5 questions--and answers--about maggot debridement therapy

A molecular approach to maggot debridement therapy with Lucilia sericata and its excretions/secretions in wound healing

Chronic wounds caused by underlying physiological causes such as diabetic wounds, pressure ulcers, venous leg ulcers and infected wounds affect a significant portion of the population. In order to treat chronic wounds, a strong debridement, removal of necrotic tissue, elimination of infection and stimulation of granulation tissue are required. Maggot debridement therapy (MDT), which is an alternative treatment method based on history, has been used quite widely. MDT is an efficient, simple, cost-effective and reliable biosurgery method using mostly larvae of Lucilia sericata fly species. Larvae can both physically remove necrotic tissue from the wound site and stimulate wound healing by activating molecular processes in the wound area through the enzymes they secrete. The larvae can stimulate wound healing by activating molecular processes in the wound area through enzymes in their excretions/secretions (ES). Studies have shown that ES has antibacterial, antifungal, anti-inflammatory, angiogenic, proliferative, hemostatic and tissue-regenerating effects both in vivo and in vitro. It is suggested that these effects stimulate wound healing and accelerate wound healing by initiating a direct signal cascade with cells in the wound area. However, the enzymes and peptides in ES are mostly still undefined. Examining the molecular content of ES and the biological effects of these ingredients is quite important to illuminate the molecular mechanism underlying MDT. More importantly, ES has the potential to have positive effects on wound healing and to be used more as a therapeutic agent in the future, so it can be applied as an alternative to MDT in wound healing.

Changing attitudes toward maggot debridement therapy in wound treatment: a review and discussion

Maggot debridement therapy is the real-time placement of maggots into a wound by health professionals for the treatment of diabetic ulcers or hard-to-heal wounds infected with antibiotic-resistant bacteria. Maggot debridement therapy shortens healing and disinfects wounds. This paper is a literature review of maggot debridement therapy in the clinical setting today and addresses the costs and benefits of this therapy. It includes recommendations to engage healthcare providers and increase awareness of this therapeutic treatment. A case study is presented on the use of maggot therapy for full debridement of a necrotic wound and clearing of a meticillin-resistant Staphylococcus aureus infection. There is also discussion on how to engage healthcare workers and reduce anxieties about the use of maggots as a treatment for hard-to-heal wounds. Education and awareness are the key factors in changing healthcare workers attitudes to maggot debridement therapy.

Telehealth-guided home-based maggot debridement therapy for chronic complex wounds: Peri- and post-pandemic potential

Patients with complex chronic lower extremity wounds require a great deal of interaction with outpatient and inpatient services. Paradoxically, these are the very patients that, because of their chronic comorbidities, are at greatest risk for COVID-related morbidity and mortality. Disinfected Phaenicia (Lucilia) sericata (Medical Maggots; Monarch Labs, Irvine, California) were applied in a standardised fashion by a home-health nurse with direct monitoring, guidance, and collaboration of the attending surgeon. A family member was able to change the outer dressing daily based on normal wound exudate. The inner maggot debridement therapy (MDT) dressing was changed at 2 days showing dramatic reduction in necrotic tissue, elimination of profound malodor, and no evidence of local or advancing infection. The entire initial telehealth-guided application took approximately 20 minutes. The first telehealth-guided MDT dressing change took 14 minutes. We used an artificial-intelligence-based algorithm to measure changes in wound characteristics. At day 0, 46% of the total surface area was covered in malodorous black, necrotic tissue. The first dressing change saw an elimination in assessed malodor with necrotic tissue constituting 14% of total surface area. The second dressing change at 5 days showed a greater than 99% reduction in necrotic tissue. This manuscript constitutes what we believe to be the first telehealth-guided MDT conducted during a resource-limited peri-pandemic period. We believe that MDT, which is an extension of efforts regularly performed in clinic and hospital, may have the potential to reduce resource usage while potentially improving care and quality of life for people with limb and life-threatening complications of diabetes and other chronic diseases.

