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Introduction ⬇

An angiogram, also known as angiography, is a vascular imaging study that utilizes contrast dye injected via catheterization to visualize blood flow though the arterial system. Digital subtraction angiography (DSA) is an imaging procedure whereas a precontrast image (mask image) is obtained and then “subtracted” from postcontrast images. The resulting image shows only the distribution of the contrast substance. DSA is used to isolate a clinically relevant subset of information and is particularly useful in preoperative and postoperative evaluations for anomalies, vascular, and tumor surgery.

Vasculature studies can be performed to evaluate carotid vessels; intracranial vessels; those vessels originating from the aortic arch; abdominal vessels, including the celiac, renal, and mesenteric branches; and other, peripheral vessels. Although carrying a greater complication risk, intra-arterial injection can be used for detailed visceral studies. The presence of the contrast material blocks the path of x-rays and makes blood vessels visible.

Visualization of the carotid and vertebral vasculature is possible in patients with a history of stroke, transient ischemic attacks, bruit, or subarachnoid hemorrhage. The procedure may be used as an adjunct to CT or magnetic resonance scanning and may be performed just before these studies in persons who have evidence of an aneurysm, vascular malformation, or hypervascular tumor. A biplane imaging device is used, producing simultaneous images 90° apart.

The study names are derived from the vascular structure studied and the study method used. Arteriogram refers to contrast agent studies of arterial vessels. Venous structures may also be visualized as these procedures progress. Venogram is the contrast agent study of peripheral or central veins. Lymphogram studies lymph vessels and nodes. Angiocardiogram investigates the interior of the heart and adjacent great vessels such as the pulmonary arteries. Aortogram refers to a contrast study of aortic segments such as the thoracic aorta (thoracic aortogram), the abdominal aorta (abdominal aortogram), or the lumbar aorta (lumbar aortogram).

Angiographic examinations also can be named for the route used to inject the contrast substance. For example, a renal arteriogram is performed by inserting a catheter into the abdominal aorta and then directing it into the renal artery. During a peripheral arteriogram, the contrast is injected directly into the vessel being studied (e.g., femoral artery). If done through the venous route, a large bolus of contrast medium is directly injected into a peripheral vein (e.g., venous aortography). X-ray images are taken to track the flow of contrast through the right side of the heart, the lungs, and the left side of the heart.

Procedure ⬆ ⬇

  1. Cleanse, prepare, and inject the vascular access area with a local anesthetic agent, using the sterile technique. Depending on the type of study and patient factors, this is commonly the femoral, brachial, or axillary artery.

  2. Follow standard procedure for the Seldinger technique:

    1. Puncture occurs in the femoral artery just below the inguinal ligament.

    2. A beveled compound needle containing an inner cannula pierces the artery.

    3. The needle is withdrawn slowly until there is blood flow.

    4. The needle’s inner cannula is removed, and a flexible guidewire is inserted.

    5. The needle is removed; pressure fixes the wire and reduces hemorrhage.

    6. The catheter is slipped over the wire and into the artery.

    7. The guidewire is removed, leaving the catheter in the artery.

  3. Remove the catheter after the procedure is terminated.

  4. Place a dressing over the insertion site and apply manual pressure to the puncture site for about 5 minutes (vein) and 15 minutes (artery) or until bleeding stops. Apply a pressure-assisted device to establish and maintain hemostasis, if necessary.

  5. Monitor the patient frequently for hemorrhage or hematoma formation at the insertion site.

  6. Follow guidelines in Chapter 1 for safe, effective, informed intratest care.

Clinical Implications ⬆ ⬇

Abnormal angiogram or DSA results may reveal the following conditions:

  1. Arterial stenosis

  2. Large aneurysms

  3. Intravascular or extravascular tumors or other masses

  4. Total occlusion of arteries

  5. Thoracic outlet syndrome

  6. Large or central pulmonary emboli

  7. Ulcerative plaque

  8. Tumor circulation

Interventions ⬆ ⬇

Pretest Patient Care

  1. Explain test purpose and procedure. Reinforce explanation of test benefits and risks.

  2. Ensure that the patient is coherent and cooperative and is able to hold their breath and remain absolutely still when so instructed.

  3. Confirm that an informed consent form is properly signed and witnessed.

  4. Follow iodine contrast test precautions.

  5. Determine whether the patient has any known allergies, especially those to iodine, contrast media, or latex.

  6. Assess pregnancy status of female patients. If positive, advise the radiology department.

  7. Ensure that preprocedure lab work is performed in accordance with departmental standards. This generally will include the following tests:

    1. PT drawn on day of procedure for any patients on anticoagulation therapy (e.g., warfarin sodium)

    2. Creatinine levels for all patients

    3. Recent PT and partial thromboplastin time and platelet count (generally within 30 days)

  8. Administer glucagon intravenously just before abdominal examinations, if ordered. This serves to reduce motion artifacts by stopping peristalsis.

