Background: The classification of acute appendicitis (AA) into various grades is not consistent, partly because it is not clear whether the perioperative or the histological findings should be the foundation of the classification. When comparing results from the literature on the frequency and treatment of AA it is important that the classifications are consistent. Furthermore, in the clinical settings, incorrect classification might lead to over diagnosing and a prolonged antibiotic treatment. The aim of our study was to investigate the concordance between perioperative diagnosis made by the surgeon and the histological findings of the removed appendix and furthermore compare this to the results from cultivation of peritoneal fluid aspirated perioperatively.
Methods: A prospective observational cohort study including patients (≥15 years of age) undergoing appendectomy.
Results: A total of 131 patients were included. In 116 (89 %) of these cases, appendicitis was confirmed histological. There was low concordance between the perioperative and histological diagnoses, varying from 16 to 76 % depending on grade of AA. Only 44 % of the patients receiving antibiotics postoperatively had a positive peritoneal fluid cultivation.
Conclusion: There was a low concordance in clinical and histopathological diagnoses of the different grades of appendicitis. Perioperative cultivation of the peritoneal fluid as a standard should be further examined. The potential could be a reduced postoperative antibiotic use. CLINICALTRIALS.GOV: Registration no.: NCT02304653.