Maggot Therapy for Diabetic Foot Ulcers Unresponsive to Conventional Therapy

Diabetic patients are often inflicted with a variety of complications, due to their disease. One of the more common is that of ulcers of the legs and feet. For many, conventional therapy does not do an adequate job in debriding the necrotic tissue. The article reviewed investigates the use of maggot therapy instead of, and in addition to, conventional therapy, as a means of treating foot and leg ulcers in patients, where conventional therapy is not effective.

Maggot Therapy

"Impaired wound healing is a common and costly problem for those with diabetes. Non-healing diabetic foot ulcers account for 25 -- 50% of all diabetic hospital admissions, and most of the 60,000 -- 70,000 yearly amputation in the U.S." (Sherman, 2003). For this reason, the researcher investigated the use of maggot therapy on diabetic patients with foot and leg ulcers.

This problem is significant to nursing, due to its prevalence and the tens of thousands of amputations that occur due to unresolved ulcers. Dr. Sherman is well qualified to study this population. He is a member of the Department of Pathology, Medical Services, for the University of California.

Literature Review:

There was no literature review conducted for this research nor were there experts in the field consulted. Therefore, there were no findings of previous studies considered in the research. In addition, because of this lack of literature review, it was not used as supporting evidence to show the need for carrying out the research.

Theoretical Framework or Concepts:

Healing rate concepts, previously studied, were utilized in this research. The concept of healing rate "was defined as the change in surface area divided by the mean circumference over time" (Sherman, 2003). This concept was meaningful to the study, as it allowed the researcher to determine the effectiveness of the maggot treatment, in relation to conventional treatment. Although they do not provide rationale for the question, hypotheses or purpose of the investigation, they are integral to the determination of the success of the research. This concept of healing rate is based on previous research.

Research Design:

The research design clearly defined the target population as male diabetic patients with non-healing foot and/or leg ulcers. Patients were excluded from the target population if they had received less than 2 weeks of treatment, had wounds that were immeasurable due to shape, or had missing or poor quality photos of the ulcers. In addition, the hypothesis was clearly stated as "retrospective comparison of changes in necrotic and total surface area of chronic wounds treated with either maggot therapy or standard (control) surgical and non-surgical therapy" (Sherman, 2003).

The operational definitions of independent variables and dependent variables were not developed by the researcher. Independent variables included the treatment received by patients. "Six wounds were treated with conventional therapy, six with maggot therapy, and eight with conventional therapy first, then maggot therapy" (Sherman, 2003). The design of this study was appropriate to answer the efficacy question of maggot therapy on non-responsive ulcers.

Data Collection and Statistics:

Informed consent was utilized in this research. And, the data collection procedure of tracing and photographing the wounds for eight weeks could be replicated. No time sequence for data collection was given, however, which would interfere in replication. It is implied that the researcher and his team performed the data collection; however, this is not clearly stated, and as such could affect the study.

It was noted that ulcer length, width, circumference, and surface area were calculated from digitized photographic images (and that these were used to determine) change in relative and absolute amounts of necrotic tissue ( ... ), change in relative amounts of granulation tissue ( ... ), change in wound surface area overtime and, the length of time until complete wound healing" (Sherman, 2003)

However, the measurement instruments or tools are not clearly described. In addition, the reliability and validity of the measurements were not addressed.

The statistical analysis was conducted using normally distributed ordinal and interval data, using Student's t test or logistic regression when variance was equal. Welch's t test was used when variance was not equal. The ordinal and interval data that was not normally distributed were evaluated using the Mann-Whitney U test. And, nominal data were analyzed using Pearson's X2 test. These methods are appropriate, given the data collected.

Discussion:

18 patients with 20 non-healing ulcers were studied. As mentioned, six wounds were treated with conventional therapy, six were treated with maggot therapy, and eight received conventional therapy first followed up with maggot therapy. There were no significant changes in necrotic tissue, except when factoring in for treatment.