As its name suggests, maggot therapy (also known as larval therapy) is a natural technique for treating wounds that involves the use of small, live larvae. This ancient method has shown significant results on wounds that are slow to heal. Less painful than conventional treatments performed with a scalpel by a healthcare professional, maggot therapy is increasingly used in the medical field. Their use often helps to avoid more extensive and painful surgery.
Christian Riesen, a nurse specialized in wound care and healing, introduced this technique at the ASSAL Centre in 2018. He explains to us in more detail what it involves.
What is maggot therapy and how can maggots help heal wounds?
The larvae of the Lucilia sericata fly have been used in forensic medicine for many years. These flies lay their eggs on corpses so that the larvae can feed immediately upon hatching. In nature, once they’ve hatched, the larvae leave their birthplace to find a dry place where they can form a cocoon and eventually become flies. The different stages of their development make it possible to estimate the time of death of their host.
As for wound treatment, they are used from birth and during the first 4 to 5 days of their life, during which they feed in order to reach their “adult” size.
They secrete an enzyme that "liquefies" the devitalized tissues (extracorporeal digestion), which they then absorb. At the same time, they secrete a kind of "natural antibiotic" to avoid being poisoned by the germs present in the dead tissue.
It is thanks to this natural process that we use the larvae of the Lucilia sericata fly to clean and treat wounds until they are healed.
When we talk about larvae or maggots, we usually think of something unhygienic. Are the larvae used the same as those we find in our trash?
No, these are fly larvae that are bred and produced exclusively in a sterile environment under the supervision of the company Entomos, based in Oberentfelden in the canton of Aargau. The larvae are produced in accordance with very strict hygiene regulations and are intended solely for medical use. The process is monitored and complies with federal standards.
They are recognized as a method of wound treatment (just like a dressing or ointment), and the therapy is listed and referenced in the LiMA (List of Medical Aids and Devices). As a result, this therapy is recognized and reimbursed by insurance companies.
On what type of wounds is maggot therapy used?
Technically, we can use it on all types of wounds, except for a few restrictions related to specific cases (tumors, exposed arteries or risk of bleeding, dry necrosis).
However, the wounds must be "to be cleaned" wounds. In fact, larvae are not used on clean wounds that are healing properly.
There are no real contraindications or known harmful side effects.
Are the maggots placed directly on the wound? Isn’t there a risk that they might escape?
There are two possible methods:
– Maggots in a pouch: we measure the wound (length x width) and receive a sealed pouch corresponding to the surface area of the wound, from a minimum of 2x2 cm to a maximum of 10x10 cm.
– Free-range maggots: we take the same measurements and receive the maggots loose, then prepare a special dressing.
In both cases, as a general rule, there is no possibility of "escape" and no health risk.
How do patients feel about this method?
There is no "general rule." As with any therapy, it is important to discuss the advantages and disadvantages of the proposed treatment with the patient and to provide alternatives. If the patient's situation is suitable for the use of larvae, then I do not hesitate to offer this option.
Some patients are indeed reluctant, while others are curious and ask a lot of questions. In general, many patients are enthusiastic about the idea that we are open to a natural and alternative therapy.
Patients who have used this method are generally satisfied with the process and would do it again if necessary.
Is it a painful technique?
As with any therapy, there is always an element of uncertainty in how the patient will react, and it depends on each individual situation.
As explained earlier, the larvae use enzymes to perform extracorporeal digestion, which allows them to destroy and remove only the dead tissue using a gentle and selective method. They do not "nibble" at the wound and, as a result, the patient does not feel any "biting."
Some patients feel the movement of the larvae inside the dressing but without experiencing any pain. This sensation is not particularly intense and does not prevent them from going about their normal activities.
In retrospect, based on the many treatments carried out in our Centre, we can say that overall, the therapy was well tolerated by our patients. In some cases, adjustments to pain management were necessary (such as introducing a pain reliever like Dafalgan, for example).
Overall, patients say that this technique is less painful than debridement with a scalpel, for example.
How long does a course of maggot therapy last, and can the patient continue to walk during this period?
The larvae are usually applied on Tuesday and removed on Friday (4–5 days of treatment). Another session can be scheduled for the following Tuesday, and so on. As long as the wound is not completely cleaned, the treatment can be repeated.
However, the activity of the larvae increases wound drainage and sometimes requires more frequent care or follow-up visits at the clinic.
For the patient, there are few instructions, but the main one is to avoid putting any weight on the treated area. Since the maggots are alive, if the patient presses on or hits the area hard, it will simply kill the larvae and the treatment will no longer be effective.
This is especially important during rest or sleep—to avoid lying on the treated area. That being said, most patients have no trouble following this instruction: even without larvae, putting pressure on a wound is still uncomfortable.
We avoid treating weight-bearing areas, such as the heel, with this method unless complete off-loading of the area can be ensured.
What happens to the larvae once their work is done?
The larvae are disposed of as medical waste, since they are sometimes in contact with infected wounds.
