Letters to the Editor

Maggot Debridement Therapy for Diabetic Necrotic Foot

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 papers^2-5 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.

JAMES BRADLEY SUMMERS, M.S., M.D.
University of South Alabama
P.O. Box 16343
Mobile, AL 36616

JOSEPH KAMINSKI, M.D.
Medical College of Georgia
1120 15th St.
Augusta, GA 30912

REFERENCES

1. Frykberg RG. Diabetic foot ulcers: pathogenesis and management. Am Fam Physician 2002;66: 1655-62.
2. Sherman RA. Maggot therapy for treating diabetic foot ulcers unresponsive to conventional therapy. Diabetes Care 2003;26:446-51.
3. Mumcuoglu KY, Ingber A, Gilead L, Stessman J, Friedmann R, Schulman H, et al. Maggot therapy for the treatment of diabetic foot ulcers. Diabetes Care 1998;21:2030-1.
4. Knowles A, Findlow A, Jackson N. Management of a diabetic foot ulcer using larval therapy. Nurs Stand 2001;16:73-6.
5. Rayman A, Stansfield G, Woollard T, Mackie A, Rayman G. Use of larvae in the treatment of the diabetic necrotic foot. Diabetic Foot 1998;1:7-13.
6. Wayman J, Nirojogi V, Walker A, Sowinski A, Walker MA. The cost effectiveness of larval therapy in venous ulcers. J Tissue Viability 2000;10:91-4.

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.

ROBERT G. FRYKBERG, D.P.M., M.P.H.
Des Moines University
3200 Grand Ave.
Des Moines, IA 50312

REFERENCE

1. Frykberg RG. Diabetic foot ulcers: pathogenesis and management. Am Fam Physician 2002;66: 1655-62.

Correction

The article "The Nature and Management of Labor Pain: Part 1. Nonpharmacologic Pain Relief" (September 15, 2003, page 1109) contained an error in the series editor attribution. The article is one in a series coordinated by the University of Utah School of Medicine, Salt Lake City. Guest editor of the series is Stephen Ratcliffe, M.D., M.S.P.H.

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