Wound Infections in Breast Cancer Surgery After Preoperative Skin Preparation With Chlorhexidine vs. Povidone-iodine

The development of surgical site infections (SSI) in clean-contaminated surgery is regarded as being preventable. Known to be effective in the prevention of surgical site infection are the adequate sterilization of the surgical instruments, asepsis during operation, antibiotic prophylaxis where indicated, and certainly the preparation of the skin at the incision site, since the patient's skin is the principal source of bacterial contamination of the wound. Products generally used for preoperative preparation of the skin are iodophores (povidone-iodine), and products containing alcohol and/or chlorhexidine.

To date, in the literature there are quite a number of case studies, but only few randomized controlled trials (RCTs) that compare different methods of preparation of the skin at the site of surgery. Only recently a major study comparing between 2 modes of skin preparation before surgery has been performed and published, and at least 2 systematic reviews of various methods can be found. At present, the use of chlorhexidine in alcohol is seen to be more effective than povidone-iodine in the prevention of surgical site infection, but the data derived from the available studies are not sufficient to definitely support a change in the daily practice, and quantitative evaluation of pharmaco-economics implications are still missing.

This study aims to investigate the efficacy in prevention of surgical site infection in clean surgery, using two different standardized methods of skin preparation: povidone-iodine 10% aqueous solution from 1.5 liter bulk bottle, versus tinted 2% chlorhexidine in 70% isopropyl alcohol in a single-dose applicator. To reduce the variables involved, a single-center study will enroll a homogeneous population, undergoing breast cancer surgery.

The patients included in this study will be randomized according to the week in which they will receive surgical treatment. The investigators expect this approach to be easier to manage within this study. The randomly assigned treatment will be weekly communicated to the chief nurse of the operating theatre who will supply the proper disinfectant without any other role in the study.

All patients will be scheduled for at least one follow up visit after about 2 weeks after surgery. All patients have access to more follow up visits, if needed, and will be asked to report all kind of wound complications.

The wound assessment will be made by persons not aware of the treatment arm the patient was assigned to, and a defined protocol assessment, based on Centers for Disease Control and prevention (CDC) definitions, which provides the following classification:

• absence of infection;
• superficial wound infection;
• deep wound infection. The final follow-up visit during which the patient will be evaluated will be conducted at 30 days (for patients without insertion of prosthesis / expander) and at 180 days (for patients with the insertion of implants / expander).

Inclusion criteria

• Patients undergoing breast surgery at the Fondazione IRCCS National Cancer Institute in Milan (Italy), with or without reconstructive surgery / prosthesis or expander insertion
• Acceptance of the procedures of the protocol
• Signature of informed consent for the study

Exclusion criteria

• Refusal of the patient
• Age < 18 years
• Pregnancy
• Patients undergoing abdominal DIEP flap reconstruction
• Allergy to one of the disinfectants;
• Pre-existing infection in any body site