Sunday, October 19, 2014

The Need for a Shunt

Today's post is about our experiences with the shunt. The shunt was developed by an engineer in the 1950's for his son.  Ironically his name was John W. Holter (Toby's Grandpa's name is John Holt). He and his wife had tried for ten years to conceive, and then their son was born with myelomeningocele and hydrocephalus. The device he invented - the shunt - helped his son live until the age of five, but then he passed away from complications related to his heart.  My information came from this article (they state his condition as "meningomyelocele").  

Hydrocephalus is a condition in which the ventricles in the brain are producing too much cerebral spinal fluid (CSF) As I understand it, and correct me if I'm wrong on this, Spina Bifida friends, but all ventricles produce CSF.  However, as a result of the open hole in the back in utero, the ventricles are programmed to overproduce fluid because it's leaking out through the open hole instead of recirculating though the CSF system.  Once that hole is closed after birth, the ventricles continue to overproduce CSF therefore causing the head to swell.  Not all kids with SB and hydrocephalus require a shunt, but Toby did.  His first shunt was placed when he was 4 days old.

Shunts are very fickle devices.  Some kids keep their first shunts into adulthood, others only last a few days. The device is a catheter (think straw) with little holes in it that is placed surgically into the ventricles of the brain.  It is attached to tubing that goes down the neck and ends into the abdominal cavity.  There the excess CSF is reabsorbed by the body.  There are risks of it clogging, failing, breaking, coming apart at the distal catheter, and also infection.  There are also programmable shunts and shunts that has tubing that ends in the region of the heart.  Toby's is a ventriculoperiteoneal (ends in the abdominal cavity), and his is not programmable.  

This site is where I found this picture of the shunt.  That same site also has a great MRI picture of the brain with normal ventricles and ones that are swollen with fluid.  Here is a link to more information on the shunt.

Toby's first shunt failure occurred when he went back into the hospital with his breathing issues around 2 1/2 weeks. He had his first shunt revision on January 25th, 2007.  He was barely a month old.  It was very obvious that he was in failure; just inconsolable - crying constantly.  I think the fact that he became hyponatremic (sodium drop), and is changes in blood pressure and temperature were also shunt related.

His second and third shunt revision wasn't until November 9th and 10th of 2010.  This was the first step in finding out whether Toby needed his spinal cord detethered.  The doctors typically explore the shunt first.  In Toby's case, he definitely needed this revision.

There have been other times when we've suspected it wasn't working - the mamas in the Spina Bifida community affectionately or unaffectionately call it SMP (Shunt Malfunction Paranoia).  Toby typically doesn't have the "normal" symptoms of shunt malfunction.  The last time he had a shunt malfunction completely turned our lives upside down.  I had been suspecting for awhile that something wasn't right.  He was impatient, ornery, and his nystagmus (eyes jumping) had gotten really bad.  I called our nurse case manager in the SB clinic that week telling her of my suspicions, so she had the doctors order a limited MRI along with his other tests for clinic that Friday.  

Before this, typically, CT scans were used to check shunts.  Unfortunately, this test exposes kids to large amounts of radiation.  I think I've read that one CT scan is the equivalent to 100 chest x-rays of radiation. The neurosurgeon Toby had at birth left to start an SB clinic in Arizona.  We switched to our current neurosurgeon and he prefers to use the limited MRI's to check brain ventricles for swelling. The benefit is the little exposure to radiation.  The downside is they are really loud, and Toby screams the entire time.  It's really hard on him.

After getting all of Toby's tests and waiting forever to see doctors that day in clinic, our nurse came in looking grim.  The MRI didn't look good - it showed swollen ventricles, and neurosurgery wanted us to head to the ER right away.  He had a few more tests, and then the resident dropped the bomb of trying out a new surgery on Toby called an ETV or Endoscopic Third Ventriculostomy.  The link explains this procedure much better than I can.  He was admitted and had surgery on March 17th, stayed a few days for observation and then went home.

That week we were keeping a close eye on him.  With the ETV, a little more CSF stays in the ventricles than with a shunt.  The risk is also that the fenestration they make in between the third and fourth ventricle can close, so we were watching for that too.  The doctors also left the shunt in, and they had discovered it was indeed clogged.  They leave it in because it requires another surgery - another incision in a different part of the head to take the shunt out.  It can also work as a back-up in case the ETV doesn't work, even though it was partially clogged, some of the catheter was still draining fluid.

Then, Saturday morning around 6 a.m. I woke up to our nurse yelling, and Toby's pulse-ox was going off.  I ran into the room only to see our son's eyes rolling and immediately I knew he was having a convulsive seizure.  We checked to make sure he didn't need to be suctioned, and then we called 911.  That ride to the hospital was one of the longest in my life.  I remember arriving, being ushered into critical care.  By this time, Toby had stopped seizing, even though, I can't really remember when the seizure actually stopped because he was just staring off into space.  My first thought was that there was too much pressure in his brain, the ETV was not working, and he needed to immediately go into shunt surgery.  The medics got an IV in, and they drew blood to test for a variety of things.  The biggest thing that came back was his sodium was low - hyponatremia again.  It was 118.  They began to run high concentrations of saline but not too quickly or it could cause seizures also.  He began to seize again, and this time I can't remember what time it stopped.

