5
. In Korea, one study reported that 32.7% of patients with VCUG showed complications such as bladder rupture, dysuria, irritability, and hematuria11)
. Bladder rupture associated with VCUG is more common in instances of chronically unused bladders such as chronic renal failure, and six cases of bladder rupture were reported in chronic renal failure12)
. Bladder rupture is a rare complication and delicate attention is needed due to its emergency situation10)
To perform a safe VCUG, we should pay attention to some factors such as bladder volume, the patient's underlying disease, the velocity of the contrast instilled, and catheter size13)
. At birth, bladder volume is about 30 mL regardless of sex, and two formulas have been proposed for bladder volume estimation in children according to their age and weight: age<1 year, bladder volume (mL)=38+(2.5×age [mo]); age>1 year, bladder volume (mL)=(age [yr]+1)×3014
. However, the bladder volume is different among individuals, and the bladder dome which is the weakest part of bladder can easily be ruptured when excess volume is injected rapidly11)
Also, catheter size and type has significance. For short-term catheterization to obtain a urine specimen or to perform an investigative procedure, a 5-Fr. feeding tube is recommended for neonates and an 8-Fr. feeding tube for children16)
. Using a Foley catheters is risky because the balloon can block the urinary flow and the bladder can rupture17)
. Therefore, much care is necessary in using a Foley catheter instead of feeding tube.
Proper catheter insertion, fluoroscopic guide, pressure, and number of filling cycles should be considered in for the instillation18)
. To avoid pressure overload, pressured manual injection of the contrast material must not be used, while a gravity method must be used18
. At this time, the contrast container should not be placed higher than 60 cm from the patient. More than two cycles of filling does not appear to be necessary18
. Underlying diseases such as chronic renal failure are also another important determining factor12
Five cases of iatrogenic bladder perforation have been reported in children following VCUG. Most of all (4 cases), the main cause of bladder rupture was manual injection of the contrast material and in one case, the chief cause was underlying disease (hutch diverticula)22
In this case, the main causes of the bladder rupture are considered to be the use of the Foley catheter instead of a feeding tube, manual injection of contrast media, and the excess volume instilled more than expected volume.
Management of infantile bladder rupture should be individualized case to case. In the review by Trulock et al.27)
, the majority of reported infants were treated with abdominal exploration and repair of the bladder leakage site, but some of the patients could be managed by the implementation of a vesicotomy or urethral catheter alone.
In conclusion, the majority of complications associated with VCUG are not critical, but in several cases, severe complications such as bacteremia and bladder rupture can occur in several cases. Therefore, the operator should be well informed of the procedure, and aseptic techniques, while delicate observation of potential for the complication is needed.