it has been a year, i would wait another 6 months just to be on the safe side. Your body is an amazing healing machine, but you dont want to stress something that has had trama.
i had a c-section when i had my son. 6 months after that, my scar looked like it had been there for years, but i didnt try my abb curler until another 6 months later. i know that sounds silly, and i prob would have had no problems, but im a better safe than sorry person. Of course, you can always call and ask the doctor that refered you for the surgery!