Purpose
Infectious mediastinitis after sternotomy is a life-threatening condition requiring thorough diagnosis and swift therapy to avoid high mortality in affected patients.1 Computed tomography (CT) is often employed to evaluate the presence and the extent of mediastinitis.
Unfortunately,
previous studies have shown that the accuracy of diagnosing this infection in postsurgical patients using CT is insufficient due to lack of specificity.
Especially,
this applies if the timeframe between initial cardiac surgery and CT scan is short,
resulting in difficult differentiation between postsurgical residuals and signs of...
Methods and Materials
Patients: Data of 134 patients with clinically suspected acute mediastinitis after sternotomy were evaluated in our study.
All patients had received a contrast enhanced chest CT prior to deep revision surgery with collection of microbiological samples .
CT-Protocol: All CT scans were performed on a dual source CT (Somatom Definition Flash,
Siemens Healthcare,
Erlangen,
Germany) according to the standard protocol in our facility.
Dose modulation was used for all scans.
In total 70 ml (400 mg Iodine/ml) of nonionic iodinated contrast medium were applied.
In...
Results
Qualitative analysis: All CT-datasets were evaluated qualitatively.
The frequencies of evaluated parameters are found in table 1.
Frequencies in mediastinitis-positive and -negative patients (according to clinical standard of reference) were compared statistically.
The comparison showed that free gas bubbles (OR=3.8,
95%CI [1.4,
10.1]) and pleural effusions (OR=4.9,
95%CI [1.8,
13.3]) occurred significantly more often in infected patients.
The remaining qualitative parameters did not show a significant difference.
Quantitative analysis: 64 CT-datasets were evaluated quantitatively.
Results are found in table 1.
Results were compared statistically between...
Conclusion
Even using established CT-parameters and newest generation scanner technology,
the differentiation between acute infectious mediastinitis and postoperative residuals remains limited.
The majority of evaluated parameters did not show a significant difference between groups.
Quantitative analysis can improve diagnostic accuracy by assessing the mediastinal volume,
mediastinal fluid and air volume,
respectively.
References
1.
Athanassiadi KA.
Infections of the mediastinum.
Thorac Surg Clin.
2009;19: 37-45.
2.
Yamashiro T,
Kamiya H,
Murayama S,
et al.
Infectious mediastinitis after cardiovascular surgery: role of computed tomography.
Radiat Med.
2008;26: 343-347.
3.
Exarhos DN,
Malagari K,
Tsatalou EG,
et al.
Acute mediastinitis: spectrum of computed tomography findings.
Eur Radiol.
2005;15: 1569-1574.
4.
Horan TC,
Andrus M,
Dudeck MA.
CDC/NHSN surveillance definition of health care–associated infection and criteria for specific types of infections in the acute care setting.
Am.
J.
Infect.
Control 2008:36:...