Ultrasound for cutaneous wound healing

Clinical bottom line: Clinical bottom line: based on limited information, there is evidence to suggest that ultrasound improves healing in cutaneous wounds including leg ulcers. More trials of better quality are required to assess the degree of benefit, and to establish whether ultrasound is of benefit for healing pressure sores.

Ultrasound has been used for a range of conditions including tennis elbow, wound healing and herpes infections. Its main effect is to generate heat within the tissues. Postulated therapeutic mechanisms include increased blood flow to the treated areas, possibly mediated through its thermal action; stimulation of fibroblasts and macrophages; stimulation of angiogenesis; bactericidal effects and enhanced permeability of biological membranes.

Systematic review:

Ernst E. Ultrasound for cutaneous wound healing. Phlebology 1995; 10:2-4.

Date review completed: 1994

Number of trials included: 5

Number of patients: approximately 80 randomised, double-blinded patients

Control groups: sham ultrasound / no ultrasound

Main outcomes: wound size, time to heal

Inclusion criteria were controlled trials of ultrasound for wound healing. Reviewers provided a descriptive summary of included trials.

Findings:

Randomised, double blind trials

Two of three trials showed significant benefit of ultrasound. The two positive trials compared ultrasound with sham ultrasound: one trial of 38 leg ulcer patients who received 12 sessions of 5 to 10 minutes of 1 W/cm2 showed 25% decrease in wound size, and the second trial using a similar treatment schedule for patients with ulcus cruris showed faster wound healing. It was unclear whether this trial was randomised. Reviewers note that the first trial had methodological weaknesses, and the second was very small. The negative trial of 40 patients with pressure sores looked at the effects of 5 minute sessions of ultrasound (0.8 W/cm2) three times per week. Reviewers and authors noted that the 4 week outcome would require 1000 patients to show significant benefit of ultrasound.

Controlled clinical trials

The remaining two trials were of weaker design. One trial of 56 chronic leg ulcer patients (mostly of venous aetiology) compared standard therapy of bandages with once weekly sessions of 0.5 W/cm2 of ultrasound with bandages alone. At 12 weeks there were significantly more healed ulcers and significantly smaller ulcers in the ultrasound group. One small open trial looking at pressure sores (trial details not given) showed no difference from control. However, as well as being of poor methodology, this trial was also very small.

This review also summarised findings from three experimental animal studies.

Adverse effects

Adverse effects were not covered by this review.

Comment

Not much evidence, and tthat we have is not very encouraging.