Investigating Ultrasound Debridement in Wound Care

The initial step of wound management, debridement, is thought to be critical in promoting wound healing. Of the numerous debridement modalities, ultrasound seems to hold promising results in accelerate healing in our own clinical experience here at St. Michael's Hospital. In brief, ultrasound debridement is a method of removing devitalized tissue through microstreaming and cavitational effects. The non-thermal energy up-regulates cellular activity and promotes growth factor and protein synthesis, fibrinolysis, and is anti-bacterial . The technology selectively emulsifies dead and dying tissues with micro-sized gas bubbles, stimulates membranes of surrounding healthy cells, and renders bacteria more susceptible to antibiotic treatment. Thus, in addition to creating an optimal environment, the modality also serves to promote the process of healing. A systematic review and meta-analysis by Voigt et al. (2011) examined the use of low-frequency (20-30 kHz) ultrasound in randomized-controlled trials. It was found that low or high-intensity delivery of low-frequency ultrasound both promoted early healing in lower-extremity wounds. At St. Michael's Hospital, ultrasound debridement is already being used in the wound clinic with promising results. However, objective comparisons need to be made to validate our clinical observations. The goal of the proposed pilot study is to assess the feasibility of our current study design. The information gathered will allow us to refine the research methodology for the development of a larger-scale study.

Ultrasound debridement is a method of removing devitalized tissue through microstreaming and cavitational effects. The non-thermal energy up-regulates cell activity and promotes growth factor and protein synthesis, fibrinolysis, and is anti-bacterial. The technology selectively emulsifies dead and dying tissues with micro-sized gas bubbles, stimulates membranes of surrounding healthy cells, and render bacteria more susceptible to antibiotic treatment. Thus, in addition to creating an optimal environment, the modality also serves to promote the process of healing. At St. Michael's Hospital, ultrasound debridement is already being used in the wound clinic with promising results. However, objective comparisons need to be made to quantify and qualify our clinical observations. The goal of the proposed pilot study is to assess feasibility of our current study design and allow us to refine the research methodology for the development of a larger-scale study.

Eligibility Criteria:
Inclusion Criteria:

1. Subjects with chronic (\>4 week duration) lower extremity wound (of any etiology) that have failed to improve despite using the clinic's standard approach for wound care during a 2-week period (Failure to improve is defined as less than 15% reduction in wound area)

Exclusion Criteria:

1. Subjects with clinical evidence of wound infection
2. Subjects with thick eschar that has not been removed
3. Subjects with severe arterial insufficiency: Absence of pedal pulses, Ankle Brachial Index \< 0.3, Toe Pressure \< 20
4. Subjects who are receiving advanced wound therapy treatment: hyperbaric therapy, biological dressings
5. Subjects who are taking antibiotics
6. Subjects who are using systemic steroids
7. Subjects who have known contraindication to the dressing product (Acticoat®)
8. Subjects who are not able to adhere to dressing change protocol or hospital visits
9. Subjects with wound area reduction of \> 15% during the initial two-week standard care period.
10. Subjects without sufficient English language proficiency to understand the consent form.