A retrospective study of surgically treated subperiosteal orbital abscesses derived from acute bacterial ethmoid sinusitis

Background: Subperiosteal abscesses (SPOA) are a complication of acute purulent sinusitis, and their optimal treatment regime is a controversial topic. Some otolaryngologists consider surgery to be mandatory in the treatment of subperiosteal abscesses others advocate that especially paediatric patients can be treated medically in some cases. The purpose of this study was to evaluate our current treatment guidelines for subperiosteal abscesses. Methodology: A retrospective study was undertaken from 2010 to 2016, including patients registered with the diagnosis of subperiosteal abscesses derived from acute sinusitis based on clinical diagnoses, and CTs or MRIs. All patients received treatment with IV-antibiotics and were booked for prompt surgery. The main outcome measures were CT-measurements and intraoperatively identified pus. Treatment included antibiotic choice, microbiology, and outcomes. Results: Thirty-one patients were included in the study having the diagnosis of sinusitis and SPOA. Per operatively, we found pus in the subperiosteal space in 21/31 patients and 17 of the patients with available contrast-enhanced CT scans. When patients were grouped based on radiographically confirmed abscesses or not per the preoperative MRI or CT, we found that the presumed abscess volume was 0.83 mL greater in the patients, who had an abscess confirmed during surgery. Two patients needed endoscopic re-operation. In addition, three patients had sequela at the last follow-up, two with minor subjective sequelae due to oedema most likely resolving themselves over time and one with memory and concentration difficulties due to intracranial