Benjamin N Gayed, MD, Paul P Szotek. Indiana University School of Medicine
Surgical site infections add significant cost to post-operative care and prolong hospitalization. Negative pressure wound therapy applied over loosely approximated incisions (incisional NPWT) has gained traction in recent years as an effective method to reduce surgical site infections (SSI). To date, few studies have evaluated cost effectiveness of this technique.
The purposes of this study are 1) to determine the effectiveness of incisional NPWT to reduce SSI in a general surgery practice including a mix of elective and emergency cases, and 2) to perform a cost analysis based on SSI reduction.
A single surgeon utilized incisional NPWT for 100 consecutive patients undergoing laparotomy between 2012 and 2014 following a standardized protocol. We performed a retrospective review of these cases to describe the population and evaluate the incidence of SSI after incisional NPWT application. Mortality in the first week of the post-operative period or return to the OR unrelated to SSI were excluded. Cost analysis included daily cost for NPWT equipment compared to the cost of complications gathered from published data.
The most commonly performed operations in this series included ventral hernia repair, exploration for hollow viscus perforation and exploration for bowel obstruction (n=91). The average age of this population was 60.3 (±15.1) and average BMI was 30.9 (±8.3). Fifty-five percent of cases were elective, 6.6% were related to trauma, and 22.0% were scheduled returns to the operating room for open abdomen in the setting of trauma or critical illness. Overall SSI rate was 2.2%. When looking at individual wound classes, there were zero SSI’s (0%) in class 1 (clean) wounds, 1 SSI (4.76%) in class 2 (clean-contaminated) wounds, zero SSI’s (0%) in class 3 (contaminated) wounds, and 1 SSI (3.9%) in class 4 (dirty) wounds. Incisional NPWT costs were $100/day including direct costs for the pump, sponge, adhesive and tubing, totaling $1,000 per patient including pulse lavage equipment routinely used as part of the closure.
This study further supports existing literature demonstrating a significant reduction in SSI rates with the use of incisional NPWT. In addition, outcomes in this population suggest that incisional NPWT is cost effective in a general surgery population, particularly in class 3 and 4 wounds. Routine application of incisional NPWT yielded $24,720 of cost savings with class 3 and 4 wounds in this series of 100 patients when compared to contemporary published rates of SSI incidence relative to wound class as well as published estimates of additional costs incurred by SSI. This cost estimate does not account for standard care costs averted by avoiding open wounds, often including dressings and home care expenses. A larger, prospective series looking at class 3 and 4 laparotomy wounds closed with incisional NPWT could more accurately capture SSI rates, improving cost savings estimates and helping to determine whether this technique should be considered a routine part of surgical care in this population.