Gentamicin-collagen sponge reduces sternal wound complications after heart surgery: a controlled, prospectively randomized, double-blind study

Objective: Prophylactic retrosternal placement of a gentamicin-collagen sponge has been the subject of several recent clinical studies and is a matter of controversy. The present study is the first controlled, prospective, randomized, double-blind, single-center study to investigate the efficacy of a retrosternal gentamicin-collagen sponge in reducing sternal wound complications after heart surgery.

Methods: From June 2009 to June 2010, 720 consecutive patients who underwent median sternotomy were assigned to a control placebo group (collagen sponge) or an intervention group (gentamicin-collagen sponge). All patients received guideline-compliant perioperative antibiotic prophylaxis. The primary end point was the occurrence of deep sternal wound infections within 30 days of index surgery (follow-up period). Secondary end points were the occurrence of superficial sternal wound infections requiring treatment, as well as further clinical parameters, including revision, bleeding volume, and need for transfusions during the follow-up period.

Results: A total of 720 of 994 patients (72.4%) were enrolled (control group: n = 367 vs intervention group: n = 353). Risk factors for sternal wound infection and demographic variables were comparable in the 2 groups. The incidence of deep sternal wound infections was 13 of 367 (3.52%) in the control group versus 2 of 353 (0.56%) in the intervention group (P = .014; adjusted odds ratio, 0.15; 95% confidence interval, 0.02-0.69). The numbers needed to treat relation for all sternal wound infections and deep sternal wound infections were 26 and 33, respectively. No statistically significant differences were demonstrated concerning secondary end points, such as postoperative bleeding and transfusion of red cell units, thrombocytes, and fresh-frozen plasma.

Conclusions: Routine prophylactic retrosternal use of a gentamicin-collagen sponge in patients undergoing cardiac surgery significantly reduces deep sternal wound infections.