Conservative approach versus urgent appendectomy in surgical management of acute appendicitis with abscess or phlegmon

Background: Surgical management of acute appendicitis with appendiceal abscess or phlegmon remains controversial. We studied the results of initial conservative treatment (antibiotics and percutaneous drainage if necessary, with or without interval appendectomy) compared with immediate surgery. Methods: We undertook an observational, retrospective cohort study of patients with a clinical and radiological diagnosis of acute appendicitis with an abscess or phlegmon, treated in our hospital between January 1997 and March 2009. Patients younger than 14, with severe sepsis or with diffuse peritonitis were excluded. A study group of 15 patients with acute appendicitis complicated with an abscess or phlegmon underwent conservative treatment. A control group was composed of the other patients, who all underwent urgent appendectomy, matched for age and later randomized 1:1. The infectious risk stratification was established with the National Nosocomial Infections Surveillance System (NNIS) index. Dependent variables were hospital stay and surgical site infection. Analysis was with SPSS, with p < 0.05 considered significant. Results: Interval appendectomy was performed in 7 study group patients. Surgical site infection episodes were more frequent in the control group (6 vs. 0, p < 0.001). A greater percentage of high risk patients (NNIS &ge; 2) was identified in the control group (80 vs. 28.7%, p < 0.03), mostly related with contaminated or dirty procedures in this group (p < 0.001). No significant difference between groups was found in hospital stay. Conclusion: Initial conservative treatment should be considered the best therapeutic choice for acute appendicitis with abscess or phlegmon.