Treatment of ischemic wounds with noncontact, low-frequency ultrasound: the Mayo clinic experience, 2004-2006

Abstract

Objective: To evaluate the clinical role of a novel, noncontact, low-intensity, low-frequency ultrasound therapy (MIST Therapy) in the treatment of nonhealing leg and foot ulcers associated with chronic critical limb ischemia.

Design: Prospective, parallel-group, randomized, controlled trial.

Setting: A multidisciplinary, vascular wound-healing clinic.

Patients: Thirty-five patients who received MIST Therapy plus the standard of wound care (treatment group) and 35 patients who received the standard of wound care alone (control group).

Interventions: Standard of wound care alone or standard of wound care plus MIST Therapy for 12 weeks or until fully healed. MIST Therapy was administered 3 times per week for 5 minutes per treatment.

Main outcome measure: Percentage of patients with greater than 50% reduction in wound size from the index measurement after 12 weeks of treatment. The relationship of transcutaneous oximetry pressure in the supine and dependent position was evaluated as a factor in assessing the potential to heal ischemic ulcerations of the foot and leg.

Main results: A significantly higher percentage of patients treated with the standard of care plus MIST Therapy achieved greater than 50% wound healing at 12 weeks than those treated with the standard of care alone (63% vs 29%; P < .001). Thus, failure to achieve the minimum wound healing requirement occurred in 37% of patients in the treatment group and 71% of patients in the control group. The predictive value of baseline transcutaneous oxygen pressure may benefit the clinician when assessing the potential to heal ischemic wounds.

Conclusion: The rate of healing of cutaneous foot and leg ulcerations in patients with chronic critical limb ischemia improved significantly when MIST Therapy was combined with the standard of wound care.