Impact of preoperative factors and waiting time on post-appendectomy complications: a retrospective study

Several factors are associated with increased postoperative complications after appendectomies. However, few studies combined these potential factors for comprehensive prediction of surgical outcomes. Whether high-risk patients benefit from a shorter waiting time for surgery remains unclear. This study aimed to explore the impact of surgical waiting time and potential risk factors on postoperative complications. A total of 1343 patients diagnosed with acute appendicitis requiring an emergent appendectomy were included from 2013 to 2018. The preoperative risk factors associated with postoperative complications were selected and the probability of postoperative complications was calculated by multivariate logistic regression model. Patients were divided into four groups based on the risk (high & low) and time to surgery (> 12 & ≤12 hours). The odds ratios for complications were evaluated between groups. The selected risk factors included age, neutrophil-lymphocyte ratio, systemic inflammatory response syndrome and abdominal pain duration. Compared with low-risk patients with time to surgery ≤12 hours, high-risk patients with time to surgery > 12 hours had significant increased overall postoperative complication rate (16.85% vs. 8.16%, p = 0.002) and a trend toward increased surgical site infection rate (10.99% vs. 6.46%, p = 0.058). When operated within 12 hours, there was no difference in outcomes between high- and low-risk patients. On the other hand, time to surgery > 12 hours did not increase complication rate in low-risk patients. The surgical outcome may be affected by preoperative factors and time to surgery. It is suggested that high-risk patients receive appendectomy within 12 hours to avoid increased postoperative complications.