How to evaluate for vesicoureteral reflux (VUR) in adults?

Evaluation of Vesicoureteral Reflux in Adults

Voiding cystourethrography (VCUG) is the gold standard for diagnosing vesicoureteral reflux (VUR) in adults, especially in those with recurrent pyelonephritis or complicated urinary tract infections. 1

Diagnostic Algorithm for Adult VUR

Initial Assessment

• Clinical Indicators that warrant VUR evaluation:
  • Recurrent febrile urinary tract infections
  • History of pyelonephritis
  • Renal scarring on imaging
  • Family history of VUR
  • Childhood history of VUR

Primary Diagnostic Tests

1. Voiding Cystourethrography (VCUG)

   • Gold standard for diagnosing and grading VUR in adults 1
   • Allows visualization of bladder and urethral configuration
   • Enables grading of reflux severity (Grades I-V)
   • Can detect intrarenal reflux, which carries higher risk of renal scarring 1

2. Contrast-Enhanced Voiding Urosonography (ceVUS)

   • Alternative to VCUG with less radiation exposure 1
   • Particularly useful for follow-up examinations

3. Renal Ultrasound

   • Assess for hydronephrosis, renal scarring, or anatomical abnormalities
   • Evaluate renal size and parenchymal thickness
   • Limited sensitivity for detecting VUR itself

Additional Diagnostic Tests

1. DMSA Renal Scan

   • Best nuclear agent for visualizing cortical tissue and differential function 1
   • Detects renal scarring and assesses differential renal function
   • Particularly important in cases with suspected renal damage

2. Video-Urodynamic Studies (VUDS)

   • Crucial for patients with suspected secondary VUR due to neurogenic bladder 1
   • Combines pressure-flow studies with fluoroscopic imaging
   • Can differentiate between primary and secondary VUR
   • Particularly important when VUR is detected at low bladder volumes 2

Special Considerations

Secondary VUR

• If VUR is detected at low bladder volumes during urodynamic testing, this strongly suggests secondary VUR associated with bladder dysfunction 2
• Secondary VUR requires treatment of the underlying bladder dysfunction rather than focusing solely on the reflux 2

Risk Stratification

• High-risk features requiring more aggressive evaluation:
  • Bilateral high-grade reflux
  • Renal cortical abnormalities
  • Persistent bladder dysfunction
  • Breakthrough febrile UTIs 1, 2

Management Implications

The diagnostic evaluation directly informs management decisions:

• Low-grade VUR with infrequent infections: Consider surveillance
• High-grade VUR with recurrent pyelonephritis: Consider endoscopic correction or surgical reimplantation 3, 4
• Secondary VUR: Address underlying bladder dysfunction first 2

Common Pitfalls to Avoid

1. Failing to consider VUR in adults with recurrent pyelonephritis

   • VUR is uncommon but important in adults with recurrent UTIs 5
   • Requires high index of suspicion

2. Focusing solely on the reflux without addressing underlying bladder dysfunction

   • Secondary VUR requires treatment of the underlying bladder condition 2

3. Overlooking the need for comprehensive renal function assessment

   • Patients with bilateral VUR need baseline and follow-up renal function tests 1

4. Neglecting to evaluate for intrarenal reflux

   • Associated with higher risk of renal scarring 1

VUR in adults is less common than in children but should be considered in patients with recurrent pyelonephritis. The diagnostic approach should be comprehensive, with VCUG remaining the gold standard test, supplemented by renal ultrasound, DMSA scanning, and video-urodynamics when appropriate.