What Are The Operative Details of Surgery for Appendectomy?

Appendectomy: It is the surgical removal of the vermiform appendix.

The word appendectomy can be divided into two parts. The first part of the word, “Append” refers to the greek root appendix, and the suffix “-ectomy” means removal or excision.

The Appendix usually lies at the right iliac fossa, the right lowermost outermost quadrant of the abdomen.

Appendectomy, Appendix, Appendicitis

The Appendix arises precisely at the junction between the small intestine and the caecum.

Acute appendicitis is the inflammation of the appendix, and it is the most common cause of acute abdomen in young adults. Thus, appendectomy is the most frequently performed emergency operation in the abdominal region.

Appendicitis is associated with peritonitis (peritoneal inflammation), which has specific signs.

Appendicitis usually occurs due to obstruction. The obstruction may occur in:

  1. The lumen by hard feces or a foreign body
  2. The appendix wall due to appendix tumors or cancer, but it is a rare condition.
  3. From the outside by cancer caecum or adhesions from previous intestinal operations.

This obstruction leads to an overgrowth of bacteria, infection occurs, and appendicitis ensues.

Appendicitis is more common in the age group of 20-30 years, but it is rare in older patients. Thus, if appendicitis occurred in old age, doctors must suspect cancer caecum. Appendicitis is also unusual in children below 5 years due to a narrow lumen of the appendix, so obstruction and stasis are not common.

Appendicitis is more common in western countries and urban areas in comparison to rural areas due to low fiber diet, which precipitates constipation and results in hard stool, favoring obstruction, and stasis.

Appendicitis is diagnosed through proper history and examination. The patient complains of severe pain that starts peri-umbilical ( peri = around) and shifts to the right iliac fossa within 6-10 hours, at which the patient can point on the site of pain with one finger. The pain is aggravated by cough or movement and decreases by analgesics.

After a while, the pain may be associated with anorexia, nausea, and vomiting.

General examination

On general examination, mild fever may be detected with a slight increase in heart rate.

Local examination

On local examination:

– Signs of acute abdomen are detected, as well as distinctive signs of appendicitis, which include:

    1. Rigidity on inspection.
    2. Guarding, tenderness and rebound tenderness on palpation.

N.B. Rebound tenderness means that pain is elicited after the removal of the hand, and it is indicative of peritonitis.

– N.B. Pathophysiology of acute abdomen:

Any inflammation that occurs within the abdominal cavity triggers the secretion of inflammatory mediators like cytokines and other substances, which in turn stimulate the white blood cells to attack the inflamed area. Also, the inflammatory mediators stimulate the omentum -a medical term referring to layers of peritoneum surrounding the abdominal organs- to wrap around and enclose the inflamed area to focalize the infection and prevent its spread. For sure, this inflammatory process depends on many factors like the immunity of the patient, the maturation of the omentum, and the virulence of the organisms. That’s why appendicitis is an emergency in children due to their immature omentum. Thus, the infection is not enclosed and it is more likely to spread, with a higher chance of developing toxemia and septicemia. Appendicitis is also an emergency in older adults because of their low immunity.

– Special signs to appendicitis:

    1. Rovsing’s sign (crossed tenderness):
      On pressure on the left iliac fossa, pain is aggravated on the right iliac fossa. Rovsing sign is due to shifting of gases from the pelvic colon to the caecum.
    2. Psoas sign:
      Pain ensues after flexing the right thigh due to spasm of the psoas muscle.

Differential diagnosis to Appendicitis:

  • Meckel’s diverticulum.
  • Ovarian cyst.
  • Mid-cyclic pain.
  • Ectopic pregnancy.
  • Terminal ileitis.
  • Ulcerative colitis.

Anatomical sites of the appendix:

  1. Retrocaecal appendix (74%).
  2. Pelvic appendix (21%).
  3. Paracaecal appendix (2%).
  4. Postileal appendix (0.5%).
  5. Subhepatic appendix.
  6. Appendix in pregnancy:
    The pain is displaced upwards as the pregnancy progresses.

Management of appendicitis:

The decision of appendectomy depends on the state of the appendix, and whether it is complicated or not.

A) Uncomplicated appendix:

In acute appendicitis, an urgent appendectomy is done through McBurney’s incision, which lies over the point of maximum tenderness (McBurney’s point is located on the abdominal wall, lying between the umbilicus and the right anterior superior iliac spine).

McBurney’s point

B) Complicated appendix:

1. Appendicular mass:

Conservative management is maintained by keeping the patient in a semi-sitting position to relax the abdominal muscles and make the pelvis more dependent. A Ryle is inserted, intravenous antibiotics are applied, as well as regular follow up of vital signs, the degree of tenderness, vomiting, and the size of the mass.

