Posts Tagged ‘Catheter’

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.

New way to create an ASD!

February 20, 2010

Here’s a report of a novel procedure that will hopefully come into use soon: creating (or enlarging) an Atrial Septal Defect (ASD) without breaking the skin.

I had a small ASD at the time of my first surgery but it needed to be larger. Back then (1967), ASDs had to be created or enlarged the old fashioned way – with a scapel. This was known as the Blalock-Hanlon Procedure, and it was pretty straightforward: cut into an Atrium, look for the ASD, and enlarge it. If you couldn’t find an ASD, make one.

Surgeons don’t perform the Blalock-Hanlon very often these days. (When I read my operative notes just a few months ago I had never even heard of the Blalock-Hanlon, much less knew that I had one!) Today the majority of ASDs are created by a balloon atrial septostomy, which is done by a catheter.

But this new procedure wouldn’t cut the skin at all. Histotripsy is “tissue liquification by ultrasonic wave” – the same technology they use when your uncle has his gallstones crushed. The suffix “-tripsy” is a Greek word that means “to massage” or “to crush.”

This was a small study of only ten dogs. Ultrasound was used to locate an appropriate point for an ASD and then the defect was created by Histotripsy. In nine out of ten cases, the shockwaves created an ASD, and later examination showed that there was “minimal damage” to surrounding cardiac tissue and no damage to the outside of the heart.There is also evidence that Histotripsy could be used for some cardiac ablations.

Much more research needs to be done before this becomes an accepted procedure, but the initial results are promising!

News and Notes

September 13, 2008

A very short post tonight, as I’m pretty busy, but I did find several articles that you will find interesting: There’s yet another report showing that Adult Stem Cells taken from heart muscle can regenerate damaged hearts. But this time the news is even better: Doctors have found a way to boost their effectiveness.

A member of the Adult Congenital Heart Association is once again in the news, as Jim Langill took on the Boston Heart Walk today (September 13, 2008). I hope it went well, Jim!

Has your doctor ever described you as a “difficult patient”? That’s a good thing!

And finally, things are really happening down at Emory University Hopsital, where I go for Adult Congenital Heart Defect care.  Emory is one of only ten hospitals nationwide that is testing a new procedure to insert heart valves without cutting the chest open!