Appendectomy

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An appendectomy is a surgical removal of the vermiform appendix.[1] Surgery remains the mainstay of therapy for acute appendicitis, although many appendectomies are now performed laparoscopically rather than through an open incision. Although appendicitis is a common disorder, there still can be difficulty in diagnosing it.

The procedure was first performed, as open surgery, by a non-surgeon in 1735, identified only as "Amyan"; H. Hancock, an English surgeon, formally performed the procedure at the end of the 19th century. [2]

For a surgical procedure, it is relatively simple, although anatomical abnormalities and infection can make the procedure a challenge to an experienced surgeon. Still, there are many examples of having a nonsurgeon guided through the procedure, as in a number of cases in the Second World War, where a medical corpsman aboard a U.S. Navy submarine at sea performed it under radio direction.

There are no absolute contraindications to the procedure, and the general practice is to be aggressive. In most patients, the risk of complications from delay are greater than the risk of the relatively simple procedure. Should significant infection exist and the appendix has perforated or ruptured, some surgeons may defer the operation until parenteral antibiotics, fluid replacement, and percutaneous drainage have stabilized the patient.

A standard practice, once an incision is made, is to remove the appendix even if it is normal. This does not increase risk to the patient, but avoids the risk of a later misdiagnosis by a physician misled, by a scar, to assume the appendix cannot be present.

Open surgery

McBurney's incision is classic; in general terms, this is on the right lower quadrant of the abdomen. Specifically, the incision is made at right angles to a line drawn between the anteriorsuperior spine of the ilium and the umbilicus. Two-thirds of the incision should be above the umbilicus.[3]

The surgeon then incises the external oblique, internal oblique and transversus abdominis muscle, and then displaces fascia and peritoneal fat to expose the peritoneum. Next, the peritoneum is opened and retracted.

Cultures of free peritoneal fluid should be taken, and the cecum mobilized and pulled through the incision. This maneuver will either pull the appendix through the incision, or make it visible. A pair of clamps is then used to divide the mesoappendix, and suture material is applied to ligate the area; this can require additional suturing if the appendix is difficult to access, or the mesoappendix is easily damaged.

With blood supply to the appendix now controlled, the appendix is lifted straight up, and two clamps are applied to its base. Two lines of sutures are then put through the base; the surgeon chooses whether or not to invert the stump of the appendix. Using a scalpel with phenol solution, or an electrocautery, the appendix is now cut away, and a purse-string suture tied around the stump.

After the appendix is removed, the operator irrigates the area, and then closes the muscle in the reverse order of their opening. If no peritonitis is present, the skin is also closed. If there is peritonitis, the wound is packed with iodoform gauze retained by suture material.

Laparoscopic procedure

In the operating room, an incision is made at the umbilicus, and the abdomen insufflated with inert gas.[4] Three 5mm laparascopic trocars are inserted:

  • In the area above the pubis, 2-4 cm below the symphysis pubis
  • In the right upper quadrant of the abdomen at the midclavicular line
  • In the right lower quadrant

Through a viewing laparoscope, the surgeon views the internal structures to confirm the diagnosis. Once appendicitis is verified, the cecum is grasped with forceps and gently pulled toward the patient's head. Next, the appendix is grasped and pulled away from the head, causing the mesoappendix to become visible.

An operative laparascope is inserted through the suprapubic port, and a clip applier through the umbilical port. The mesoappendix is then clipped and separated. Two ligating loops go through the right lower quadrant port and are applied to ligae the base of the appendix. After applying a third, more distal loop, the appendix is then divided, grasped, and removed through the umbilical port.

The area is cultured, irrigated, and closed.

References

  1. Anonymous (2015), Appendectomy (English). Medical Subject Headings. U.S. National Library of Medicine.
  2. Luigi Santacroce and Juan B Ochoa (August 14, 2008), "Appendicitis", eMedicine
  3. J.E. Skandalakis, P.N. Skandalakis, L.J. Skandalakis (2000), Appendectomy, Surgical Anatomy and Technique: a Pocket Manual (Second Edition ed.), Springer, pp. 446-563
  4. Skandalakis, pp. 453-455