In Japan, vesicoureteral Reflux is managed by nephrologists. Vesicoureteral reflux (VUR) is the retrograde flow of urine from the bladder up the ureter and sometimes into the kidney, predisposing to febrile urinary tract infections, pyelonephritis, and renal scarring. Primary VUR is present in roughly 1-3% of healthy children and is found in 30-40% of children evaluated after a first febrile UTI.
Vesicoureteral reflux (ICD-10: N13.70 unspecified, N13.71 without reflux nephropathy, N13.72 with reflux nephropathy without hydroureter, N13.73 with reflux nephropathy with hydroureter) is the retrograde flow of urine from the bladder into one or both ureters and possibly into the renal pelvis and intrarenal collecting system. Primary VUR is caused by a deficient ureterovesical junction (short submucosal ureteric tunnel, abnormal angle of insertion) that fails to provide a competent flap-valve mechanism during bladder filling and voiding. Secondary VUR is the consequence of elevated bladder pressure or distal obstruction, including posterior urethral valves, neurogenic bladder, dysfunctional voiding, and severe bladder outlet obstruction. The International Reflux Study Committee grades VUR I to V based on the voiding cystourethrogram appearance: grade I (reflux into ureter only), II (reflux up to renal pelvis without dilatation), III (mild ureteric and pelvic dilatation), IV (moderate dilatation with blunting of fornices), and V (severe dilatation with tortuous ureter and loss of papillary impressions).
The key symptoms of Vesicoureteral Reflux are: Febrile urinary tract infection in an infant or young child, often with fever above 38.5°C, irritability, poor feeding, and vomiting; UTI is the typical presentation of previously undiagnosed VUR., Recurrent febrile UTIs (two or more episodes), often with the same or different organisms; pattern raises suspicion for VUR even before imaging., Pyelonephritis with flank pain, costovertebral tenderness, fever, and pyuria in an older child or adolescent., Dysfunctional voiding symptoms: urgency, frequency, urinary incontinence (daytime wetting), constipation, holding maneuvers, and incomplete bladder emptying., Failure to thrive, poor weight gain, or unexplained anemia in an infant with recurrent UTIs and reflux., Hypertension in older children or adolescents with established reflux nephropathy and renal scarring., Proteinuria detected on routine urinalysis in an older child with prior pyelonephritis or known reflux nephropathy..
Diagnosis is initiated by clinical suspicion (febrile UTI, recurrent UTIs, prenatal hydronephrosis, family history, or dysfunctional voiding) and confirmed with imaging. The standard imaging pathway combines renal and bladder ultrasound with voiding cystourethrogram (VCUG), the gold-standard test for grading VUR. Ultrasound assesses for hydronephrosis, ureteric dilatation, bladder wall thickening, post-void residual, and other anatomical issues; it can suggest but cannot exclude VUR. VCUG fills the bladder with iodinated contrast through a urethral catheter and obtains fluoroscopic images during filling and voiding, grading reflux I-V by the International Reflux Study Committee. Radionuclide cystography (RNC) is a lower-radiation alternative used for follow-up after diagnosis but less anatomical detail than VCUG. Contrast-enhanced voiding ultrasound is gaining adoption as a radiation-free alternative in some centers. 99m-Tc DMSA renal scintigraphy detects renal parenchymal scarring (reflux nephropathy) and acute pyelonephritis with high sensitivity; it is recommended at baseline in high-grade VUR and after febrile UTIs. Functional bladder evaluation with non-invasive uroflowmetry and post-void residual addresses bladder-bowel dysfunction; formal urodynamics is reserved for neurogenic bladder and complex cases. Laboratory workup includes urinalysis, urine culture during UTI, complete blood count, renal function, and blood pressure measurement. Imaging follow-up depends on grade, age, and clinical course; spontaneous resolution is documented by repeat VCUG every 12-24 months until reflux resolves or surgical intervention is selected.
Most children with low-grade VUR (I-III) without renal scarring have an excellent long-term prognosis. Spontaneous resolution occurs in 80% of grade I, 60% of grade II, and 40% of grade III within 5 years; resolution is less common in higher grades and bilateral disease. Endoscopic injection and ureteric reimplantation each have high success rates (70-85% and 95-98% respectively) in achieving anatomical correction. Long-term renal outcomes depend on the presence of renal scarring at diagnosis and on prevention of recurrent pyelonephritis: children without scarring have normal long-term renal function in over 95%, while those with bilateral scarring have a 10-20% risk of progressive chronic kidney disease, hypertension, or proteinuria by adulthood. Reflux nephropathy accounts for 7-17% of pediatric end-stage renal disease and a small but meaningful share of adult dialysis. Hypertension develops in 10-30% of those with bilateral scarring during long-term follow-up. Pregnancy in women with prior VUR and renal scarring carries higher risks of pyelonephritis, hypertension, and preterm birth and warrants pre-pregnancy counseling and close obstetric monitoring.
Pediatric urology and pediatric nephrology jointly manage VUR. Pediatric urologists evaluate anatomy, perform endoscopic injection and reimplantation surgery, and manage posterior urethral valves and neurogenic bladder. Pediatric nephrologists assess renal function, hypertension, and proteinuria, and manage children with reflux nephropathy and chronic kidney disease. Referral to a pediatric center is recommended for grade IV-V VUR, breakthrough UTIs, renal scarring, and complex secondary VUR.
Find specialists →Acute UTI resolves over 7-14 days with appropriate antibiotics. Bladder-bowel dysfunction therapy yields measurable improvement over 3-6 months. Spontaneous resolution of low-grade VUR typically over 12-60 months. Endoscopic injection: bladder catheter rarely needed; return to normal activity within 24-48 hours. Open ureteric reimplantation: hospital stay 1-3 days, full recovery 4-6 weeks. Long-term monitoring with annual to biennial imaging and renal function testing for at least 5-10 years.
Normal age-appropriate physical activity is encouraged. Children with VUR participate fully in sports. After ureteric reimplantation, contact sports are typically restricted for 4-6 weeks to allow healing. After endoscopic injection, normal activity can resume within 24-48 hours.
Choose a pediatric urology center with experience in endoscopic injection (Deflux), open and minimally invasive reimplantation, and management of neurogenic bladder. Combined pediatric urology and nephrology programs offer integrated long-term care. Confirm availability of nuclear medicine (DMSA) and contrast-enhanced voiding ultrasound where preferred.
Medically reviewed by AIHealz Medical Editorial Board · May 13, 2026
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