### Date : 2024-06-24 17:44 ### Topic : Contraindications of Cerebral Angiography #medicine #neurology #angiography #stroke ---- ### Contraindications of Cerebral Angiography Cerebral angiography, also known as cerebral arteriography, is an imaging procedure used to visualize the blood vessels in the brain. It involves injecting a contrast dye into the cerebral arteries and taking X-ray images. While it is a valuable diagnostic tool for detecting vascular abnormalities such as aneurysms, stenoses, and arteriovenous malformations (AVMs), it has several contraindications. These contraindications can be absolute or relative, depending on the specific clinical scenario. ### Absolute Contraindications 1. **Severe Contrast Allergy:** - Patients with a history of severe allergic reactions (anaphylaxis) to iodinated contrast media are at high risk of another severe reaction, making the procedure unsafe without appropriate premedication or use of alternative imaging methods. 2. **Severe Renal Insufficiency:** - Patients with significantly impaired kidney function (e.g., those with chronic kidney disease or acute kidney injury) are at high risk of contrast-induced nephropathy, which can further damage the kidneys. 3. **Uncontrolled Coagulopathy:** - Patients with uncorrected bleeding disorders or on anticoagulant therapy that cannot be safely discontinued are at risk of serious bleeding complications during the procedure. 4. **Severe Uncontrolled Hypertension:** - High blood pressure can increase the risk of complications such as vessel rupture or hemorrhage during the procedure. ### Relative Contraindications 1. **Mild to Moderate Renal Insufficiency:** - Patients with reduced kidney function may still undergo the procedure with careful hydration, use of low- or iso-osmolar contrast agents, and pre- and post-procedural renal protective measures. 2. **Pregnancy:** - Although the risk to the fetus from radiation and contrast exposure is a concern, the procedure may be justified if the benefits outweigh the risks and if other imaging modalities are insufficient. 3. **Unstable Cardiac Conditions:** - Patients with unstable angina, recent myocardial infarction, or severe heart failure may be at increased risk during the procedure. However, if the angiography is essential, it may still be performed with appropriate cardiac monitoring and support. 4. **Infection at the Access Site:** - Local infection at the intended catheter insertion site (typically the femoral artery) can increase the risk of systemic infection. The procedure may be postponed until the infection is resolved or an alternative access site may be used. 5. **Dehydration:** - Dehydrated patients are at higher risk for contrast-induced nephropathy. Adequate hydration before and after the procedure can mitigate this risk. ### Pre-Procedural Considerations - **Allergy Prophylaxis:** For patients with a known contrast allergy, premedication with corticosteroids and antihistamines may be considered to reduce the risk of an allergic reaction. - **Renal Protection:** Measures to protect renal function include hydration, minimizing the volume of contrast used, and using non-ionic, low-osmolar or iso-osmolar contrast agents. - **Coagulation Status:** Ensure that the patient's coagulation parameters are within acceptable ranges. Temporarily discontinuing anticoagulants may be necessary, with a careful balance to prevent thrombotic complications. - **Blood Pressure Control:** Manage and stabilize blood pressure before the procedure to minimize the risk of vascular complications. ### Example Case Scenario **Patient Profile:** - **Name:** Jee Hoon Ju - **Age:** 60 - **Medical History:** Chronic kidney disease (eGFR 40 mL/min), hypertension, and a previous mild allergic reaction to contrast dye. **Clinical Scenario:** - Jee Hoon Ju is scheduled for cerebral angiography to evaluate a suspected intracranial aneurysm. **Pre-Procedural Management:** - **Allergy Prophylaxis:** Premedication with corticosteroids and antihistamines due to a previous mild allergic reaction. - **Renal Protection:** Adequate hydration before and after the procedure and use of low-osmolar contrast media to minimize renal impact. - **Blood Pressure Control:** Ensure blood pressure is within target range before the procedure. **Procedure Decision:** - Proceed with caution, given the controlled risks and the necessity of the diagnostic information from the cerebral angiography. ### Conclusion Cerebral angiography is a critical diagnostic tool with specific contraindications that need careful consideration. Absolute contraindications like severe contrast allergy, severe renal insufficiency, uncontrolled coagulopathy, and severe uncontrolled hypertension generally preclude the procedure. Relative contraindications require a risk-benefit analysis and appropriate pre-procedural preparation to mitigate risks. Understanding these contraindications and implementing pre-procedural measures ensures patient safety and optimal outcomes.