If the pain is resolved, appendectomy is performed 3 months later. If the pain increases, an abscess is usually present.

2. An appendicular abscess (complicated mass):

Once there is an abscess, drainage of the abscess is the treatment of choice. Pain, fever, and vomiting will not resolve unless the abscess is drained, and the pus is eliminated.

There are 2 types of abscess drainage, either ultrasound-guided drainage or open drainage.

Thus, indications of Appendectomy are:

  1. Acute Appendicitis.
  2. Chronic Appendicitis, with recurrent attacks of acute appendicitis.
  3. During other intra-abdominal operations.
  4. As a prophylactic from Ulcerative Colitis. Studies found that appendectomy could be prophylactic in families with history of ulcerative colitis.

While contraindications of appendectomy are as follows:

  1. Appendicular mass.
  2. Appendicular abscess.
  3. Open appendectomy is contraindicated in females during the childbearing period to avoid extensive postoperative fibrosis, which may lead to infertility. Thus, Laparoscopic appendectomy is indicated in such condition.

Preoperative principles:

Appendectomy is indicated whenever the diagnosis of acute appendicitis is made within 4-5 days of the onset of the symptoms.

If there are signs of peritonitis, the patient must receive medications to relieve the inflammation and reduce the symptoms. Thus, broad-spectrum antibiotics covering all types of bacteria should be prescribed to the patient. Also, if there is vomiting, a nasogastric tube should be placed, and intravenous line has to be set up.

It is important to note that the patient’s stomach must be empty during the operation to avoid aspiration and suffocation during the recovery stage (in which the patient regains consciousness). So, the patient should not eat for 4-5 hours before operation.

Anesthesia:

General anesthesia is induced and maintained with endotracheal intubation.

Operative details:

The patient should be laid on his back on the operating table. Sterilization of the skin from the nipple line to the upper thigh should be done, followed by positioning of the towels and diathermy pad. The drapes are put to expose the right iliac fossa, the midline, the umbilicus, and the anterior superior iliac spine.

Then, a 5cm incision perpendicular to McBurney’s point is done, subcutaneous fat is incised until the surgeon reaches the external oblique muscles. The area should be widened by removing the subcutaneous fat with the back of the scalpel.

Here, the surgeon cut through the external oblique aponeurosis, followed by splitting the internal oblique and transversus abdominis, which is achieved by inserting the jaws of a large artery forceps in the direction of the muscles to split the fibres of the internal oblique and transversus abdominis and allow the insertion of the retractors to provide adequate exposure.

The next step is to incise the peritoneum to allow for the entry to the abdominal structures.

Removing the appendix requires to find the caecum. The caecum is identified by the presence of taenia coli (white stranded fibers resembles the muscles of the colon). The 3 taenia coli converge in the appendix. So, during surgery, the surgeon locates the appendix by tracing the taenia coli to the appendicular base. The appendix is attached to the posteromedial aspect of the caecum.

Once the surgeon locates the appendix, a Babcock tissue forceps is placed around the appendix. Gentle manipulation is mandatory because any attempt to pull or push the appendix forcibly may lead to rupture of the structure, especially if the appendix is gangrenous and likely to burst. After that, securing the appendicular vessels should be done through clipping, dividing and ligating these vessels. This is followed by insertion of a purse-string suture. A purse-string suture is obtained by holding the appendix vertically and suturing through the seromuscular layer of the base of the appendix, but the surgeon does not tighten the suture until the next step is done. This is followed by crushing the base of the appendix with an artery forceps. Then, the appendix is divided by a scalpel, and the stump is invaginated into the caecum where it is retained by tightening the purse-string suture.

Any bleeding must be ligated or stopped using the diathermy to achieve proper hemostasis (to prevent losing a lot of blood, especially if we want to avoid blood transfusion and its dangerous complications).

Logically, to complete the surgery, the incision is closed in the opposite direction. We start by closing the peritoneum, followed by transversus abdominis muscle, the internal oblique muscle, external oblique aponeurosis, then the subcutaneous fat, followed by suturing the skin using prolene sutures with a technique of simple sutures, mattress sutures or subcuticular sutures (the best one, cosmetically speaking).

Post-operative:

The patient is kept under observation for 1 or 2 days, and adequate analgesics and antiemetics are given as required. Also, a 5 day course of metronidazole is prescribed. At first, metronidazole suppository is inserted rectally until the patient is able to take the drug orally.