If you have o go ahead and have it then DO IT, End of the day you will have the best doctors that will look after you. 12 hours is a long time. damn.My surgery took 12 hours, i've had mixed feelings of i don't wanna give up and i don't care about it anymore, really plays with your patience and your struggle within. Hell i wish i could have more control over myself for these kind of things.
On the otherside i'm doing regularly i think, not too much not very few.