What is a surgical drain?

Surgeons use small plastic tubes to help drain away fluid after an operation: without them the fluid might gather up and cause infection. Or, in the case of an operation on the lungs or chest, air might gather up and squash the lungs.

They are usually special small, flexible plastic tubes which the surgeon places during the operation and then leaves poking out your skin, attached to a small bag.

This is an example of a drain coming out of someone's leg:

Surgical drain

© ChristianKazur, Public domain, via Wikimedia Commons

Although they look a bit gruesome, they aren't usually painful.

Here's an example of a surgical drain after hand surgery:

Hand surgical drain

© Pavel Ševela, CC BY-SA 3.0,viaWikimedia Commons

Some operations involve quite 'juicy' parts of the body: areas where the body usually makes lots of fluid or juices. An example would be surgery on someone's armpit (axilla): this is often done as part of breast cancer surgery. The armpit makes a lot of fluid after being operated on. Without a drain, the fluid might gather up in a large pool and be painful.

The pressure of the fluid inside might stop the wound healing properly. So the surgical drain allows extra fluid to drain off harmlessly.

If you have had to have an emergency operation - for example, for a burst digestive tract (what doctors would call a perforated bowel) - then there can be infected juices left behind inside you. A surgical drain allows those juices to drain away and hopefully reduce the chances of getting an infection after the operation.

Surgical drains usually stay in the body for a few days after an operation. When the fluid production has faded away, the drain can be removed painlessly.

There are differences of opinion between surgeons as to whether surgical drains are always needed. Some studies have shown that they don't necessarily allow things to heal any faster. Other drawbacks include:

• They can cause problems like infection around where the drain comes out; or they can interfere with things healing inside your body.

• They can keep you in hospital longer.

• Sometimes they can stop you moving around as much as you'd like, particularly if you have a drain from your chest area.

• If they are left in for too long accidentally, they can be difficult to pull out and may leave a small tract which will take a while to heal up.

• Operations around the neck, including on the thyroid gland.

• Operations on the armpit (axilla).

• Operations done in an emergency for something which has ruptured inside you.

• Some types of brain surgery.

• Operations on the stomach (the drain often then comes out your nose and is called a 'nasogastric tube').

• Operations on the bladder (the drain then usually comes out the urine tube and is called a 'urinary catheter').

Your surgeon will discuss with you before the operation whether you will need a surgical drain and where it will be.