In vitro evaluation of the association of medicinal larvae (Insecta, Diptera, Calliphoridae) and topical agents conventionally used for the treatment of wounds

Wound healing is a complex process involving multiple biochemical and cellular events and represents a neglected public health issue. As a consequence, millions of people worldwide suffer from chronic wounds. The search for new treatment alternatives is therefore an important issue. In the context of wound healing, Maggot Debridement Therapy (MDT) is an inexpensive treatment with few contraindications and very promising results. This study aimed to evaluate the in vitro feasibility and implications of larvae (= MDT) use when combined with topical agents as a strategy to identify additive or synergistic combinations. The weight and survival rate of Cochliomyia macellaria (Fabricius) (Insecta, Diptera, Calliphoridae) larvae reared in an in vitro wound with either honey, hydrogel, 10% papain gel, essential fatty acids (EFA), collagenase, or silver sulfadiazine were evaluated after 24, 48 and 72 h. Hydrogel (for weight: 24 and 72 h; for survival: 24 h) and 10% papain gel (for weight: 48 h; for survival: 48 and 72 h) demonstrated the least interference in larval weight gain and survival rate, when compared to the control group. The results obtained in this study showed that the combined use of larvae and hydrogel or 10% papain gel may be promising to maximize the tissue repair. Honey, EFA and collagenase could be used to prepare the bed of the dry wounds to receive the MDT.

Maggot debridement therapy for the treatment of diabetic foot ulcers: a meta-analysis

OBJECTIVE

To assess the potential efficacy of maggot debridement therapy (MDT) compared with standard care for diabetic foot ulcers (DFUs).

METHOD

A meta-analysis was performed on the evidence for MDT for DFUs. Databases, including PubMed, Web of Science, the Cochrane Library, EMbase, EBSCOhost, Springer Link, ScienceDirect and Ovid-Medline, were electronically searched for randomised controlled trials, case-control studies and controlled clinical trials, up to 31 December 2012, and relevant references of the included articles were also manually searched. The literature was screened, the data were extracted and the methodological quality of the included studies was assessed. Meta-analyses were performed on the included data, for the outcomes healing rate, time to healing, incidence of infection, amputation rate and antibiotic-free days or antibiotics usage.

RESULTS

Overall, four studies comparing MDT with standard therapy on a total of 356 participants were included. The results of meta-analyses suggested that the MDT group was significantly superior to the control group in the percentage of DFUs to achieve full healing (RR=1.8, 95%CI=1.07; 3.02; p=0.03), amputation rate (RR=0.41, 95%CI=0.20; 0.85; p=0.02), time to healing (RR=-3.70, 95%CI=-5.76; -1.64; p=0.0004) and number of antibiotic-free days (126.8 ± 30.3 days vs 81.9 ± 42.1 days; p=0.001); however, collated differences in incidence of infection after intervention revealed no evidence of a difference between the MDT and control groups (RR=0.82, 95%CI=0.65; 1.04, p=0.10).

CONCLUSION

Although MDT may be a scientific and effective therapy in treatment of DFUs, the evidence is too weak to routinely recommend it for treatment. Large studies and sample sizes are needed to assess the efficacy and safety of MDT in the treatment of DFUs.

DECLARATION OF INTEREST

There were no external sources of funding for this study. The authors have no conflicts of interest to declare with regard to this work or its contents. X. Tian and X.M. Liang contributed equally to this work.

Larval therapy as a palliative treatment for severe arteriosclerotic gangrene on the feet

Larval therapy (LT) is known to be a gentle and effective method for removing necrotic tissue and bacteria and reducing the accompanying unpleasant odour. Ischaemia has been considered a relative contraindication for LT. We report a patient with ischaemia treated with LT. Inguinal revascularization was performed on a 69-year-old man with critical limb ischaemia, diabetes mellitus, heart failure and end-stage renal disease. Areas of dry black malodorous gangrene remained on the distal areas of the feet after surgery and the patient's poor health did not allow any additional surgery. The patient was referred to the dermatology department for LT. Although patients are usually given this treatment as inpatients, the patient requested treatment at home. After the first LT, there was a marked reduction in odour. The gangrene needed repeated applications of larvae to remove the dead tissue. After eight treatments, the result was more positive than we had expected, with total lack of odour and initiation of healing. Larvae cannot penetrate eschar, thus free-range larvae were used because they can move beneath the hard necrotic tissue and dissolve it.

Clinical and microbiological efficacy of MDT in the treatment of diabetic foot ulcers

OBJECTIVE

To assess the clinical and microbiological efficacy of maggot debridement therapy (MDT) in the management of diabetic foot ulcers unresponsive to conventional treatment and surgical intervention.

METHOD

Consecutive diabetic patients with foot wounds presenting at the vascular surgery unit and the diabetic foot unit of Alexandria Main University Hospital were selected for MDT. Lucilia sericata medicinal maggots were applied to the ulcers for three days per week. Changes in the percentage of necrotic tissue and ulcer surface area were recorded each week over the 12-week follow-up period. Semiquantitative swab technique was used to determine the bacterial load before and after MDT.

