Can a seroma start to develop just three days after i stop using a vac-pac?

No empty spaces: A seromma is a fluid collection our bodies produce in response to the inflammation of healing. After surgery, any "empty spaces" that do not have tissues moved into them fill with serum. Excess serum causes the wound to expand and prevent healing so removing it helps the space close. However, after removing the vac-pac, there still may be a little space left and so some serum will recur.