mitral valve re repair

[trooper95]

Where to take a 13 year old for a mitral valve repair for mitral valve stenosis when she already has a annuloplasty ring. The outlook for  a tissue valve not a mechanical valve if replacement is the only option. Menses has already started.However Noonans syndrome is a real possiblility.

[Jeffrey R Boris, M.D.]

Dear Trooper,

This is a tough set of questions (there is more than one question here).  I want to do a bit of explaining for our other readers, first.  Mitral valve stenosis is obstruction to inflow at the mitral valve, the first valve on the left side of the heart.  Since I don’t have all of the information, I’m going to have to make a few guesses about your daughter’s history, based on what you’ve told me.  She had an annuloplasty ring placed, which is a stiff ring that is sewn into the inlet of the mitral valve to reduce the size of the annulus, or valve ring.  I am presuming that this was done due to severe mitral valve regurgitation.  However, now, with growth, your daughter has outgrown the ring size and has obstruction to inflow of the valve.

The choice of the mitral valve is dependent on multiple issues, for which you allude to several.  Her native valve is not likely to be able to be salvaged at this point.  This leaves placement of a tissue prosthetic valve or a mechanical prosthetic valve.  Neither are perfect options.  Tissue valves can either wear out or become calcified and stiffen over time.  However, they are better valves for use in childbearing years, as I’ll soon explain.  Mechanical valves are much more durable, and can last up to a lifetime.  However, they require lifelong anticoagulation with medications such as warfarin, so that blood clots don’t form on the valve.  Warfarin can cause major birth defects for unborn fetuses, and thus becomes more problematic for use during childbearing.  However, with adequate planning, it can be done by switching to routine heparin injection.  Of these choices, neither valve grows with the patient, so it is important to ensure that the largest possible valve that can be tolerated by the heart is placed so as to minimize the number of follow-up operations.  Sometimes what happens is placing a tissue valve during childbearing years, and then switching out to a mechanical valve.  Unfortunately, without knowing your daughter’s anatomy or prior surgical indication, etc, I can’t say for sure what needs to happen here.

Noonan syndrome complicates things a little bit.  These patients can be at risk for development of hypertrophic cardiomyopathy, an abnormal thickening of the heart muscle that can lead to arrhythmias.  There can also be some developmental delay, although most are within the low-normal IQ range.  However, for females with Noonan syndrome, fertility is felt to be normal.  Mitral valve structural disorders have been described in these patients, as well.

Finally, how to choose the center in which she will have her surgery is also an interesting problem.  I would definitely make sure that you choose a pediatric cardiac center (as opposed to a hospital that also does heart surgery for children).  Doing a threshold level of 150 to 200 total pediatric cardiac surgical cases a year is probably good, although no one knows what the real threshold for quality is at this point.  Talking to the surgeon about individual experience and case number is probably helpful, as well.  Beyond that, it comes down to where you feel comfortable with the various interactions that you will be having, and where you are getting your questions answered completely.

[rimom1964]

My son, aged 6, also has Noonan Syndrome.  He does have a mechanical mitral valve that is doing quite well.  I do understand your significant concern with having a female child with the anticoagulation therapy that goes with a mechanical valve.  I just wanted to wish you well with your decision of what to use and who will do it.  It is a big decision that can't be made lightly.

Best wishes!