The patient was admitted and taken to the OR the evening of admission where he underwent an open appendectomy. The patient tolerated the procedure well, and was transferred to the surgical ward post op. On post op day 4 the patient had a normal white count, was tolerating a regular diet, and was transitioned to oral abx, oral pain medicine, and d/c to home.
Since the first description of acute appendicitis in 1886 by Reginald Fitz, it has been recognized as one of the most common causes of the acute abdomen worldwide; with 250,000 cases yearly in the United States. Sixty five percent of patients that have symptoms of acute appendicitis for longer than 48 hours present with perforation of the appendix due to significant inflammation and necrosis. Perforation of the appendix can cause widespread intraperitoneal contamination or a sealed-off abscess, and can be lethal if not promptly recognized. The size of the perforation, the virulence of bacterial infection, and the ability of the infection to be contained will determine the extent of the inflammatory response. Abscesses are variable in size, have low attenuation numbers (10 to 30 Hounsfield units) and may display an identifiable capsule which signals chronicity. If the abscess is due to gas-forming bacteria or fistulization to bowel occurs, bubbles of air or air-fluid levels may be observed. Abscesses may be found in locations distant from the cecum due to variable position of the appendix and the patterns of fluid migration in the peritoneal cavity. Most abscesses are located inferior, medial, or posterior to the cecum or in the right paracolic gutter.
It has been suggested that imaging is not necessary if a patient presents with history and physical exam strongly suggestive of acute appendicitis. However, imaging is advisable for the patients with atypical symptoms, infants, small children, and young women
Radiographs demonstrate some abnormality in up to 80% of patients with acute appendicitis. Appendicoliths are the most specific radiographic sign, but are only found in 10% of patients with acute appendicitis. However, when an appendicolith is present, the incidence of perforation is nearly 50%. Appendicoliths can be differentiated from bone islands, ureteral stones and pheleboliths by their calcified rims. In cases of retrocecal appendicitis, the appendicolith may be located in the right upper quadrant. Other radiographic findings suggestive of acute appendicitis are: cecal ileus, right lower quadrant fluid levels, paucity of right lower quadrant gas, distortion of flank stripe, loss of psoas margin, loss of properitoneal flank stripe, thickening of cecal wall, scoliosis, mottled gas collection in right lower quadrant, and pneumoperitoneum
High resolution or helical CT techniques have been shown to be superior to radiographs in establishing the diagnosis of acute appendicitis due to high accuracy and sensitivity. CT scans have accuracy of 96% to 98%, sensitivity of 96% to 100%, specificity 95% to 97%, a PPV of 97% to 99%, and a NPV of 88% to 100%
The diagnosis of appendicitis can be made with confidence when an abnormal appendix is identified or when an appendicolith associated with a phlegmon or abscess is detected in the right lower quadrant. The abnormal appendix appears slightly distended, fluid filled structure about 0.5 to 2cm in diameter. In almost all cases of acute appendicitis, the appendiceal wall may display circumferential and asymmetrical thickening. Periappendicieal inflammation is another hallmark of acute appendicitis. The inflammatory response is variable and may show the following: Slightly increased hazy density of the mesenteric fat, linear strands, fluid containing abscesses, or heterogeneous ill defined soft tissue densities representing a phelgmon. A summary of findings of acute appendicitis seen on CT scan are listed below:
Circumferential mural thickening of appendix
Mural contrast enhancement
Hazy, streaked periappendiceal densities
Pericecal soft tissue mass (phlegmon)
Pericecal fluid collection (abscess)
Mural thickening of adjacent cecum and terminal ileum â€śArrowhead signâ€ť
Focal cecal apical thickening
Enlarged lymph nodes
In patients without acute appendicitis CT is also useful as it is able to diagnose other intra abdominal conditions. Using CT in patients with equivocal clinical presentations leads to a substantial decrease in the expected negative appendectomy rate. (4% compared to an expected 20% negative laparotomy rate based on clinical evaluation.)