Prediction of healing for postoperative diabetic foot wounds based on early wound area progression

OBJECTIVE - To evaluate the probability of wound healing based on percentage of wound area reduction (PWAR) at 1 and 4 weeks in individuals with large, chronic, nonischemic 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 (NPWT) delivered through the V.A.C. Therapy System (Kinetic Concepts, San Antonio, TX) (n=77) versus standard moist wound therapy (MWT) (n=85). The 1- 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 1 week or ≥60% PWAR at 4 weeks had a 68 and 77% (respectively) probability of healing vs. a 31 and 30% probability if these wound area reductions were not achieved. Patients receiving NPWT were 2.5 times more likely to achieve both a 15% PWAR at 1 week and a 60% area reduction at 1 month (odds ratios 2.51 and 2.49, respectively) compared with those receiving MWT. CONCLUSION - Results of this study suggest that clinicians can calculate the PWAR of a wound as early as 1 week into treatment to predict the likelihood of healing at 16 weeks. This might also assist in identifying a rationale to reevaluate the wound and change wound therapies.