to the editor: We read with interest the recent article, “Diabetic Foot Ulcers: Pathogenesis and Management,”1 by Dr. Frykberg. While debridement of an ulcer is important to provide a clean wound base conducive to wound granulation and healing, Dr. Frykberg asserts that topical enzymes are ineffective as the sole debridement agent and cautions against soaking ulcers in patients with neuropathy. An effective adjunctive therapy for wound debridement that was not mentioned is maggot therapy.
Several papers2–5 have described the utility of maggot debridement therapy (MDT) for debridement of diabetic foot ulcers, specifically chronic nonhealing ulcers having failed multiple conventional wound therapies. A recent retrospective study2 demonstrated that MDT was more effective for wound debridement of nonhealing lower extremity ulcers compared with conventional therapies, and produced increased amounts of granulation tissue and a more rapid decrease in wound size. A large prospective trial will be necessary to evaluate whether MDT accelerates closure of diabetic lower extremity wounds, but until then available studies and anecdotal reports indicate that MDT can be useful in treating this variety of wound. Importantly, MDT may help reduce the number3 or extent4 of amputations, which is an aim of the “Healthy People 2000” project.2 One study3 reports that in five patients who were referred for leg amputation after multiple surgical and nonsurgical methods failed to heal their wounds, the affected limb was salvaged by MDT without the need for amputation.
The advantage of MDT over sharp debridement is that it generally causes less blood loss. A study6 on the cost effectiveness of MDT compared with a standard hydrogel dressing for the one-month treatment of venous ulcers demonstrated that MDT, in addition to debriding the wounds more quickly, reduced the overall treatment costs by reducing the number of nursing visits, total nursing time and wages, and dressing costs.
The primary disadvantages of MDT are esthetic and wound pain/pruritus, and the latter is treatable with analgesics. Rarely, patients may have influenza-like symptoms, transient pyrexia, or allergic reactions. MDT may be ineffective in treating some diabetic wounds, particularly in patients with severe hypoperfusion.2 Also, wounds where the larvae may be crushed (such as those between the toes or the heel) may make MDT less efficacious, unless patients are specifically instructed to avoid walking or other activities injurious to the maggots. Although larvae employed in MDT typically ingest only necrotic tissue and spare living tissue, wounds involving vital organs, exposed larger caliber blood vessels, and tracheostomies are considered contraindications for larval use by some. But, MDT can be effective in treating some chronic, nonhealing diabetic lower extremity ulcers and should be considered as an adjunctive therapy for this type of wound.
in reply: Drs. Summers and Kaminski correctly mention that maggot debridement therapy is a potential option for the management of diabetic foot ulcers, especially in the presence of necrotic tissue. I have used biodebridement numerous times as an adjunct to sharp debridement. This therapy was not specifically addressed in my article1 because of space constraints, its limited acceptance at the time of publication, and because it is not a particularly suitable treatment regimen for the average family physician. However, it was mentioned as an option in Table 4 of my article1 and was referred to as “biodebridement.” I continue to employ maggot biodebridement therapy in my practice for select patients and await further confirmation of its utility and efficacy with the publication of definitive randomized controlled clinical trials.