Mediastinitis after cardiac surgery: risk factors and our vacuum-assisted closure results

Introduction
Mediastinitis after cardiac surgery is a rare complication, but with high morbidity and mortality.

Aim
To determine its risk factors and to investigate the efficacy of vacuum-assisted closure (VAC).

Material and methods
Nine thousand one hundred sixty cases of patients who underwent cardiac surgery during 2010–2017 were reviewed retrospectively. One hundred and twenty-seven patients, the case group, were treated by VAC. Three hundred cases with no diagnosis of mediastinitis were selected as the control group. Both groups’ clinical and demographic characteristics, preoperative variables, and postoperative follow-up parameters were compared. Factors affecting treatment were analyzed.

Results
We found that the presence of diabetes mellitus, bilateral internal thoracic artery and intra-aortic balloon pump usage are independent risk factors for the development of mediastinitis (p < 0.05). It was found that 74% of tissue cultures were positive and the most common detected organism was Staphylococcus. It was found that many perioperative parameters had a significant effect on the duration of treatment (p < 0.05). However, regression analysis revealed that bacterial growth was the only independent variable in prolonging the treatment period.

Conclusions
We believe that the establishment of perioperative blood glucose regulation, patient selection to use bilateral internal thoracic artery grafts, and maximum attention to sepsis and antisepsis rules in patients who need mechanical support devices such as intra-aortic balloon pump, will significantly reduce the development of mediastinitis. Since we could not find an independent risk factor for the duration of VAC treatment other than culture growth, we think that VAC therapy is successful and safe in the treatment of mediastinitis and should be used more widely.