Angiography: History, Technique, Uses, Preparation, Procedure, Complications and Results

Also known as arteriography, it is a medical imaging technique used to visualize the inside, or lumen, of the body’s blood vessels and organs.

It is used with a special interest in visualizing the arteries, veins, and chambers of the heart .

This is traditionally done by injecting a radiopaque contrast agent into the blood vessel and imaging using X-ray-based techniques such as fluoroscopy.

The word itself comes from the Greek words ἀγγεῖον angeion, “vessel,” and γράφειν graphein, “to write” or “to record.” The film or image of the blood vessels is called angiography or, more commonly, angiography.

Although the word can describe both an arteriogram and a venogram, in everyday use the terms angiogram and arteriogram are often used synonymously, while the term venogram is used more precisely.

The term angiography has been applied to radionuclide angiography and to newer vascular imaging techniques such as computed tomography angiography and magnetic resonance angiography.

The term isotopic angiography has also been used, although this is more correctly known as isotopic perfusion scan.

History of angiography

The technique was first developed in 1927 by the Portuguese doctor and neurologist Egas Moniz from the University of Lisbon to perform contrast X-ray brain angiography in order to diagnose various types of nerve diseases, such as tumors, arterial diseases and arteriovenous malformations.

Moniz is recognized as the pioneer in this field. He performed the first cerebral angiogram in Lisbon in 1927, and Reynaldo Cid dos Santos performed the first aortogram in the same city in 1929.

In fact, many of the current angiography techniques were developed by the Portuguese at the University of Lisbon.

For example, in 1932, Lopo de Carvalho performed the first pulmonary angiogram by venipuncture of the upper limb; in 1948 the first cavogram was made by Sousa Pereira.

The radial access technique for angiography dates back to 1953, when Eduardo Pereira first channeled the radial artery to perform a coronary angiography.

With the introduction of the Seldinger technique in 1953, the procedure became markedly safer, as no sharp introductory devices were needed to remain within the vascular lumen.

Technique

Depending on the type of angiogram, access to the blood vessels is most commonly obtained through the femoral artery, to view the left side of the heart and the arterial system; or the jugular or femoral vein, to look at the right side of the heart and the venous system.

Using a system of guidewires and catheters, a type of contrast agent (which appears by absorbing X-rays) is added to the blood to make it visible on X-ray images.

X-ray images taken can be still, displayed on an image intensifier or film, or moving images.

For all structures except the heart, the images are usually taken using a technique called digital subtraction angiography (DSA).

In this case, the images are generally taken at 2 or 3 frames per second, which allows the interventional radiologist to assess the flow of blood through one or more vessels.

This technique “subtracts” the bones and other organs so that only the vessels filled with the contrast agent can be seen. Images of the heart are taken at 15-30 frames per second, without using a subtraction technique.

Because digital subtraction angiography requires the patient to remain immobile, it cannot be used on the heart.

Both techniques allow the interventional radiologist or cardiologist to see strictures (blockages or narrowing) within the vessel that may be inhibiting blood flow and causing pain.

Preparing for an angiogram

Before having an angiogram, you may be asked to keep an appointment at the hospital to verify that you can have the test. This may involve:

Receive questions about your medical history, even if you have any allergies. You will be asked if you need to stop taking any medications before the test.

Undergo a series of tests to check your general health, including a physical exam and blood tests.

You will have a discussion about the angiogram with your doctor, including what it entails, what the risks are, what you need to do beforehand, and whether you would like to have sedative medication for the day to help you relax.

If you decide to take a sedative, you will be asked not to eat for a few hours before the test.

If you are breastfeeding at the time of the exam, you should ask your doctor how to proceed. It may be helpful to express breast milk ahead of time and keep it on hand for use after the contrast material has cleared from the body, about 24 hours after the exam.

You will also have to arrange for someone to pick you up at the hospital, as you will not be able to drive home.

Process

You will usually be awake for an angiogram, although general anesthesia (where you are asleep) can be used for young children. For the test:

You will be asked to change into a hospital gown and lie down on a special table. A small incision is made in the skin over one of the arteries, usually near the groin or wrist; Local anesthesia is used to numb the area so that it does not hurt.

A long, thin, flexible tube (catheter) is inserted into the artery and carefully guided to the area being examined. A special dye (contrast agent) is injected through the catheter, you may feel hot, flushed, and like you need to urinate for a few seconds after you do.

A series of X-rays are taken as the contrast medium flows through the blood vessels. Sometimes treatment can be done at the same time, such as inserting a balloon or small tube to open a narrowed artery. This is known as angioplasty.

