A Basic Overview of the Norwood Procedure
04/24/13 Update - This post is probably one of the most popular on this blog. Due to this, it gets a fair amount of comments with irrelevant/spam links that do not get through the moderator and do. Because of this, comments on this post that do not link to anything directly connected to SCH or that add peer-reviewed information that I have left out or omitted will be removed. Thanks for your co-operation.
This post is separate from the others as it is intended to be an overview of what the Norwood surgery is. This will be much easier to understand if you've previously read my post on HLHS and heart function itself located here. To help recap though, here's the picture of a normal heart vs a pre operative HLHS heart.
The first surgery of a three surgery track, the Norwood procedure is a long and complicated surgery, taking anywhere from 4 to 10 hours on average. It has a 85% survival rate in children with a textbook case of HLHS; for Lillian this is 80% or lower due to her aorta being far smaller than normal. I think the easiest way to describe the surgery is as a re-plumbing of the heart.
As the most pressing issue with HLHS babies is an inability to pump blood the the body, the goal of the Norwood is to connect the right ventricle of the heart to the systemic circulation (i.e., the blood flow that carries blood with oxygen to the body). The systemic circulation is normally connected to the left ventricle, but since that is not able to pump, it must be switched to the right. Consequently, the blood flow that is normally present in the right ventricle will be disrupted, so part of the surgery has to create a new way for that blood to flow back to the lungs. Since HLHS babies also have small aortas, part of the surgery involves rebuilding the aorta using donated tissue so it is large enough to sustain blood flow to the systemic circulation. Finally, a Norwood procedure must include a shunt as a way to help blood flow back to the lungs. For Lillian this with be a Sano shunt, which connects the right ventricle to the pulmonary arteries through a Gore-Tex conduit. The end result of the surgery is a heart that looks like something like this.
Children's does deviate from other hospitals in how they do the Norwood procedure. Since it's a directly invasive surgery on the heart itself, all patients must be on full heart/lung bypass and typically have their bodies cooled to a near death state to protect the brain since they do not send blood to the brain during surgery. Children's differs in that even though they put the body in a near death state, they keep blood flow to the brain. Kathryn and I were very happy to hear that, as we (and Children's does as well) that no good can come from depriving the brain of blood that long, even in the cooled near death state.
Lillian's Norwood Surgery
Not feeling like sitting and waiting for up to 10 hours, Kathryn and I left the hospital to go spend time with Annabelle during the surgery. The surgical team kept us up to date with pages on an actual pager throughout the surgery, which is where the following information came from.
After taking Lillian back into the OR at 8:37 AM, they started by putting Lillian under general anesthesia, and prepping and draping her chest. and then conducted a pre operative echocardiogram at 10:35 AM. This is standard procedure, as even though they have already done echocardiograms as leadup to the surgery, they want to know as much as possible before they actually open the chest and start the surgery.
At 11:15 AM we were informed that they had started the actual surgery itself. By 11:45 AM, she was on full heart/lung bypass and they had started the actual repair described above. The repair took until around 3:00 PM, at which point they finished and started bringing Lillian's temperature back up, so they could take her off the bypass machine. At 3:55 PM, they succeeded in taking her off bypass, with her own heart finally beating well enough to sustain her life. At this point, we were told to come back to the hospital despite that we would not be able to see her right away.
Once we arrived back at Children's at 5:00 PM, we had a little of a surprise, and not in a good way. The front desk staff informed us that they had not actually taken her off life support, and the surgeons wanted us there, and I quote, "just in case". This is all that they could/would tell us, which was extremely stressful. We found a waiting room and waited for them to tell us more information. We were informed at 5:30 PM that they were going to be putting Lillian on what is called ECMO, short for extracorporeal membrane oxygenation. ECMO is a full heart/lung bypass machine that is portable enough that a baby can be on it outside of the operating room and in the ICU. We were informed at a later time that about 10 to 15% of the Norwood surgery patients came out on ECMO so it isn't common, but isn't unexpected either. It isn't idea to have to be on ECMO, but it is better to need it and be on it than to not be on it. This apparently caused some problems though, as they were still trying to put her on the ECMO machine at 8:30 PM, the delay caused by bleeding issues. Around this time, Kathryn left to take care of Annabelle, so I was at the hospital by myself waiting for them to finish.
