# Primary Sternal Osteomyelitis with Acute Mediastinitis, Successfully Treated with Minimally Invasive Surgical Drainage

## TL;DR

A rare case of sternal infection leading to chest infection was successfully treated with minimally invasive surgery, avoiding major procedures.

## Contribution

Demonstrates successful minimally invasive treatment for a rare condition causing acute mediastinitis.

## Key findings

- Minimally invasive drainage resolved mediastinal abscess and sternal infection without major surgery.
- Patient recovered fully with oral antibiotics after drainage procedures.
- PSO can rapidly progress to mediastinitis and should be considered in chest pain cases.

## Abstract

Primary sternal osteomyelitis (PSO) is a rare disease that occurs without any contiguous focus of infection, and there are few reports of acute mediastinitis due to PSO. In this report, we describe a case of PSO with acute mediastinitis successfully treated with a minimally invasive approach.

A 71-year-old man visited his local doctor for anterior chest pain. He had no history of trauma or chest surgery. He was treated conservatively because of a few abnormalities on CT. However, his symptoms worsened, and a CT was re-taken 13 days later. The CT showed an abscess on the left side of the anterior mediastinum and subcutaneous tissues, as well as destruction of the sternum. With the diagnosis of acute mediastinitis and mediastinal abscess, thoracoscopic and subcutaneous drainages of the abscess were performed. After surgery, blood culture examination showed methicillin-sensitive Staphylococcus aureus, and we judged the mediastinitis to be caused by PSO. The thoracic drain was removed on postoperative day 39, the open subcutaneous wound closed spontaneously, and the patient was discharged on postoperative day 45. He continued oral antibiotics for the next 2 months, and the abscess cavity completely resolved.

Although PSO is rare, it can lead to mediastinitis and should be suspected when anterior chest pain is present. Our case of PSO with acute mediastinitis progressed rapidly over a few days but could be treated with minimally invasive thoracoscopic and subcutaneous drainages, without the need for invasive sternal debridement and drainage.