Delay to surgery does not influence the pathological outcome of acute appendicitis

Emergency surgery is performed on patients with appendicitis in the belief that inflammation of the appendix may progress to necrosis and perforation. Many cases of appendicitis, however, resolve with conservative treatment, and necrotic appendicitis may represent a different disease rather than the end result of inflammation of the appendix. We wished to explore the relationship between the interval to surgery after admission to hospital with appendicitis and the proportion of patients developing necrosis.

Appendicectomy operations performed between 2005 and 2010 were reviewed. End points included age, sex, interval from admission to surgery, and final pathological diagnosis.

A total of 2403 evaluable patients were identified (1266 females). Necrotic appendicitis occurred more commonly in children (17.5%) and the elderly (25.4%) compared with adults (10.5%). The median interval to surgery of patients with normal histology (17.1 h) was longer than the time to removal of inflamed (13 h) or necrotic (13.5 h) appendices (p < 0.001).The ratio of necrotic to inflamed appendicitis in the entire cohort was 0.24. Multivariate analysis reveals that necrosis of the appendix is more common in children and the elderly and that the proportion of patients with necrosis does not change with increasing interval to surgery.

Our observations show that appendicitis is not more likely to lead to perforation if a short delay prior to surgery is allowed. In addition, our findings add weight to the increasing volume of data showing that necrosis of the appendix is a disease different from simple inflammation.