A trocar (variant: trochar^[1]; from French: alteration of trois-quart from trois (three) + carre (edge)) is a hollow cylinder with a sharply pointed end, often three-sided, that is used to introduce cannulas and other similar implements into blood vessels or body cavities. Trocars are also used as ports in laparoscopic surgery.

The trocar is often passed inside a cannula, and functions as a portal for the subsequent placement of other devices, such as a chest drain, intravenous cannula, etc.

Surgical trocars are used to perform laparoscopic ('keyhole') surgery. They are used as a means of introduction for 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. Surgical trocars are today 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.

Trocars are also used near the end of the embalming process to provide drainage of bodily fluids and organs after the vascular replacement of blood with embalming chemicals. It is attached to a suction hose (which usually is attached to a running water source and drain known as a hydroaspirator). The process of removing gas, fluids,and semi-solids from the body cavities and hollow organs using the trocar is known as aspiration. The instrument is inserted into the body two inches to the left and two inches up from the navel. After the thoracic, abdominal, and pelvic cavities have been aspirated, the embalmer injects cavity fluid into the thoracic, abdominal and pelvic cavities using a smaller trocar attached via a hose which is connected to a bottle of high index cavity fluid. The bottle is held upside down in the air so as to let gravity take the cavity fluid through the trocar and into the cavities. The embalmer moves the trocar in the same manner that he or she used when aspirating the cavities in order to fully and evenly distribute the chemical.

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

[edit] References

This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (August 2007)

1. ^ http://www.merriam-webster.com/dictionary/trocar

• Mayer, Robert (in English). Embalming: History, Theory, and Practice (4th ed.). McGraw-Hill. ISBN 0-07-143950-1.