Comparison of negative pressure wound therapy with an ultraportable mechanically powered device vs. traditional electrically powered device for the treatment of chronic lower extremity ulcers: a multicenter randomized-controlled trial.

The purpose of this study was to compare the ultraportable mechanically powered Smart Negative Pressure (SNaP(®)) Wound Care System to the traditional electrically powered Vacuum-Assisted Closure (VAC(®)) Therapy System in the treatment of chronic lower extremity wounds. This 12-center randomized-controlled trial of patients with noninfected, nonischemic, nonplantar lower extremity wounds had enrolled 65 patients, as of January 5, 2010, at the time of a planned interim analysis. Subjects were randomly assigned to treatment with either the SNaP(®) or VAC(®) Systems. The trial evaluated treatment for up to 16 weeks or till complete closure was achieved. Fifty-three patients (N=27 SNaP(®), N=26 VAC(®)) completed at least 4 weeks of therapy. Thirty-three patients (N=18 SNaP(®), N=15 VAC(®)) completed the study with either healing or 16 weeks of therapy. At the time of planned interim analysis, no significant differences (p=0.99) in the proportion of subjects healed between the two devices evaluated were found. In addition, the percent wound size reduction between treatment groups was not significantly different at 4, 8, 12, and 16 weeks, with noninferiority analysis at 4 weeks of treatment reaching the p-value <0.05 significance level (*p=0.019). These interim data suggest no difference in wound closure between the SNaP(®) System and the VAC(®) System in the population studied. We look forward to the final analysis results.