Antibiotic Impregnated Sponges Reduced Chest Wound Infections After Heart Surgery Interview with:
Mariusz Kowalewski, MD
Department of Cardiac Surgery, Dr Antoni Jurasz Memorial University Hospital
Systematic Investigation and Research on Interventions and Outcomes
Medicine Research Network, Poland

Medical Research: What is the background for this study? What are the main findings?

Dr. Kowalewski: Sternal wound infections occurring after heart surgery performed via median sternotomy, and in particular, after coronary artery bypass grafting (CABG), although rare, still pose serious postoperative complications that increase the length of hospital stay and healthcare costs. One of many ways to prevent them from happening, except from optimal glucose control, tight-fixed closure of the sternum at the end of surgery and perioperative iv. antibiotics, is to insert a gentamicin collagen sponge between two sternal edges, just before wiring them together. High local concentrations of gentamicin were shown to eliminate any microbial growth in the area, in the same time, not affecting the kidneys, as would be the case with systemic administration. Gentamicin sponges are widely used in orthopadic, gastro-intestinal and vascular surgery and were shown to reduce postoperative infection rates. Although extensively tested in the field of heart surgery, findings of one recent multicenter study have questioned their true benefit. We aimed to perform a comprehensive meta-analysis of studies assessing the efficacy of implantable gentamicin-collagen sponges in sternal wound infection prevention.

After screening multiple databases, a total of 14 studies (N = 22,135 patients, among them 4 randomized controlled trials [N = 4,672 pts]) were included in the analysis. Implantable gentamicin-collagen sponges significantly reduced the risk of sternal wound infection by approximately 40% when compared with control (risk ratio [RR], 0.61; 95% confidence interval [CI], 0.39-0.98; P = .04 for randomized controlled trials and RR, 0.61; 95% CI, 0.42-0.89; P = .01 for observational studies). A similar, significant benefit was demonstrated for deep sternal wound infection (RR, 0.60; 95% CI, 0.42-0.88; P = .008) and superficial sternal wound infection (RR, 0.60; 95% CI, 0.43-0.83; P = .002). The overall analysis revealed a reduced risk of mediastinitis (RR, 0.64; 95% CI, 0.45-0.91; P = .01). The risk of death was unchanged.

In addition, we investigated, by means of meta-regression, the correlation between sternal wound infections and extent to which the bilateral internal thoracic artery (BITA) was harvested. We found that the benefit provided by the gentamicin sponge was attenuated when BITA was harvested; these results suggest that another potentially preventive measure must be taken in such patients, as with severely reduced blood supply to the sternum (as is the case with BITA), sponge itself might not be enough to prevent wound infection.

Medical Research: What should clinicians and patients take away from your report?

Dr. Kowalewski: Current report is the largest to date database analyzed to assess the role of gentamicin sponge in sternal wound prevention after heart surgery. While international guidelines are not conclusive regarding topical antibiotic administration after heart surgery, findings of the present report, suggest reduced infection rates in patients in whom, gentamicin sponge was implanted. The evidence was strikingly consistent across randomized and observational studies.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Kowalewski: We would encourage cardiac surgeons to introduce the gentamicin sponge to their institutional protocols, at least in patients at high risk of developing sternal wound infections (BMI >30, type 2 DM, COPD, BITA). What remains to be ascertained is the best combination of gentamicin sponge and iv. antibiotic. Also the results of 2×2 study comparing pedicled vs skeletonized internal thoracic artery and gentamicin sponge vs control could shed a new light to the topic.


J Thorac Cardiovasc Surg. 2015 Jun;149(6):1631-1640.e6. doi: 10.1016/j.jtcvs.2015.01.034. Epub 2015 Jan 23.

Gentamicin-collagen sponge reduces the risk of sternal wound infections after heart surgery: Meta-analysis.

Kowalewski M1, Pawliszak W2, Zaborowska K3, Navarese EP4, Szwed KA5, Kowalkowska ME6, Kowalewski J7, Borkowska A5, Anisimowicz L2.

[wysija_form id=”3″]


Mariusz Kowalewski, MD, Department of Cardiac Surgery, Dr Antoni Jurasz Memorial University Hospital, Bydgoszcz,, Systematic Investigation and Research on Interventions and Outcomes, & Medicine Research Network, Poland (2015). Antibiotic Impregnated Sponges Reduced Chest Wound Infections After Heart Surgery

Last Updated on June 13, 2015 by Marie Benz MD FAAD