A vermiform appendix is a small, blind ended hollow tube. It is closed from an end and attached at the other side to the caecum, which is a pouch shaped opening of the colon (large intestine), where the contents of the small intestine are emptied. An appendix is considered to be a vestigial organ in the human body, with no clear function or any useful purpose in humans. It is however suspected that previously in humans it served the purpose of cultivation of gut flora that could be beneficial in repopulating the intestines after being affecting by a gut flora attacking disease. It also supposedly functioned in the production of the endocrine cells during fetal life, whose function was regulation of hemostasis.
A possible function of exposing the white blood cells to antigens in the abdominal tract during the initial years of life that aided in the stimulation of production of antibody and thus regulating the immune reactions in the gastro-intestinal tract is also speculated. An evolutionary disappearance of the appendix has been proved in humans. If an appendix is present in the body and undergoes any kind of blockage, it can lead to appendicitis which is a very painful and a potentially fatal inflammation.
The appendix is around 3-5 inches in length and 0.4-0.5 inches in width. Cavity of the appendix is narrow at the end where it joins the cecum. It constitutes of muscular walls that aid in expulsion of mucous secretions of the walls of appendix into the cecum. A blockage to the opening of appendix that prevents the expulsion of the mucus secretions of the cecum cause appendicitis. A fecalith, a solidified mass of the fecal matter is a common source of blockage of the appendix. Obstruction can also be a result of enlarged lymphoid follicles, worms in the intestine, trauma or tumors. The mucus secretions get collected in the appendix causing an edema and the distension of the organ itself. With an increase in the distension of the organ, blood supply is affected. Discontinuation of the blood supply to the organ cause death due to necrosis of the appendiceal tissues.
Certain micro-organisms like the Yersinia species, Actinomyces, Mycobacteria species, Histoplasma species, viral agents like Cytomegalovirus, Adenovirus are implicated in the pathology of appendicitis. Microbial load on the necrosed organ further worsens the inflammation. Increased distension of the inflamed organ can cause it to burst and spill the contents into the abdominal cavity. The membranes that line the abdominal cavity and form the covering of the abdominal organs is known as the peritoneum. Spilling of the mucus contents from the appendix may affect the peritoneum too.
The presenting symptom of appendicitis is moderate to severe pain in the abdomen. With the progression of infection, pain becomes localized to the lower right part of abdomen called as the ‘McBurney’s point’. Other common symptoms are abdominal tenderness, a progressive worsening of pain, pain during coughing or sneezing, nausea, vomiting, diarrhea, difficulty or inability to pass gas, fever, acute constipation, loss of appetite and sometimes even a urinary tract infection.
Appendicitis is diagnosed on the basis of a patient's history and physical examination by the physician. For a confirmatory diagnosis white blood cell count, a urine analysis, abdominal X-ray, barium enema, ultrasonography of the abdomen, computerized tomography scan, and laparoscopy can be advised.
In patients with a mild and confined appendicitis, antibiotics treatment is sufficient to resolve inflammation. The appendix may be removed later if required. The most common treatment of appendicitis is an appendectomy, where the inflamed appendix is removed before it bursts. Surgical removal of appendix remains the most sought after treatment option by the physicians.
In an open appendectomy, an incision of two to three inches in length is made on the skin and the passed the layers of abdominal wall over the location of appendix. The appendix is freed from its mesenteric attachment to the colon and obliterating the opening on the colon with sutures. Pus is drained and the incision is closed.