During an angioplasty, why is the catheter inserted through the wrist?

DEAR DOCTOR K:

I am scheduled to have an angioplasty next week. The doctor plans to insert the catheter through my wrist. Is there some advantage to doing it through the wrist rather than the thigh?

DEAR READER:

Angioplasty is a procedure used to open a narrowed or blocked artery. Angioplasties are usually done to open up blocked coronary arteries — the blood vessels that provide blood to the heart muscle.

The blocked coronary arteries lie deep within the chest. An angioplasty is able to open the blockage without opening the chest. How? By taking advantage of how the body’s blood supply is built.

The heart pumps blood around the body through multiple arteries. Some arteries carry blood from the heart to the legs, and other arteries go from the heart to the arms. Any artery that carries blood from the heart to the leg or arm is also a highway leading from the leg or arm back to the heart.

Radial artery angioplasty

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Using the radial artery to access the heart during an angioplasty has some advantages over the femoral artery approach.

During the procedure, a doctor inserts a thin tube called a catheter into a blood vessel. He or she gently maneuvers the catheter through the vessel. The tip of the catheter is gently guided up the “highway” from the leg or arm to the heart. Then the tip of the catheter is pushed into the blocked coronary artery. A balloon that is part of the catheter is inflated to open the artery. Usually a tiny wire mesh stent is placed to keep the artery open.

Most doctors in the United States begin angioplasty at the femoral artery, the large blood vessel at the top of the thigh. But a growing number of doctors are beginning angioplasty through the radial artery in the wrist. On the right, I’ve put an illustration showing the path from the radial artery to the heart.

The radial artery is narrower than the femoral artery, which makes it harder to get the catheter inside. However, the radial artery lies right below the skin, whereas the femoral artery is deep beneath the skin. In some people, the femoral artery can be hard to reach.

Once a catheter successfully enters the radial artery, the fact that this artery is narrower becomes an advantage. When an angioplasty is done through the larger femoral artery, that artery tends to bleed after the catheter is pulled out of the body. You have to lie in bed for several hours with a weight pressing down on the artery.

In contrast, immediately after a radial artery angioplasty, people are able to get up and walk around. They can often go home the same day and resume normal activities by the next day.

Radial angioplasties have been slow to catch on. That may be because most doctors in the U.S. were trained in the femoral approach. The radial artery is smaller and has more twists and turns, and advancing a catheter through it requires practice. But once doctors gain experience with the wrist approach, they are likely to use it more often.