A trocar (or trochar) is a medical or veterinary device that is made up of an awl (which may be a metal or plastic sharpened or non-bladed tip), a cannula (essentially a hollow tube), and a seal. Trocars are placed through the abdomen during laparoscopic surgery. The trocar functions as a portal for the subsequent placement of other instruments, such as graspers, scissors, staplers, etc. Trocars also allow the escape of gas or fluid from organs within the body.