Prognostic factors for predicting recurrence of cases of acute appendicitis undergoing conservative therapy

Introduction: The purpose of the present study was to determine the factors to predict recurrence in patients with acute appendicitis undergoing conservative therapy. Materials and methods: Between 2002 and 2006, we reviewed 135 patients with acute appendicitis in whom conservative treatment was effective. We studied recurrence rates of acute appendicitis in those patients after conservative treatment and compared clinical features and findings on CT scan between recurrent and non-recurrent patients. Results: Recurrent right lower quadrant abdominal pain developed in 33 of 101 patients. Thirty patients (29.7%) were given diagnoses of recurrent acute appendicitis at medical institutions, and 18 patients (17.8%) underwent operation. Rate of recurrent appendicitis was greater in young patients (under 18 years old) and in patients having high white blood cell (over 13,500/μl) at the onset of appendicitis. Ascites, inflammatory change in the fat surrounding the appendix, and an appendix diameter of over 9 mm on CT scan at the onset of appendicitis increased the risk of recurrence, Incarcerated fecal stone in the appendix was not related to the recurrence rate. Summary: The following were considered as risk factors for recurrent acute appendicitis; young patients less than 18 years old, patients with elevated white blood cell counts, and patients with a swollen appendix with a diameter of greater than 9 mm. We should take these facts into consideration when we treat patients with acute appendicitis.