Is Voiding Cystourethrogram (VCUG) contraindicated in patients with Chronic Kidney Disease (CKD)?

From the Guidelines

A Voiding Cystourethrogram (VCUG) is not absolutely contraindicated in patients with chronic kidney disease (CKD), but caution is warranted, as the most recent and highest quality study suggests that the procedure should be performed only when the diagnostic benefits outweigh the risks 1.

Considerations for VCUG in CKD Patients

The primary concern with VCUG in CKD patients is that the iodinated contrast can cause additional stress on already compromised kidneys, potentially accelerating kidney function decline.

• In CKD patients, there are concerns about contrast-induced nephropathy, which could potentially worsen kidney function.
• If a VCUG is deemed necessary, several precautions should be taken:
  • Ensure adequate hydration before and after the procedure.
  • Use the minimum amount of contrast medium required for diagnostic accuracy.
  • Consider alternative imaging techniques when possible.

Precautions and Alternatives

For patients with advanced CKD (stages 4-5), nephrology consultation prior to the procedure is advisable.

• The decision should be individualized based on the patient's specific GFR, the urgency of the diagnostic information needed, and the availability of alternative diagnostic approaches.
• Alternative imaging techniques, such as ultrasonography or nuclear cystography, may be considered to minimize the risk of contrast-induced nephropathy.

Diagnostic Benefits and Risks

The diagnostic benefits of VCUG in CKD patients must be carefully weighed against the potential risks, including contrast-induced nephropathy and radiation exposure 1.

• The procedure should only be performed when the diagnostic benefits outweigh the risks, and alternative imaging techniques have been considered.
• The use of VCUG in CKD patients should be guided by the most recent and highest quality evidence, taking into account the individual patient's specific needs and circumstances.

From the Research

Voiding Cystourethrogram (VCUG) and Chronic Kidney Disease (CKD)

• VCUG is a medical imaging technique that uses contrast agents to visualize the urinary system, including the kidneys, ureters, and bladder.
• Patients with CKD are at increased risk of contrast-induced nephropathy (CIN), a potentially serious complication of contrast agent exposure 2, 3, 4, 5, 6.

Risk Factors for CIN

• CKD is a primary predisposing factor for CIN, with estimated glomerular filtration rate <60 ml/1.73 m2 representing significant renal dysfunction and defining patients at high risk 5.
• Other modifiable risk factors for CIN include hydration status, the type and amount of contrast, use of concomitant nephrotoxic agents, and recent contrast administration 5.

Prevention of CIN

• The cornerstone of CIN prevention is adequate parenteral volume repletion, with isotonic volume expansion recommended to decrease CIN 2, 3, 4, 5.
• Withholding potentially nephrotoxic medications and considering the use of low or iso-osmolar contrast agents can also help minimize the risk of CIN 2, 3, 4, 5.
• Strategies to minimize contrast volume and avoid repeat contrast injections within 48 hours are also recommended 4.

VCUG and CKD

• While there is no direct evidence to suggest that VCUG is contraindicated in patients with CKD, the risk of CIN must be carefully considered and mitigated using the strategies outlined above 2, 3, 4, 5, 6.
• Patients with CKD should be closely monitored for signs of CIN after VCUG, and alternative imaging modalities should be considered if possible 3.