Is it possible for a shunt to come loose?
 

I'm not sure about the exact apparatus, but I assume there is a part that attaches to the skull and then a tube. Are there opportunities for those pieces to separate? would that be possible?

very much so
 

I have had my shunt and tubing in for over 30 years and last summer out of the blue I had to have major surgury on the tubing. I had my shunt put in in november or 1979 and had a few revisions on it as a child in the 1980s. I went thru my teenage years and my twenties with no issues. I felt sick one day last june and just thought i was dehydrated. After an afternoon of being miserable I went to the er and they did some testing. As it turned out my tube had broke in my stomach and was making me feel sick all day. So I would say that it is definately possible for it to happen. good luck

I am 14 and have had a shunt since I was 4 in 2003 and had an LP shunt until 2010 when a CT scan showed that the tubing was disconnected, but it was flowing enough when I was laying down that I wasn't having extreme symptoms.

Yes, It is possible for a shunt to come apart, even if it is surrounded by a lot of scar tissue.