Deflux injection for reflux
A Deflux injection treats vesicoureteral reflux (urine flowing backward from the bladder toward the kidney) by injecting a small amount of gel under the ureter opening through a scope. The gel forms a cushion that helps the opening close, with no incision and usually a same-day discharge.
Also called Deflux, endoscopic injection for reflux, endoscopic treatment of VUR, subureteral injection, STING procedure, HIT procedure, dextranomer hyaluronic acid injection, bulking injection for reflux
- Where
- Children's hospital or outpatient surgery center operating room
- Anesthesia
- Brief general anesthesia
- Time in the room
- About 15 to 45 minutes
- Hospital stay
- Same day
- Back to normal
- 1 to 2 days
- Back to work
- School or daycare in 1 to 2 days
Overview
In vesicoureteral reflux, or VUR, urine flows backward from the bladder up the ureter (the tube from each kidney) toward the kidney. This happens when the ureter's tunnel through the bladder wall is too short to act as a one-way valve. Reflux matters mainly because it lets bacteria from a bladder infection reach the kidney, causing a kidney infection with fever and sometimes scarring.
Deflux is a gel made of two sugar-based substances, dextranomer and hyaluronic acid, and has been used in the United States since 2001. Using a small camera passed through the urethra into the bladder, the surgeon injects a small amount of the gel just under the opening of the ureter. The gel forms a mound that supports the opening so it closes when the bladder fills and squeezes. There are no incisions, and most children go home a couple of hours later.
Injection is less invasive than ureteral reimplantation, the open or robotic operation that rebuilds the tunnel, but it is also less certain. After one injection, reflux goes away in about 7 in 10 ureters on average, more often for milder reflux and less often for severe reflux. Some children need a second injection, and in some the reflux returns over the years. Your child's urologist will help you weigh these numbers against the bigger operation.
The parts of your body involved
Each ureter enters the bladder at the trigone, a triangle-shaped area on the bladder floor. The ureter runs through a short tunnel in the bladder wall and opens through a small slit called the ureteral orifice. In reflux, the opening is often wider and the tunnel shorter than normal, so urine escapes back up when the bladder squeezes.
- Kidneys and ureters
The kidneys make urine, and the ureters carry it down to the bladder.
- Bladder
The stretchy bag that stores urine until your child pees.
- Trigone
The triangle-shaped area on the bladder floor where both ureters open.
- Ureter opening
The small slit where each ureter empties into the bladder. The gel is placed just beneath it.
- Bladder lining
The smooth inner surface of the bladder. The needle passes just under it, so the gel sits in the wall.
Why it’s done
Most children with reflux never need a procedure. Injection may be offered when reflux keeps causing infections or is not going away, and the family prefers a less invasive option than surgery.
- Kidney infections despite a daily antibiotic
Infections with fever while on prevention are a common reason to correct the reflux.
- Reflux that is not going away
Reflux still present after years of follow-up is less likely to resolve on its own.
- Stopping daily antibiotics
Some families want to stop giving a daily antibiotic, or the child cannot take it.
- No incision
A short outpatient procedure with a very quick recovery appeals to many families, even with lower success than surgery.
- Lower to middle grades
Results are best for grades 2 and 3, which makes injection a good fit for many of these children.
Other options
- Watching and waiting
Many children outgrow reflux, especially grades 1 to 3. This means regular check-ups and ultrasounds, and prompt treatment of any fever.
- Daily low-dose antibiotic
A small daily dose to prevent infections. In a large U.S. trial (RIVUR), it cut repeat urinary infections by about half, though it did not reduce kidney scarring.
- Treating bladder and bowel habits
Constipation and holding urine make infections and reflux worse. Regular toilet times, plenty of water and treating constipation help many children, and they also improve the success of injection.
- Ureteral reimplantation
Surgery that rebuilds a longer tunnel for the ureter. It cures reflux in about 95 to 98 of every 100 ureters with open surgery, with an incision and a 1 to 2 night hospital stay.
