Maggot Therapy for Treating Diabetic Foot Ulcers Unresponsive to Conventional Therapy
Maggot Therapy for Treating Diabetic Foot Ulcers Unresponsive to Conventional Therapy
Received for publication 14 January 2002 and accepted in revised form 1 November 2002.
Ronald A. Sherman, MD, MSC
Diabetes Care
© 2003 by the American Diabetes Association, Inc.
From the Veterans Affairs Medical Center, Long Beach, California and the Department of Medicine, University of California, Irvine, California
ABSTRACT
OBJECTIVE—To assess the efficacy of maggot therapy for treating foot and leg ulcers in diabetic patients failing conventional therapy.
RESEARCH DESIGN AND METHODS—Retrospective comparison of changes in necrotic and total surface area of chronic wounds treated with either maggot therapy or standard (control) surgical or nonsurgical therapy.
RESULTS—In this cohort of 18 patients with 20 nonhealing ulcers, six wounds were treated with conventional therapy, six with maggot therapy, and eight with conventional therapy first, then maggot therapy. Repeated measures ANOVA indicated no significant change in necrotic tissue, except when factoring for treatment (F [1.7, 34] = 5.27, P = 0.013). During the first 14 days of conventional therapy, there was no significant debridement of necrotic tissue; during the same period with maggot therapy, necrotic tissue decreased by an average of 4.1 cm2 (P = 0.02). After 5 weeks of therapy, conventionally treated wounds were still covered with necrotic tissue over 33% of their surface, whereas after only 4 weeks of therapy maggot-treated wounds were completely debrided (P = 0.001). Maggot therapy was also associated with hastened growth of granulation tissue and greater wound healing rates.
CONCLUSIONS—Maggot therapy was more effective and efficient in debriding nonhealing foot and leg ulcers in male diabetic veterans than was continued conventional care.
Abbreviations: MDT, maggot debridement therapy
INTRODUCTION
Impaired wound healing is a common and costly problem for those with diabetes. Nonhealing diabetic foot ulcers account for 25–50% of all diabetic hospital admissions, and most of the 60,000–70,000 yearly amputations in the U.S. (1,2). Almost 15% of all diabetic patients will develop one or more foot ulcers, and 15–25% of those ultimately will require amputation (2). It is no wonder that one of the disease prevention objectives outlined in the "Healthy People 2000" project was a 40% reduction in the amputation rate for diabetic patients. That objective has not been met (3), despite many advances in wound care.
We evaluated the efficacy of an unconventional but simple treatment, long acclaimed as an effective last resort: maggot therapy. For 70 years, maggot therapy has been recognized as an aid in debridement and wound healing (4–6). Medicinal maggots secrete digestive enzymes that selectively dissolve necrotic tissue (7), disinfect the wound (8–10), and stimulate wound healing (11–13). During the 1930s, maggot debridement therapy (MDT) was routinely used in hundreds of hospitals around the world for treating bone and soft-tissue infections (14). With the introduction of antibiotics and other improvements in wound care, by the 1960s maggot therapy was used only as salvage therapy for the most serious wounds.
Over the past few years, there has been a resurgence in the use of maggot therapy (15), even though its optimal role has not been clearly defined. Large prospective clinical trials have not been conducted for maggot therapy, and there are no commercial backers to support such studies. To assess the utility of maggot therapy, we analyzed the clinical course and outcomes of a cohort of diabetic patients whose foot and leg ulcers were treated with conventional (control) or maggot therapy.
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