CT Scan Findings Can Predict the Safety of Delayed Appendectomy for Acute Appendicitis

The relationship between duration of in-hospital waiting time and outcomes from appendectomy in patients with suspected appendicitis remains equivocal. The aim of this study was to investigate the influence of in-hospital waiting time on perforation rates and clinical outcomes in patients with suspected appendicitis who underwent appendectomy.

A retrospective review of 5956 patients who underwent appendectomy at a single institution from January 2008 to December 2016 was performed. Patients were separated into two groups based on the duration from hospital arrival to surgery: patients with an in-hospital waiting time ≤ 12 h (no-delay group; n = 5287) and those with an in-hospital waiting time > 12 h (delayed group; n = 669). One-to-one propensity score matching (n = 421 per group) was performed to compare perforation rates and postoperative outcomes between the groups.

After propensity score matching, an in-hospital waiting time > 12 h was not associated with increased rates of perforation and significant complications, such as wound infection and abscess. However, in the matched cohorts and in the patients whose initial CT scans suggested perforated appendicitis, the delayed group had a higher risk of developing postoperative ileus (OR 9.18, 95% CI 1.16-72.74, p = 0.021; OR 2.17, 95% CI 1.03-4.59, p = 0.048, respectively) and longer postoperative length of hospital stay (87.38 vs. 79.07 h, p = 0.008; 161.61 vs. 130.87 h, p < 0.001, respectively) than the no-delay group.

Our results indicate that a > 12-h in-hospital waiting time to surgery for appendicitis presents very little risk to the patient. However, the surgeon needs to carefully weigh the "safety" of a delay to surgery for appendicitis in patients whose initial CT scans suggested perforated appendicitis.