Little Miss Minion had her third shunt surgery this morning. This shunt story started two days ago. Mr Minion and I feel her fontanel (soft spot on her head) on a pretty regular basis and we both thought it felt different Monday night. Tuesday morning, it felt slightly more different, so we took her in to the ER to get it looked at. She was acting fine and not really showing signs of pressure, so we caught it very early.
The plan was to have an MRI done yesterday to take a look at the ventricle walls and the third ventricle to decide which of two surgical options would be the best.
In a normal brain, there are 2 ventricles in the center of the brain. These are like water balloons and they are normally slightly full of cerebrospinal fluid (Gatorade for your brain). When she had meningitis (which is pretty much confirmed at this point by different things that have happened), the infection caused some scarring in her brain tissue, including the wall that separates the two ventricles. Normally, CSF can flow between them, which would allow her shunt to drain both. The scarring blocks one ventricle from draining, so pressure was starting to build up. There was also a blockage, probably caused by the meningitis, in the third ventricle, which is like the S bend in a toilet (for lack of a better description). The two main ventricles would be in the bowl, and then they drain through the third ventricle.
There were two options to solve these problems. The first option would be to place a second shunt. This would mechanically solve the drainage issue, but would create a second area of concern for infection or shunt malfunction.
The second option (and the one we went with, at the recommendation of her neurosurgeon) is called ETV (endoscopic third ventriculostomy) and fenestration (creating an opening). This procedure creates a hole between the two main ventricles, allowing fluid to flow between them (fenestration) and creates a “drain” in the third ventricle to allow fluid to flow out that way. So the fluid can now flow down through the third ventricle and exit around where it should, and the shunt can still drain anything that doesn’t go out that way. There is a valve on the shunt that reacts to pressure, so it shouldn’t drain unless it needs to.
The ETV could negate the need for the shunt, but they don’t like to remove the shunts unless there is a good reason to do so. Plus, there is a slightly higher failure rate with the ETV than the regular shunt at first.
So that’s what’s been going on with us.