The Children's Hospital of Philadelphia
Hypoplastic Left Heart Syndrome — HLHS Surgery
Jack Rychik, MD: Our current strategy for reconstruction of the heart for HLHS involves three stages, one done initially at birth, one at approximately 3 to 6 months of age, and the third stage at approximately 2 to 3 years of age.
Thomas Spray, MD: This is not an operation that creates a normal heart.
Jack Rychik, MD: You can't fix the heart.
J. William Gaynor, MD: We cannot make another pumping chamber.
Thomas Spray, MD: What we do surgically is rearrange things, close holes, make connections--
J. William Gaynor, MD: --so that you can have blood going to the lungs and blood going to the body with only one pumping chamber.
Thomas Spray, MD: But that isn't the same as a normal heart.
Jack Rychik, MD: By rerouting the plumbing, we normalize the circulation.
J. William Gaynor, MD: The principle of the Fontan operation was really that if you had low resistance in the lungs, that is, if blood could pass through the lungs without much difficulty, then you didn't have to have a pumping chamber pushing blood through the lungs.
J. William Gaynor, MD: However, you can't do it in a newborn, the lungs are too immature, the babies are too small.
Peter Gruber, MD: Essentially the pressure in the lungs is too high--
Thomas Spray, MD: --to allow blood flow to go through without something pushing it. So we already knew how to do a final operation for hypoplastic left heart syndrome. The problem was the first operation.
Peter Gruber, MD: The principal advance, with respect to hypoplastic left heart syndrome, took place here at CHOP with Dr. Norwood, who found a way to reconstruct this very difficult subset of patients who have single ventricle, those with hypoplastic left heart syndrome.
J. William Gaynor, MD: And that's called either the Norwood procedure or Stage I reconstruction.
Thomas Spray, MD: We like to do that surgery in the first week after birth, but it can be a day, two days, three days, it just depends on how stable the baby is. And the principles of the that operation are to connect everything so that 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.
Peter Gruber, MD: In HLHS the aorta is usually too small. So we correct that by putting a patch on to enlarge it.
J. William Gaynor, MD: 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.
Thomas Spray, MD: 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.
Peter Gruber, MD: 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.
Thomas Spray, MD: That is enough flow that you can get enough oxygen in the bloodstream but not so much flow that you have resistance problems. Because that resistance is what prevents you from doing any further surgery.
Unknown Speaker: It's very, very important that the family feels comfortable with you as an individual taking their child from them and that the child recognizes that nothing bad is going to happen to them, that they can do this without being awake for any painful experience.
J. William Gaynor, MD: They'll go to the operating room. The anesthesiologist will put them to sleep. We'll then clean, prepare everything, their chest and abdomen sterilely so that we can do the operation without infection. It's performed through an incision in the front over the breastbone, and we put them on the heart-lung machine, and cool them down to take care of their brain and other organs while we do the repair.
Peter Gruber, MD: We're bypassing the heart and the lungs. So that the operative field, the area where we're working, is clean, and we can see what's going on. The heart's generally not beating, although occasionally it is, but at least it's decompressed, there isn't blood flowing through it.
J. William Gaynor, MD: We'll then do the operation, warm them up, bring them off the heart-lung machine. We'll make sure that the heart is working okay, that the blood pressure is okay. That there's enough oxygen in the blood, that there's no bleeding. And then usually we leave a couple little tubes inside the heart that let us measure pressures in the heart and give drugs. These come out through the skin. There's also usually two, little blue pacing wires which let us change the heart rhythm. We then leave a drainage tube, and once everything's stable, the baby will come back up to the Intensive Care Unit, and the operation usually takes about 3 1/2 to 4 hours.
Robert Shaddy, MD: We anticipate the hospital stay after surgery for hypoplastic left heart syndrome to be approximately two weeks. It can be longer sometimes three or four weeks or even longer if there are significant complications.
Andrea Thrush, Mother: She pulled through that with flying colors. She was in and out of the hospital in a week after her surgery. Her second surgery was when she was three and a half months old.
J. William Gaynor, MD: Once a baby has had the Norwood procedure, then eventually we're going to go to the Fontan operation. And in the Fontan operation what we do is we connect up the blood flow coming back from the body directly to the lungs. You can do it in one operation, but we've learned that babies do much better if we split it up, and do it in two operations.
Thomas Spray, MD: When you have this single ventricle malformation, all the blood that goes to the lungs comes back to the heart goes out to the body and a portion to the lungs again and the amount that is going to the lungs is an extra amount of blood that the heart has to pump. The second stage operation, done somewhere between 3 and 6 months of age generally, takes away that extra volume that the heart has to pump, and it does that by getting rid of the shunt or getting rid of the blood flow to the lungs directly from the heart and connecting the veins from the upper part of the body directly to the arteries to the lungs.
Peter Gruber, MD: You have to wait until the lungs essentially mature enough that you can provide a different source of pulmonary blood flow.
Thomas Spray, MD: This is called either a bidirectional Glenn shunt or a Hemi-Fontan operation, half of the Fontan operation.
J. William Gaynor, MD: We go back through the same incision. And this is sort of the risky part of a redo operation because there's scarring from the first operation, and so we have to be very careful when we go through the breastbone, that we don't damage the heart, the lungs, the aorta. And every now and then there can be bleeding from the heart just because of the scar tissue and we have to go in the heart-lung machine through other blood vessels either in the neck or in the groin. It's rare to need to do that, but we're always ready to do that, if we have to.
Thomas Spray, MD: Once we get to that second operation, the heart is in a much better condition and usually the risk of that surgery is extremely low and the risk after that surgery becomes quite low also of any sudden event. So I always breathe a sigh of relief when we get to that second operation or that second stage procedure because it's a much better physiologic situation for the heart.
Andrea Thrush: She did well with that procedure as well. She was in and out of the hospital in five days. It was a little easier in that you know what to expect of the routine of the hospital the staff that you're working with.
Thomas Spray, MD: The third stage operation is a variant of the Fontan operation.
Peter Gruber, MD: And that generally takes place somewhere after two years. But the child's physiology really tells us the best time to do that.
Andrea Thrush: Her third surgery was when she was almost 3 1/2 years old.
Shane Thrush, Father: This last one was definitely tougher. She was well aware of what was going on--what was coming to her. And, I mean, she still talks about it today.
Andrea Thrush: So it was hard for us leading up to that third surgery.
J. William Gaynor, MD: There are two types of Fontan operations. One is called the lateral tunnel Fontan in which a baffle is placed inside the heart to redirect the blood flow from the lower part of the body to the lungs. The other is called the extracardiac Fontan where we actually use a tube that brings the blood outside the heart up to the pulmonary arteries.
Thomas Spray, MD: But the Fontan operation is based on connecting the veins from the body directly to the arteries to the lungs.
Peter Gruber, MD: Normally, the inferior vena cava, which drains the bottom of the body, attaches to the heart at the inferior, or 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.
Thomas Spray, MD: 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. It cannot work unless there's low resistance in the lungs. And the key is you have to have a good pumping chamber on the other side which essentially sort of sucks blood through the lungs.
Peter Gruber, MD: Now the one modification is that we put a small hole in the side of the heart and in the side of the graft and sew it together with what's called a fenestration.
Thomas Spray, MD: 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. Effusions used to be the biggest problem after the Fontan operation. Children would have the surgery and do quite well, but they would develop a lot of fluid that collected around the lung, and they'd often have to have a tube in the chest for weeks or even months to drain that fluid. Nowadays, with the use of this fenestration, that is a very uncommon event, whereas it used to be routine.