Getting ready
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Weeks before
The week before
The day before and the morning of
In the operating room, step by step
Press play or pick a step. Each drawing shows what your surgeon is doing at that moment. Your team may do some steps differently.
1. Going to sleep
Your child falls asleep breathing anesthesia gas through a mask, often with a parent nearby. An antibiotic is given once your child is asleep.
After the operation
Right afterward
- Waking up
Your child may be groggy, cry or seem confused for a short time after anesthesia.
- The first pee
Most teams like your child to pee before going home. It may sting.
- Pain
Discomfort is usually mild. Acetaminophen or ibuprofen is enough for most children.
- Going home
Most children go home within a few hours.
At home
- Burning
Stinging with peeing for a day or two is common. Extra fluids help.
- Pink urine
Slightly pink urine or a little blood for a day or two is normal.
- Activity
Most children are back to normal play and school the next day or the day after.
- Bathing
Normal baths or showers are fine from the same or next day.
- Antibiotics
Many urologists continue the daily antibiotic until the follow-up X-ray shows the reflux is gone. Follow your own team's advice.
- Toilet and bowel habits
Keep up regular toilet times, plenty of water and treatment of constipation. These protect against infections whether or not the reflux is cured.
- Watching for fever
Any fever needs a urine check, since kidney infections are still possible until the result is confirmed.
Recovery timeline
- Day 0Procedure
A short procedure, and home the same day.
- Days 1 to 2Back to normal
Burning fades, and most children return to school or daycare.
- Week 1Routine
Life is back to normal. Keep up good toilet habits.
- 1 to 3 monthsFollow-up ultrasound
A kidney and bladder ultrasound checks for any swelling of the kidney.
- About 2 to 3 monthsChecking the result
Because the result is less certain than with surgery, most urologists repeat the VCUG to see whether the reflux is gone.
- If reflux remainsNext steps
Options include a second injection, ureteral reimplantation, or continuing to watch.
- Long termStaying watchful
Keep treating fevers promptly with a urine check, since reflux can return in some children over the years.
What it feels like
Parents often describe this as easier than they expected: a short procedure, a few hours at the hospital, and a child back to normal the next day. The harder part is waiting for the follow-up test to find out whether it worked.
Choosing a treatment
Parents weigh the easier procedure against its lower success, and it can be hard to decide.
What helpsAsk for success rates for your child's grade and for the surgeon's own results. There is no single right answer, and either choice is reasonable for many children.
The morning of
Anxiety about anesthesia, even for a short procedure.
What helpsBring comfort items, and ask to stay until your child is asleep.
Waking up
Children may be groggy, cry or seem upset for a short while, even without pain.
What helpsHold and comfort your child. It usually passes within half an hour.
The first pee
Stinging, and some children try to hold it.
What helpsEncourage drinks, let them sit and relax, and if allowed, pee in a warm bath.
The next day
Most children are back to their usual selves, and many parents are surprised by how quick it was.
What helpsReturn to normal routines, with plenty of fluids.
Waiting for the follow-up X-ray
Weeks of uncertainty about whether the reflux is gone.
What helpsAsk when the test will be and how you will hear the results. If reflux remains, a second injection or surgery are good options.
How well it works
Success means the reflux is gone on the follow-up X-ray and your child stays free of kidney infections.
- After one injection
In a large review of studies, reflux went away in about 8 in 10 ureters with grades 1 and 2, about 7 in 10 with grade 3, about 6 in 10 with grade 4, and about half with grade 5. Results vary with surgeon experience and technique.
- After a second injection
A second injection raises the overall success to roughly 8 to 9 in 10 ureters in many reports.
- Lasting results
In some children whose reflux was gone after injection, it returns over the following years. Kidney infections with fever can still happen in a small number of children.
- How it is checked
A follow-up VCUG and kidney ultrasound, and watching for fevers or urine infections.
Risks
Every operation has risks. These are the ones people ask about most, with honest odds where good numbers exist. Your surgeon’s own results matter more than averages.
Common
Common for a day or two.
A little pink urine for a day or two.
