RESUMEN
BACKGROUND: Hypertrophic scar (HSc) treatment continues to be a clinical challenge. OBJECTIVE: To evaluate the efficacy of a combined regimen of calcium channel blocker (verapamil), steroid, and interferon in treating HSc. MATERIALS AND METHODS: Ten excised human HSc fragments obtained from surgically treated burn patients were divided into 3 groups: A (no drug), B (steroid, 0.05 mL), and C (verapamil, steroid, and interferon, 0.016 mL each). These specimens were implanted on the backs of nude mice after treatment with intralesional injections of drugs and observed for 4 weeks. Fibroblast proliferation, scar weights, hematoxylin-eosin (HE) staining, fibroblast activity using the fibroblast-populated collagen lattice (FPCL) method, and the quantity of collagen were determined to evaluate the efficacy of the treatments. Data were analyzed using analysis of variance. RESULTS: All the implants were removed from animal body 4 weeks later for study. For the fibroblasts activity study, another 10 days of cell culture was done. The viability and proliferation of HSc fibroblasts in group C mice were significantly decreased at 10 days after explantation. The fibroblast numbers in the 3 groups were as follows: (A) 16.6×105; (B) 1.5×105; and (C) 0.4×105 (P<0.05). At 4 weeks after implantation, group C showed the significantly least amount of type I collagen (A, 0.12 µg/mL; B, 0.07 µg/mL; C, 0.055 µg/mL; P<0.05). In the nonimplanted scars, the collagen in group C was 0.4 µg/mL, less than that in groups B (0.6 µg/mL) and A (1.7 µg/mL; P<0.05). Significant differences were observed in reduction of scar weight among the 3 groups (A, 85%; B, 82.3%; C, 78.6%; P<0.05). The combination therapy group, that is, group C, significant inhibition of FPCL contraction and delayed contraction of burn scar fibroblasts compared with the other groups. The FPCL contraction rate at 4 weeks in groups A, B, and C was 15.4%, 65%, and 73.4% of the original size, respectively (P<0.05). CONCLUSIONS: Combined intralesional injection of steroid, verapamil, and interferon exhibits significant therapeutic efficacy than does a single high dose of steroid in the treatment of hypertrophic burn scars.