If Reflux Continues After Injection: Repeat Injection or Surgery?

The follow-up voiding cystourethrogram (VCUG) or contrast-enhanced voiding urosonography (ceVUS), obtained roughly 3–6 months after the injection, shows whether reflux is still present. Seeing reflux on this study may sound like failure, but it does not always mean the same thing.

Single-session success is closely tied to the grade of reflux: it is reported at roughly 80–90% for grade I–II, 70–75% for grade III, 60–65% for grade IV, and around 30–50% for grade V. In other words, a first session not being enough in high-grade reflux is not an unexpected outcome.

For ongoing reflux, a second injection is a reasonable step for most children. It is again a same-day, incision-free, short procedure; the needle position and the amount of material used are adjusted based on what was done in the first session and where the bulking agent has ended up.

Ureteral reimplantation (reconnecting the ureter to the bladder with a new, longer tunnel) achieves higher success than repeat injection; resolution of reflux is reported in the literature at roughly 95–98%. For this reason, in some children it makes more sense to skip the second injection and move straight to surgery.

• Having a febrile urinary tract infection after injection (especially while on antibiotic prophylaxis)
• Grade III or higher reflux persisting despite two injections
• A new or progressing scar on DMSA renal scan
• Ureteral obstruction caused by the bulking agent, or kidney swelling, on ultrasound
• Anatomical conditions that are difficult to correct with injection, such as a duplex collecting system, ureterocele, or paraureteral diverticulum
• The family's preference for a permanent solution

• A previously performed injection generally does not stand in the way of surgery; the bulking material is removed during the operation, and the literature reports that reimplantation success is preserved in these children. The decision is made through the joint assessment of the two pediatric urologists, together with the family's expectations and the child's findings.

In a child whose reflux has dropped to grade I–II after injection, who has not had a febrile infection, and whose kidneys are healthy, an immediate second procedure is not needed. The tunnel continues to lengthen with growth; these children can be followed with yearly ultrasound and clinical monitoring, and antibiotic prophylaxis if needed.

• In short, reflux on the follow-up imaging alone does not determine the next step; grade, infection history, kidney status, the child's age, and bladder habits are all evaluated together. In our practice, because the injection is performed by the same two specialists who would also take on reimplantation if needed, the decision to repeat the injection or move to surgery is made by a single, consistent team.