Why Does a Baby Need the Glenn Procedure?

Without medicines and a series of three surgeries to rebuild the heart, babies with hypoplastic left heart syndrome (HLHS) won't survive. The left side of the heart can't be fixed, so the goal of the surgeries is to rebuild parts of the heart and "redirect" the way blood flows.

After the Norwood procedure, babies get the Glenn procedure when they're between 4 and 6 months old. This is because they outgrow the shunt placed during the Norwood procedure.

Illustration: A child with HLHS needs the Glenn Procedure because

What Is the Glenn Procedure?

The Glenn procedure is a type of open-heart surgery. The goals are to:

  • Make blood from the upper part of the body (the head, neck, and arms) go directly to the lungs. This lets the blood pick up oxygen without passing through the heart.
  • Take some of the extra work away from the right ventricle. Until now, the right ventricle has been doing two jobs: pumping blood to the lungs and to the body.

What Happens During the Glenn Procedure?

The Glenn procedure redirects blood flow from the upper body to the lungs. In the Glenn procedure:

  1. The superior vena cava (SVC) (which brings blood back from the upper part of the body) is disconnected from the heart and connected directly to the pulmonary artery.
  2. The shunt placed during the Norwood procedure is removed.Illustration: During the Glenn Procedure

Blood from the upper body now goes to the pulmonary artery, and then to the lungs, without having to go to the heart. Because blood can now get to the lungs, the shunt is no longer needed. Also, the right ventricle now has a single job: pumping blood to the body.

Illustration: How blood flows after the Glenn Procedure

What Happens After the Glenn Procedure?

Babies who have the Glenn procedure usually spend 1 to 2 weeks in the hospital to recover. They get-around-the-clock care and monitoring. They also get medicines to help the heart and improve blood flow.

What's the Next Procedure?

The third surgery is called the Fontan procedure. It's usually done when a child is 18 to 36 months (3 years) of age.

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