RESUMO
Low-frequency ultrasound may facilitate debridement and healing of chronic wounds, including lower leg wounds in patients with chronic venous insufficiency (CVI). To evaluate the use of a low-frequency ultrasound (LFU) device with a curette, two patients with CVI and chronic wounds were treated for a period of 2 to 3 weeks. A 63-year-old woman with rheumatoid arthritis and two wounds, one on the right lower leg (250 cm³) and one wound on the left medial leg (0.80 cm³), present for 12 months; and a 77-year-old man with cardiopulmonary issues with seven wounds, three on the left medial calf (1.2 cm³, 11.40 cm³, and 0.72 cm³), one on the left anterior calf (0.30 cm³), two on the right posterior calf (0.90 cm³, 0.30 cm³), and one on the right anterior calf (0.14 cm³), present for 3 months consented to participate in the study. Both patients received low-intensity (50-70 µm), low-frequency (35 kHz) ultrasound at an intensity of 50% through a saline mist in addition to antimicrobial dressing with silver, a multilayer compression bandage system applied at every visit, and pain medication as needed. Both patients received treatments every 1 to 3 weeks that were not timed. Treatment continued until no additional slough or other necrotic tissue could be removed from the wound bed; the female patient received two treatment sessions and the male received three. Average wound volume did not change significantly from the first to last treatment session (t(8)-1.2, P = 0.26). Five wounds (56%) with initial measurements of 0.8 cm³, 0.72 cm³, 0.3 cm³, 0.3 cm³, and 0.14 cm³ reduced in volume by 100%. Mean wound characteristic scores changed significantly (P <0.05) for amount of fibrin, periwound skin, drainage amount, and color. In addition, the number of wounds filled with slough decreased from 89% at the first session to 22% at the final treatment session. The results of this study suggest LFU may have been beneficial for these patients with CVI. Additional studies using larger sample sizes are needed to evaluate the effect of this treatment on a variety of chronic wounds and to compare its effectiveness to other debridement methods.