Safety of in-hospital delay of appendectomy - a propensity score-matched analysis of 4900 consecutive patients undergoing surgery for suspected appendicitis.

Background: Historically, urgent surgery was advocated in patients with suspected appendicitis because of the risk of perforation and possible complications. Although recent studies have shown that it is safe to delay surgery under certain circumstances, many studies do not report adjusted data and exclude patients based on risk factors. Furthermore, it is unclear whether an ultrasound-based diagnostic workup is sufficient to safely delay surgery. This large retrospective study aimed to analyze the risk-adjusted association between delayed appendectomy and perforation and complication rates.

Methods: Data from consecutive patients who underwent appendectomy for suspected appendicitis at a single institution were reviewed and analyzed. The investigated outcomes were perforation and complication rates. Propensity score (PS) matching was used to create equal groups regarding confounding factors, and multivariate analysis was performed to control for risk factors and to calculate adjusted odds ratios (ORs) for in-hospital delay.

Results: Between January 2008 and June 2023, 4900 patients underwent appendectomy for suspected appendicitis. Ultrasound imaging was performed in 4754 patients. Multivariate analysis of PS-matched data showed no association between a waiting time of >12 h and perforation rate (OR, 0.93; 95% CI, 0.67-1.31; P =.69) or complication rate (OR, 0.90; 95% CI, 0.62-1.30; P =.56). Similar results were obtained for a waiting time of 18 h and perforation rate (OR, 0.96; 95% CI, 0.48-1.56; P =.88) or complication rate (adjusted OR, 0.97; 95% CI, 0.57-1.68; P =.93).

Conclusion: This large PS-matched analysis showed that it is safe to delay surgery by 12 and 18 h, even when the diagnostic workup is based on ultrasound. In patients with risk factors for complications, postponement of the procedure can be considered if it can improve overall conditions or allow the procedure to be performed with a higher level of expertise.