Vesicoureteral reflux

Retrograde flow of urine from the bladder into the ureters and kidneys due to incompetent ureterovesical junction (UVJ). Primary VUR is usually a congenital UVJ defect (short intramural ureter), whereas secondary VUR results from high bladder pressures (e.g., due to outlet obstruction or neurogenic bladder).

• VUR is a common cause of recurrent pediatric urinary tract infections and can lead to pyelonephritis and permanent renal scarring. Scarring from reflux nephropathy may impair kidney growth and cause hypertension or chronic kidney disease later in life.

• Infants or young children with recurrent febrile UTIs (especially if a boy, or if <2 years old).
• Prenatal ultrasound may show hydronephrosis; postnatal evaluation then reveals VUR.
• Possible history of a sibling with VUR (familial tendency).
• Secondary VUR clues: e.g. a male infant with distended bladder and weak urinary stream (suggesting posterior urethral valves).

1. Initial test: Renal and bladder ultrasound to check for hydronephrosis or anatomic anomalies.
2. Voiding cystourethrogram (VCUG) is the gold standard to diagnose and grade VUR.
3. Consider secondary causes if VUR is detected (evaluate for posterior urethral valves in boys, dysfunctional voiding, etc.).

1. Low-grade (I–II) VUR: often managed conservatively – many cases resolve with growth. Antibiotic prophylaxis (low-dose daily antibiotics) is used to prevent UTIs while observing.
2. High-grade (III–V) or persistent VUR: higher risk of renal damage – consider surgical correction. Options include ureteral reimplantation or endoscopic injection to fix the UVJ. Indicated if breakthrough infections or new scars occur despite prophylaxis.

• Think of VCUG for VUR – the names sound similar (VCUG is the key test for reflux).
• Primary VUR tends to improve as the child grows (maturation lengthens the intramural ureter), whereas secondary VUR persists until the underlying issue is fixed.

• Any febrile UTI in a young child (<2 years) is a red flag – evaluate for possible VUR to prevent missed renal damage.
• Known VUR with breakthrough pyelonephritis or worsening hydronephrosis → escalation of care (surgical intervention) is needed to protect the kidneys.

1. Child with first febrile UTI → obtain renal ultrasound (look for hydronephrosis or scarring).
2. If ultrasound is abnormal or UTIs recur → perform VCUG to confirm and grade VUR.
3. VUR present: Grades I–II → observe with prophylaxis; Grades III–V or complications → urology referral for possible surgery.

• Toddler with recurrent fevers and UTIs; ultrasound shows renal scarring → suspect VUR causing reflux nephropathy.
• Newborn boy with bilateral hydronephrosis and poor urinary stream → think posterior urethral valves (secondary VUR).