After years of yo-yo dieting and eating disorders my breasts are saggy, can a surgeon manipulate the tissue back into shape?

Since you are looking for upper pole fullness, in addition to repositioning of your current breast tissue, you may want to explore the options of doing a breast implant along with the breast lift/mastopexy.  The breast implant will give you that upper pole fullness you are looking for. 

The technique you are describing is The Bellesoma Method.  This technique reshapes your breast tissue creating upper pole fullness without implants, elevates them higher on the chest wall and more medial to increase your cleavage.  The weight of the breast is transferred to the underlying pectoralis major muscle resulting in pain relief and long term stability.  Vertical scars are avoided, nipple sensation and the ability to breast feed are maintained.  At the same time or later, fat transfers can be performed if additional volume is desired.Best Wishes,Gary Horndeski, M.D.