Norm of Digital Subtraction Angiography (DSA) and Transvenous Digital Subtraction
Normal carotid arteries, vertebral arteries, abdominal aorta and branches, renal arteries, and peripheral vessels.
Usage of Digital Subtraction Angiography (DSA) and Transvenous Digital Subtraction
Aneurysms, aortic valvular stenosis, arterial occlusion, bypass surgery (postoperative), carotid stenosis, dural sinus thrombosis, hepatocellular carcinoma, jugular tumors, nutcracker renal phenomenon, pheochromocytoma, pulmonary emboli, thoracic outlet syndrome, and ulcerative plaques.
Description of Digital Subtraction Angiography (DSA) and Transvenous Digital Subtraction
A noninvasive computer imaging procedure that allows examination of the arteries in the body after an IV injection of contrast medium. Images of the cardiac region are subtracted from images obtained after contrast medium injection as the dense images of soft tissue and bone are removed by the computer. There is less discomfort and risk of complications than with an arteriogram, but visualization of the arteries is less precise, and visualization of stenotic lesions in sequential branches may not occur.
Professional Considerations of Digital Subtraction Angiography (DSA) and Transvenous Digital Subtraction
Consent form IS required.
Allergic reaction to dye (itching, hives, rash, tight feeling in the throat, shortness of breath, bronchospasm, anaphylaxis, death), aphasia, hemiplegia, hemorrhage, paresthesia, thromboemboli, infection, renal toxicity from contrast medium.
Recent myocardial infarction, severe renal failure, previous allergy to dye, iodine, or shellfish; during pregnancy (because of radioactive iodine crossing the blood-placental barrier).
- Assess for normal renal function.
- Have emergency equipment readily available.
- Glycogen may be administered intravenously to reduce motion artifacts by stopping peristalsis.
- Record baseline vital signs.
- Just before beginning the procedure, take a “time out” to verify the correct client, procedure, and site.
- A local anesthetic is given over the basilic or cephalic veins in the antecubital area.
- Venous catheterization is performed and iodine contrast medium is injected at a rate of 14 mL/second.
- Radiographic images are taken of arteries made visible by the contrast medium.
- Monitor vital signs every 15 minutes until stable.
- Observe the puncture site of catheterization for infection, hemorrhage, and hematoma.
- Force fluids after the procedure to help flush the contrast medium through the kidneys. A liter of IV fluid may be given as a precautionary measure to clients having an increased risk of developing renal toxicity from the contrast medium, such as the elderly, and clients with dehydration, diabetes, or multiple myeloma.
- Monitor renal function (BUN and creatinine) for 2 days after the procedure in all clients to be sure the levels remain normal. If the levels become abnormally elevated, indicating nephrotoxicity, continuous IV fluids should be given until the levels return to normal limits. An adverse reaction to IV contrast medium should be noted in a prominent place on the chart and the client informed that he or she should not receive a contrast medium in the future.
- If the study is necessary in a client with renal insufficiency, a newer, less nephrotoxic agent should be used, even though it is more expensive, and the client should be well hydrated.
Client and Family Teaching
- You must remain still during the procedure.
- The procedure takes approximately 45 minutes.
- In women who are breast-feeding, formula should be substituted for breast milk for 1 or more days after the procedure.
Factors That Affect Results
- Small amounts of motion by the individual including swallowing and respirations obscure results.
- Intracardiac or intra-arterial injection of contrast medium can also obscure results.
- The femoral vein may also be used for catheterization.
- Flat panel detectors represent the most suitable substitute for digital subtraction angiography.