At around 10:15 PM, we were told that they were back in Lillian's chest working again, which is never a good sign. Whatever they were doing, it appeared to be working as at 11:00 PM the charge nurse told us that it looked like they were applying the patch to Lillian's chest. Finally, around 11:45 PM she was out of surgery and was wheeled back into the CICU. She had been in surgery for over 15 hours, one of the longest surgeries they've done for this procedure. Keep in mind that this procedure has a range of 4 to 10 hours, with an average of 5, so Lillian was far above average. Even though she was out of surgery, they still had to stabilize her, so I was unable to see her. During this time, the main surgeon, Dr. Michael McMullan, came and discussed the surgery with me.
According to Dr. McMullan, the surgery overall went as expected, but they did have some major surprises. One of the biggest was the fact that her aorta was on average .5mm, the smallest the other surgeon, Dr. Lester Permut had seen in 20 years. The size of the aorta also explains why we were never able to see it on earlier echos. The size of the aorta was due in part to the valve to it being basically closed off entirely. On top of having a tiny aorta, Lillian's coronary arteries (of which there are normally two) actually consisted of one coronary artery which had mutated (for lack of a better word) into going down its side as expected but then coming back up the other side of the heart and serving that as well. Additionally, this is when we discovered that her heart muscle was extremely thick, which makes actually getting blood to the heart itself much more difficult.
One of the reasons for the 15+ hour surgery was the difficulty they had taking her off bypass. It is expected after the surgery that the heart should be able to resume activity and support the body on its own even directly after surgery. This is true for about 90% of patients, but the other 10% have to stay on heart/lung bypass. Before they put her on ECMO, they tried to take her off the bypass machine. Her heart was pumping on its own, but not at the level they expected, so they put her on bypass again and gave her heart a chance to rest. After 30 minutes of rest, they tried again. This time they noticed increased function, but not sufficient, so they gave her a 2 hour break and tried again. And again, they saw increased function, but again, it was insufficient. They finally decided that putting her on ECMO would give her heart the best chance it needed to recover. At this point, she was stable, but touch and go considering all that she had gone through. She still had blood oozing from her heart, and she had 12 hours to stem the tide of bleeding or she would have gotten a second surgery. Dr McMullen informed me at this time that our goals at this time were, in order of significance: getting bleeding under control, getting swelling down, getting her off ECMO and closing her chest.
After explaining all this to me, he left to check on her and write his report (which I've copied in the following post for those interested). As they were still stabilizing her, I had to wait a little longer to see her. During that time, they did an x-ray, where you can see the shunt in her heart.
Finally, at around 12:30, 16 hours after entering surgery, I was able to see Lillian.
This picture shows most everything that was used to support her. To the right, you can see the top of the ECMO machine (gray panel), to the far left you can see 10 of the 13 IV pumps she was on, with the ventilator being directly behind the nurse. And in the middle, almost impossible to see among the machines is Lillian.
Just a couple extra angles to see just how she looked. I was fully expecting to be a little light headed when she had her chest open, but it wasn't that bad in person. Perhaps it was the exhaustion and emotions at the time, but it was relieving to see her there. Even though she was on so many machines, she was still there, and that was reason enough to celebrate.
A closer look at the ECMO machine.
Lillian's surgery was one of the hardest days of my life. It was full of extremely trying moments, especially while waiting in the waiting room of the hospital with no word on her status. Even seeing her in the shape she was in, it was so good to see Lillian again, and with a heart that could actually sustain her.