Usefulness of several factors and clinical scoring models in preoperative diagnosis of complicated appendicitis

BACKGROUND: The preoperative distinction between uncomplicated and complicated appendicitis is important to determine the appropriate treatments, such as antibiotics, surgery, or interval appendectomy. Computed tomography (CT) plays an important role; however, combining clinical and imaging factors may make preoperative evaluation more reliable. This study evaluated and analyzed cases and the usefulness of several preoperative factors and clinical scoring models to detect complicated appendicitis. METHODS: A total of 203 patients preoperatively diagnosed with acute appendicitis at our facility were included. Complicated appendicitis was defined as appendicitis with gangrene, perforated appendix, and/or abscess formation. Preoperative factors were collected from published clinical scoring models; patient information, symptoms, signs, results of laboratory tests, and findings of CT. Factors were analyzed using a chi-squared test and the Mann-Whitney U test. RESULTS: The preoperative factors were compared between 151 uncomplicated and 52 complicated appendicitis patients. The significant factors were age ≥40, duration of symptoms >24 hours, body temperature ≥37.3°C, high levels of CRP, findings in CT scan (appendix diameter ≥10 mm, stranding of the adjacent fat, presence of fluid collection, and suspicion of abscess or perforation). We also evaluated the usefulness of clinical scoring models for the detection of complicated appendicitis and found the Appendicitis Inflammatory Response score and two prediction models (Atema score and Imaoka score) showed significance (p < 0.05). High serum CRP level was significantly associated with complicated appendicitis (p < 0.001), and the predicted existence rates of complicated appendicitis were 52.7% for serum CRP level ≥50mg/L, 74.4% for ≥100mg/L, and 82.6% for ≥150mg/L. CONCLUSION: The results demonstrated several preoperative factors and clinical scoring models to increase suspicion of complicated appendicitis. Specifically, high serum levels of CRP may be a useful factor in predicting complicated appendicitis prior to surgery when supported by clinical findings and imaging; however, further research is needed.