Vesicoureteral Reflux

On this page

VUR Basics - Backflow Blues

  • Definition: Retrograde flow of urine from bladder to ureter/kidney.
  • Types:
    • Primary VUR: Most common; due to incompetent ureterovesical junction (UVJ) from congenital short intravesical ureter.
    • Secondary VUR: Acquired; due to ↑ bladder pressure (e.g., posterior urethral valves, neurogenic bladder).
  • Epidemiology: Affects 1-2% of children; higher in those with UTIs. F>M.

Normal vs. VUR ureterovesical junction

⭐ Primary VUR often resolves spontaneously, especially lower grades, by age 5-6 years due to UVJ maturation (ureter elongation).

Etiology & Pathophysiology - Faulty Flaps

VUR arises from an incompetent vesicoureteral junction (VUJ). The normal "flap-valve" mechanism, due to oblique ureteric entry, is faulty.

TypePathophysiologyKey Causes
Primary VURCongenital VUJ anatomical defect; faulty flap-valve.- Short/lateral ectopic intravesical ureteric tunnel.
- Abnormal ureteric orifice ("golf-hole").
Secondary VURAcquired; ↑ bladder pressure overcomes VUJ or VUJ damage/inflammation.- Bladder Outlet Obstruction (BOO) e.g., PUV.
- Neurogenic bladder.
- Dysfunctional voiding.

⭐ The most common anatomical defect in primary VUR is a congenitally short intravesical (intramural) ureter.

Clinical Features & Complications - Trouble Track

  • Clinical Presentation:
    • Recurrent febrile UTIs: Hallmark, especially in young children.
    • Hydronephrosis: Detected on ultrasound (antenatal/postnatal), indicates urine backup.
    • Failure to Thrive (FTT): Poor weight gain/growth in infants with severe VUR/frequent UTIs.
    • Other: Abdominal/flank pain, enuresis.
  • Complications (Trouble Track):
    • Renal Scarring (Reflux Nephropathy): Irreversible kidney damage from infections & high-pressure reflux. DMSA scan showing renal scarring in VUR
    • Hypertension: Secondary to renal scarring & altered renin-angiotensin activity.
    • Chronic Kidney Disease (CKD): Progressive loss of kidney function, may lead to ESRD.

⭐ Breakthrough febrile UTIs despite antibiotic prophylaxis often indicate need for surgical VUR correction.

Diagnosis & Grading - Scan & Score

  • Investigations:

    • VCUG/MCUG (Voiding Cystourethrogram/Micturating Cystourethrogram): Gold standard for diagnosis & grading.
    • DMSA Scan (Dimercaptosuccinic Acid): Detects renal cortical scarring.
    • Ultrasound (KUB): Initial; assesses hydronephrosis, renal size, anomalies.
  • International VUR Grading System:

GradeDescription & Significance
IUreter only, non-dilated. Minimal significance.
IIUreter & pelvicalyceal system (PCS), no dilatation. Low risk.
IIIMild/mod ureter & PCS dilatation; mild fornix blunting. Moderate scarring risk.
IVMod ureter & PCS dilatation/tortuosity; obvious fornix blunting. High scarring risk.
VGross ureter & PCS dilatation/tortuosity; papillary impressions lost. Highest damage risk.

⭐ VCUG is key: performed during voiding, when reflux commonly occurs.

Management Strategies - Fixing the Flow

Goals: Prevent pyelonephritis & renal damage.

  • Observation: Low grades (I-II) often resolve spontaneously.
  • Medical (CAP): Continuous Antibiotic Prophylaxis (e.g., TMP-SMX, Nitrofurantoin).
    • Indications: All grades if recurrent febrile UTI (fUTI), renal scarring; Grade III-V; Age <1 yr.
  • Surgical:
    • Indications: Breakthrough fUTI on CAP, new/progressive renal scars, persistent high-grade VUR (IV-V esp. >2-3 yrs), non-compliance/intolerance to CAP.
    • Types:
      • Ureteral reimplantation (Open/Robotic).
      • Endoscopic injection (e.g., Deflux).

⭐ Endoscopic Deflux: less invasive, generally lower success rates for high-grade VUR compared to open reimplantation.

High‑Yield Points - ⚡ Biggest Takeaways

  • Vesicoureteral Reflux (VUR) is a key cause of recurrent pediatric UTIs, risking renal scarring.
  • Voiding Cystourethrogram (VCUG) is the gold standard for diagnosis and grading (I-V).
  • Low grades (I-II) often resolve spontaneously; higher grades may require intervention.
  • Antibiotic prophylaxis is key to prevent UTIs and subsequent renal damage.
  • Renal scarring, hypertension, and CKD are major long-term complications.
  • Surgical correction (e.g., ureteral reimplantation) is for severe/persistent VUR or breakthrough UTIs.

Practice Questions: Vesicoureteral Reflux

Test your understanding with these related questions

An otherwise asymptomatic child was found to have hypertension. On further evaluation, his urine analysis revealed 2-3 pus cells/HPF and 2-4 RBCs. Which of the following would be the most likely diagnosis?

1 of 5

Flashcards: Vesicoureteral Reflux

1/10

Duplex collecting system is strongly associated with vesicoureteral _____ and/or ureteral obstruction

TAP TO REVEAL ANSWER

Duplex collecting system is strongly associated with vesicoureteral _____ and/or ureteral obstruction

reflux

browseSpaceflip

Enjoying this lesson?

Get full access to all lessons, practice questions, and more.

Start Your Free Trial