Ultrasonographic Appendix Diameter: A Predictive Factor for Non-Operative Treatment of Acute Appendicitis in Pediatrics

Background: Nonoperative treatment of acute appendicitis (NOTA) has been demonstrated to be a safe and effective approach in children, but when it fails can be associated with serious morbidity. Since 2012, our department has implemented NOTA as an option for uncomplicated cases of appendicitis. Objective: We aim to analyse NOTA efficacy and safety and seek predictive factors for the success of this approach, enhancing patient selection. Methods: Data from all patients with uncomplicated acute appendicitis who underwent NOTA between 2012 and 2022 were collected and analysed. Patients with complicated appendicitis, appendiceal mass, intraluminal appendicolith or inability to oral feed were excluded. NOTA failure was defined as no clinical improvement during treatment. Appendicitis recurrence was defined as a new acute appendicitis onset. Patients were divided into two groups: Successful versus Failure NOTA. Results: A total of 114 patients were included. NOTA was successful in 89.5% of cases and failed in 10.5%. In the failure NOTA group (n=12) the ultrasonographic appendiceal diameter was significantly higher (p<0.001). A multivariable logistic regression analysis pointed the appendiceal diameter as a significant predictor of NOTA failure, with a cut-off of 8.6 mm obtained after a ROC curve analysis. The hospitalization length admission of the patients from the Failed NOTA group was significantly higher (median time of 4.5 days). Conclusion: The criterion identified in this study—appendiceal size as measured by ultrasonography—may help minimize some of the failures and the associated morbidity in patients approached by NOTA.