Aortogram - Procedure, Uses, and Complications

Introduction

An aortogram depicts an aortic radiograph. The aorta is the body’s chief artery that carries blood from the heart to the rest of the body. The procedure is called aortography. A dye (contrast media) is used for the same following which the patient is exposed to X-rays. Aortography has been used as a diagnostic tool in urology for a long time. However, advanced imaging modalities such as computed tomography (CT), magnetic resonance imaging (MRI), and echocardiography (transesophageal) have replaced the technique.

What Is the Procedure of Aortography?

An aortogram is performed by a radiologist. Prior to the procedure, local, general, or spinal anesthesia is given. The patient lies on an X-ray table. The contrast medium is introduced via trans lumbar aortic puncture (at the level of lumbar- L1 vertebra) or femoral (thigh) artery. A catheter is inserted and directed to the desired location. The contrast medium is injected, and the patient is exposed to X-rays. The contrast medium usually contains iodine. In patients contraindicated to iodine use, gadolinium is used. The catheter is removed following the procedure completion.

An aortography is interpreted on a series of X-ray films through various phases. The first phase shows a column of contrast medium in the thoracic (chest) aorta. The second phase represents the abdominal aorta and its branches. The third phase highlights the renal veins and some arterial branches. Finally, the fourth phase depicts a nephrogram. In this phase, the kidneys can be clearly visualized.

What Are the Indications for an Aortogram?

An aortogram is helpful in diagnosing many conditions. It is sometimes also used for therapeutic purposes. An aorta has four main sections: abdominal aorta, descending (thoracic) aorta, aortic arch, and ascending aorta. Aortography can be done to view either of these.

1. Adult Congenital Heart Disease (ACHD): ACHD is a condition present since a person’s birth. It affects the heart’s blood vessels, chambers, and valves. The symptoms include irregular heartbeat, bluish discoloration of skin and mucosa, tiredness, and swelling of the body’s tissues and organs. Aortogram is useful in viewing the structures involved in ACHD.

2. Renal Artery Stenosis: Renal (kidney) artery stenosis is the constriction of one or both renal arteries. Aortogram is used to detect the condition. Other indications include blood supply assessment in renal tumors and possible kidney donor evaluation through the arterial blood supply. However, in renal impairment, transient (temporary) renal damage can occur. Hence, it is contraindicated in renal disease.

3. Aortic Inflammation: Inflammation affects the walls of the aorta in this condition. It is also called Takayasu arteritis. It is an autoimmune disease. It can be diagnosed by aortography after the detection of aortic stenosis and blocking.

4. Abdominal Aneurysm: Abdominal aneurysm is the abnormal dilation of the aorta. An aortogram is of definite value in a suspected abdominal aortic aneurysm. It corroborates the clinical impression. It can also reveal the exact level and extent of the lesion.

5. Aortic Dissection (Tears): It is a serious condition in which a tear occurs in the inner aspect of the aorta. It is followed by aortic dissection (the aortic wall ruptures). It is a life-threatening condition.

6. Aortic Valve Stenosis: Aortic valve is the structure that controls the blood flow from the heart into the aorta. An aortogram can determine the condition’s severity if other diagnostic tests fail. The pressure inside the heart’s chambers can also be measured through the technique.

7. Artery Blockage Near the Aorta: When arteries around the aorta are blocked, new branches develop called collateral arteries. One of the conditions is coronary artery disease (CAD). Aortogram is done via coronary artery catheterization. CT (computed tomography) is sometimes combined with the procedure for a three-dimensional (3D) image.

An interventional aortogram is done upon encountering a pathology. The physician intervenes according to the situation. Examples include clot dissolution and stent placement.

What Are the Advantages and Disadvantages of Aortography?

• The advantages of aortography include lesion delineation. Further, it can determine the extent of involvement of the aorta and its branches.

• The disadvantages are that it is invasive and requires iodinated contrast media. Therefore, it can lead to allergic reactions. Iodine sensitivity prevents the use of this technique. Another disadvantage is that any major surgery cannot be performed immediately after aortography. Hence, it is advised to leave a gap of a few days before any surgery.

What Are the Complications of Aortography?

Aortography should be done in a hospital. It cannot be safely done as an outpatient procedure. The patients must be informed of the type and the associated risks before the procedure. All the patients must be closely observed after the procedure. The complications are few and rarely serious. They also depend upon the type of aortography.

1. Intramural Injection: Intramural injection represents a forced injection into a vessel wall. An intramural injection can cause vessel wall dissection. A contrast medium can also be injected into the wall through the same. It can be one of the most severe accidents during aortography. It is because it can lead to a restricted oxygen supply, blood clotting, and subsequent organ necrosis (death of the body tissue). Studies have reported injections into the renal artery.

2. Artery Occlusion: It is more common in thoracic aortography, performed through the transfemoral route. It can be due to blood collection (hematoma) and thrombus (blood clot) formation.

3. Blood Extravasation: Extravasation is leakage from the blood vessel. It can happen during aortography following the withdrawal of the catheter needle and aortic rupture.

4. Periaortic Injection: It depicts an injection into the periaortic (surrounding the aorta) tissues.

5. Allergic Reactions: Allergies occur due to the injected contrast medium. Sodium acetrizoate is an example of a contrast medium. Sodium iodide is the densest contrast medium. However, its toxicity is a disadvantage. It was replaced by an organic iodide solution (diodone). It causes fewer and less severe allergic reactions.

6. Backache or Leg Pain: As the procedure is done at the level of the lumbar vertebra, it manifests as lumbar back pain (below the ribcage) or bilateral sciatic leg pain.

7. Brachial Plexus Lesion: Brachial plexus is a nerve network that carries sensory (sensation) and motor (movement) nerve impulses from the spinal cord to the arms and hands. Thoracic aortography can cause transient brachial plexus injury.

Conclusion

Aortography is a safe procedure if a simple technique is used. However, cooperation and coordination among doctors are required for the best results. Preliminary practice is also helpful. Further, it should be selectively used where other procedures have failed.