Diagnostic, Therapy and Complications in Acute Appendicitis of 19,749 Cases Based on Routine Data: A Retrospective Multicenter Observational Study

Background: Acute appendicitis is one of the most common emergencies in general surgery. The gold standard treatment is surgery. Complications may occur during or after an appendectomy. In addition to age, clinically important factors for the outcome after appendicitis seems to be the comorbidities and the stage of the appendicitis at the time of the operation. Large observational data describing these facts are missing. Methods: In this retrospective multicenter observational study, all inpatients over the age of 17 years with a diagnosis of acute appendicitis in 47 hospitals of the Clinotel Hospital Group between 2010 and 2017 were included. Results: A total of 19,749 patients with acute appendicitis were operated on. The number of patients with more than five secondary diagnoses has increased from 8.4% (2010) to 14.5% (2017). The number of secondary diagnoses correlates with the ages of the patients and leads to a significantly longer hospital stay. Computer tomography (CT) has gained in importance in recent years in the diagnosis of acute appendicitis. A total of 19.9% of patients received a CT in 2017. Laparoscopic appendectomy increased from 88% in 2010 to 95% in 2017 (p < 0.001). The conversion rate did not change relevant in the study period (i.e., 2.3% in 2017). Appendicitis with perforation, abscess, or generalized peritonitis was observed in 24.8% of patients. Mortality was 0.6% during the observation period and was associated with age and the number of secondary diagnoses. The analysis is based on administrative data collected primarily for billing purposes, subject to the usual limitations of such data. This includes partially incomplete clinical data. Conclusions: Multimorbidity is increasingly present in patients with acute appendicitis. Mortality is still in an acceptably low range with no increase. A CT scan is necessary for a precise diagnosis in unclear clinical situations to avoid unnecessary operations and was performed more often at the end of the study than at the beginning.