After the procedure is complete, the catheter is removed and the incision is pressed to stop any bleeding. No stitches are needed.

Uses of angiography

Coronary angiography

One of the most common angiograms performed is to view the blood in the coronary arteries. A long, thin, flexible tube called ram catheters is used to deliver the X-ray contrast medium to the area you want to see.

The catheter is inserted into an artery in the forearm and the tip is advanced through the arterial system to the main coronary artery.

X-ray images of the transient distribution of radiocontrast within the blood flowing into the coronary arteries allow the size of the openings in the arteries to be visualized.

The presence or absence of atherosclerosis or atheroma within the artery walls cannot be clearly determined.

A coronary catheterization is a minimally invasive procedure to access the coronary circulation and blood-filled chambers of the heart using a catheter. It is performed for both diagnostic and interventional (treatment) purposes.

Coronary catheterization is one of several cardiology diagnostic tests and procedures. Specifically, coronary catheterization is a visually interpreted test performed to recognize occlusion.

Stenosis, restenosis, thrombosis, or aneurysmal enlargement of the coronary artery lumens, the size of the heart chamber, the performance of heart muscle contraction, and some aspects of heart valve function.

Important internal blood pressures of the heart and lungs, which cannot be measured from outside the body, can be accurately measured during the exam.

The relevant problems that the test most commonly addresses occur as a result of advanced atherosclerosis (atheroma activity within the wall of the coronary arteries). Less commonly, heart muscle, heart muscle, or arrhythmia problems are the main focus of the exam.

Lumbar narrowing of the coronary arteries reduces the reserve of oxygenated blood flow to the heart, which usually results in intermittent angina. Very advanced luminal occlusion usually leads to a heart attack.

However, it is increasingly recognized since the late 1980s that coronary catheterization does not allow recognition of the presence or absence of coronary atherosclerosis itself, but only significant light changes that have occurred as a result of end-stage complications of the atherosclerotic process.

One of the most common angiograms performed is to view the blood in the coronary arteries. A long, thin, flexible tube called ram catheters is used to deliver the X-ray contrast medium to the area you want to see.

The catheter is inserted into an artery in the forearm and the tip is advanced through the arterial system to the main coronary artery.

X-ray images of the transient distribution of radiocontrast within the blood flowing into the coronary arteries allow the size of the openings in the arteries to be visualized. The presence or absence of atherosclerosis or atheroma within the artery walls cannot be clearly determined.

To detect coronary artery disease, computed tomography (CT) is better than magnetic resonance imaging (MRI).

The sensitivity and specificity between computed tomography and magnetic resonance imaging were (97.2 percent and 87.4 percent) and (87.1 percent and 70.3 percent), respectively.

Therefore, computed tomography (primarily multislice computed tomography) is more accepted, more widely available, more favored by patients, and more economical. In addition, computed tomography requires a shorter breath hold time than magnetic resonance imaging.

Fluorescein angiography

It is a medical procedure in which a fluorescent dye is injected into the bloodstream. The dye highlights the blood vessels at the back of the eye so they can be photographed.

This test is often used to monitor eye disorders. An ocular optical coherence angiography (OCTA) imaging technique is currently being developed to simulate the results of fluorescein angiography without the need to inject an intravenous dye into patients.

Microangiografía

Microangiography is commonly used to visualize tiny blood vessels.

Neurovascular angiography

Another increasingly common angiographic procedure is neurovascular digital subtraction angiography to visualize the arterial and venous supply to the brain.

Interventional work such as spiral embolization of aneurysms and gluing of arteriovenous malformations can also be performed.

Peripheral angiography

Angiography is also commonly performed to identify narrowing of blood vessels in patients with claudication or leg cramps, caused by reduced blood flow down the legs and to the feet.

In patients with renal stenosis (which commonly causes high blood pressure ) and can be used on the head to find and repair stroke.

All of this is routinely done through the femoral artery, but can also be done through the brachial or axillary (arm) artery. Any strictures found can be treated using atherectomy.

Post mortem computed tomography angiography for medical (legal) cases

Post mortem computed tomography angiography for medicolegal cases is a method initially developed by the virtual autopsy or virtopsy group. From this project, both aqueous and oily solutions have been evaluated.

While oily solutions require special deposition equipment to collect wastewater, aqueous solutions seem to be considered less problematic.

Aqueous solutions were also documented to improve tissue differentiation from post-mortem computed tomography, whereas oily solutions were not.

