Hi Franck, welcome to this site!
As I've got about your age, I'm curious to know what symptoms you had before the surgery and what decided your neuro to have your thymus removed. Above 65, I think it's quite unusual unless there is sign of thymoma.
Also, what was the technique used, robotic, transternal or else?
Don't worry about Mestinon, if you don't need that much, you'll soon lower it, with your neuro's approuval.
By the way, what Mestinon tablets do you take, 60 mg or else?
Maurice.