apendicitis aguda

                                                 Appendicitis can be a life-threatening condition because of systemic sepsis (systemic

inflammatory response syndrome/SIRS leading to multiple organ failure) following rupture and abscess formation. It is therefore important to operate before rupture

occurs. While the following presentation focuses on the technique of appendectomy, it is worthwhile to note a few points about the diagnosis. Appendicitis can mimic a

variety of other conditions and vice versa. The young, elderly, diabetics and immuno-compromised patients are prone to rupture earlier than normal adults. While the

appendix can be highly mobile, the most reliable indication for operation is localized right lower quadrant tenderness. Guarding and rebound may be absent because the

majority of appendices are partially or totally retro-cecal.

                                                 The classic McBurney incision is made at a point two-thirds the distance (McBurney's point) between umbilicus and

anterior superior spine of the ilium. The incision is perpendicular to the connecting line, and is made one third above and two thirds below the line. It is often adjusted to

coincide with the point of maximal tenderness.

                                                 The distance between the lateral edge of the rectus abdominis and the anterior superior iliac spine is only a few

centimeters, so it is beneficial to move the line of a McBurney incision even more lateral than the two thirds

point in order to have maximal working room.

The common alternate incision favored by some is the Rocky-Davis transverse incision

. Half of this incision lies over the rectus muscle and limits available exposure.

The trade off is theoretically cosmetic, especially in young women (however, with the high lateral cut of today's bathing suits, it may no

longer be an advantage).

The cecum lies in the iliac fossa. The appendix may cross the brim of the true pelvis (where it can cause bladder and rectal irritation resulting in dysuria or diarrhea).

It may cross the mid-line and produce left sided signs. In over half

of individuals it is partially or totally retrocecal.

A vertical direction may end up outside the peritoneal reflection.

The direction of deepening the incision should be 45 degrees

from vertical to be perpendicular to the surface of the curving parietal peritoneal contour.

                                                 The skin incision is made with a knife, maintaining

tension on either side. As the skin parts, the tension is increased to maintain a steady state

through the length of the incision.

                                                 The incision is deepened to

external oblique aponeurosis using electrocautery.

A nick is made in the external oblique with the knife.

                                                 The external oblique aponeurosis is opened the length of the skin incision in the line of its fibers using the tips of the Mezzenbaum

scissors.

                                                 The external oblique edges are retracted with McBurney or

Roux retractors (not shown), exposing the underlying internal oblique muscle. The fascia on the surface of the internal oblique is incised

sharply in the line of the muscle fibers to facilitate atraumatic spreading.

                                                 Using two large blunt clamps (Pean)

perpendicular to each other, the muscle fibers are spread down to the level of the

transversus.

                                                 Two fingers are used to gently

spread the internal oblique fibers, making room to place two

retractors.

                                               Care must be taken in spreading the internal oblique. The iliohypogastric nerve is found laterally in the cleft between internal oblique and transversus muscles. Excess stretching can

tear the vasa nervorum running with this nerve. Clamping to control the bleeding

can injure the nerve.

                                                 The thin transversus muscle is split in a similar fashion to expose the preperitoneal fat and underlying

peritoneum. The preperitoneal fat is pushed aside from medial to lateral using a moist gauze sponge on a

fingertip.

The peritoneum may show signs of inflammation as depicted.

                                                 The peritoneum is picked up carefully with two clamps

and the resulting fold is pinched between two fingers to ensure

there is nothing beneath.

                                                 A nick is made in the peritoneal fold. Cultures are taken of any

fluid present.

                                                 The peritoneum is opened a short distance in the line of the incision. The peritoneal incision does not need to be

as long as the skin incision because the peritoneum easily stretches. The shorter cut makes closure easier.

                                                 The appendiceal artery is the terminal branch of the

iliocolic and runs beneath the terminal ileum in the veil of appendiceal mesentery. Note the antemesenteric crest of fat (crista galli/cocks comb) on the terminal ileum which

helps identify TI in the small appendectomy incision.

                                                 Appendicitis is most commonly initiated by swelling of the submucosal lymphoid tissue which blocks the appendiceal

lumen. Rarely is a fecolith found. The successive compression of lymphatics, veins and finally arteries combined with overgrowth of luminal bacteria is the

normal sequence of events.

                                                 The early inflammatory changes progress to suppuration

and gangrene. In the normal individual, inflammatory products on the

surface of the appendix cause adjacent omentum, mesentery and loops of bowel to adhere to the appendix and wall it off. These adherent structures constitute the mass that is sometimes felt. If perforation occurs, it may form an abscess if the walling off process is complete.

If free perforation occurs, peritoneal soilage raises the risk of later intra-abdominal abscess formation.

                                              Since the appendiceal mesentery runs from medial to lateral, it is safest to sweep a finger from the lateral parietal peritoneum under the appendix toward the

medial side to explore and assess the situation. Fibrinous adhesions around the appendix can be freed in this

fashion.

                                                 Sometimes the appendix can be mobilized and delivered by finger dissection alone. Care should be taken in the finger dissection not to hook the underlying ureter. The

tip of the appendix is controlled by a Babcock clamp closed around the tip on the appendiceal mesentery .

In this case, the appendix was bluntly separated from an

adherent blanket of omentum.

                                                 If the appendix is not easily accessible or

retrocecal, the next maneuver is to identify the cecum and gently lift it into the wound by

hooking a finger under a taenea.

                                                 The cecum is then broadly grasped with a moist sponge and gently rocked back and forth to deliver it and the

attached appendix. The three taeneae converge at the appendiceal base.

                                                 Sometimes, the mid portion of the

appendix is tethered down by a band which must be cut to mobilize the

appendix.

In more than half the population, the appendix is partially or totally retrocecal. It may lie behind a floppy

cecum and be easily mobilized, or it may be sealed behind the cecum by the cecal peritoneal reflections. The interposition of the cecum between the appendix

and the abdominal wall may blunt the classic right lower quadrant peritoneal signs