It's very common for the sinus infection to come back after surgery. In fact, the best sinus surgeon in New York City wrote a book about his continuing chronic sinusitis.
Wait until your CT scans come back, and do everything the doctor says short of surgery. The Flip-Turn Sinus Flush, for an infection that does not include physical blockage in the sinuses, will wash out almost all infections. If you've already tried sinus irrigation and failed, it's because gravity prevents saline from reaching the upper sinuses, where chronic infections like to hide, and where surgery often comes up short. The flip-turn defeats gravity.
http://www.medhelp.org/user_journals/show/2322
The Flip-Turn Sinus Flush is mildly risky, because you have to bend over to do it, preferably in a shower, but you can also do it outside on soft ground.