Glenn Procedure

What is the Glenn procedure?

The Glenn (or bidirectional Glenn) procedure is an operation to improve how blood flows through a heart that has a small left or right side (either the valve that connects the upper chamber to the lower chamber or the pumping chamber itself). Connecting your child’s superior vena cava to their pulmonary arteries allows blood that needs oxygen to go straight to your child’s lungs.

Your superior vena cava brings oxygen-poor blood back from your upper body. Normally, this blood would go through your heart chambers and then to your pulmonary artery to get oxygen. The Glenn surgery allows the blood to bypass a problematic area in your heart to get the oxygen-poor blood right to your lungs.

This surgery often comes after one or more surgeries babies can have soon after birth. Babies may then have another surgery a few years later for a more permanent solution.

What does the Glenn procedure do?

The bidirectional Glenn procedure makes blood circulation better in people who have a congenital (present at birth) heart defect that keeps them from having a normal circulation route through their heart. Usually, the issue is a single ventricle defect, which means one of your heart’s valves or lower chambers (which pump blood) isn’t working right or is too small to be effective.

When is the Glenn procedure done?

Surgeons perform the Glenn heart procedure when a child is 3 to 6 months old (usually no younger than 2 months old). Survival odds are best when a child has the Glenn procedure three to six months after the first operation in the neonatal period (if they have a condition requiring that procedure to improve their circulation).

What does a Glenn procedure treat?

Healthcare providers perform a Glenn procedure to treat these heart defects:

• Pulmonary atresia with an intact ventricular septum.
• Tricuspid atresia (tricuspid valve that didn’t form between chambers).
• Double inlet left or right ventricle.
• Hypoplastic left heart syndrome.
• Unbalanced atrioventricular canal defects.
• Some forms of congenitally corrected transposition of the great arteries (pulmonary artery and aorta in the wrong place, and the valves and ventricles connect improperly).

How common is a Glenn procedure?

Glenn procedures are rare. In fact, there were only 2,692 bidirectional Glenn procedures in 2019, representing 2.3% of all operations performed.

What happens before a Glenn procedure?

Usually, people who have a Glenn cardiac procedure have already had a Blalock-Taussig (BT) shunt or a pulmonary artery band. The Glenn procedure is often the next stage in improving blood flow in a heart with only one effective atrioventricular valve or ventricle (pumping chamber).

Before surgery, your child’s healthcare provider will want to:

• Do a cardiac catheterization or heart MRI to look at your child’s anatomy.
• Know about all of your child’s medications (including non-prescription medicines and supplements they take).

What happens during a Glenn heart procedure?

A Glenn procedure takes about four hours. However, it could take more or less time depending on the situation. Your child’s healthcare team will update you as often as they can.

During a Glenn surgery, your child will sleep deeply (with general anesthesia). They won’t feel or remember anything. Some children need a cardiopulmonary bypass machine to do the work of their heart and lungs, but not everyone needs this. Then, your child’s surgeon will address any issues from previous procedures and connect your child’s superior vena cava to their right or left pulmonary artery. They can also make any other necessary heart repairs at this time.

What happens after a Glenn procedure?

It’s normal to feel nervous when your baby is connected to tubes and monitors, as they may be following a Glenn procedure. Your child’s surgical team will monitor them closely for a while in the Intensive Care Unit and it may be a few weeks before they feel like themselves again.

Not everyone who has a Glenn procedure for a single ventricle issue will need a Fontan procedure in the future. If they need a Fontan procedure, this will create different systems to handle getting oxygen from your child’s lungs into their blood and getting oxygen-rich blood to their body.

How long does the Glenn procedure last?

A Glenn procedure can last until your baby is ready for their next surgery. Most children need to have a Fontan procedure, the next operation after a Glenn surgery, when they’re walking. This exercise makes their low oxygen levels worse.

What are the advantages of a Glenn procedure?

Glenn procedure advantages include:

• Making it easier on the one ventricle that’s working.
• Stopping the overworked ventricle from becoming enlarged.
• Making it simpler to do the next operation in the series (the Fontan procedure).
• Possibly improving survival rates in people who go on to have the Fontan procedure.
• Providing another option for people who don’t need or can’t have a Fontan procedure.

What are the risks or complications of a Glenn procedure?

About 30% of people who have a Glenn procedure have complications, such as:

• Low oxygen level.
• High blood pressure.
• A new neurologic deficit.
• Pleural effusions (extra fluid outside your child’s lungs).
• Emergency cardiac catheterization.
• Trouble feeding leading to the need for a feeding tube.
• The need for a reoperation.
• Cardiac arrest.

What is the recovery time?

Your child will need to spend about three days in the Intensive Care Unit. Then they’ll need several more days in a regular hospital room before they can go home.

What’s the survival rate for a bidirectional Glenn procedure?

The Glenn procedure survival rate is about 99%.

When should my child see their healthcare provider?

Your child will need regular follow-up visits with their provider. The first visit with your cardiologist (heart doctor) will be arranged before you leave the hospital.

After taking your child home from the hospital, contact their provider if your child has:

• A fever.
• Blood or other fluids coming out of their chest wound.
• Difficulty feeding.
• Trouble gaining weight.

A note from Cleveland Clinic

The Glenn procedure is one of the operations responsible for improving survival in babies with congenital heart issues. These advances didn’t even exist for previous generations. The success rate for the Glenn procedure is high. Still, caring for your child means they’ll need regular checkups with their healthcare provider and take medication for many years. Be sure to ask your child’s provider any questions you have about the Glenn procedure and how to care for your child.