New Research Emerges On Benefits Of Ultrasound Use

Pages: 8 - 16
By Brian McCurdy, Associate Editor

Emerging research on the therapeutic and diagnostic uses of ultrasound will be among the abstracts presented at the 17th Annual Symposium on Advanced Wound Care (SAWC) in May. Two of the studies focus on the potential benefits of using ultrasound to assist in treating problematic wounds. Paul Quintavalle, DPM, says there has been an increase of studies in recent years on the use of therapeutic ultrasound in wound healing. “It has been shown to be a safe and potentially effective treatment,” notes Dr. Quintavalle. “It is a widely used modality in Europe, but has not become widely used in the United States.” For one of the SAWC abstracts, “The Use of Low-Frequency Ultrasound in the Treatment of Chronic Foot Ulcerations,” researchers tracked 51 patients with chronic wounds who were treated with the modality. Of the patients studied, 65 percent had diabetes and 20 percent had a history of amputation in addition to ulcers. For the patients who received ultrasound treatment in addition to the standard of care, researchers saw a 93.3 percent reduction in wound size over an average of six weeks. “It appears to have some significant advances for wound healing and wound bed preparation in the studies that we have done,” says study author Steven J. Kavros, DPM. “I think it has a very strong position for people who are dealing with wounds.” “I believe that these statistics represent a relatively quick healing time, indicating that the ultrasound intervention has a positive benefit to wound healing,” notes Dr. Quintavalle. “Although more work needs to be done studying the efficacy of ultrasound treatment, it appears that it can be a valuable adjunct to wound care.” Mary Dyson, PhD, recalls a 1997 study by Peschen, et. al., in which low-frequency ultrasound significantly increased the reduction of 24 chronic venous ulcers. As she explains, the researchers applied ultrasound through water to generate acoustic streaming, which facilitated the removal of superficial necrotic tissue. This technique can be used in place of sharp debridement, according to Dr. Dyson. “The confirmation of the technique as a method of reducing wound size is of clinical value,” says Dr. Dyson. Can Ultrasound Be Beneficial For MRSA And VRE? On that subject, a second SAWC abstract explores using low-frequency ultrasonic wound treatment as an alternative method for wound debridement. The abstract, “Ultrasonic-Assisted Wound Treatment (SONOCA) vs. MRSA and VRE: A Case Series,” notes this modality penetrates into deep tissue with associated microcavitations causing bacterial destruction. As the abstract authors note, low-frequency ultrasound has been used to treat patients with recalcitrant chronic wounds and multiple drug resistant strains of bacteria such as MRSA and VRE. After performing these treatments, the researchers noted that patients who previously had positive cultures for MRSA and VRE infection had negative cultures for such infections following ultrasonic debridement. As Dr. Dyson notes, ultrasound can be bactericidal in vitro. She emphasizes that demonstrating this in vivo with a technique that activates cells involved in healing wounds makes this study potentially one of “considerable clinical significance.” While Dr. Quintavalle believes the modality has “great adjunctive potential” in wound care, he says more controlled animal studies would answer the question of whether ultrasound can reduce a wound’s bacterial load. Tracking The Origin Of Heel Ulcers A third SAWC abstract, “The Use of High-Frequency Ultrasound to Investigate the Pathogenesis of Heel Pressure Ulcers,” tracks 15 patients who were scanned with ultrasound after the application of constant controlled heel pressure for varying time periods. As Dr. Quintavalle notes in his study, high-frequency ultrasound provides microscopic detail of subcutaneous soft tissue. The study offers a timeline that shows the beginning of the patient’s edema, its peak and ends with the resolution of the condition. The technology allows clinicians to detect edema that is localized to the subcutaneous layer before it is apparent in the skin. Dr. Quintavalle notes that tissue damage can occur before clinical signs and this diagnostic tool may help in initiating preventative measures. “This study will allow for a better understanding of the pathogenesis of heel pressure ulcers and demonstrates that by removing pressure, the body can repair damaged tissue before ulcer formation,” notes Dr. Quintavalle in the abstract. Dr. Dyson concurs. In the mid-1990s, she notes that she co-authored a study in which they used high-frequency ultrasound to image edema in the subcutaneous heels of geriatric patients. She says the edema was imaged before they observed nonblanchable erythema. Editor’s Note: The Symposium on Advanced Wound Care will be held May 2-5 at the Disney Coronado Springs Resort in Lake Buena Vista, Fla. For