Localized perforation occurs when the periappendiceal infection of appendix becomes walled off by omentum and adjacent viscera. The clinical presentation consists of the usual findings in appendicitis plus a right lower quadrant mass. An ultrasound or CT scan should be performed; if an abscess is found, it is best treated by percutaneous ultrasound-guided aspiration. Opinion differs about how small abscesses and phlegmons should be handled. Some surgeons prefer a regimen consisting of antibiotics and expectant management followed by elective appendectomy 6 weeks later. The purpose is to avoid spreading the localized infection, which usually resolves in response to the antibiotics. Other surgeons recommend immediate appendectomy, which some believe shortens the duration of the illness. However, the immediate surgery approach has significant complications in a higher percentage of patients. There is not currently a consensus.
In the past it was common to perform an incidental appendectomy in people under age 50 during the course of an abdominal operation for another illness—as long as the exposure was adequate and there were no specific contraindications. The declining lifetime risk of appendicitis now calls this practice into question. A related question concerns the appropriate course when a laparoscopy is performed for presumptive appendicitis and the appendix looks normal. The trend in this case is to leave the appendix intact—not to remove it prophylactically or on the assumption that the visual assessment may be inaccurate.
Chronic abdominal pain is a common problem, and when the complaints are confined to the right lower quadrant, the question of chronic appendicitis is usually raised. Patients with genuine chronicappendicitis experience pain that lasts for 3 weeks or more. The history usually includes an acute illness at some time in the past, compatible with acute appendicitis, which was managed nonoperatively. On examination, the appendix is chronically inflamed or fibrotic. The symptoms resolve with appendectomy.
Chronic intermittent pain in the right lower quadrant is most often caused by something other thanappendicitis, such as Crohn’s disease or renal disease. Barium x-rays are sometimes helpful, particularly in children. In many patients, the diagnosis is not obvious. Appendectomy relieves symptoms occasionally, but laparotomy for chronic abdominal pain is generally unproductive in the absence of objective findings (eg, localized tenderness, palpable mass, leukocytosis).
Pylephlebitis is suppurative thrombophlebitis of the portal venous system. Chills, high fever, low-grade jaundice, and, later, hepatic abscesses are the hallmarks of this grave condition. The appearance of shaking chills in a patient with acute appendicitis demands vigorous antibiotic therapy to prevent the development of pylephlebitis.
CT scanning is the best means of detecting thrombosis and gas in the portal vein. In addition to antibiotics, prompt surgery is indicated to treat appendicitis or other primary sources of infection (eg, diverticulitis).