I've just been to see Dr Kollias for a check up 2 weeks after surgery. Thankfully he was able to aspirate the swelling under my arm. This involved him sticking a needle in and syringing out the fluid. Took about a minute.
Sounds yukky but because I am numb under there anyway I couldn't feel it!. He said it wasn't too much and hopefully the body will start to get rid of the fluid itself. There is a little bit of fluid also under the wound on my chest but he said the body would probably get rid of this itself.
If I need him to aspirate a swelling again I am just to ring his rooms and he will slot me in between patients. It's that simple!