In 2012 the American Society of Plastic Surgery published guidlines for breast reduction surgery, and stated that placement of drains after surgery was not beneficial (see the attached link). So you will likely see more and more surgeons moving away from routinely placing drains. I rarely place drains after breast reduction, but when I do, they stay in place for about 5-7 days. Best of luck to you!
You will find that some plastic surgeons do, some don't, use drains with breast reduction surgery. In my practice, when I do use drains, I remove them when the output is low (this is usually possible 3 to 5 days after surgery). I hope this, and the attached link, helps.