In contrast, oily solutions appear to only minimally disturb subsequent toxicological analysis, whereas aqueous solutions can significantly hamper toxicological analysis, requiring preservation of the blood sample prior to postmortem computed tomography angiography.

Complications

After an angiogram, a sudden shock may cause some pain in the area of ​​surgery, but heart attacks and strokes generally do not occur, as they can in bypass surgery.

A heart attack occurs when blood flow to part of the heart is blocked, usually by a blood clot. Without oxygenated blood, the heart muscle begins to die.

A stroke is a brain attack that cuts off vital blood flow and oxygen to the brain. Stroke occurs when a blood vessel that feeds the brain becomes blocked or ruptured.

Bleeding or bruising

Bleeding (hematoma) occurs in less than 5% of angiograms. This is usually seen as a raised hematoma at the site, usually in the right groin, where the catheter is inserted.

In most cases this is not serious and will go away after a few weeks. One in 100 people who have an angiogram will require overnight hospital observation, and fewer than 1 in 500 will require another procedure, surgery, or blood transfusion to correct the bleeding.

If you discover a rapidly enlarging bruise where the catheter was inserted into the artery (usually in the groin) while you are resting in the hospital immediately after the procedure, press the area firmly and notify the medical or nursing staff.

In the unlikely event that this occurs after you have left the facility, press firmly on the area and contact the staff where the angiography was performed or your local physician.

If it is at night or on a weekend, you will need to contact your local emergency department for advice on what to do.

In less than 1% of cases, the procedure could damage a blood vessel, causing a blockage. This will be noticed by the doctor at the time of the angiogram and may require an additional procedure to treat the problem.

You will be informed about this, and can often be corrected on the spot without the need for further action.

Contrast medium

A contrast medium that contains iodine is used. This has a very small risk of causing an allergic reaction.

Such reactions range from itching and rash to shortness of breath and, extremely rarely, even death.

It is very important to inform your medical team if you have had an allergic reaction to contrast dye in the past, or if you are allergic to any food or substance before having an angiogram.

X-ray imaging

X-ray images have risks because they are a form of radiation. Radiation doses are small, and the risk must be balanced against the benefits of angiography for the individual patient.

Cerebral angiography

Major complications in cerebral angiography, such as digital subtraction angiography or contrast MRI, are also rare, but include stroke, an allergic reaction to the anesthetic or other medication or to the contrast medium, blockage or damage to the one of the access veins in the leg, or formation of thrombosis and embolism.

Bleeding or bruising at the site where the contrast medium is injected are minor complications. Delayed bleeding may also occur, but they are rare.

Additional risks

The dye that is used generally produces a warm sensation that lasts only a few seconds, but may be felt to a greater degree at the injection site.

If the patient is allergic to the contrast medium, much more serious side effects are unavoidable; however, with the newer contrast agents the risk of a severe reaction is less than one in 80,000 exams.

Also, damage to blood vessels can occur at the puncture / injection site and anywhere along the vessel during passage of the catheter.

If digital subtraction angiography is used instead, the risks are greatly reduced, since the catheter does not have to be passed into the blood vessels, reducing the chances of damage or obstruction.

After an angiogram

After the exam, you will be taken to a recovery room where you will be asked to lie still for a few hours to prevent bleeding from the cut.

You can usually go home the same day, although sometimes you may need to stay in the hospital overnight.

It may be possible to tell you the test results before you go home, but x-rays often need to be studied in detail and the results are not available for a few weeks.

While you are recovering at home:

Rest the rest of the day, it is a good idea to have someone stay with you for at least 24 hours in case you have a problem.

Eat and drink as soon as you feel ready, the contrast dye leaves your body in your urine, so drinking plenty of water can help flush it out faster.

You can usually return to most of your normal activities the next day, although you may need to avoid heavy lifting and vigorous exercise for a few days. You will probably have some bruising and pain for at least a few days.

Waiting time for results

The time it takes for your doctor to receive a written report about the test or procedure you have had will vary, depending on:

The urgency with which the result is needed, the complexity of the exam, and whether more information is needed from your doctor before the radiologist can interpret the exam.

If you have had previous X-rays or other medical images that need to be compared with this new test or procedure (this is commonly the case if you have a disease or condition that is being followed to assess your progress).

How the report is transmitted from the office or hospital to your doctor (ie, by phone, email, fax, or mail).

Often times, the physician performing the procedure will inform you of the results of the angiogram and any necessary treatment at the time of the procedure. If this doesn’t happen, you can ask a staff member when your own doctor is likely to have the written report.