Direct sternal administration of Vancomycin and Gentamicin during closure prevents wound infection

Deep sternal wound infection is still a major complication in patients undergoing cardiac surgery. We previously identified mammary artery harvesting as a risk factor for decreased antibiotic tissue penetration. In addition, other risk factors including diabetes may inhibit sufficient tissue penetration of perioperative antibiotic prophylaxis. A novel closure protocol applying 2 topical antibiotics and further recommendations for sternal wiring was introduced at our department to decrease the incidence of sternal wound infections.

A 12-month period prior to (March 2013-February 2014) and after (July 2014-June 2015) the introduction of a novel sternal closure protocol was studied. All sternal wound infections resulting from an operation during this period were analysed. The closure protocol consisted of the intra-sternal application of vancomycin and the subcutaneous application of gentamicin. Furthermore, we increased the number of sternal wires for more uniform distribution of lateral forces.

Patients in both groups were comparable regarding demographic data and risk factors. Fifty-three out of 919 patients operated prior to the protocol change developed an infection (5.8%). The introduction of the novel sternal closure protocol reduced this number to 19 out of 932 patients (2.0%; P  < 0.001). A binary regression including common risk factors revealed a strong independent risk reduction by the novel protocol (OR 0.322, P  < 0.001). The number of sternal wires was not significant in this analysis.

The topical application of 2 antibiotic agents significantly reduced sternal wound infection. However, the results of this trial should be confirmed in a randomized trial.