According to data from two different phase 3 studies, insertion of a gentamicin-collagen sponge at the time of surgical closure following either colorectal or cardiac surgery did not reduce the rate of surgical site infections (SSI) when compared with placebo. In patients who had undergone colorectal surgery, insertion of the sponge resulted in significantly more surgical-site infections. The results from the cardiac surgery trial dispute data from a large 2005 Swedish trial suggesting that the sponge reduced SSI by 50% in patients who underwent cardiac surgery.

Despite the use of prophylactic systemic antibiotics, postoperative SSIs continue to be a serious problem after surgical procedures, especially in the increasing population of patients with diabetes and/or obesity. These infections are associated with significant morbidity and cost. The gentamicin-collagen sponge, a surgically implantable topical antibiotic, is currently approved in 54 countries and, to date, more than 2 million sponges have been used to treat SSIs across a broad range of clinical indications. The sponge is not yet approved in the United States, and the two clinical trials reported here were designed to support U.S. regulatory approval. 

Conceived and conducted by a team based at the Duke Clinical Research Institute, the two randomized controlled trials were of similar design, with all patients receiving standardized care, including prophylactic systemic antibiotics. In the first study,¹ 602 patients at 39 sites throughout the United States who underwent either open or laparoscopic colorectal surgery were randomized to receive two gentamicin-collagen sponges inserted above the fascia during surgical closure (sponge group, n=300) or no intervention (control group, n=302).  The incidence of SSIs was significantly higher in the sponge group (30%) compared with placebo (21%; P=0.01). While there was a significantly greater incidence of superficial SSI in the sponge group versus placebo (P=0.03), no significant difference was noted in the incidence of deep SSI with either group (P=0.26). Patients in the sponge group were significantly more likely to be seen in the emergency department for a wound-related complication than those in the placebo group (P=0.004); however, there was no significant difference in rehospitalization rates for SSI between the groups.  

The second study²  included 1502 cardiac surgery patients at 48 U.S. sites between December 2007 and March 2009, all who were at high risk for sternal wound infection.  Two thirds of the patients had diabetes (n=1006) and 76% (n=1137) were obese.  Patients were randomized to either insertion of two gentamicin-collagen sponges between the sternal halves at surgical closure (n=753) versus no intervention (control group, n=749). The researchers found no significant difference in sternal wound infections in either the sponge or the control group (P=0.83). No significant differences were observed in either superficial (P=0.77) or deep sternal wound infection (P=0.37) between the two groups, or in rehospitalization for sternal wound infection (P=0.87). The researchers believe that their findings differ from the positive Swedish results because of important differences in several quality-control measures that were not incorporated in the previous study, as well as a possible effect of ethnic and regional differences.

To learn more about the gentamicin-collagen sponge, please see the Hayes Technology Prognosis Report.

1. Bennett-Guerrero E, Pappas T, Koltun W, et al.  Gentamicin-collagen sponge for infection prophylaxis in colorectal surgery. N Engl J Med. 2010 Aug 4; (Epub ahead of print). Full text available at: http://www.nejm.org/doi/full/10.1056/NEJMoa1000837. Accessed August 19, 2010.
2. Bennett-Guerrero E, Ferguson TB, Lin M, et al. Effect of an implantable gentamicin-collagen sponge on sternal wound infections following cardiac surgery. JAMA. 2010;304(7):755-762. Abstract available at: http://jama.ama-assn.org/cgi/content/abstract/304/7/755. Accessed August 19, 2010.

Posted in News Service
This entry was posted on Thursday, August 19th, 2010 at 12:00 pm.