Archive for the ‘Norwood Procedure’ Category

What you need in a Surgeon

September 15, 2010

It had to happen. Consumer Reports is now rating Surgical groups that perform Bypass Surgery. Just pick up an issue; you’ll be able to find out who makes the best toasters, washing machines, and who can re-route your arteries.

If it were only that easy for Congenital Heart Surgery. There are 35 different heart defects – this is the “base” number, that doesn’t count any defect that may have elements of two or more defects – and a multitude of different surgical options. Consumer Reports only looks at Bypass Surgery, a Congenital Surgeon may repair an Atrial Septal Defect (ASD) in the morning and perform a Bidirectional Glenn Shunt in the afternoon. If he’s on call he may come to the hospital in the middle of the night not knowing what problem he’s facing.

So assuming you have time to pick a Congenital Heart Surgeon, what do you need to look for? Experience and skill are the two basic factors, with a little understanding of what the numbers mean.

Experience is easy – Doc, how many years have you been operating? How many heart surgeries have you done, total? The Cardiologist says my son needs to have the *** Procedure, how many of those have you done? Answers to these questions will help you decide.

Now comes the not so easy part – try to determine your surgeons skill level. Let’s invent a situation: You ask the surgeon how his patients do after the operation, and he tells you that 80% of them go on to lead full lives. Now we need to know something else – what kind of operations is he doing? If our fictitious surgeon is fixing ASDs and 80% his patients “go on to lead full lives”… RUN! That’s a pretty low number. But if he is an Hypoplastic Left Heart Syndrome specialist and he usually performs the Norwood Procedure, 80% is very successful.

This is where it helps to be familiar with the Aristotle Complexity Score, and like so much about heart defects, the general public doesn’t know it exists. Most of the CHD community is even unaware of its existence. The Aristotle Score is a “rating system” of congenital heart surgical procedures, based on the three factors. Each factor is assigned a score of 1 to 5 points, then the points are totaled to find the Aristotle Complexity Score.

The first factor considered is Mortality: Historically, what percentage of patients having this surgery perish during or immediately after the procedure? An operation with a low Mortality receives one point; the highest Mortality receives 5. The next concern is Morbidity. Morbidity is defined as “a diseased state or symptom”, but in this context it is a measure of how long the average patient spends in the ICU after the operation. Again, short stays earn one point and the longest earn a five. The third consideration is the perceived difficulty of the operation. All heart surgery is difficult and requires years of practice and training – if it wasn’t, there would be a surgical center on every corner. But closing an ASD is easier than performing the Arterial Switch.

So every heart surgery is rated, with the “easiest” (a straightforward ASD repair) being rated at 3.0 and the most difficult (A Biventricular repair) receiving a 15.0. For example, my 1967 Glenn Shunt would be scored a 7.0. The Blalock-Taussig Shunt is a 6.8, while the Modified Blalock-Taussig (which uses an artificial tube to make the Subclavian Artery to Pulmonary Artery connection) is considered not quite as difficult at 6.3. The Score does not exist as a “ranking system” of surgeons (almost like Consumer Reports)  but as information. If the OR calls Recovery and tells them that we’re sending down a patient with an Aristotle Score of 10, they know a very ill person is on the way.

So knowing the surgeon’s experience and skill level is really only half the question. If you were to be able to determine how difficult his work is, that could increase (or decrease) your confidence level.

The Hybrid Procedure

May 24, 2010

Until the 1980’s, most forms of Hypoplastic Left Heart Syndrome (HLHS) were fatal. That group of defects involve the left side of the heart, the side that pumps blood to the body, and surgeons had no procedure that could offer any hope. More often than not, all Pediatric Cardiologists could do was to offer Compassionate Care. This country has put men on the moon, many doctors would ask themselves. So why in the hell can’t we save these kids?

That changed with the development of the Norwood Procedure (a three operation sequence developed in 1981) and the first Neonatal Heart Transplant in the United States (1986) . But even though it was an answer, the Norwood Stage I is a difficult procedure.  It is a six-hour operation, a major re-plumbing of the heart and surrounding blood vessels performed when the child is less than one week old. Imagine, if you can, operating on a damaged heart the size of a walnut. And the delicate part isn’t the repair, it is balancing the blood flow correctly. Everything flows through the Tricuspid Valve, and you can increase the flow rate (which increases the pressure on the valve) some, but not a lot. Get the pressure too high and you damage the Tricuspid Valve, and we can’t have that. For a HLHS patient, the Norwood Stage I is the most important, the most difficult, and the most dangerous operation of the three.

What if it were possible for the Stage I to be an easier operation? Or better yet, what if you were able to eliminate it completely?

Well you can’t just disregard the Stage I – major HLHS requires some type of surgical intervention – but it can be an easier operation. Doctors in major heart hospitals around the US are refining what is known as the “Hybrid approach” and the early results are promising.

