Interobserver Variability in Intraoperative Classification of Acute Appendicitis and Postoperative Antibiotic Management

Acute appendicitis is among the most common diseases requiring emergency surgery. Despite its high prevalence, AA remains incompletely understood, and optimal management continues to be debated and refined. The severity of the disease is currently classified by the macroscopic appearance of the appendix during surgery as either phlegmonous, gangrenous, or perforated (with or without a periappendiceal abscess), In cases of complex appendicitis (i.e., gangrenous or perforated) 1–5 days of postoperative antibiotics are recommended, whereas simple appendicitis (i.e. phlegmonous) is treated with perioperative antibiotics alone. Consequently, the operative findings determine the postoperative antibiotic management, and thus, the biases and experience level of the surgeon could have important implications for patient outcomes. The goal of the current study was to examine the interobserver variability in the classification of Acute Appendicitis severity and to examine the impact of the classification on postoperative antibiotic choice.

The study was designed as a multicentre cross-sectional inter-rater reliability study. Video recordings of 30 laparoscopies with a duration of 20 seconds each for suspected appendicitis were shown to 89 surgeons and surgical trainees at seven different Danish hospitals between January 2024 and May 2024.

Each video segment was followed by two multiple-choice questions, which the participants answered anonymously on a study form. The participants were asked to categorize the appendix as either normal, phlegmonous, gangrenous, perforated without an abscess, or perforated with an abscess. Answers were further categorized into “normal appendix or appendicitis” (Category 1) and into “complex appendicitis or not” (Category 2).

Interobserver agreement was moderate for distinguishing a normal appendix from appendicitis (κ = 0.72, 95% CI 0.61–0.85) and for identifying complex appendicitis (κ = 0.66, 95% CI 0.52–0.80). Agreement regarding postoperative antibiotics was high: 96% for phlegmonous, 81% for gangrenous, and 99.7% for perforated appendicitis.