Original researchThe outcome of antibiotic therapy for uncomplicated appendicitis with diameters ≤10 mm

•Antibiotic therapy with appendicitis is problematic for high failure and recurrence.•About 80% of patients with diameters ≤10 mm showed successful treatment outcome.

Purpose: Although many patients receive antibiotic therapy for uncomplicated appendicitis, the relatively high treatment failure and recurrence rates are problematic. We assumed that patients with appendicitis and appendiceal diameters ≤10 mm, have better outcomes. The purpose of this prospective non-randomized study was to assess the outcomes of antibiotic therapy in patients with uncomplicated appendicitis and appendiceal diameters ≤10 mm. Methods: Over 2 years, we enrolled 119 patients who initially received antibiotic therapy. The failure of antibiotic therapy was defined as the need for appendectomy and true appendicitis. Peritonitis was defined as either complicated appendicitis or intra-abdominal abscess postoperatively. We evaluated the rates of treatment failure, peritonitis, and recurrence. Results: Nine patients (7.6%) failed to respond to initial antibiotic therapy, and 6 had true appendicitis after subsequent surgery. Two patients had complicated appendicitis (peritonitis), but no patient displayed intra-abdominal abscess postoperatively. During a median follow-up period months of 14 months, 14 patients (12.7%) experienced recurrence. Conclusions: Antibiotic therapy without surgery may be a safe treatment for uncomplicated appendicitis in select patients with appendiceal diameters ≤10 mm.