Expedited wound healing with noncontact, low-frequency ultrasound therapy in chronic wounds: a retrospective analysis.

OBJECTIVE To evaluate the clinical role of noncontact, low-frequency ultrasound therapy (MIST Therapy System; Celleration, Eden Prairie, Minnesota) in the treatment of chronic lower-extremity wounds. DESIGN A retrospective observational study. SETTING A multidisciplinary, vascular wound-healing clinic. PATIENTS One hundred sixty-three patients who received MIST Therapy plus standard of care (treatment group) and 47 patients who received the standard of care alone (control group). INTERVENTIONS All wounds in the control and treatment groups received the standard of wound care and were followed for 6 months. In the treatment group, MIST Therapy was administered to wounds 3 times per week for 90 days or until healed. MAIN OUTCOME MEASURES Proportion of wounds healed and wound volume reduction. Rate of healing was also quantified using 1-way analysis of variance to determine the slope of the regression line from starting volume to ending volume, where a steeper slope indicates a faster healing rate. Outcomes were evaluated in all wounds and etiology-specific subgroups. MAIN RESULTS A significantly greater percentage of wounds treated with MIST Therapy and standard of care healed as compared with those treated with the standard of care alone (53% vs 32%; P = 0.009). The slope of the regression line in the MIST arm (1.4) was steeper than the slope in the control arm (0.22; P = .002), indicating a faster rate of healing in the MIST-treated wounds. CONCLUSION The rate of healing and complete closure of chronic wounds in patients improved significantly when MIST Therapy was combined with standard wound care.