Larval Therapy for Chronic Cutaneous Ulcers

Historical Review and Future Perspectives

Edoardo Raposio, MD, PhD, FICS; Sara Bortolini, MSc, PhD; Lara Maistrello, MSc, PhD; and Donato A. Grasso, MSc, PhD

Disclosures

Wounds. 2017;29(12):367-373. 

In This Article

Past and Current Methods

Larval debridement therapy has been utilized for medical purposes for hundreds, if not thousands, of years and is recorded in ancient folk medicine, such as the Chinese in Yunan, the hill people of Burma, the Aborigines in Australia, and the Mayans in Central America.[3] Since the 1700s, surgeons have documented that the larvae of certain common blow flies or greenbottles (LS) only remove dead tissue while promoting healthy tissue in the wound bed, helping wounds heal faster.[2] The beneficial effects of using larvae in wounds were first noticed by Ambroise Paré in 1557.[5] Dominique-Jean Larrey (1766–1842), another French surgeon, observed that maggots of the blue fly only removed dead tissue and had a positive effect on the remaining healthy tissue during the Egyptian expedition in Syria.[3] The first officially documented application of maggots was performed by John Forney Zacharias (1837–1901), a surgeon from Maryland during the American Civil War (1861–1865).[3] Later, William Baer refined the technique by using sterile maggots to prevent maggot-induced wound infection.[5] The therapy became increasingly popular and was widely used for the treatment of infected or chronic wounds across Europe and North America during the 1930s.[3]

Mechanism of action. Experiments performed by Barnes et al[6] have demonstrated that LS excretions/secretions are able to inhibit bacteria growth in both stationary and exponential phases. For these reasons, maggot debridement was approved by the US Food and Drug Administration in 2004.[5]

Prete[7] demonstrated that hemolymph and alimentary secretions of larvae were growth stimulatory for in vitro human fibroblasts. Both factors increased the proliferation of fibroblasts stimulated by epidermal growth factor or interleukin 6. Clinical observations provided evidence for growth stimulation in chronic wounds.[8]

Lucilia sericata larvae digest necrotic tissue and pathogens (Figure 1); they discriminate between necrotic and healthy (granulating) tissue. This technique is rapid and selective, although some of the evidence to support its use is still derived from anecdotal reports.[9] Depending on the size and depth of the wound, 50 to 1000 sterile maggots, about 24 to 48 hours old, are applied 2 to 4 times per week and left on for a period of 24 to 72 hours.[5] Several papers have described the utility of maggot debridement therapy,[10–22] though there is only 1 randomized, specific LS clinical debridement trial using maggot therapy.[23] Clinical studies have demonstrated maggot therapy to be safe and effective in patients both with and without diabetes and for many problematic wounds, including pressure ulcers, venous stasis leg ulcers, wound bed preparation prior to surgical closure, and a variety of other traumatic, infectious, and vascular wounds.[24–39]

Figure 1.

Chronic cutaneous ulcer of the lower limb with Lucilia sericata larvae.

Wayman et al[40] compared the cost of larval therapy with hydrogel dressings in the treatment of necrotic venous ulcers. Twelve patients with sloughy venous ulcers were randomized to receive either larval therapy or the control hydrogel therapy. Effective debridement occurred with a maximum of 1 larval application in all 6 experimental patients; 2 of the 6 hydrogel patients still required dressings at 1 month. The median cost of treatment of the larval group was £78.64 compared with £136.23 for the control group (P < .05). Thus, this study confirmed both the clinical efficacy and cost effectiveness of larval therapy in the debridement of sloughy venous ulcers.[40]

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