over 500 lbs what can I expect before and after surgery
Which kind of WLS? (and don't forget to cross post this post to the specific forum for that type) Congrats on making the "big" decision ... 
Frank talk about the DS / "All I ever wanted to be was thin, like that Rolling Stones dude ... "
HW/461 LW/251 GW/189 CW/274 (yep, a DS semi-failure - it happens :-( )
Yes, I would recommend same, given your super size/BMI .. In fact, for safety reasons, the surgeon may want to make it a two-parter (V.S.G. performed first, then return later for the "common channel" work) .. 
Also, you might want to look into the S.A.D.I. version of the procedure .. I have been hearing some good things about it of late (e.g. avoiding malabsorption complications), and, if I had it to do over again 17 years ago (it wasn't around back then), may have gone with same myself. 
Frank talk about the DS / "All I ever wanted to be was thin, like that Rolling Stones dude ... "
HW/461 LW/251 GW/189 CW/274 (yep, a DS semi-failure - it happens :-( )
Understandable, but a good, competent surgeon should still get you through it w/o problems, esp. if they do it as a two-parter as I mentioned. I was 461 lbs./61 BMI ("super-obese") when I had my surgery (my DS was done all at the same time, and laparoscopically + gallbladder removal, btw), and there are many others on here who weighed even more at the time of theirs. 
Have faith, and just do it!
Frank talk about the DS / "All I ever wanted to be was thin, like that Rolling Stones dude ... "
HW/461 LW/251 GW/189 CW/274 (yep, a DS semi-failure - it happens :-( )