more information, go to Study Reveals The Efficacy Of Linezolid In Treating Diabetic Foot Infections By Brian McCurdy, Associate Editor A recently published study in Clinical Infectious Diseases demonstrates the efficacy of linezolid (Zyvox, Pfizer) in treating diabetic foot infections as compared to standard therapy. The study led to the FDA granting linezolid an indication for diabetic foot infections. It is only the second drug to receive such an indication, according to Benjamin Lipsky, MD, the lead author of the study. The study involved 371 patients in eight countries and was conducted at 45 sites in the United States and Europe. Patients with diabetic foot infections received either linezolid or aminopenicillin-beta lactamase inhibitor. If patients in the non-linezolid group had MRSA, researchers were able to add vancomycin to their treatments, according to the study. Study results showed 81 percent of patients attained a clinical cure with linezolid whereas the combination treatment was effective for 71 percent of patients. According to Dr. Lipsky, linezolid also provided “statistically superior results” among the subset of patients with infected ulcers. These patients comprised approximately 75 percent of the patients in the study. Dr. Lipsky, the Director of the General Internal Medicine and Antibiotic Research Clinics at the VA Puget Sound Health Care System, called that finding a surprise because the study was only statistically powered to demonstrate equivalence between the two therapies. “Because (linezolid) is active against antibiotic-resistant, gram-positive organisms, especially methicillin-resistant Staphylococcus aureus, it has a special place when infection with these bacteria is suspected or proven,” says Dr. Lipsky, a Professor of Medicine at the University of Washington Medical School in Seattle. While there is always a potential for an organism to develop a resistance to any antibiotic, Dr. Lipsky says “very few linezolid-resistant strains have been noted to date and it is difficult to induce resistance to the antibiotic in the laboratory.” However, he cautions that “some believe this agent should be used judiciously in order to prevent the emergence of resistance to this potent anti-gram-positive agent.” New Study Takes Closer Look At Regenerative Tissue Matrix By Brian McCurdy, Associate Editor A new pilot study examines the use of a regenerative tissue matrix to heal wounds. The study, “Effective Management of Lower Extremity Wounds Using an Acellular Regenerative Tissue Matrix: a Pilot Study,” was published recently in Orthopedics and concerns the GraftJacket Tissue Matrix (Wright Medical). The study involved 40 diabetic patients who had full-thickness wounds with an average area of 9.7 cm2. They received conventional therapy or the GraftJacket. After a month, those receiving the GraftJacket showed an 89.1 percent wound depth reduction, compared to 25 percent in the control group, according to the study. In addition to using the GraftJacket to treat wounds, study author Steven F. Boc, DPM, says he uses the product to repair osseous defects and for tendon grafts. He says the GraftJacket is effective for both procedures. An advantage to using the product is there is no need for skin harvesting. The graft is “safe, effective and easy to use,” notes Dr. Boc, the Chairman of the Department of Foot and Ankle Surgery and Director of Residency Training at St. Agnes Medical Center in Philadelphia. He adds that the product facilitates better patient compliance as many patients only need one application, which requires four to six weeks to take. “Pain is diminished exponentially with this type of graft so the patient feels better,” adds Dr. Boc. In Brief A clinical study in Diabetes Care is the second to focus on the Anodyne Therapy System’s efficacy in restoring sensation in neuropathic diabetic patients. According to Anodyne Therapy, the manufacturer of the modality, the study showed that after 12 45-minute treatments, patient sensation improved by 46 percent and pain decreased by 45 percent. Organogenesis Inc. has announced that Medicare has nearly doubled what it will pay for Apligraf. The payment will increase from $680 to $1,199 per treatment. Etonic Athletic Worldwide is forging a partnership with the American Diabetes Association (ADA) and estimates the partnership will generate over $250,000 to benefit those with diabetes and increase awareness. Etonic is also introducing its ProHealth Walker walking shoe and will team with national retailers to donate $1 per pair of shoes to the ADA. Stratus Pharmaceuticals, Inc. has received a five-year contract with the Veterans Administration for all company products, including papain and urea debriding ointments Kovia and Ziox. Smith and Nephew has acquired HydroCision’s VersaJet surgical debridement product. VersaJet is a specialized fluid instrument that was launched in January 2003.

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