Biological debridement: maggots

Abstract

Biological debridement: maggots M Jones (UK) When the orthopaedic surgeon William S. Baer presented his method and results of maggot therapy in 19311 his focus of interest was bone and soft tissue infection. Later, it was mainly the work of Ronald Sherman which enlarged the scope of indications to chronic wounds, like stasis ulcers and bed sores2 Presently, clinical emphasis is put to the problem of impaired wound healing as found in diabetic patients3 Maggots secrete digestive juices into the wound which contain growth factors, antiseptic substances and proteases. The high proteolytic activity liquefies necrotic tissue, which is the main food source of maggots4. Clinically, there is an effective, atraumatic debridement of the wound and contaminating bacteria are removed as well as dead tissue. Maggots may either be applied directly to the wound surface or enclosed in a porous pouch, so that there is only a fluid but not a physical contact to the wound. With regard to patients' comfort, ease of maggot application, hygiene and aesthetics the maggot pouch dressing revolutionizes maggot therapy5 In superficial defect wounds like stasis and diabetic ulcers or some bed sores mechanical macro-debridement (scalpel etc.) should be performed as a first measure, mainly to accelerate healing and reduce costs of treatment. Maggots are then used for microdebridement and as an antiseptic agent. In deep soft tissue and bone infections the septic focus is either completely removed by surgery or extensively exposed by tissue incisions or excisions to give maggots and their secretions enough space to do their work. To prevent suffocation of maggots when put into deep wounds either textile spacers or polyvinyl-alcohol sponges are introduced to keep the wound edges apart. Profuse wound secretions need to be drawn off with drainage systems. To enhance the survival rate of maggots in particularly deep wounds special drains for ventilation purposes may be necessary. Having achieved a clean, healing wound by maggot therapy vacuum dressings may be applied for acceleration of wound healing and external skin expansion for rapid closure of remaining wound defects (Concept of Biosurgical-Mechanical Wound treatment, BMW). Maggots are an excellent low-risk tool for the therapy of necrotic, infected and chronic wounds, given that it is embedded in an effective concept of interdisciplinary wound management.