Rosalyn Jordan, RN, BSN, MSc, CWOCN, WCC

I have a colleague who would like to trial maggot therapy. Can you provide some information about it?

Larval (maggot) therapy is a form of biological debridement used to remove non-viable tissue in a wound. Historically, larvae were used for debridement between World War I until the 1940s, when the availability of antibiotics emerged. In the 1990s, larval therapy use reappeared because antibiotic-resistant bacteria increased rampantly.

There are three processes medical larvae provide to address wound healing: debridement, disinfection and tissue growth promotion. The medicinal larvae are grown in a sterile, controlled environment. Some manufacturers provide the larvae in a pouch-like medium to place in the wound bed while others supply larvae that are applied directly.

Maggot larvae secrete a proteolytic enzyme that helps break down the devitalized tissue and then they debride the tissue by ingestion. The action of the larvae provide both enzymatic and actual physical debridement.

Disinfection provides an important antimicrobial effect on the bacteria in the wound bed and the pathogen is killed in the maggot gut. The larvae also secrete antimicrobial solutions directly on the wound bed. Tissue growth leading to wound healing is promoted by cellular proliferation, enhanced epithelial migration and increased local perfusion. 

Indications for use are debridement of non-healing necrotic wounds. This includes pressure ulcers, venous stasis ulcers, neuropathic foot ulcers and traumatic or post-surgical wounds.

Contraindications include exposed blood vessels, life threatening acute infection, wounds that must be visualized often, infection of a limb that may require an amputation, necrotic bone or tendon, bleeding, circulatory impairment that would not promote healing, and pain.