  9. Be alert to the risk of venous thrombosis and infection. When contrast is administered through the venous route, the arteries—which are normally under higher pressure than the veins—can clear the contrast agent through the process of normal circulation. For the same reason, there is less risk for loosening plaques.

  10. Advise the patient that no food (6 hours) or clear fluids (2 hours) should be taken before the study to minimize vomiting if an iodine contrast reaction occurs.

  11. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

Clinical Alert

  1. These tests should be used cautiously in patients with renal insufficiency or unstable cardiac disease. Assess for contraindications to iodinated contrast drugs.

  2. In the presence of diabetes, assess whether the patient is taking metformin. Because of an increased risk for AKI and lactic acidosis, this medication regimen must be discontinued the day of and several days after administration of contrast media. Consult the radiology department for specific instructions.

Posttest Patient Care

  1. Review test results; report and record findings. Modify the nursing care plan as needed.

  2. Check vital signs frequently and report unstable signs to the healthcare provider.

  3. Observe the catheter insertion site for signs of infection, hemorrhage, or hematoma. Use sterile aseptic technique at all times. Monitor neurovascular status of the extremity. Report problems to the healthcare provider promptly.

  4. Observe for allergic reactions to iodine. Mild side effects include nausea, vomiting, dizziness, and urticaria. Assess for other complications such as abdominal pain, hypertension, heart failure, angina, myocardial infarction, and anaphylaxis. In susceptible persons, AKI may occur because higher doses of contrast materials are given compared with conventional arteriograms. Resuscitation equipment and emergency supplies should be readily available. Immediately report these conditions to the healthcare provider.

  5. Instruct the patient to increase fluid intake, unless contraindicated, to at least 2000 mL (2 L) during the 24 hours following the procedure to facilitate excretion of the iodine contrast substance.

  6. Review test outcomes and monitor appropriately.

  7. Follow guidelines in Chapter 1 for safe, effective, informed posttest care.

Clinical Alert

  1. The catheter puncture site must be observed frequently and monitored closely for hemorrhage, pseudoaneurysm, or hematoma formation. These can be serious complications and require immediate attention should they occur.

  2. Vital sign assessment, puncture site assessment, and neurovascular assessments may need to be done as frequently as every 15 minutes for the first few hours after the procedure. Neurovascular assessments include evaluation of color, motion, sensation, capillary refill time, pulse quality, and temperature (warm or cool) of the affected extremity. Compare the affected extremity with the nonaffected extremity.

  3. Review the chart or question the patient or healthcare provider regarding deficits that were present before the procedure to establish baseline levels of circulatory function. Report post procedure changes immediately.

  4. If a femoral arterial puncture was performed, the affected extremity must not be bent for several hours, and the patient must lie flat other than a pillow under the head. Do not raise the head of the bed or cart because this can put a strain on the puncture site. The patient may turn if the affected extremity is maintained in a straight position without putting strain on the femoral puncture site. If needed, a fracture bedpan can lessen strain on a groin puncture site.

  5. If bleeding or hematoma occurs, apply pressure to the site. Sometimes, a pressure assistive device may be applied to the puncture site as a routine part of post procedure protocols.

  6. Maintain a functional IV access site. Usually, the patient will return to the nursing unit with an IV line in place.

  7. Utilize a Doppler ultrasound device to identify audible pulse sounds if pulses are nonpalpable.

  8. Note sudden onset of pain, numbness or tingling, greater degree of coolness, decreased or absent pulses, and blanching of extremities as they are always cues to notify the healthcare provider immediately. These signs can indicate arterial occlusion, which may require rapid surgical intervention.

Interfering Factors ⬆ ⬇

  1. Because this examination is very sensitive to physical movement, motion artifact will produce poor images. Consequently, uncooperative or agitated patients cannot be studied. Even the act of swallowing results in unsatisfactory images. Measures to reduce swallowing, such as breath-holding, do not always yield satisfactory results.

  2. Vessel overlap of external and internal carotid arteries makes it almost impossible to obtain a select view of a specific carotid artery because contrast fills both arteries almost simultaneously.

Reference Values ⬆

Normal

Normal carotid arteries, vertebral arteries, abdominal aorta and its branches, renal arteries, and peripheral arteries