An appendicectomy (or appendectomy) is the surgical removal of the vermiform appendix. This procedure is normally performed as an emergency procedure when the patient is suffering from acute appendicitis. In the absence of surgical facilities, intravenous antibiotics are used to delay or avoid the onset of sepsis; it is now recognised that many cases will resolve when treated conservatively. In some cases the appendicitis resolves completely; more often, an inflammatory mass forms around the appendix. This is a relative contraindication to surgery.

Appendicectomy may be performed laparoscopically or as an open operation. Laparoscopy is often used if the diagnosis is in doubt, or if it is desirable to hide the scars in the umbilicus or in the pubic hair line. Recovery may be a little quicker with laparoscopic surgery; the procedure is more expensive and resource-intensive than open surgery and generally takes a little longer, with the (low in most patients) additional risks associated with pneumoperitoneum (inflating the abdomen with gas). Advanced pelvic sepsis occasionally requires a lower midline laparotomy.

In general terms, the procedure for an open appendicectomy is as follows.

Antibiotics are given immediately if there are signs of sepsis, otherwise a single dose of prophylactic intravenous antibiotics is given immediately prior to surgery.

General anaesthesia is induced, with endotracheal intubation and full muscle relaxation, and the patient is positioned supine.

The abdomen is prepared and draped and is examined under anaesthesia. If a mass is present, the incision is made over the mass; otherwise, the incision is made over McBurney's point, one third of the way from the anterior superior iliac spine (ASIS) and the umbilicus; this represents the position of the base of the appendix (the position of the tip is variable).