Single Center Prospective Randomized Control Trial on Negative Pressure Wound Therapy for Incisions Following Major Lower-limb Amputation to Reduce Surgical Site Infection

Amputations are common vascular surgery procedures performed on patients with multiple medical comorbidities. Historically, morbidity and mortality following major amputation of the lower extremity in this patient population has been high. Recent studies have cited 30-day mortality rates ranging from 6% to 17%, with greater risk among patients with transfemoral vs transtibial amputation. Postoperative goals after amputation include uncomplicated wound healing and, for appropriate candidates, progression to use of a prosthesis for ambulation or transfer. Perioperative wound complications can be devastating in this already debilitated population and can range from 13% to 40%.

Postoperative wound complications, such as infection, dehiscence, and formation of haematoma or seroma, are common complications of surgical procedures; particularly among patients with risk factors such as obesity and diabetes. Wound complications may delay recovery, increase patient discomfort and reduce overall quality of life. Increased healthcare costs may be incurred due to prolonged inpatient stay, repeat surgery and the need for increased follow-up.

Wounds that are secondary to amputation are reported in 13-40% of cases and are one of the most challenging types of lower extremity wounds to heal. These patients often have compromised healing capacity. Kayssi et al studied Canadian readmission rates, early (<30 days) and late (30-365) readmissions were attributed to stump complications in 13% and 10% of patients respectively.

Wound complications in major limb amputation frequently result in the need for further major surgery in a group of patients with significant co-morbidity and enhanced operative risk. 1, 3, and 5 year reamputation rates for diabetics who have had major amputations are 4.7%, 11.8%, and 13.3% respectively. Henry et al suggested that undergoing multiple amputation revisions may indicate aggressive measures to treat critical limb ischemia or chronic infection that precede conversion to a more proximal amputation. Kono et al studied the incidence and risk factors for reamputation after forefoot amputation. They found that 16/116 (14%) patients developed postoperative infection, and 10 of these required reamputation (62.5%). Five of the ten reamputations occurred within 30 days after the patients developed postoperative infections.

In addition to the morbidity from infection there is also an increased rate of phantom pain as well as a delay to mobilisation with prosthesis. Minimizing postoperative infections would likely have improvements in clinical outcomes, quality of life, and utilization of resources. Currently, all patients are given prophylactic broad spectrum antibiotics to reduce the incidence of wound infection. Sadat et al investigated whether a prolonged 5 day course of antibiotics wound reduce stump infections, their results were positive however this treatment is associated with the increased risk of antimicrobial resistance and c. difficile infection.