Emergency appendectomy versus elective appendectomy following conservative treatment for acute appendicitis: a multicenter retrospective clinical study by the Japanese Society for Abdominal Emergency Medicine

Purpose: To establish the best treatment strategy for acute appendicitis. Methods: We collected data on 2142 appendectomies performed in 2017 and compared the backgrounds and surgical outcomes of patients who underwent early surgery (ES) (< 48 h) with those managed with non-ES (> 48 h). We performed a risk factor analysis to predict postoperative complications and subgroup analysis to propose a standard treatment strategy. Results: The incidence of postoperative complications was significantly higher in the ES group than in the non-ES group, and significantly lower in the laparoscopic surgery group than in the laparotomy group. Surgical outcomes, including the incidence of postoperative complications, were comparable after acute surgery (< 12 h) and subacute surgery (12–48 h), following antibiotic treatment. The risk factors for postoperative complications in the ES group were a higher age, history of abdominal surgery, perforation, high C-reactive protein level, histological evidence of gangrenous or perforated appendicitis, a long operation time, and intraoperative complications. The risk factors for postoperative complications in the non-ES group were perforation and unsuccessful conservative treatment. Conclusions: Non-early appendectomy is feasible for acute appendicitis but should be applied with care in patients with risk factors for postoperative complications or failure of pretreatment, including diabetes mellitus, abscess formation, and perforation.