Usefulness and Cost-effectiveness of Interval Appendectomy for Complicated Appendicitis

Abstract

Background: The management for abscess-forming appendicitis, including interval appendectomy, is controversial. Emergency surgery for abscess-forming appendicitis may lead to expanded surgery, which is associated with many perioperative complications. To prevent complications, we introduced the Interval Appendectomy protocol (IA protocol), and examined its efficacy compared to emergency appendectomy. Methods: Patients treated for complicated appendicitis at our hospital from January 2010 to January 2018 were consecutively enrolled into this study. They were classified into two groups based on enrollment before and after April 2014: emergency appendectomy group (EA group, before April 2014) and interval appendectomy group (IA group, after April 2014). We compared the perioperative treatment outcomes and examined the necessity for elective surgery, focusing on the postoperative pathological results of the IA group. Results: We enrolled 49 consecutive patients with complicated appendicitis who were treated during this study period. The IA protocol was applied to 38 patients; 32 patients completed this protocol and were assigned to the IA group. Patient characteristics were not significantly different between the IA and EA group. The IA group had significantly less postoperative complications (p=0.002) and medical costs (p=0.01). Residual inflammation in the appendix was observed in 16 cases (50%) pathologically. Conclusions: Interval appendectomy for complicated appendicitis was associated with a low incidence of perioperative complications and was effective in terms of cost. Interval appendectomy seems necessary to prevent recurrent appendicitis, given that inflammation remains on pathological examination.