Wound Protector Dual-ring Alexis® in Pancreaticoduodenectomy: a Randomized Single-blind Controlled Clinical Trial

Surgical site infection (SSI) is a leading cause of preventable morbidity and mortality in North America and worldwide. This condition has consistently been reported to account for up to 25% of all healthcare-associated infections. Prolonged hospitalization, more frequent hospital re-admissions after surgery and a greater than twofold increase in costs and mortality have consistently been associated with this condition over the past decade. The SSI is associated with an increased risk of postsurgical pain, poor wound healing and aesthetic results and an increased risk of incisional hernias. The literature shows an incidence rate of SSI at 30 days after surgery that reaches 51% of cases. In particular, the incidence of wound infection is 15%. In our experience, the rate of wound infection in patients undergoing Pancreaticoduodenectomy (PD) is 10%.

SSI is an infectious process that is localized to surgical incision level and it is classified as being either incisional or organ/space. Incisional SSI is further divided into those involving only skin and subcutaneous tissue (superficial incisional SSI) and those involving deeper soft tissues of the incision (deep incisional SSI).

In a cost analysis, SSIs post-PD dramatically increases the treatment costs. More importantly, postoperative wound infections delay postoperative adjuvant chemotherapy, which is indicated in the majority of patients undergoing PD for pancreatic cancer. During recent years there is also an increasing incidence of antibiotic-resistant pathogens in hospitals, so several studies have suggested primary or secondary prevention strategies to reduce SSI rate. In order to minimize the risk of SSI, various measures of perioperative care have already been adopted, including the cleaning of the skin, the hair removal of the intervention area, the prevention of intraoperative hypothermia and perioperative antibiotic therapy. However there are few studies on the effectiveness of surgical procedures for primary prevention to reduce the contamination in the surgical site, especially in patients undergoing major gastrointestinal surgery. The surgical procedures classified as contaminated or dirty (with a higher bacterial load within the surgical site and/or regarding gastrointestinal or biliary tracts) remain associated with an increased risk of SSI, about two times, compared to the interventions classified as clean or clean-contaminated. The PD is classified as surgery contaminated / dirty.

The use of adhesive membrane barriers over the skin of the surgical site emerged 50 years ago as a possible solution to minimize endogenous cross-contamination during surgery. The initial idea relied on the principle of reducing exposure of the surgical site to bacteria inherent in the surrounding skin or to airborne bacteria in the operating room. Major applicability was expected in clean surgeries, where the skin is considered the main source of bacteria. Unfortunately, however, no evidence in support of plastic adhesive drapes was found in a recently updated systematic review of randomized controlled trials (RCTs) including five studies and 3082 patients. In fact, a 23% increase in the risk of SSI was found in the group that received adhesive drapes. In the 1960s, other devices were described and then developed based on the concept of combining a non-traumatic surgical wound retractor with a protective membrane covering of the incisional margin in abdominal surgeries. Such protective covers or 'wound protectors' (WP) were hypothesized to be an improvement over adhesive membrane barriers as they were believed to reduce intraoperative contamination while concomitantly preserving the temperature and humidity of the surgical wound. In support of this hypothesis, early studies demonstrated reduced exposure of the surgical wound to enteric bacteria at the end of gastrointestinal operations. These results were further supported by several RCTs, which demonstrated that wound protectors were efficacious in reducing the incidence of incisional SSI as compared to usual care in patients undergoing gastrointestinal surgeries. A recently meta-analysis of RCTs on the WP enrolled 6 studies and 1008 patients, finding that the pooled estimated risk of SSI among patients fitted with wound protectors during surgery was 0.55 (95% CI 0.31 to 0.98) times the pooled estimated risk of SSI in control groups.

The aim of this study is to assess if the use of WP can reduce the wound infection rate in patients undergoing to PD.