see Lumbar drainage.

see Subdural drain.

see Suction drain.

The purpose of a drain is to prevent fluid (blood or other) build-up in a closed (“dead”) space, which may cause either disruption of the wound and the healing process or become an infected abscess, with either scenario possibly requiring a formal drainage/repair procedure (and possibly another trip to the operating room). The drain is also used to evacuate an internal abscess before surgery when an infection already exists.