Thursday, July 21, 2011

Liver Transplant Team Meeting Results

Today we met with the liver transplant team at Sick Kids, and learned the following.

1) The surgeon has no conditions on minimum age or weight.  As soon as a liver is available, either cadaver liver or living donor liver, he will do the surgery.  This was probably the most surprising piece of information for us, since we assumed there would be a minimum age/weight or both.  He said if we had a living donor ready the day baby was born, he would perform the surgery that day.

A living donor is someone (related or unrelated) who donates (via surgery) a part of their liver to be transplanted.  The donor's liver regenerates and grows back into a full's the only organ that will regenerate.  Pretty cool, eh?

2) Having a living donor for the day of the birth is nearly impossible because they do a maximum of a 15:1 weight ratio for donor to baby.  My previous two pregnancies have resulted in babies that were less than 6.5 lbs.  At 6.5 lbs for baby, the adult donor (18 years old or older) would have to weigh a maximum of 6.5 lbs * 15 = 98lbs!!

However, it is possible (but doubtful!) I would have a bigger baby, and also possible that baby will grow after birth.  With this in mind, here are some potential weights of baby vs weights of potential donor.

Baby weight  = Maximum Donor Weight
6.5 lbs = max donor weight of 98 lbs
8 lbs =    max donor weight of 120 lbs
10 lbs =  max donor weight of 150 lbs

3) Living donor would also have to match blood types with the baby. We know based on our own bloodtypes that the baby will either be B or O blood type.  The +/- part doesn't matter for liver transplant.  We will try to find out which one baby is before he is born.

If baby is O, then donor must be O blood type.
If baby is B, then donor can be either B or O blood type.

4) Sick Kids typically does 20-25 liver transplants each year, but this year the numbers have been much higher.  They are currently working on transplant number 22 for the year, and it is still July.  Approximately half of the transplants are via living donor, and the other half are from cadaver livers.

5) Approximately three transplants have been done over the last 2 years for urea cycle disorders (of which OTC is one of six), but all were for babies that were diagnosed after birth.

6)  This is the first time they have had a liver transplant in the planning stages before the baby is born.  Typically only heart transplants are prenatally known to be needed after birth.

7)  As soon as baby is born, he will go on the transplant list to receive a cadaver liver.  Wait times to receive a liver can never be guaranteed.  The hope is that baby can survive long enough to receive one using the medical treatment that the metabolic genetics team has come up with, as stated in my previous post The Treatment Plan (click here).

I'm sure I've probably missed some info in here.  If there is anything I missed that you would like to know, ask, and I'll answer!

Sunday, July 10, 2011

The Treatment Plan

We had a long meeting this week with metabolic genetics. We were not originally sure if the hospital would be willing to treat baby's OTC (ornithine transcarbamylase deficiency) or not.  I wouldn't have been surprised if they had said "Sorry, but this is beyond the scope of our abilities."

However, they are optimistic (much more so than we are) that they can treat baby.  It requires a LOT of work, and co-ordination between numerous departments of a number of different hospitals.  Since I know we have many people interested in how this will work, I will try to outline what we know so far.  We will know more specific details later, as we have not yet met with the transplant team, and they will answer many questions regarding transplant at that point.

1) Ideally the doctors would have me deliver by planned c-section, so that they will be ready and prepared for us and baby with a known time of arrival, but I have decided against this for a combination of reasons.  It's surgery and I've never had surgery before.  The surgery itself could potentially make ME sick with my body and OTC reacting to the stress of the surgery.  But mostly, I've decided to deliver naturally because it's the one thing in this whole process I can keep "normal", and I need that one piece of normality!

2) When I'm in labour, I will be given a drug called Ammonul by IV which will reduce the ammonia in my bloodstream.  The theoretical thought is that the drug will also pass through to the baby, helping the baby to have lower ammonia levels after birth as well, since the birth process itself is hard on baby and breaks down protein turning it into the dangerous ammonia. Medical literature says this has only been done once, but we suspect it may have been done more often than this.

3) Once baby is born, he will immediately be given an IV with a 10% glucose solution in order to give him calories so that protein isn't broken down.

4) After this, I'm guessing within an hour of birth, baby will be taken across the road from Mount Sinai Hospital to Toronto Sick Kids Hospital.  NICU is not set up for this situation, so baby will go straight to Pediatric ICU (PICU).  The "tube" team (I don't remember what they are actually called!) will put tubing into baby to be ready for dialysis.  Baby will most likely be on dialysis 24/7 most of the time.  Baby will also be put on a strict, medical diet of a special formula made up of amino acids and sugars.  Ammonia levels will be monitored constantly.  The hope is that baby will eat by mouth, but if not, baby will be fed through an NG tube (yes, more tubing) 

5) It's really important to keep a balance between calories needed for growth and formula given so that baby isn't taking in protein, or breaking down his own protein.  If this happens, ammonia can build up, which would cause brain damage.  This is why ammonia is constantly measured, and if it goes high, dialysis will be started.

6) Using the above methods, we hope that baby does ok and grows well in the meantime.  Everyday holds potential unknowns, and we have been told to expect baby to take 4-5 weeks to become stable.

7) If baby needs some extra help during this time, it looks like I will be flown down to Pittsburgh with baby for an experimental clinical trial where healthy liver cells will be injected into baby's liver daily for a week.  This is a very controversial cell therapy trial, that just opened in the last couple months, and they are looking at having 20 children in the trial over a period of 5 years.

8) All of the above is being done in order to keep baby alive long enough to have a liver transplant.  We will be meeting with the liver transplant team soon and have many more answers after this meeting.  Once a liver transplant occurs, there is no more risk of brain damage from elevated ammonia levels, and baby can begin eating foods that contain protein.  How long we have to wait after birth until a transplant can be performed will be known after we meet with them, as well as how long baby will be kept in hospital after the liver transplant.  I'll update on all the transplant issues after we meet with that team.

We aren't feeling overly optimistic about this, probably because we've been through the death of a baby from this genetic issue already, but with the advances that have been made since then in the last 8 years, we are willing to try for treatment.