Trocar

A trocar is a medical device that is made up of an (which may be a metal or plastic sharpened or non-bladed tip), a cannula (basically 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.

Trocar is a variant of trochar; from French troquard, an alteration of trois-quarts meaning three-quarters, from trois meaning three + quart meaning ; first recorded in the Dictionnaire des Arts et des Sciences, 1694, by Thomas Corneille, younger brother of Pierre Corneille.

Originally, doctors used trocars to relieve pressure build-up of fluids (edema) or gasses (bloating). Patents for trocars appeared early in the 19th century, although their use dated back possibly thousands of years. By the middle of the 19th century, trocar-cannulas had become sophisticated, such as Reginald Southey's invention of the Southey tube.

Trocars are used in medicine to access and drain collections of fluid such as in a patient with hydrothorax or ascites.

In modern times, surgical trocars are used to perform laparoscopic (keyhole) surgery. 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 ('open' surgery), something that has revolutionized patient care. Today, surgical trocars are most commonly a single patient use instrument and have graduated from the 'three point' design that gave them their name, to either a flat bladed 'dilating-tip' product, or something that is entirely blade free. This latter design offers greater patient safety due to the technique used to insert them.

Trocar insertion can lead to a perforating puncture wound of an underlying organ resulting in a medical complication. Thus, for instance, a laparoscopic intraabdominal trocar insertion can lead to bowel injury leading to peritonitis or injury to large blood vessels with hemorrhage.

...
Wikipedia