In this video, experts from the Cardiac Center at The Children’s Hospital of Philadelphia explain the three reconstructive operations, known as "Staged Reconstruction," required to redirect the oxygen-rich ("red") blood and oxygen-poor ("blue") blood.
Stage 1 Reconstruction of a Heart with HLHS - Norwood Procedure
The one good pumping chamber, which in hypoplastic left heart syndrome is the right ventricle, that ventricle has to pump to the body. So you have to connect the arteries to the lungs and the body in such a way that all the blood goes out to the body without any obstruction.
In HLHS, the aorta is usually too small. So we correct that by putting a patch on to enlarge it.
And that's done by connecting the pulmonary artery, which comes from the right ventricle to the aorta, and then usually putting a patch on to finish the connection of those two blood vessels and enlarge the aorta.
In addition, you have to prevent blood from backing up inside the left side of the heart. So you have to cut out the partition between the two upper chambers of the heart. And then the third principle of the Norwood operation, or the first-stage operation, is to provide some restricted blood flow to the lungs.
What we call "pulmonary blood flow." And we do that by placing a shunt, or a small tube, from one of the systemic arteries, or arteries that goes from the heart to the body, to the pulmonary artery.
That is enough flow that you can get enough oxygen in the bloodstream but not so much flow that you have resistance problems.
Stage 2 Reconstruction of a Heart with HLHS - Glenn Procedure
The second-stage operation takes away that extra volume that the heart has to pump, and it does that by getting rid of the shunt and connecting the veins from the upper part of the body directly to the arteries to the lungs.
You have to wait until the lungs essentially mature enough that you can provide a different source of pulmonary blood flow.
This is called either a "Bidirectional Glenn Shunt" or a "Hemi-Fontan operation."
Stage 3 Reconstruction of a Heart with HLHS - Fontan Procedure
Normally, the inferior vena cava, which drains the bottom of the body, attaches to the heart at the inferior bottom portion. And what we do is to literally divide this from the heart. We sew up the portion of the heart where the inferior vena cava entered, and then we sew a tube end to end to the remnant of the inferior vena cava. We take this tube and loop it around the side of the heart and sew it into a hole we make into the pulmonary artery. So we, essentially, bypass the entire heart.
It's a more efficient connection because the tube is a very specific size and the blood going through there is not turbulent. Turbulence loses power and power loss is a problem if you don't have anything pushing blood through the lungs.
Now the one modification is that we put a small hole in the side of the heart and in the side of this graft and sew it together with what's called a "fenestration."
And the reason we do that is that it's been shown that having that little hole, while it does allow some blue blood to mix with the red blood, it also decreases the risk of developing fluid around the lungs after surgery, something called a "pleural effusion."
Related Centers and Programs: Cardiac Center