Local gentamicin reduces sternal wound infections after cardiac surgery:: A randomized controlled trial

Background. Sternal wound infections remain a major cause of morbidity after cardiac surgery. Vancomycin is often the only effective antibiotic available for their treatment but its use for routine prophylaxis is inadvisable for ecological reasons. Local application of gentamicin produces high antibiotic concentrations in the wound. We aimed to determine whether this treatment could have an additive effect on the incidence of sternal wound infections when combined with routine prophylaxis. Methods. Two thousand cardiac surgery patients were randomized to routine prophylaxis with intravenous isoxazolyl-penicillin alone (control group) or to this prophylaxis combined with application of collagen-gentamicin (260 mg gentamicin) sponges within the sternotomy before wound closure. Endpoint was any sternal wound infection within 2 months postoperatively. Evaluations were double-blind and made on an intention-to-treat basis. Results. Evaluation was possible in 967 and 983 patients in the control and treatment groups, respectively. The incidence of sternal wound infection was 4.3% in the treatment group and 9.0% in the control group (relative risk 0.47; 95% confidence interval 0.33-0.68; p < 0.001). Early reoperation for bleeding was more common in the treatment group (4.0% vs 2.3%, p = 0.03). No difference in postoperative renal function was noted. Conclusions. Local collagen-gentamicin reduced the risk for postoperative sternal wound infections. Further studies are warranted to confirm these results, particularly with regard to deep infections.