If this is a fluid-filled pocket (a seroma), I would think that draining
it with use of a pressure dressing would be the best way to prevent
re-forming of the sac.  Wounds heal best from side to side, nt end to
end.  The seroma is caused when fluid accumulates in the space where
tissue was removed.  The healing cannot cross the fluid; the healing
edges need to be in direct contact.  It is often necessary to drain
these repeatedly, one hopes getting less fluid each time.  The down side
is that each time you introduce a needle to drain it, there is a risk of
introducing bacteria and getting a secondary infection.   The dressing
with mild pressure will help limit the reaccumulation of fluid, but
probably won't stop it completely.

Darla,

I also had swelling and pain from fluid accumulation.  I had to go back to
the doctor 3 times to have him remove some of the fluid with a syringe,
because it hurt so much and felt like it would burst. Eventually the rest of
the extra fluid was reabsorbed into my body.

Marianne