High Frequency and Noncontact Low Frequency Ultrasound Therapy for Venous Leg Ulcer Treatment: a Randomized Controlled Study

Background:

Ultrasound therapy can be utilized to manage chronic wounds including venous leg ulcers (VLUs).

Objectives:

A randomized controlled clinical study was conducted to compare the effectiveness of standard treatment and standard treatment plus either high frequency ultrasound (HFU) or noncontact low-frequency ultrasound (NCLFU) on VLU outcomes.

Patients and Methods:

Ninety outpatients (47 men, 43 women; average age, 38.3 [SD, 11.5] years) were randomly assigned into either of the standard care (n = 30), HFU (n = 30) or NCLFU groups (n = 30). Standard care included multilayered compression bandaging (40 mm Hg of pressure at the ankle graduated to 17 mm Hg to 20 mm Hg below the knee) nonadherent dressing and regular debridement. Standard care dressing changes and ultrasound therapy were provided three times per week for 3 months or until healing. HFU delivers high intensity (0.5 1 W/cm²) high frequency (1 3 MHz) ultrasound for 5 to 10 minutes and NCLFU delivers low-intensity (0.1 0.8 W/cm2) low frequency (40 kHz) ultrasound for 4-10 minutes. Patients were followed until healing. Wound size wound pain and lower leg edema was assessed at baseline and after 2 and 4 months. Data were analyzed using Student's t test ANOVA, chi square or Fisher s exact test. P value of less than 0.05 was considered significant.

Results:

Initial wound measurements were 9.60 cm² (SD 5.54) 9.86 cm2 (SD 3.95) and 10.01 cm² (SD 4.58) for the standard treatment HFU and NCLFU groups respectively. After 4 months measurements were reduced to 4.28 cm² (SD 2.80) 3.23 cm² (SD 2.39) and 2.72 cm² (SD 2.16) for the standard treatment HFU and NCLFU groups respectively which was statistically significant (P = 0.04). All wounds were healed after an average of 8.50 (SD 2.17) 6.86 (SD 2.04) and 6.65 (SD 1.59) months in the standard treatment, HFU and NCLFU groups respectively (P = 0.001). Differences in the amount of edema and pain rating scores were also significant at the 4th month follow up visit (P = 0.05).

Conclusions:

Outcomes of both methods of ultrasound therapy were better than standard care alone, and some differences between the two ultrasound therapy groups were observed, but they were not statistically significant.