I don't remember much after that, but here are a few memories:
*His sodium was corrected and he was still seizing....
*Bagging - I remember the RT's and nurses bagging him off the ventilator because his oxygen was dropping, and he was fighting the vent.
*A nurse with a face I don't remember hugging me as I stood watching them work on him, and I could only break down into sobs.
*Bruce showing up in the ER and he and I sitting on the floor watching them wheel him up to the PICU.
*An employee from admitting trying to get my insurance information as we tried to follow Toby up to the ICU - and a great feeling of wanting to smack her - this wasn't the right time.
*Being ushered out of the PICU as the chief resident in neurosurgery prepared to put in an ICP Monitor - basically they put a cathether in through the ventricle to test the levels of pressure.  
They ended up having to do this bedside as the OR was booked with other cases (It was the weekend).
*Sitting in a room waiting, praying, sobbing...

God was definitely with us through this entire process, even though I really questioned His wisdom in allowing this to happen.  I felt like He had moved His hand of protection from Toby - we hadn't had an emergency like this in awhile, and so I wondered why He had decided to allow this.  In the PICU that day, the neurologist on call for the hospital was sent by God.  She was/is so knowledgeable about seizures, and her approach to Toby's care was so family centered.  One of the rotating doctors in the PICU also had just finished up time with neurology, so I felt like they both had a plan.

I remember laying on Toby and crying out to God to stop the seizure as he continued to seize, medication after medication had been thrown his way, and still nothing was working.  He tremored every few minutes, which they said was still convulsive seizing, but his body was just too tired to do it all over.  I remember asking the doctor what would happen if they couldn't get it to stop, what would they do. Her response was anesthesia or some type of heavy sedation.  They finally had to use versed to get it to stop (a sedative).

Then, they put on the EEG leads to see if his brain was still seizing, but his body could no longer respond. The intracranial pressure monitor never did show an increase of pressure in his brain.  It was clamped most of the time (it's the yellow/orange tube coming out of Toby's head in the photo below).  The doctors couldn't really explain why this had happened.  We believe it was a reaction to the ETV surgery and his sodium dropping.  There were only a few cases of kids having seizures after the surgery, but Toby added one more to the medical literature.
The middle photo on the right with his one arm in the air, was the first time we saw him make a voluntary movement.  Bottom left was his first smile.  Middle were the incisions from the ETV, and the other was the intra-cranial pressure monitor.  
By the next evening, he did start to wake up and the EEG showed no seizure activity.  I'm not sure why, but seizures have always been one of my greatest fears.  The doctors haven't ever been able to give me a straight answer on how long he seized - we know it was between 4-6 or maybe even 7 hours straight.  I kept praying that I would hear his voice again, see his smile, and have him look me in the eye. I also realized how greatly I had taken those things for granted.  It reminded me again to be thankful.

Even though, Toby was waking up and was moved out of the PICU. He could barely hold his own head up, so the doctors began to talk of moving to the Rehabilitation unit.  This way he could get consistent therapy and learn to sit up, move, write, and eat again.  We did move to that floor after about a week.

Toby was learning to throw a ball again he could barely hold himself up or his arms over his head; he was so weak.
Toby only spent about 5 days in rehab.  You could tell by the end of the week that he just needed to go home.  In two days it would be Easter, and I couldn't handle one more day being in the hospital.  He was discharged on Good Friday!

I read Psalm 31 over and over during this hospital stay.  The verse below rings out its' truth over and over:

Psalm 31:4-5a "But I trust in you, LORD: I say, "You are my God."  My times are in your hands..."

Just last month we had a follow up appointment with his neurologist.  The same one that was there in the chaos, the same who happened to be on call for the hospital.  We talked about the seizure again, and I asked her to pin down for me how long he actually seized.  It was going to take too long to dig through all of his medical records, even electronically (that's scary), but she reminded me that once someone convulsively seizes for 20 minutes it's too long.  After that they risk damage to their hippocampus in their brain.  The amazing thing, and this is God's healing, is that Toby's MRI right afterwards, and every one since has shown no damage to that area of his brain.  I am reminded that our times are in His hands - our very life and breath. He knows all.  So much good has come out of that situation:

*A reminder to me that I am not in control was one of the biggest, a renewed trust in God's faithfulness.
*Deeper thankfulness for the abilities that Toby does have, instead of focusing on what he cannot do.
*A renewal of our full nursing hours; this sounds crazy, but right before this our insurance tried to cut them and then because of this situation, they couldn't justify it.
*The ability to declare God's healing in Toby's body and brain.
*In many ways I think it prepared us for the road ahead with the multiple surgeries on Toby's back/scoliosis.
*We saw the body of Christ reach out to us through a brand new church we had only been attending for a few short weeks before this situation...and it led us to stay there - a church that has a passion/gift for reaching families of children with special needs. 

Two times in Toby's life his sodium has dropped below normal levels and both were closely related to shunt failure. The condition is called hyponotremia. Just last week a neuro-ophthalmologist told me that at the base of the third ventricle in the brain is the hypothalamus, which controls sodium levels/hormones, etc. It's possible that too much pressure there or a cut as in the case with the ETV messed with his sodium levels and caused them to dip.  It was interesting to learn this bit of information.

Some may ask if we had do make the decision to do the ETV all over again, would we?  I think we would, we made the best decision we could with the information we had at the time.  Even though there are days, I still question whether it's working properly, it has taken away some of the worry whether or not the shunt is working.  This is only what I can think of right now, although I know there may be many more in years to come as God reveals His purpose as He sees fit.  He has a way of bringing back these situations and we can say, "Oh, that's why that happened." To God be the Glory, Great things He has done.

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