Seroma after liposuction
This fluid collection is called a seroma. They are rather uncommon after liposuction, but are a known possible complication.
The usual treatment is aspiration, often a few times. Insertion of a drain, as has been done for you is often the next step for the occasion patient who continues to collect fluid despite aspirations.
If the seroma still persists, injecting a caustic agent through the drain, such as betadine, tetracycline, or alcohol will usually cause the seroma cavity...