Catheter angiography and embolization

Angiography is a minimally invasive medical test that helps physicians diagnose and treat children with medical conditions affecting blood vessels or using blood vessels as a route to treat various conditions. Angiography is used when a blood vessel is narrowed or if the blood vessel suddenly becomes blocked and does not allow blood to flow. This procedure uses one of the following three imaging technologies along with the injection of contrast agent within the blood vessel to highlight the production of pictures of blood vessels in the body. Angiography is performed using:

• x-rays with catheters inserted across the skin (percutaneously) into the blood vessel
• computed tomography (CT)
• magnetic resonance imaging (MRI)

In catheter angiography, a catheter (thin plastic tube), is inserted into an artery across the skin (percutaneously) through a small incision. The catheter is guided to the area being examined with the use of x-rays then a contrast material is injected through the tube and x-ray images are obtained to produce an angiogram (picture of the blood vessel).

Angioplasty is the process of inserting a small inflatable balloon inside a blood vessel that has been identified to be narrowed by the angiogram. Inflating the angioplasty balloon will dilate the vessel and make it bigger. This helps to improve the blood flow through the blood vessel.

Embolization is the process of blocking the flow of blood flow through a blood vessel. This is performed by placing various materials through the angiography catheter while it is inside the blood vessel to block the blood flow. The embolic material can be a coil, small beads, or liquid medicine that induces the blood to clot and block the flow of blood.

Either procedure typically requires 45 minutes- several hours depending on the location and complexity of the condition.

Body areas or organs treated with catheter angiography

• brain
• neck
• heart
• chest
• abdomen (such as the kidneys, liver, spleen)
• pelvis
• legs and feet
• arms and hands

Conditions treated with a catheter angiography

• Identify abnormalities, such as aneurysms (abnormal ballooning) or abnormal narrowing in the aorta, both in the chest and abdomen, or in other arteries
• Detect disease in the carotid artery of the neck, which may limit blood flow to the brain or abnormal blood vessel development in the brain
• Identify arteriovenous malformation or AVM (abnormal communications between blood vessels) inside the brain or other parts of the body
  • May be a condition the child was born with (congenital or developmental) or acquired as a result of an injury
• Identify extent of inflammatory diseases (vasculitis) that can narrow the arteries to blood vessels throughout the body
• Detect disease in the arteries to the kidneys or visualize blood flow to help prepare for a kidney transplant
• Guide interventional radiologists before making repairs to diseased blood vessels, such as implanting stents or evaluating a stent after implantation
• Detect injury to one or more arteries in the neck, chest, abdomen, pelvis or extremities in patients after trauma and prepare for stopping the bleeding by infusing material through the same catheter that could occlude the blood vessel
• Evaluate arteries feeding a tumor prior to surgery or other procedures such as chemoembolization (infusion of chemotherapy directly into the tumor)
• Examine pulmonary arteries in the lungs to detect pulmonary embolism (blood clots, such as those traveling from leg veins) or pulmonary arteriovenous malformations

Conditions treated with an embolization

• Trauma and a blood vessel is injured and the patient is bleeding.
• Patients that have tumors. Blocking blood vessels that supply tumors can help them stop growing, shrink the tumor, or help decrease bleeding prior to the child going for surgical removal of the tumor.
• Some conditions in which blood vessels develop abnormally (vascular malformations) can cause pain. Blocking the flow to the blood flow can decrease symptoms

Treatment process

Angiogram is the basic procedure for all the procedures discussed in this description. The area of the groin or arm where the catheter will be inserted is cleaned, and numbed with local anesthetic. The pediatric interventional radiologist will make a tiny incision (usually a few millimeters) in the skin where the catheter will be inserted into the artery.

The catheter is then guided to the arteries and area to be examined. The contrast material is injected through the catheter and will highlight the blood vessels being studied. X-ray images of the blood vessels (angiogram) will be obtained. When all the vessels that need to be studied are complete the decision can be made if needed to treat an abnormality through the same point.

Once treatment is completed the catheter can be removed and the incision site is closed by applying pressure on the area for approximately 10 to 20 minutes (or by using a special closure device). Holding pressure or using a special closure device helps prevent continued bleeding. A small bandage dressing will be placed to cover the puncture site. No skin sutures are required.

Frequently, sedation or anesthesia will be used to help facilitate the successful completion of the procedure. This helps to minimize anxiety for the child and decrease risk of complications as a result of movement during the procedure.

Recovery

Your child will be asked to remain at bed-rest and keep the leg (if the groin is used to access the artery) still for 4-6 hours following the procedure. This helps to minimize the risk that bleeding will recur at the puncture site. Your child will be allowed to sit with their head elevated up to 30-45 degrees during this bed-rest period. This helps permit the ability to eat and drink after the procedure. Typically the child may remain sedate from the anesthesia following the procedure therefore help facilitate comfort during the bed-rest period.

Upon conclusion of the bed-rest period, your child can resume activities as tolerated. Your child can have a shower the day following the procedure but will be instructed to keep the dressing and bandage in place to cover the puncture site. The bandage or dressing covering the puncture site will be kept in place and changed as needed for several days.

Your child may have some soreness and bruising at the puncture site. Typically, this can be well controlled with ibuprofen or Tylenol.

Benefits and risk of treatment

Benefits

• Catheter angiography is able to demonstrate a very detailed, clear and accurate picture of the blood vessels. This is especially helpful when a intervention is being considered such as an angioplasty procedure.
• Angiography may eliminate the need for surgery. If surgery remains necessary, it can be performed more accurately.
• Superselective angiography can be performed by passing the catheter directly into small branch vessels supplying a specific area of tissue or tumor. This provides an unobstructed view of the vessels and distribution of blood flow.
• Unlike computed tomography (CT) or magnetic resonance (MR) angiography, use of a catheter also allows the opportunity to immediately combine diagnosis and treatment in a single procedure. An example is identifying an area of blood vessel narrowing, followed by angioplasty and placement of a stent.
• The degree of detail displayed by catheter angiography may not be available with any other noninvasive procedures.

Risks

• Any procedure where the skin is penetrated carries a potential risk of infection. The chance of developing an infection that requires added antibiotic treatment appears to be less than one in 1,000.
• If your child has a history of allergy to x-ray contrast material, your radiologist may advise that you take special medication for 24 hours before catheter angiography to lessen the risk of allergic reaction.
• The risk of serious allergic reaction to contrast materials that contain iodine is extremely rare, and radiology departments are well-equipped to deal with them.
• There is a small risk that blood will form a clot around the tip of the catheter, blocking the artery requiring a procedure to remove the clot.
• If your child has diabetes or kidney disease, the kidneys may be senistive due to the contrast material
• Rarely, the catheter punctures the artery, causing internal bleeding.