. 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. Surgica… (More on Trocar)