How Significantly Do Fluid Drains Reduce Swelling?

Some plastic surgeons place drains after breast augmentation surgery to remove any fluid that might accumulate next to the prosthesis.

The function of drain placement following revision breast surgery is to help reduce fluid collection inside the breast. Failing to place drains in some instances may increase the risk of development of a seroma surrounding a breast implant. However, they do not technically reduce swelling that occurs within the breast tissue itself.
 

if you had a capsular contracture then the surgery was probably a capsulectomy, which is often associated with swelling and fluid weeping into the space. The drains prevent the fluid buildup but the swelling may take a while to go down. Since a capsulectomy by definition removes some tissue, the slightly larger implant should compensate for that without the breast size changing much. As for size, 500 cc of silicone is the same volume as 500 cc of saline, though the appearance may differ because of implant dimensions.