Evaluating conservative treatment for acute appendicitis with lump formation.

Interval appendectomy after acute appendicitis with lump formation (phlegmon) remains controversial. We conducted this study to determine the risk of recurrent appendicitis following initial non-operative treatment for appendicitis, and evaluate factors associated with recurrence. Secondarily, we evaluate the efficacy of interval appendectomy versus no appendectomy.Patients who received conservative treatment for appendicitis with lump formation were prospectively studied from June 2006 to June 2008. These patients were followed for recurrence of appendicitis.Of 763 patients with acute appendicitis some 220 patients had lump formation (28.8%). Median age was 28 years. Conservative treatment was successful in 213 (96.8%) patients. The rate of recurrence was 13.1%, all occurring within six months after the index admission. Mean follow-up was 26±18 months.Conservative treatment of appendicitis with lump formation is efficient and the recurrence rate is low. Routine interval appendectomy after initial conservative treatment for lump formation is not a cost-effective intervention and not recommended.