Predictors of recurrent appendicitis after nonoperative management: a prospective cohort study

ABSTRACT

Background: Appendectomy has been the standard of care for treatment of appendicitis for decades. Nonoperative management (NOM) of appendicitis is an alternative treatment strategy and had a resurgence of interest owing to the COVID-19 pandemic and the need for alternate care delivery models. One of the concerns for treatment of appendicitis with NOM is the recurrence rate. Despite this, there are few data examining the predictors of recurrence to tailor patient selection for NOM of appendicitis. The objective of this study was to identify predictors for recurrent appendicitis in patients with appendicitis previously treated nonoperatively. Methods: We conducted a prospective cohort study of all adult patients with appendicitis treated at a tertiary care hospital between May 1, 2019, and Apr. 30, 2021. Patients with appendicitis who were treated nonoperatively were identified. Patient demographics, radiographic information, management, and clinical outcomes were recorded. Results: The primary outcome was recurrent appendicitis within 6 months after discharge from the index admission. Given the competing risk of interval appendectomy, a univariate and multivariate time-toevent competing-risk analysis was performed with Cox regression. Of the 74 patients, 35 (47.3%) were women (median age 48 [interquartile range (IQR) 33-64] yr) with appendicitis treated successfully nonoperatively, 21 patients (29.2%) had recurrent appendicitis and 20 (27.8%) underwent an interval appendectomy. Median time to recurrence was 17 days (IQR 7-66). Presence of an appendicolith on imaging was associated with a higher cause-specific hazard of recurrent appendicitis. Age, sex and history of diabetes were not found to be associated with recurrence of appendicitis. The adjusted cause-specific hazard ratio of recurrent appendicitis for presence of appendicolith was 2.67 (95% confidence interval 1.09-6.56, p = 0.032). Conclusion: Our study found that presence of appendicolith was associated with a 2.67 increase in cause-specific hazard of developing recurrent appendicitis within 6 months. This information can help tailor patient selection for nonoperative management.