RESULTS

The sample comprised 10 patients with 13 diabetic foot ulcers. The mean baseline ulcer surface area was 23.5cm2 (range 1.3-63.1), and the mean percentage of necrotic tissue was 74.9% (range 29.9-100). Complete debridement was achieved in all ulcers in a mean of 1.9 weeks (range 1-4). Five ulcers (38.5%) were completely debrided with one three-day MDT cycle. The mean reduction in ulcer size was significant at 90.2%, and this occurred in a mean of 8.1 weeks (range 2-12). The mean weekly reduction in ulcer size was 16.1% (range 8.3-50). Full wound healing occurred in 11 ulcers (84.6%) within a mean of 7.3 weeks (range 2-10). The bacterial load of all ulcers reduced sharply after the first MDT cycle to below the 10(5) threshold, which facilitates healing.

CONCLUSION

The results highlight the potential benefits of MDT in diabetic wound care in developing countries. MDT was proved to be a rapid, simple and efficient method of treating these ulcers.

Optimising Antimicrobial Therapy in Diabetic Foot Infections

Foot infections are common and the most serious lower extremity complication contributing to amputations, particularly in patients with diabetes mellitus. Infection is most often a consequence of foot ulcerations, which typically follows trauma to a neuropathic foot. Foot infections may be classified as mild, moderate and severe; this largely determines the approach to therapy. Gram-positive bacteria are the sole causative pathogens for most mild and moderate infections. These infections can usually be treated with culture-based narrow-spectrum antibacterials along with appropriate surgical debridement in an outpatient setting. In contrast, severe infections are often polymicrobial, requiring hospitalisation and treatment with broad-spectrum antibacterials along with appropriate medical and surgical interventions. The initial empirical antibacterial regimen may be tailored based on the results of culture and sensitivity tests from properly obtained specimens. Several antibacterial regimens have demonstrated effectiveness in randomised controlled trials, but no single regimen has shown superiority. Managing diabetic foot osteomyelitis is particularly controversial and requires reliable cultures to select an appropriate antibacterial regimen. Surgical resection of the infected and necrotic bone favours a good outcome in chronic osteomyelitis. The recommended duration of antibacterial therapy ranges from 1 to 4 weeks for soft tissue infection, to >6 weeks for unresected osteomyelitis. The incidence of meticillin-resistant Staphylococcus aureus infection is increasing in both the healthcare setting and the community. This should be considered when selecting an antibacterial, especially if the patient does not improve with initial antibacterial therapy. Certain other organisms, such as Pseudomonas aeruginosa and Enterococcus spp., while potentially pathogenic, are often colonisers that do not require targeted therapy.

Debridement

PURPOSE

To provide practitioners with an overview of debridement and its role in wound healing.

TARGET AUDIENCE

This continuing education activity is intended for physicians and nurses who assess and treat wounds.

OBJECTIVES

After reading the article and taking the test, the reader should be able to: 1. Discuss the physiologic process of wound healing and the rationale for debridement. 2. Describe evidence-based indications for and methods of debridement.

