Aetna HMO insurance for FU??

I've been through a tough double surgery, (4/10 & 4/17/03) and my incision is almost closed. In the next month or so we have to change insurance cos. probably to Aetna, HMO. I still have a large hernia to take care of and alot of stomach skin that has to be removed. Any input as to how much trouble I'll have getting approval with Aetna Health Plan? There aren't supposed to be any waiting periods for pre-existing conditions. I've been with Kaiser for a long time and hate to have to change!! Janis