The Hybrid was developed at Nemours Cardiac Center in Orlando, Florida in 1999 and takes place not in the Operating Room, but in the Catheterization Lab. The chest is opened and both Pulmonary arteries are banded to restrict blood flow. Next, a stent is implanted in the Ductus Arteriosus to keep it open (creating a Patent Ductus Arteriosus, or PDA). And while the stent is placed via Catheter, it is not inserted through the groin. The Catheter is inserted directly into the Pulmonary Artery via the incision in the chest. At times, an Atrial Septal Defect (ASD) will also need to be created.

Once the stent is in place, the operation is over. Total time: 60 to 90 minutes, and the Heart/Lung bypass machine was not used. After the Hybrid, the rest of the Norwood is carried out as before. But the Hybrid Procedure allows the major surgery to be delayed, until the child is older and stronger.

A 2008 study showed that the results of this new operation were favorable. The University of Chicago started using the Hybrid for their high risk HLHS patients, but found that the results were so good that it is offered to all Norwood Procedure candidates. (Observant readers will notice that the “60 to 90 minutes” link and the “results were so good” link quote the same doctor, who worked at Chicago but later moved to Boston.)

Very few hospitals perform the Hybrid Procedure for HLHS; so if you get a prenatal diagnosis of Hypoplastic Left Heart Syndrome, be sure to ask about all treatment options – including (and especially) the Hybrid.

The Dirty Little Secret of HLHS

October 1, 2009

She didn’t even have a name for it.

When Dr. Helen Taussig wrote Congenital Malformations of the Heart in 1947, she described one malformation as “Atresia or marked hypoplasia of the aortic orifice prevents the expulsion of blood from the left ventricle in the normal manner.” Taussig described several variations of the defect – actually different defects, later grouped together under the same deadly name – but could offer no treatment suggestions. Her Tetralogy of Fallot (ToF) patients could at least squat and get some temporary relief; children cursed with this malady died in less than one week. The left side of the heart wasn’t damaged as much as it just wasn’t there.

It wasn’t until 1958 that Dr. Jacqueline Noonan and Dr. Alexander Nadas named the group of defects Hypoplastic Left Heart Syndrome (HLHS). Hypoplastic comes from the root word hypoplasia, which means “small”.

But having a name for it didn’t make it any less deadly as HLHS continued to claim 100% of its victims. This sad story continued until 1985, when the first successful infant heart transplant took place.

At about the same time the Norwood Procedure was developed. Originally designed as one operation (which consistently failed) the procedure was soon split into two heart operations – and eventually three – which seemed to work. HLHS children now had a chance. Obviously long term survival rates aren’t known yet, but approximately 70% survive the three surgery protocol.

And thats when the dirty little secret of HLHS showed itself: While survival rates for the three operation procedure may be in the 70% range, getting from Stage I to Stage II is the hardest step.

The goal of the Stage I operation is to make the Right Ventricle do the job of the defective Left Ventricle – getting the blood to the body. With all of the blood flowing through the right side of the heart, that side is subject to higher flow pressures than it usually receives. A lot higher. In a defect in which the entire left side of the heart is damaged, a successful outcome usually depends on the Tricuspid Valve – located on the right side of the heart.

The inital results were confusing. The Norwood worked – then it didn’t. There didn’t seem to be any rhyme or reason to it, no way to predict outcomes. The surgery itself worked, but too often the results  seemed to be as random as a roll of the dice. The answer was the Sano Shunt, invented by Japanese surgeon Shunji Sano – a direct connection from the Right Ventricle to the Pulmonary Artery through a Gortex conduit. (this sounds redundant, but the Pulmonary Artery is normally disconnected from the ventricle in the Stage I operation). Studies showed that survival chances with the Modified Norwood was 11 times greater than with the Classic Norwood.

And now it is time to turn the tables – we’ve got a nasty little trick of our own. Heart defects have to start somewhere… at some point in fetal development, there must be one isolated problem that seems to “snowball” into something bigger as time passes. If we could find that one little problem and repair it then, maybe we can stop the snowball before it gets too big. A pretty cool idea, and maybe one day…

Someday…

A study released Monday (September 28, 2009) revealed that for seven years, doctors at several hospitals in Boston and Harvard Medical School have been detecting Aortic Stenosis in fetuses. Fetal Aortic Stenosis is a snowball; it usually becomes HLHS as the fetus develops.

70 future HLHS patients underwent surgery while still in the womb – a needle was inserted into the mother’s abdomen, passed into the fetus, and into the heart of the unborn child. A small balloon was used to enlarge the abnormally small Aortic Valve. 51 of the procedures were considered successful… and 30% (17 children of the 51) were born with two functional ventricles. That’s 17 children who won’t have HLHS.

Mark September 28  on your calendar… that was the day that the CHD world changed forever.