Computed tomography findings of mediastinitis after cardiovascular surgery

Background: To our knowledge, no systematic study has been conducted on computed tomography (CT) imaging of mediastinitis in children post-cardiovascular surgery. We aimed to assess the CT findings of pediatric patients diagnosed with mediastinitis after cardiovascular surgery. Methods: We included 28 pediatric patients with suspected mediastinitis after undergoing cardiovascular surgery and who underwent CT. Patients were divided into a group with mediastinitis requiring antibiotic therapy (n = 15) confirmed by positive bacterial culture from the mediastinum and a group without mediastinitis (n = 13). Fisher's exact test was used to compare the following CT findings between the two groups: (i) mediastinal fluid collection; (ii) free gas bubble within fluid collection; (iii) sternal destruction; and (iv) capsular ring enhancement. The enhancement extent was categorized into the following four grades: whole rim enhancement, >50% of the rim enhancement, <50% of the rim enhancement, and no rim enhancement. A receiver operating characteristic curve analysis was performed to establish a cut-off point for obtaining the maximum diagnostic accuracy. Results: A significant difference was observed between patients, with and without mediastinitis in sternal destruction (73.6% vs 0%, P = <0.0001) and capsular ring enhancement (100.0% vs 38.5%, P = 0.0004). By using a cut-off grade of the whole rim enhancement, the estimated sensitivity and specificity for mediastinitis diagnosis were 100% and 92.3%, respectively. Conclusion: Computed tomography findings of sternal destruction and capsular ring enhancement were observed more in patients with mediastinitis than in those without mediastinitis, and should be assessed carefully to diagnose mediastinitis accurately in pediatric patients who have undergone cardiac surgery.