(A612) Radiographic Features Associated with Poor Outcomes in Head and Neck Necrotizing Fasciitis

Introduction: Introduction
Necrotizing fasciitis (NF) of the head and neck (HN) is a rapidly progressive infection with risk for descending necrotizing mediastinitis (DNM). Radiographic features of HN NF overlap with cellulitis, complicating diagnosis and prognosis at presentation.

Methods: Methods
In this retrospective cohort study, patients with suspected HN NF were sorted into groups based on outcome, with the “poor outcomes” group defined by death and/or DNM. Imaging review was conducted by a neuroradiologist to assess for prognostic features. Comparisons between groups were made with Fisher’s exact, Mann-Whitney U, and Chi-square tests.

Results: Results
Thirty-nine patients with clinical concern for HN NF were included in the study. Thirty-two had surgically confirmed NF, and 7 had cellulitis only. Patients with poor outcomes were more likely to have gas or abscess extend infrahyoid (p=0.04) and infracricoid (p=0.003) with greater median craniocaudal extent of abscess or gas (p=0.004). Bilateral extent was also more common in poor outcomes (p=0.05). All patients with poor outcomes had an abscess, and patients with only fat stranding/edema at the time of presentation either had cellulitis or NF without DNM.

Conclusions: Conclusion
There remain no definitive imaging characteristics that can reliably distinguish HN NF from cellulitis. Radiographic findings of infrahyoid/infracricoid spread and bilateral extent are associated with poor outcomes. Fat stranding/edema only with lack of an abscess was associated with good outcomes.