Topical spraying of cefazolin and gentamicin reduces deep sternal wound infections after heart surgery: a multicenter, large volume, retrospective study

Objective The use of topical antimicrobials applied to the sternum during cardiac procedures in combination with intravenous agents to prevent mediastinitis has been reported to yield good results. The objective of this study is to provide optimal method of topical antimicrobials for the prevention of sternal wound infection after cardiac surgery. Methods We retrospectively evaluated the patients undergoing adult cardiac surgery at five institutions between January 1994 and August 2013 for the incidence of deep sternal wound infection (DSWI). The patients were sprayed with a solution of cefazolin and gentamicin into the surgical site several times during surgery. The incidence of DSWI was evaluated. Four major risk factors [diabetes mellitus (DM), emergency operation, dialysis and prolonged operation] were also evaluated for their implications in the outcome with the antimicrobial spraying. Results Totally, 6960 patients were analyzed. The incidence of DSWI was 0.46 % in the spraying group versus 1.7 % in control group ( p < 0.0001). There is no significant difference of the incidence of DSWI between DM and non-DM groups ( p = 1.00), emergency and elective operation groups ( p = 0.25) under usage of antimicrobial spraying. However, there is significant difference of the incidence of DSWI between dialysis and non-dialysis groups ( p = 0.0222), longer than six-hour duration and lesser than six-hour duration operation groups ( p = 0.0269). Conclusion Topical spraying of cefazolin and gentamicin reduces deep sternal wound infections after cardiac surgery. DM and emergency operation were not the risk factors of DSWI when antimicrobial spraying is administered. Considering the benefits, antimicrobial spraying could be used intermittently during such procedures.