Transposition of the ventricles

[MichelleDematos]

Hello

I have a 5 year old son with what they call "Anatomically corrected transposition of the vantricles with a slight leak in the velve".

My cardiologist has recently suggested that we do preventative surgery by putting a Band on the Palmonary artery.
Can you please give me more information on this proceedure and statistics on success rate. some of my questions are:
1. How do they know how tight to make the band....
2. Will they have to do more opps because the band will need to be made larger as he grows
3. will the band not cause damage to the artery itself.
4. by making the Artery narrow are we not at risk of blood clots at the point of the narrowing
5. If they band the PA wont the ventricle get to full of blood and damage the ventricle as well?
6. What is the effect of this banding on the leaking Valve
7. Where have they done the most of these surgeries and what are the results.
8. Where can I found out more information?????

Thank you for taking the time to answer my questions
Kind regards
Michelle

[Jeffrey R Boris, M.D.]

Dear Michelle,

For our other readers, l-transposition of the great arteries (L-TGA, or "corrected transposition") occurs when there is a right atrium feeding into a left ventricle which then goes to the pulmonary artery.  As well, the left atrium sends blood into a right ventricle which goes then out to the aorta and the body.  Everything is in the right place EXCEPT for the ventricles, which are in an "inverted" position.  The problem with patients with this heart is that the right ventricle was never meant to work as a systemic ventricle, pumping systemic-level blood pressures.  Thus, over time, the right ventricle fails.

Placement of a pulmonary artery band is the first part of "strengthening" the left ventricle to be able to tolerate the higher pressures of pumping blood out to the body.  It does not cause an increased risk of blood clots, as the band is not THAT tight.  It does sometimes require a second surgery to tighten the band further, but that depends on how well the left ventricle tolerates the change in pressure.  The tightness of the band is determined by the surgeon to cause a specific increase in pressure in the ventricle that is measured in the operating room.  It is not made so tight as to prevent the ventricle from pumping the blood out of the chamber.  It can cause some permanent narrowing to the pulmonary artery, but this can be augmented with a patch at the time of the subsequent surgery.  

Often, PA banding can actually decrease the amount of tricuspid valve regurgitation, because the increased left ventricular pressure causes it to expand somewhat and normalize the configuration of the right ventricle.  This can cause the leaky tricuspid valve to perform better, and leak less.

The subsequent surgery mentioned above is the double-switch operation.  The double-switch operation is one in which baffles are placed within the atria to direct the blood from the atria to the correct ventricle (i.e. right to right and left to left).  The second part of the double-switch occurs with a switching of the great arteries (pulmonary artery and aorta) as well as the coronary arteries, so that the redirected blood goes to the correct location.

So, how do you choose a surgeon for this?  The short answer is that it's REALLY difficult.  This is not a common diagnosis, so it is not a frequently performed surgery at many places.  It may be that there are some surgical centers that are referral centers, as they do more of these than others.  However, in total, they are rare.  And, since they are rare, these are surgical procedures whose outcomes are not widely reported.  I would recommend having your pediatric cardiologist do the footwork here, and find the center(s) that do more of these.  In the absence of that, do remember that it's not just the surgeon but also the entire team, including the intensive care unit afterwards.  This means that cardiac ICU outcomes matter, as well.

In these patients, sa you have already been advised, it is best to not wait for symptoms.  If you get to the point where the cihld is symptomatic, the surgical outcome will be worse, as there is less "cardiac reserve" to be able to tolerate the surgery.

There are patients w/ l-TGA that are able to go a number of years prior to requiring surgery.  I think that we don't really know exactly what the appropriate time to do the intervention is.  There are those who say it should be done before age 5 years.  However, there are those who would say that it should be done when the right ventricle just starts to have problems, and that may not occur until years later.  The bottom line here is that we have little data on what the best thing is to do.

[Jeffrey R Boris, M.D.]

Dear Michelle,

That time varies, of course, depending upon the amount of time it appears that the ventricle is "retrained."  I am not sure of the exact amount of time, but I believe that it typically there for less than 2 years.

[MichelleDematos]

Thank you for your reply on the 17th.

I was wondering once you put on the Palmonary band. what is the longest time you can have it there before you have to do the switch.

Kind regards
Michelle

[MichelleDematos]

I understand from further research that the PA banding in itself is not the “biggest” part of the opp. It is what will happen after. As I understand his condition is very very rare and there is not much research done. Please can u give me any statistics that u may have on what has happened to other patients with his condition.

I was also wondering how long before a Dr answers my questions

[MichelleDematos]

Sorry just to add

He is in very good health at present and from just looking at him you would never say there is anything wrong with him.