Usefulness of Preoperative Predictors of Pathological Complicated Appendicitis.

Introduction: Complicated appendicitis (CA) is often indicated for emergency surgery; however, preoperative predictors of pathological CA (pCA) remain unclear. Furthermore, characteristics of CA that can be treated conservatively have not yet been established.

Methods: 305 consecutive patients diagnosed with acute appendicitis were reviewed. The patients were divided into two groups: an emergency surgery and a conservative treatment group. The emergency surgery group was pathologically classified as having uncomplicated appendicitis (pUA) and pCA, and the preoperative predictors of pCA were retrospectively assessed. Based on the preoperative pCA predictors, a predictive nomogram whether conservative treatment would be successful or not was created. The predictors were applied to the conservative treatment group, and the outcomes were investigated.

Results: In the multiple logistic regression analysis of the factors contributing to pCA, C-reactive protein ≥3.5 mg/dL, ascites, appendiceal wall defect, and periappendiceal fluid collection were independent risk factors. Over 90% of cases without any of the above four preoperative pCA predictors were pUA. The accuracy of the nomogram was 0.938.

Conclusion: Our preoperative predictors and nomogram are useful to aid in distinguishing pCA and pUA and to predict whether or not conservative treatment will be successful. Some CA can be treated with conservative treatment.