Paediatric urology · KIMS Secunderabad
Vesicoureteral Reflux (VUR) — Protecting the Kidneys from Backward Urine Flow
Vesicoureteral reflux (VUR) is the abnormal backward flow of urine from the bladder up the ureter and into the kidney — the opposite of the normal one-way flow from kidney to bladder. In healthy anatomy, the ureter enters the bladder wall at an oblique angle, creating a flap-valve mechanism that allows urine to flow downward but prevents it from being pushed back when the bladder contracts during voiding. When this mechanism is defective — from a congenitally short intramural ureter, abnormal ureteric insertion, or bladder outlet obstruction — urine refluxes back toward the kidney during voiding.
VUR matters because of what it does to the kidneys. Sterile urine refluxing into the kidney — even without infection — can cause renal parenchymal damage through the high-pressure wave of voiding. But refluxing infected urine is far more damaging: each episode of pyelonephritis in a child with VUR leaves a focal scar in the kidney — reflux nephropathy — that contributes to hypertension, proteinuria, and CKD in later life. The goal of VUR management is to prevent infected reflux while the child grows, protecting the kidneys from cumulative scarring while allowing the VUR to resolve spontaneously (which it does in the majority of low-grade cases) or correcting it surgically when resolution is unlikely.
How VUR is graded — the international grading system
VUR is graded on a 1-to-5 scale based on how far the refluxed urine reaches and how much the collecting system dilates. The grade directly predicts both the chance of spontaneous resolution and the likely need for surgical correction.
Grade I — reflux into ureter only (does not reach the kidney)
Spontaneous resolution rate: 80–90% resolve by age 5. Clinical significance: observe with antibiotic prophylaxis. The flap-valve immaturity at this grade is highly likely to mature with growth.
Grade II — reflux to kidney pelvis, no dilation of ureter or pelvis
Spontaneous resolution rate: 75–80% resolve. Clinical significance: observe, antibiotic prophylaxis. Most cases will resolve without surgical intervention.
Grade III — mild dilation of ureter and renal pelvis with mild calyceal blunting
Spontaneous resolution rate: 50–60% resolve. Clinical significance: observe or treat depending on breakthrough UTIs and kidney scarring on DMSA. Decision is individualised.
Grade IV — moderate ureteric and pelvic dilation with moderate calyceal blunting
Spontaneous resolution rate: 25–35% resolve. Clinical significance: usually requires intervention (endoscopic injection or ureteric reimplantation).
Grade V — severe dilation and tortuosity of the ureter with loss of calyceal architecture
Spontaneous resolution rate: less than 10% resolve. Clinical significance: surgical correction almost always required. Ureteric reimplantation is the definitive treatment.
Who gets VUR and why it matters
VUR is present in approximately 1% of all children and in 30 to 50% of children who present with a febrile urinary tract infection.
It runs in families — siblings of children with VUR have a 25 to 33% risk of having VUR themselves, and children of VUR-affected parents have a 35 to 45% risk.
VUR is the cause of reflux nephropathy — focal cortical scars from recurrent pyelonephritis episodes — which accounts for 5 to 15% of all end-stage renal disease in adults. This CKD is entirely preventable if VUR is detected and managed early.
Girls are more commonly diagnosed with symptomatic VUR (because UTIs are more common in girls, prompting investigation).
Boys often have more severe grades of VUR but fewer symptomatic UTIs (because the longer male urethra reduces ascending infection).
Diagnosis at KIMS
VCUG (Voiding Cystourethrogram)
The gold standard for VUR diagnosis and grading. Contrast is instilled into the bladder through a urethral catheter, and X-ray images are taken during filling and voiding. Contrast refluxing into the ureter and kidney is directly visualised and graded. VCUG is recommended after a first febrile UTI in children who have not responded normally to antibiotics, in all children with a second febrile UTI, and in children with antenatal hydronephrosis or a family history of VUR.
DMSA (Dimercaptosuccinic acid) scan
A nuclear medicine scan that uses a radiotracer selectively taken up by functioning renal cortex. In reflux nephropathy, cortical scars appear as areas of absent uptake on DMSA. The scan has two roles: detecting acute pyelonephritis (the affected area of kidney shows reduced function 4 to 6 months after the acute episode if scarring has occurred), and assessing the differential function of each kidney (essential before surgical correction and for long-term follow-up).
Renal and bladder ultrasound
Identifies hydronephrosis, ureteric dilation, and bladder abnormalities. Not sensitive for detecting low-grade VUR (grades I and II are often missed on ultrasound alone) but useful for assessing the degree of renal dilation and detecting bladder outlet obstruction.
Treatment — observation, antibiotic prophylaxis, or surgery
Continuous antibiotic prophylaxis (CAP)
Low-dose daily antibiotics — trimethoprim or nitrofurantoin — prevent UTIs in children with VUR during the years of observation while awaiting spontaneous resolution. The evidence for CAP reducing kidney scarring compared to observation alone is debated — the RIVUR trial showed modest benefit in reducing febrile UTI recurrence but not in reducing kidney scarring. CAP is continued until: the VUR resolves on follow-up VCUG, surgical correction is performed, or the child grows old enough (typically above 5 to 6 years) that spontaneous resolution becomes unlikely and the risk-benefit of long-term antibiotics is reassessed.
Endoscopic submucosal injection (STING/HIT procedure)
A minimally invasive endoscopic procedure — a bulking agent (dextranomer/hyaluronic acid — Deflux) is injected beneath the ureteric orifice through a cystoscope, creating a mound that reconstructs the flap-valve mechanism and prevents reflux. Performed as a day-case under general anaesthesia at KIMS. Success rate (VUR resolution or downgrading) of 80 to 90% for grades II and III after a single injection; lower success for grades IV and V. May require repeat injection. First-choice surgical intervention for grades II to IV VUR in most centres.
