A Parallel Randomized Clinical Trial for Comparison of Two Methods of Maggot Therapy, Free-Range Larvae and Larval-bag, in Diabetic Ulcer (Wagner 2)

Abstract

In the present study, the efficiency of two formulations of maggot therapy: free-range larvae on the wounds and larvae in a special bag (larval-bag), was compared for healing diabetic ulcers with Wagner 2 diabetic ulcer. This study was conducted as a parallel randomized clinical trial. Out of 281 patients with Wagner grade 2 diabetic ulcers referred to the wound clinic, 54 patients who met the inclusion criteria were randomly assigned to intervention groups. The disinfected larvae of Lucilia sericata were put on the wounds with 2 methods, free-range larvae and larval-bag. Follow up was done at every 48 h interval until the full appearance of granulated tissues. The main measures were wound bed preparation, removing of necrotic tissues, appearing of granulated tissues, and removing of bacterial infections in the wounds. Statistical analysis based on the Kaplan–Meier curve and the Wilcoxon (Breslow) test showed a significant reduction in wound healing time by using free-range larvae in comparison with larval-bag ( P = .03). The median time to debridement was 4 days in the free-range larval group (95% confidence interval: 3-9 days) while it was 9 days in the larval-bag group (95% confidence interval: 5-16 days). Debridement rate (proportion of removed necrotic tissue surfaces) at any time in the free-ranged larvae group was 1.78 times that of the bagged larvae group (95% confidence interval 1.01-3.15, P = .036). There was no significant difference between free-range larval use and larval-bag in the acceptability of maggot therapy by patients ( P = .48). It can be concluded that both of two formulations of the larval therapy (free-range larvae and larval-bag) could be recommended for cleaning out and bed preparation of diabetic ulcers. However, using free-range larvae is hardly recommended on the wounds which are eligible to use.