Healing Rate of Chronic and Subacute Lower Extremity Ulcers Treated With Contact Ultrasound Followed by Noncontact...

Contact and noncontact ultrasounds are types of low-frequency ultrasonic treatments for wound care.

The purpose of this research was to collect data in order to see if healing rates are accelerated when both forms of ultrasound therapies are utilized.

The Viana-Pompeo (VIP) Ultrasound Protocol consists of high-intensity, low-frequency, contact ultrasound therapy followed by low-intensity, low-frequency, noncontact ultrasound therapy. A total of 11 subjects with a total of 24 chronic or subacute lower extremity wounds were enrolled in the study. Of the 11 subjects, 6 finished the protocol (12 wounds). All subjects started with contact ultrasound for debridement at a frequency of 25 kHz and at the maximum intensity the subject could tolerate (equipment range, 20%-100% of 1.0 W/cm²). Once the wound was sufficiently clean with ≤ 20% of necrotic tissue or adherent slough, therapy was switched to noncontact, low-frequency ultrasound (NLFU) for cellular stimulation at 40 kHz and intensities of 0.1 W/cm² to 0.5 W/cm². Subjects received ultrasound treatment 3 times weekly for the 12-week study. Progress was analyzed based on reductions in wound area, volume, and slough and increases in granulation and epithelialization. Wounds were divided into 2 groups: group A, wound duration between 4 and 21 weeks; and group B, wound duration ≥ 47 weeks. There were no wounds between 21 and 47 weeks.

In group A (4 wounds), all wounds improved in wound area and epithelialization; 75% achieved an improvement of > 99% before or at 12 weeks of treatment. In addition, all wounds saw a wound volume reduction of 93% to 100%. Granulation in group A was 100%, and by visit 10 of 36, all wounds had 0% slough or eschar. In group B (8 wounds), 50% of wounds improved with a wound volume reduction of 50%; all wounds increased in granulation, with 50% achieving 75% to 100% granulation. Sixty-two percent of wounds in group B saw an increase in epithelialization, and 75% of wounds had 85% to 100% reduction in slough and eschar by the last visit (end of week 12). There was a strong positive correlation between wound age and healing time (r = 0.94).

Both groups benefited from the VIP Protocol, which promoted wound closure or wound bed preparation for graft. The results seem to favor an earlier start of the protocol for best outcomes and indicate that contact and noncontact ultrasound therapies are not exclusionary but rather complementary.