The most common reason for a second injection or surgery. More likely with higher grades.
Less common
Can still happen, especially with constipation or holding habits.
Some children whose reflux was gone at first have it again on later tests.
Reflux sometimes appears on the untreated side and often goes away on its own.
Over years, the gel can harden with calcium and look like a stone in the lower ureter on X-rays or CT scans. It is harmless, but tell future doctors about the injection so it is not mistaken for a stone.
Rare
Rarely the gel mound blocks urine flow, causing pain in the side and vomiting. A temporary stent may be needed.
Serious problems with a brief anesthetic in a healthy child are very rare.
Call your care team or go to the emergency room if
- Fever of 101°F (38.3°C) or higher
- Pain in the side or back, especially with vomiting
- No urine for 8 hours, or straining without passing urine
- Bright red urine or clots
- Vomiting or not able to keep fluids down
- Burning, foul-smelling urine, new daytime accidents in a toilet-trained child, or belly pain
Questions to ask your surgeon
- What grade is my child's reflux, and what is the chance of success with injection for that grade?
- How many injections do you perform each year, and what are your own results?
- How does injection compare with ureteral reimplantation for my child?
- What happens if the first injection does not work?
- Should my child keep taking the daily antibiotic, and until when?
- Will we need a follow-up VCUG, and when?
- What should we do about constipation and toilet habits before and after?
- Can the gel cause any problems later in life?
- Which symptoms should make us call you?
Words you may hear
- Vesicoureteral reflux (VUR)
- Urine flowing backward from the bladder up the ureter toward the kidney.
- Deflux
- The brand name of the gel used for this injection.
- Dextranomer/hyaluronic acid
- The two sugar-based substances that make up the gel.
- Cystoscope
- A thin camera passed through the urethra to see inside the bladder.
- Ureteral orifice
- The opening of the ureter inside the bladder.
- Trigone
- The triangle-shaped area on the bladder floor where the ureters open.
- VCUG
- Voiding cystourethrogram: an X-ray taken as the bladder fills with dye and empties, to show reflux.
- Reflux grade
- A scale from 1 (mild) to 5 (severe) describing how much urine flows back.
- Antibiotic prophylaxis
- A small daily dose of antibiotic to prevent infections.
- Ureteral reimplantation
- Surgery that rebuilds a longer tunnel for the ureter in the bladder wall.
- Calcification
- Hardening of tissue or gel with calcium, which can show up on X-rays.
Common questions
Is it safe for the gel to stay in the body?
Yes. The gel has been used for reflux in the United States since 2001. The body forms a thin layer of tissue around it, and it stays in place.
Will my child need an incision or a catheter?
No incision is needed, and most children go home without a catheter.
Can the injection be repeated?
Yes. If reflux remains, a second injection is often offered, and it raises the overall chance of success.
If the injection does not work, can my child still have surgery?
Yes. Ureteral reimplantation remains possible and works well after an injection, although the gel can make the operation a little more involved.
Will the gel show up on future scans?
It can. Years later it may look like a small stone near the bladder on X-rays or CT scans. Tell future doctors about the injection.
Would my child have outgrown the reflux anyway?
Some children would have, especially with lower grades, which is why many families watch and wait first. Your urologist can estimate your child's chances.
Sources this page draws on
- American Urological Association (AUA), Management and Screening of Primary Vesicoureteral Reflux in Children: AUA Guideline (2010)
- The Journal of Urology, Endoscopic therapy for vesicoureteral reflux: a meta-analysis. I. Reflux resolution and urinary tract infection (2006)
- New England Journal of Medicine, Antimicrobial Prophylaxis for Children with Vesicoureteral Reflux (RIVUR trial) (2014)
- European Association of Urology (EAU) and European Society for Paediatric Urology (ESPU), Guidelines on Paediatric Urology
- Urology Care Foundation, Vesicoureteral Reflux (VUR)
Written November 2026. This page explains what usually happens. It is not medical advice and does not replace a conversation with your own surgeon, whose plan for you comes first.