Objective: To review the Hospital of Sick Children, Toronto's experience of the diagnosis and management of retropharyngeal and parapharyngeal infections with particular emphasis on the role of computed tomography (CT) imaging in diagnosing the presence of an abscess.
Methods: A retrospective analysis of all patients diagnosed with retropharyngeal and parapharyngeal infections from 1987 to 1999 was performed. Demographic data, presenting symptoms, season of presentation, management and complications were reviewed. The CT scans of 27 patients who underwent surgical treatment were retrospectively examined by two neuroradiologists who were blinded to the patient's history and outcome. The sensitivity, specificity and predictive values for the specific features and overall assessment were calculated.
Results: Fifty-four children were identified. There were 46 retropharyngeal infections, 6 parapharyngeal infections and 2 patients had both retropharyngeal and parapharyngeal infections. All patients were treated with parenteral antibiotics. Thirty-seven patients underwent surgical drainage and in 27 there was a positive finding of pus. The retrospectively assessed CT scans of the 21 patients who underwent surgery were found to have a sensitivity of 81% in detecting an abscess by CT scan but the specificity was 57%. There were four complications including mediastinitis, aspiration pneumonia, internal jugular vein thrombosis and common carotid artery aneurysm. All patients recovered but abscess recurred in five patients.
Conclusion: Not all patients with retropharyngeal and parapharyngeal abscesses require surgery. Whilst CT scans are helpful in diagnosing and assessing the extent of these infections they are not always accurate in detecting an abscess. A decision to drain an abscess should therefore not be made based solely on the CT findings.