Invited comment on R. L. Nelson et al. “Topical antimicrobial prophylaxis in colorectal surgery for the prevention of surgical wound infection: a systematic review and meta-analysis”

Excerpt

The question asked by Nelson et al. is relevant and timely. The incidence of surgical site infection (SSI) following colorectal surgery remains high with one-fifth of hospital acquired infections attributed to SSI. SSI are associated with substantial postoperative morbidity and are used as a metric for hospital performance ranking and reimbursements [1, 2]. Dr. Nelson et al. performed a systematic review of randomized-controlled trials (RTCs) that associated the use topical antimicrobials, excluding antimicrobial ointments, with SSI reduction. They performed a meta-analysis of the literature at large, and subgroup analyses for use of gentamicin sponges/beads, chlorhexidine impregnated suture, and antibiotic powders/lavages/injection into the wound calculating relative risk reduction of SSI with the use of these agents. The methodology is thorough, attentive to bias, and well executed. However, in limiting their meta-analysis to RTCs, the interpretation is subject to significant limitations. These limitations include limited external validity, lack of power, the heterogeneity of the aggregate study population and intervention, and publication bias [3]. RCTs are the gold standard for detecting an effect of interventions. However, this effect is seen in patients who are stringently selected by inclusion criteria, and compliance with the intervention is strictly overseen. These parameters limit the external validity of RTCs in practice where the patients are heterogeneous and compliance with established protocols may be lax. With these limitations, the effects of RTCs must be confirmed in studies that have improved generalizability to contemporary practice patterns. …