Trocar

Trocars are typically made up of an awl (which may be metal or plastic with a pointed or tapered tip), a cannula (essentially a rigid hollow tube) and often a seal.

They are deployed as a means of introduction for cameras and laparoscopic hand instruments, such as scissors, graspers, etc., to perform surgery hitherto carried out by making a large abdominal incision, something that has revolutionized patient care.

Rather than a round tube being inserted, the three-sided knife of the classic trocar would split the outer skin into three "wings" which was then easily sutured closed.

After cavity embalming has been finished, the puncture is commonly sealed using a small plastic object resembling a screw, called a trocar button.

Trocars are widely used by veterinarians not only for draining hydrothorax, ascites, or for introducing instruments in laparoscopic surgery, but for acute animal-specific conditions as well.

In the movie Far from the Madding Crowd (1967) Gabriel Oak, played by Alan Bates, uses a trocar to aspirate abdominal gasses from Bathsheba Everdene's herd of sheep who had strayed into a field of clover and were bloated.

In the movie True Lies, Arnold Schwarzenegger's character, having picked the lock on his handcuffs, uses a Patterson trocar to kill his guard prior to breaking the neck of his torturer.