Gastric Lapband surgery for teens?

Recently I found that I might be approved for Gastric Lapband at least thats what one of my doctors told me which I was so very excited about but I'm only 16 years old! & I weight about 337 pounds! I was hoping if someone can tell me a bit more about Gastric Lapband & please don't tell me to change my mind I have lots of health issues which My doctor & I! think can greatly be fixed..But I just want to know the basics on Gastric Lapband & I also wanted to know if anyone can tell me how long it would take to get to my goal weight of 150? once the sugery is done,anyways! can someone please help a young soul out?