Open or laparoscopic ureteric reimplantation
The definitive surgical correction for high-grade VUR (grade IV and V) or VUR that has not responded to endoscopic injection. The ureter is detached from the bladder and reimplanted through a new, longer submucosal tunnel — recreating the flap-valve mechanism. Success rate above 95% for primary VUR. Open ureteric reimplantation (Cohen or Politano-Leadbetter technique) has a very high long-term success rate and is the procedure of choice for high-grade VUR requiring definitive correction. Laparoscopic or robotic approaches are available for selected cases.
VUR screening in siblings and children of affected individuals: siblings of a child with VUR have a 25 to 33% risk of VUR — paediatric urology screening with renal ultrasound is recommended for all siblings below age 3. Children of adults with a history of VUR (particularly if they have reflux nephropathy or hypertension) have a 35 to 45% risk — screen with renal ultrasound in infancy.
Book a VUR Assessment at KIMS — VCUG, DMSA, and Surgical Correction Available
Frequently Asked Questions — VUR
Yes — VUR is present in 30 to 50% of children who present with febrile urinary tract infections (pyelonephritis). If your child has had two or more febrile UTIs, or one severe febrile UTI with hospitalisation, a VCUG (voiding cystourethrogram) and renal ultrasound should be performed to determine whether VUR is contributing. The investigation is important because untreated VUR with recurrent pyelonephritis causes cumulative kidney scarring — a preventable cause of adult CKD and hypertension. Contact KIMS Paediatric Renal Centre at 040-4488-5000 for a VUR evaluation appointment.
No — the majority of low-grade VUR (grades I, II, and many grade III cases) resolves spontaneously as the child grows and the intramural ureter lengthens. These cases are managed with observation and antibiotic prophylaxis until resolution is confirmed on follow-up VCUG. Surgery is recommended for: high-grade VUR (grades IV and V) that is unlikely to resolve, breakthrough pyelonephritis despite antibiotic prophylaxis, VUR in a child with progressive kidney scarring on DMSA scans, or VUR that has not resolved by age 5 to 6 in higher grades. The KIMS paediatric urology team reviews each case individually and recommends the approach based on the VUR grade, kidney function, and clinical history.
VCUG (voiding cystourethrogram) is a radiology procedure in which a catheter is placed into the bladder through the urethra, contrast dye is instilled until the bladder is full, and X-ray images are taken during filling and then during voluntary voiding. The catheter insertion causes brief discomfort — similar to a urinary catheter insertion. The procedure itself is not painful once the catheter is in place. In young children and infants, the procedure is performed by experienced paediatric radiology staff with appropriate preparation and minimal handling time. Cyclic VCUG (performing the bladder fill and void cycle two or three times) increases the sensitivity for detecting intermittent VUR.
Yes — repeated episodes of infected urine refluxing into the kidney (pyelonephritis in the context of VUR) cause focal cortical scars — reflux nephropathy. Each episode of pyelonephritis can add another scar. Over years, cumulative scarring reduces the functional kidney mass, causing: hypertension (in 10 to 20% of children with bilateral reflux nephropathy), proteinuria (a marker of glomerular hyperfiltration in the remaining functional kidney tissue), and CKD in adult life. This is why reflux nephropathy is responsible for 5 to 15% of all ESRD in adults — a consequence of untreated or inadequately managed childhood VUR. Early detection and management prevents this scarring.
Yes — VUR has a strong genetic component. Siblings of children with VUR have a 25 to 33% risk of VUR themselves. Children born to parents with a history of VUR have a 35 to 45% risk. The inherited abnormality is typically in the development of the ureterovesical junction — the length and insertion angle of the intramural ureter. Because of this familial risk, sibling screening with renal ultrasound (and VCUG if hydronephrosis is present) is recommended for all siblings below age 3 of a child diagnosed with VUR.
Deflux (dextranomer/hyaluronic acid) is a biocompatible gel that is injected endoscopically beneath the ureteric orifice through a cystoscope — creating a raised mound that reconstructs the ureteric tunnel and prevents reflux. The procedure is performed as a day-case under general anaesthesia and takes approximately 10 to 15 minutes. Success rates (VUR resolution or reduction to grade I on follow-up VCUG at 3 months) are 80 to 90% for grades II and III after a single injection. Higher-grade VUR has lower success rates with injection alone. The Deflux injection is preferred over open surgery for grades II to III VUR as the first surgical intervention because of its minimal invasiveness and short recovery. If the first injection fails, a second injection or open reimplantation is considered.
VUR that was not detected and managed in childhood may cause lasting consequences in adulthood: reflux nephropathy (kidney scars from recurrent childhood pyelonephritis), hypertension (from the scarred kidney producing excess renin), proteinuria (from hyperfiltration in the remaining functional kidney tissue), and CKD. Women with a history of childhood VUR are at higher risk of recurrent UTIs and pyelonephritis during pregnancy — which can cause preterm labour — and should inform their obstetrician and nephrologist. Adults with unexplained CKD, hypertension, or recurrent UTIs and a history of childhood kidney infections should be evaluated for reflux nephropathy with DMSA imaging.
KIMS Secunderabad — Dr. Neil Narendra Trivedi (MCh Urology KEM Mumbai, Member SIU, Paediatric Urology), VCUG, DMSA scan, antibiotic prophylaxis programme, endoscopic Deflux injection, open ureteric reimplantation, KIMS Paediatric Renal Centre coordination. NABH and NABL accredited. Call 040-4488-5000.