arteriography

Angiography.

To locate and assess narrowing, occlusions, and other abnormalities of various arteries, especially the femoral arteries of the legs; the carotid arteries in the neck; and the arterial systems of the brain, heart, and kidneys. It also displays the vascular anatomy to organs such as the brain, liver, and gastrointestinal tract.

• X-rays are taken after a contrast agent is injected into the artery under examination.
• The contrast agent, usually an iodine solution, provides the density needed for detailed X-rays of the blood vessels.

• Blood tests are done beforehand to make sure that the blood will clot normally.
• You may be instructed to forgo aspirin and other medications that hinder blood clotting for several days before the test, and you will be instructed to fast for at least eight hours before the examination.
• A sedative (e.g., a benzodiazepine such as Valium) may be given to help you relax during the examination.
• The area where the catheter will be inserted is thoroughly cleansed and perhaps shaved; you may also be instructed to shower with an antiseptic soap.
• A local anesthetic will be injected into the skin to numb the area prior to the procedure.
• For a lengthy examination, a bladder catheter may be inserted; otherwise, you may simply be instructed to void before going into the angiography suite.
• During the examination, you will wear a hospital gown or sterile drape and lie on an X-ray table. An intravenous line will be inserted in your arm, which can then be used to administer a sedative, pain medication, and other drugs if the need arises.
• ECG electrodes will be affixed to your chest, and a pulse oximeter will be clipped to a finger; these devices allow constant monitoring during the procedure.

• A needle puncture is made, usually in the femoral artery in the groin; a guide wire is threaded through the needle; and the catheter is inserted over this wire and into the artery. (Pressure is applied to the puncture area to minimize bleeding.)
• The catheter is then threaded through the arterial system until it reaches the area to be examined.
• The progression of the catheter is monitored on a fluoroscope monitor to make sure it is positioned properly.
• At this point, the contrast agent will be injected through the catheter, causing a burning or flushing sensation; some patients also experience temporary visual disturbances and a headache, especially if the arteries of the brain are being examined.
• As the contrast agent spreads through the arteries, a rapid series of X-rays is taken by the fluoroscopy unit; these images are intensified, digitized by a computer, and processed almost immediately so that the attending physicians can review them during the examination.

• Cerebral angiography in which the arteries of the brain are examined for blockages and abnormalities, such as aneurysms or tangles.
• Coronary angiography, in which the blood vessels of the heart are evaluated.
• Lower extremity angiography, in which the arteries of the legs are evaluated.
• Renal angiography, in which the renal artery and other blood vessels in the kidney are examined for narrowing.

• As pressure is maintained at the puncture site, the catheter is withdrawn.
• After a few minutes, a sandbag or other weight is placed on the puncture site, and you will be moved to a recovery room where blood pressure, pulse, and other vital signs will be monitored periodically over the next eight hours or so.
• During this time, you will be instructed to drink water, apple juice, or other fluids to prevent dehydration and speed the body's removal of the contrast agent.
• You will also be observed for any delayed allergic reaction or other complications, including possible bleeding, blocked blood flow, abnormal heart rhythms, and stroke (a rare complication).
• If the test is done on an outpatient basis, most patients can go home after two to six hours of observation. However, you may be instructed to remain quiet for the next 12 to 18 hours, to continue applying pressure to the puncture site, and to keep the extremity elevated to prevent swelling.
• If bleeding or other complications arise, you should call your doctor or emergency medical service immediately.
• Depending on the circumstances, most patients can resume normal activities in a couple of days.

In rare instances, the test may have to be halted if serious complications arise.

The angiograms, which may be computer-enhanced, are interpreted by a radiologist or other medical specialist.

Angiography provides the most accurate information about the state of the arteries.

• The test is invasive and carries a risk of serious complications, including an allergic reaction to the contrast material, hemorrhaging, stroke, cardiac arrhythmias, arterial occlusion, and infection.
• The test is also expensive and should be performed only by an experienced angiographer.