how long do fills last?
There are a couple of answers to this question. First, as you lose weight, the fat around your stomach also decereases, so sometimes people need to get an adjustment because of that. Also, over time, some people have found that they had a certain amount in their bands and then they had it checked later on they had a bit less in it. so people do beleive that a bit of the saline may get absorbed by the body. The saline does stay in your band forever unless you decide to have an adjustment for whatever reason.
There have been books written on the how, why and when to adjust the lapband. You might want to read Jesse Ahroni's book on the subject. Also, the lapband board on OH is a great source of great info on the band.