[Skip to Content]
Find care at Nemours Children's HealthDoctorsLocations

The Glenn Procedure

Reviewed by: Michael A. Bingler, MD
  • Listen
      mp3

What Is the Glenn Procedure?

The Glenn procedure is a type of open-heart surgery Babies who need this surgery typically have it when they’re 4–6 months old.

Why Is the Glenn Procedure Done?

The Glenn procedure is done for children who are born with heart problems like hypoplastic left heart syndrome (HLHS), tricuspid atresia, and double outlet right ventricle.

Depending on the heart problem, children may need the Norwood procedure before the Glenn surgery.

What Does the Glenn Procedure Do?

Normally, the right ventricle pumps blood to the lungs to get oxygen, and the left ventricle pumps the blood with oxygen to the body. But in some types of heart problems, called single ventricle defects, one ventricle is too small, so the other ventricle not only pumps blood to the lungs, but also to the body.

The Glenn procedure sends blood from the upper body directly to the lungs. This way, the single ventricle only has to pump blood to the body (and not to the lungs), so it doesn’t have to work as hard.

What Happens During the Glenn Procedure?

During the Glenn procedure, the surgeon disconnects the superior vena cava (SVC) from the heart and connects it to the pulmonary artery. Now the blood from the upper part of the body flows directly into the pulmonary artery. The pulmonary artery takes the blood to the lungs.

If the baby had the Norwood procedure, the surgeon will remove the shunt that was placed then.

Illustration: During 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. They will keep taking some of these medicines at home.

During this time, the care team teaches parents how to care for their baby at home. Babies usually can go home when they are feeding well, growing well, and gaining weight.

Depending on the heart problem, a child might need another surgery, the Fontan procedure, when they’re around 18–36 months old.

Many children thrive and do well after heart surgery. They'll need to see a cardiologist regularly, and get EKGs, echocardiograms, lab tests, and occasional cardiac catheterizations. A cardiac catheterization is a procedure that lets cardiologists check how the heart is working and do some types of treatments.

Illustration: How blood flows after the Glenn Procedure

How Can Parents Help?

At home with your baby, follow the care team’s instructions about:

  • giving any medicines
  • feeding your baby
  • checking your baby’s weight 
  • checking oxygen levels with a pulse-oximeter
  • going to follow-up doctor visits

When Should I Call the Doctor?

Call the care team right away if your baby:

  • is not eating
  • is vomiting
  • seems to be breathing fast or working hard to breathe
  • oxygen levels drop lower than usual
  • seems very irritable
  • just doesn't seem quite right

What Else Should I Know?

Caring for a child after heart surgery can be overwhelming for any family. But you’re not alone. The doctors, nurses, social workers, and other members of the care team are there to help you and your child.

It can help to find a support group for parents whose kids have a serious heart condition. Ask the care team for recommendations. You also can find support and more information online at:

Date reviewed: July 2021