A cannula is a thin hollow metal surgical instrument used during liposuction through which the patient's excess unwanted fat cells are suctioned out of the body. Though the first liposuction cannulas were simple tubular devices used for suctioning fat, some modern liposuction cannulas also have added features that vibrate and / or emit ultrasound or laser energy to "liquefy" the fat before it is suctioned. Today's cannulas are also narrower than early versions, allowing for even smaller incisions.
