In cosmetic surgery terms, a cannula is a hollow tube made of stainless steel that is used, in conjunction with an aspirator (vacuum suction device), to remove fat deposits from beneath the skin during liposuction and fat removal procedures.
Cannulas are effective devices for the removal of fluids, and are small enough that they do not usually cause skin irregularities when employed under the surface. By working on deeper levels of fat, cosmetic surgeons can ensure that damage to skin resulting from the cannula insertion is minimal.
Use of cannulas in liposuction
To remove fat during suction-assisted liposuction (SAL) procedures, the surgeon inserts a cannula into small incisions made in the skin. The surgeon then guides the cannula through the fat layer to break up fat cells, which are drawn out of the body through a vacuum.
The size of cannula varies depending on the extent of the liposuction - larger cannulas tend to be employed by surgeons carrying out liposuction across larger areas of the body, while more concentrated surgery can employ microcannulas of less than three millimetres in diameter.
Microcannulas remove fat in a more uniform fashion than larger cannulas, but their slower speed can be a drawback when carrying out liposuction in more than one area of the body.