Abstract

Objective: To evaluate the probability of wound healing based on percent wound area reduction (PWAR) at one week and 4 weeks in persons with large, chronic, non-ischemic diabetic foot wounds following partial foot amputation.

Methods: Data from a 16-week randomized clinical trial (RCT) of 162 patients were analyzed to compare outcomes associated with Negative Pressure Wound Therapy delivered through the VAC Therapy System (KCI USA San Antonio, TX) (NPWT) (n=77) versus standard moist wound therapy (MWT) (n=85). One and 4-week regression models included 153 and 129 of the RCT patients, respectively.

Results: Early changes in PWAR were predictive of final healing at 16 weeks. Specifically, wounds that reached ≥15% PWAR at one week or ≥60% PWAR at four weeks had a 68% and 77% (respectively) probability of healing versus 31% and 30% (respectively) if these wound area reductions were not achieved. Patients receiving NPWT were 2.5 times more likely to achieve both a 15% PWAR at one week and 60% area reduction at one month (odds ratio = 2.51 and 2.49, respectively) compared to MWT.

Conclusion: Results of this study suggest that clinicians can calculate the PWAR of a wound as early as week one of treatment to predict the likelihood of healing at 16 weeks. This might also assist in identifying a rationale to re-evaluate the wound and change wound therapies.