Vesicoureteric reflux

Overview & Definition

A child who presents with a febrile urinary tract infection in infancy, or an infant found to have hydronephrosis on the antenatal scan, leads the clinician to the diagnosis of vesicoureteric reflux. The condition is the retrograde flow of urine from the bladder up into the ureter and the renal pelvis, and it is the most common urological abnormality in children, found in approximately 1 to 2 percent of all children and in up to 30 to 40 percent of those who present with a febrile urinary tract infection. The abnormality lies at the ureterovesical junction, where the ureter enters the bladder through a short or absent intramural tunnel that fails to act as a one-way valve. [8]

The clinical significance of reflux is twofold. First, it allows infected bladder urine to ascend to the kidney, which converts a lower urinary tract infection into pyelonephritis and causes renal scarring. Second, the refluxing urine creates a residual volume that predisposes to recurrent infection. The scarred kidney carries a life-long risk of hypertension, proteinuria, and chronic kidney disease, and in pregnancy it increases the risk of pre-eclampsia. This cascade from a febrile infection to permanent renal damage is the entire rationale for the investigation, grading, and management of reflux. [8]

Primary reflux is the congenital form, in which the ureterovesical junction is structurally abnormal from a short intramural tunnel, and it is the form that resolves spontaneously as the child grows. Secondary reflux arises from a high-pressure or abnormal bladder, such as posterior urethral valves, a neurogenic bladder, or bladder and bowel dysfunction, and it persists until the underlying cause is treated. The distinction is critical, because primary reflux is managed on the grade and the infection history, while secondary reflux is managed by treating the bladder. [3]

References12Show ledgerHide ledger

1. [1]Lebowitz RL, Olbing H, Parkkulainen KV, et al. International system of radiographic grading of vesicoureteric reflux. International Reflux Study in Children. Pediatr Radiol, 1985.PMID 3975102
2. [2]Hoberman A, Greenfield SP, Mattoo TK, et al. Antimicrobial prophylaxis for children with vesicoureteral reflux. N Engl J Med, 2014.PMID 24795142
3. [3]Peters CA, Skoog SJ, Arant BS Jr, et al Summary of the AUA Guideline on Management of Primary Vesicoureteral Reflux in Children. J Urol, 2010.PMID 20650499
4. [4]Mathews R, Mattoo TK The role of antimicrobial prophylaxis in the management of children with vesicoureteral reflux--the RIVUR study outcomes. Adv Chronic Kidney Dis, 2015.PMID 26088078
5. [5]Elder JS, Diaz M Vesicoureteral reflux--the role of bladder and bowel dysfunction. Nat Rev Urol, 2013.PMID 24126731
6. [6]Stein R, Dogan HS, Hoebeke P, et al Urinary tract infections in children: EAU/ESPU guidelines. Eur Urol, 2015.PMID 25477258
7. [7]Kirsch AJ, Cooper CS, Läckgren G Non-Animal Stabilized Hyaluronic Acid/Dextranomer Gel (NASHA/Dx, Deflux) for Endoscopic Treatment of Vesicoureteral Reflux: What Have We Learned Over the Last 20 Years? Urology, 2021.PMID 34411597
8. [8]Mattoo TK, Mohammad D Primary Vesicoureteral Reflux and Renal Scarring. Pediatr Clin North Am, 2022.PMID 36880925
9. [9]Mattoo TK, Shaikh N, Nelson CP Contemporary Management of Urinary Tract Infection in Children. Pediatrics, 2021.PMID 33479164
10. [10]Zhao B, Ivanova A, Shaikh N, et al Antimicrobial prophylaxis for vesicoureteral reflux: which subgroups of children benefit the most? Pediatr Nephrol, 2024.PMID 38244067
11. [11]Farhat W, McLorie G, Geary D, et al The natural history of neonatal vesicoureteral reflux associated with antenatal hydronephrosis. J Urol, 2000.PMID 10958740
12. [12]Connolly LP, Zurakowski D, Connolly SA, et al Natural history of vesicoureteral reflux in girls after age 5 years. J Urol, 2001.PMID 11696785