The biobag - a new device for the application of medicinal maggots.

In the issue of Lancet of September 30, 2000, Bonn presented a concise update on the current use and benefit of maggots in wound therapy [1]. To improve the acceptance of live maggots, facilitate their use and avoid physical discomfort, we have recently introduced the Biobag [2] (fig. 1A). Live larvae are enclosed between two 0.5-mm-thin layers of a polyvinylalcohol hydrosponge, which are heat sealed over a small cube of spacer material to form a bag. The thin membranes of the porous dressing are permeable enough for wound fluids and liquefied necrotic tissue components to enter and support the survival and nourishment of the larvae (fig. 1B). At the same time, the larval secretions pass through the Biobag to debride the wound, stimulate wound healing and control infection. Larvae cannot escape from the Biobag, a condition which is essential for hospital hygiene. The patients’ and physicians’ acceptance of maggots seems to be higher as they are hidden from view. In addition, the device can be moved during therapy facilitating a more focused and controlled treatment of the infected area. Since their first use in June 2000, Biobags have been applied nearly 1,000 times to more than 200 patients in our outpatient department and the hospital’s wards. It may be noted that approximately 50 centers in North America, 400 in the UK, more than 140 in Germany and many more elsewhere in the world include maggot therapy as an option for treatment in wound care and could profit from the Biobag [3]. For the treatment of diabetic ulcers, e.g. malum perforans of long standing, a rapid and safe closure is achieved by the combination of progressive skin stretching with the application of the Biobag for the prevention of infection. Over centuries, the beneficial effects of maggot infestation of war wounds to prevent infection have been described, although in modern medicine indications have been restricted exclusively to the treatment of infection. Startling benefits can be expected from the prophylactic use of fly larvae in earthquake or war-stricken parts of the world to substantially reduce mortality resulting from wound infection.