Diagnosis and treatment of diabetic foot infections

EXECUTIVE SUMMARY: 1. Foot infections in patients with diabetes cause substantial morbidity and frequent visits to health care professionals and may lead to amputation of a lower extremity. 2. Diabetic foot infections require attention to local (foot) and systemic (metabolic) issues and coordinated management, preferably by a multidisciplinary foot-care team (A-II). The team managing these infections should include, or have ready access to, an infectious diseases specialist or a medical microbiologist (B-II). 3. The major predisposing factor to these infections is foot ulceration, which is usually related to peripheral neuropathy. Peripheral vascular disease and various immunological disturbances play a secondary role. 4. Aerobic Gram-positive cocci (especially Staphylococcus aureus) are the predominant pathogens in diabetic foot infections. Patients who have chronic wounds or who have recently received antibiotic therapy may also be infected with Gram-negative rods, and those with foot ischemia or gangrene may have obligate anaerobic pathogens. 5. Wound infections must be diagnosed clinically on the basis of local (and occasionally systemic) signs and symptoms of inflammation. Laboratory (including microbiological) investigations are of limited use for diagnosing infection, except in cases of osteomyelitis (B-II). 6. Send appropriately obtained specimens for culture before starting empirical antibiotic therapy in all cases of infection, except perhaps those that are mild and previously untreated (B-III). Tissue specimens obtained by biopsy, ulcer curettage, or aspiration are preferable to wound swab specimens (A-I). 7. Imaging studies may help diagnose or better define deep, soft-tissue purulent collections and are usually needed to detect pathological findings in bone. Plain radiography may be adequate in many cases, but MRI (in preference to isotope scanning) is more sensitive and specific, especially for detection of soft-tissue lesions (A-I). 8. Infections should be categorized by their severity on the basis of readily assessable clinical and laboratory features (B-II). Most important among these are the specific tissues involved, the adequacy of arterial perfusion, and the presence of systemic toxicity or metabolic instability. Categorization helps determine the degree of risk to the patient and the limb and, thus, the urgency and venue of management. 9. Available evidence does not support treating clinically uninfected ulcers with antibiotic therapy (D-III). Antibiotic therapy is necessary for virtually all infected wounds, but it is often insufficient without appropriate wound care. 10. Select an empirical antibiotic regimen on the basis of the severity of the infection and the likely etiologic agent(s) (B-II). Therapy aimed solely at aerobic Gram-positive cocci may be sufficient for mild-to-moderate infections in patients who have not recently received antibiotic therapy (A-II). Broad-spectrum empirical therapy is not routinely required but is indicated for severe infections, pending culture results and antibiotic susceptibility data (B-III). Take into consideration any recent antibiotic therapy and local antibiotic susceptibility data, especially the prevalence of methicillin-resistant S. aureus (MRSA) or other resistant organisms. Definitive therapy should be based on both the culture results and susceptibility data and the clinical response to the empirical regimen (C-III). 11. There is only limited evidence with which to make informed choices among the various topical, oral, and parenteral antibiotic agents. Virtually all severe and some moderate infections require parenteral therapy, at least initially (C-III). Highly bioavailable oral antibiotics can be used in most mild and in many moderate infections, including some cases of osteomyelitis (A-II). Topical therapy may be used for some mild superficial infections (B-I). 12. Continue antibiotic therapy until there is evidence that the infection has resolved but not necessarily until a wound has healed. Suggestions for the duration of antibiotic therapy are as follows: for mild infections, 12 weeks usually suffices, but some require an additional 12 weeks; for moderate and severe infections, usually 24 weeks is sufficient, depending on the structures involved, the adequacy of debridement, the type of soft-tissue wound cover, and wound vascularity (A-II); and for osteomyelitis, generally at least 46 weeks is required, but a shorter duration is sufficient if the entire infected bone is removed, and probably a longer duration is needed if infected bone remains (B-II). 13. If an infection in a clinically stable patient fails to respond to 1 antibiotic courses, consider discontinuing all antimicrobials and, after a few days, obtaining optimal culture specimens (C-III). 14. Seek surgical consultation and, when needed, intervention for infections accompanied by a deep abscess, extensive bone or joint involvement, crepitus, substantial necrosis or gangrene, or necrotizing fasciitis (A-II). Evaluating the limb's arterial supply and revascularizing when indicated are particularly important. Surgeons with experience and interest in the field should be recruited by the foot-care team, if possible. 15. Providing optimal wound care, in addition to appropriate antibiotic treatment of the infection, is crucial for healing (A-I). This includes proper wound cleansing, debridement of any callus and necrotic tissue, and, especially, off-loading of pressure. There is insufficient evidence to recommend use of a specific wound dressing or any type of wound healing agents or products for infected foot wounds. 16. Patients with infected wounds require early and careful follow-up observation to ensure that the selected medical and surgical treatment regimens have been appropriate and effective (B-III). 17. Studies have not adequately defined the role of most adjunctive therapies for diabetic foot infections, but systematic reviews suggest that granulocyte colony-stimulating factors and systemic hyperbaric oxygen therapy may help prevent amputations (B-I). These treatments may be useful for severe infections or for those that have not adequately responded to therapy, despite correcting for all amenable local and systemic adverse factors. 18. Spread of infection to bone (osteitis or osteomyelitis) may be difficult to distinguish from noninfectious osteoarthropathy. Clinical examination and imaging tests may suffice, but bone biopsy is valuable for establishing the diagnosis of osteomyelitis, for defining the pathogenic organism(s), and for determining the antibiotic susceptibilities of such organisms (B-II). 19. Although this field has matured, further research is much needed. The committee especially recommends that adequately powered prospective studies be undertaken to elucidate and validate systems for classifying infection, diagnosing osteomyelitis, defining optimal antibiotic regimens in various situations, and clarifying the role of surgery in treating osteomyelitis (A-III).

Wound Debridement: Therapeutic Options and Care Considerations

Wound debridement is a critical component of promoting optimal healing for a wound with necrotic tissue. Although much is known about the multiple barriers to healing that necrotic detritus presents, much is still unknown about the best ways, timing, and approaches to constructing a healthy wound bed. Falanga's "black box," a metaphor for the unknown components of wound healing and debridement, should remind all practitioners that future research needs to address the continuing questions and issues associated with promotion of quality chronic wound healing outcomes.