Would you trust a fellow to perform your surgery?

I am assuming you mean a plastic and reconstructive surgery fellow. If that is the case fellows have completed the full 6 years of plastic surgery training and can be out practicing independently but have chosen to do an additional year specializing in a particular part of plastic surgery. They are also working hand in hand with another plastic surgeon who is well into their career so it is unlikely that you have much to worry about. At the end of the day you should feel comfortable about the surgeon you have chosen before proceeding with surgery so the decision is up to you.

Breast reduction surgery is usually a covered medical procedure so you should have access to fully trained board certified providers to do your procedure.
When having surgery done at an academic medical Center procedures are often done, either partially or completely by physicians who are going through their training program.
When I did my plastic surgery residency Most cosmetic surgical procedures were primarily performed by the attending physician and the most we did as residence was assist and help suture.
Each training program will have their own system of getting their residence exposure and training.
In some clinics patients who have indigent medical insurance May be the patient that have the entire procedure performed by a resident.
Sometimes an attending provider who may or may not be extremely talented, may be overseeing and assisting.
Reviews are not particularly important when it comes to plastic surgery. What is important is having skill and experience.
if you want to minimize the chance of having complications and increase the chance of the quality outcome, knowing your procedure is done by someone who has skill and experience then you need to have a conversation with the resident physician asking who is going to be overseeing the procedure and how much of the procedure the attending is going to be doing and how much of it is going to be done by the residence.
You should probably also find out What year the resident is in their training program.
Most most plastic surgery program programs tend to be two or three years of plastic surgery.
Breast reduction surgery does have a fairly high complication rate and when complications happen, they can be fairly severe.