Abstract
The development of necrosis of the appendix increases the risk of perforation with peritonitis. Mechanical obstruction of the lumen, inflammation-induced ischemia, thrombosis, and bacterial overgrowth together contribute to the development of gangrene. In addition, genetic factors may play a protecting role in response to local infection, thus preventing progression of inflammation into gangrene (1). Necrosis does not develop during the earliest phase of the inflammation. If necrosis of the appendix develops, it does not immediately proceed to perforation as many non-perforated appendices have gangrene in pathological examination. On the contrary, perforation occurs always at the site of gangrenous wall of the appendix. A number of earlier studies have demonstrated that longer duration of symptoms before surgery is associated with perforation of the appendix (1–3). Early diagnosis and surgical removal of the appendix has therefore been a gold standard in patients with appendicitis in order to prevent perforation and peritonitis.
Hornby and colleagues report results of a registry-based study of over 2400 patients operated on for suspected appendicitis. The main finding in the study was that the proportion of patients having their normal appendix removed increased as the time interval to surgery increased but the proportion of necrotic appendicitis did not change. These results most likely reflect problems in diagnostic workup in patients with suspected appendicitis. The decision to operate was most probably done earlier in those patients with typical signs and symptoms whereas in other patients more follow-up or other diagnostic workup may have been needed before the decision to operate was done. The high proportion of normal appendices found at surgery probably indicates that computed tomography (CT)-scan was not used in patients with suspected appendicitis during the study period. In patients presenting with atypical symptoms and equivocal signs, the use of CT-scan could result in significantly lower amount of incidental appendectomies.
Although the time interval to surgery did not increase the proportion of necrotic appendicitis, this does not allow the conclusion that delaying surgery is safe. Perforated appendicitis has been shown to associate with longer duration of symptoms before admission in many earlier studies, and a substantial amount of perforations occur before hospital admission, which may have caused significant bias to these results (2, 4). Patients presenting with already perforated appendix have advanced symptoms and are thus likely to be operated on earlier than other patients (2). This increases the proportion of advanced appendicitis in patients operated on earlier. Retrospective studies that cannot control significant biases caused by different prehospital delays and advanced symptoms cannot conclude that delaying surgery is not harmful. Only an adequately powered randomized study comparing two different time intervals to surgery (long versus short) controlled by prehospital delay could provide definite answer to this debate of delaying appendectomy.
Although most patients with appendicitis do not progress to gangrene and perforation, at present, there is no reliable diagnostic method to differentiate those patients who will develop perforation from those who will not. Therefore, it would be better to offer surgery for all patients with appendicitis without a delay.