Surgical Site Infection in Cancer Patients

Reference: Gallagher M, Jones DJ, Bell-Syer SV. Prophylactic antibiotics to prevent surgical site infection after breast cancer surgery. Cochrane Database Syst Rev. 2019;9(9):CD005360. doi:10.1002/14651858.CD005360.pub5

Rationale: Prophylactic antibiotics reduce surgical site infection (SSI) rates in other surgical procedures, but their use is not standard practice for breast cancer surgery.

Objective: The purpose of the study was to determine the efficacy of preoperative or perioperative prophylactic antibiotics in reducing SSI following breast cancer surgery.

Methods: The study authors searched the Cochrane Wounds Specialized and Central Registries, EBSCO CINAHL Plus, Ovid MEDLINE, and Ovid Embase reference databases through August 2018, in addition to derivative and unpublished studies in clinical trial registries for randomized controlled trials (RCTs) comparing the effects on SSI of any type of preoperatively or perioperatively administered antibiotic to either placebo or no antibiotic used on patients undergoing surgery to remove breast cancer. Meta-analysis calculated the relative risk of a patient acquiring an SSI or experiencing an adverse event as primary outcomes. Secondary outcomes included time to SSI onset, readmission to the hospital, and costs of care. Statistical significance was set at probability of type 1 error less than .05.

Results: Ten RCTs qualified for meta-analysis. Preoperative antibiotics reduced SSI risk following breast cancer surgery compared with either placebo (7 RCTs with 1784 patients; P =.03) or no preoperative antibiotic (3 RCTs with 1039 patients; P =.01). No consistent effect was reported for antibiotics administered during breast cancer surgery or on any secondary outcome. No single antibiotic agent exceeded efficacy of another antibiotic.

Authors’ Conclusions: Preoperative prophylactic antibiotics likely reduce SSI risk for those undergoing breast cancer surgery. More studies are needed to determine best protocols for clinical practice.

Reference: Benedetto AV, Staidle JP, Schoenfeld J, Benedetto EA, Benedetto PX. Comparing the use of a novel antibiotic-free film-forming topical wound dressing versus a topical triple antibiotic in dermatologic surgical procedures including Mohs micrographic surgery. J Eur Acad Dermatol Venereol. 2021;35(1):247–255. doi:10.1111/jdv.16965

Rationale: Dermatologic surgery wounds are typically dressed with ointments containing antibiotic agents, despite the growing evidence of antibiotic-related allergies, contact dermatitis, and development of antibiotic-resistant bacteria.

Objective: The prevalence of SSI, contact dermatitis, and healing and infection rates of Mohs and non-Mohs routine dermatologic surgery wounds managed topically with a triple antibiotic ointment (TA) or an antibiotic-free, film-forming, moisture-retentive silicone gel wound dressing (WD) was compared.

Methods: The study design was an open-label, prospective, single-blind RCT based on a survey of patients (n = 962), 45.8% of whom preferred the TA ointment containing bacitracin, neomycin, and polymyxin B antibiotics as first aid for minor cuts, burns, and abrasions. This TA was standardized as control treatment randomly assigned to 30 patients undergoing Mohs surgery for nonmelanoma skin cancer and 82 patients undergoing non-Mohs dermatologic surgery. Wound dressing was randomly assigned to 30 similar patients in the Mohs arm and 75 patients in the non-Mohs arm. All patients received their assigned topical treatment immediately after the surgical wounds were closed with sutures. The TA dressings or WDs were held in place with a taped, nonadhesive dressing and kept from external moisture for 48 hours. Patients were instructed to apply their assigned dressing twice daily beginning on day 3 and continuing until sutures were removed. Patients who met indications of the 2008 dermatologic surgery advisory⁸ (eg, with prostheses or immunology issues) also received appropriate postoperative systemic antibiotics. Primary outcomes evaluated by a dermatologic surgeon blinded to treatment were patch test–confirmed contact dermatitis, microbially confirmed SSI or standardized subjective measures of wound healing, healing time, erythema, and tissue quality rated as +4 (much better) to −4 (much worse), with 0 meaning “as expected.” Secondary outcomes included patient ratings of pruritus or pain on a 10-point scale and a 5-point rating scale from “excellent” to “unsatisfactory” of topical product comfort, satisfaction, and ease of application. Chi-square tests analyzed group differences in contact dermatitis and SSI. All other variables were analyzed using the Mann-Whitney U test. A 2-tailed level of significance was set at α less than .05.

Results: The TA and WD patients in each arm of the study were similar at baseline. Seventeen patients were excluded from the SSI analyses due to known allergy to a TA ingredient (4 in the Mohs arm of the study, 13 in the non-Mohs arm). One patient in the Mohs arm receiving WD was excluded for not adhering to the study protocol. The most common Mohs surgery sites were the nose, neck, and upper arm, and the most common surgery sites for non-Mohs surgery were the abdomen, back, scalp, thigh, and upper arm. Contact dermatitis was present in 18.9% of patients randomized to receive TA and in none of the patients who received WD (n = 230; P <.001). Two SSIs were reported among WD patients (1.9%) compared with none in TA patients (P =.14). Clinician-blinded ratings of healing time and quality, quality of newly formed tissue, erythema, comfort, and overall satisfaction were higher for the WD group (P <.05). Ease of application was similar for the WD and TA groups, but both treatments were rated easier to apply in non-Mohs patients. No other difference was significant between Mohs and non-Mohs patients. Patient ratings were similar for TA and WD during treatment for comfort, ease of product application, pain, and pruritus, and at the final visit for product tolerability, efficacy, ease of use, feel on skin, and overall patient satisfaction. A study limitation observed by the authors is that differences in wound location and size may have affected results.

Authors’ Conclusions: Using a moisture-retentive, film-forming silicone gel as a postoperative wound dressing may limit SSI while alleviating growing concerns about the increasing incidence of antimicrobial resistance.

It is important to recognize that patient-appropriate preoperative systemic antibiotics reduce the likelihood of SSI following cancer surgery as they do in other surgical applications.^3,8 While focusing on this issue and on patient risk factors for the development of SSI,^1,2 those in clinical practice may be ignoring decades of compelling evidence that a moist local wound environment profoundly reduces the likelihood of SSI⁵ while accelerating healing, reducing wound pain, and limiting scarring.^5,9,10  In 1988, in an RCT of 58 patients assessed weekly during healing following open Mohs micrographic surgery, Hien et al¹⁰ discovered that these excisions healed faster with less scarring with use of a moisture-retentive film dressing as compared with those dressed with gauze containing antibiotic ointment. No SSI was detected in either group. Surgeons should consider the use of the moist local wound environment to improve patient outcomes and limit development of resistant organisms, a missed opportunity recently rediscovered by Benedetto et al.⁷ Are clinicians turning a blind eye to the wound environment as has been done to that of Earth's environment? What improvements in SSI might occur if surgeons harness the powerful evidence supporting the benefit of moist local wound environments?