Intralesional treatments for hypertrophic scars: comparison among corticosteroid, 5-fluorouracil and botulinum toxin in rabbit ear hypertrophic scar model.

OBJECTIVE: Different treatment modalities have been used either alone, or in combination to achieve an optimum improvement for hypertrophic scars. Intralesional injections of corticosteroids and 5-fluorouracil are among the most commonly used treatments. Recently, botulinum toxin is proposed as a new treatment option. In this study, it is aimed to compare the efficacies of intralesional triamcinolone acetonide, 5-fluorouracil and botulinum toxin-A for hypertrophic scars. In order to minimize the variables affecting scar formation, standardized wounds in rabbit ear hypertrophic scar model was used. MATERIALS AND METHODS: Four surgical wounds were created on both ears of eight rabbits. Injections to be compared (triamcinolone acetonide, 5-fluorouracil, botulinum toxin-A and control) are administered intralesionally to established scars on day 30. Scars were harvested on day 60 for morphometric analysis including hypertrophic index, fibroblast density, and relative collagen density. RESULTS: Triamcinolone acetonide and 5-fluorouracil injections decreased hypertrophic indexes significantly compared to botulinum toxin-A and control group. However, only 5-fluorouracil was effective to reduce fibroblast counts significantly. No statistically significant differences were found between the treatment groups in terms of collagen index. CONCLUSIONS: According to the results of our study, triamcinolone acetonide and 5-fluorouracil are comparatively effective as monotherapy, but botulinum toxin-A was not effective on established hypertrophic scars.

Effects of human amniotic fluid on costal cartilage regeneration (an experimental study).

OBJECTIVE: After surgical correction of thoracic wall deformities, promoting neochondrogenesis in the perichondrial bed is very important for obtaining a flexible chest wall. In this experimental study, we aimed to investigate the effects of human amniotic fluid on cartilage regeneration in the costal perichondrial bed in a rabbit model. METHODS: Fifty-four adult New Zealand rabbits were divided into three groups, with 18 rabbits in each group. The third and fifth costal cartilages were excised totally on the right side and partially excised on the left side in all groups. Group 1 served as controls. All rabbits in group 1 underwent closure of the perichondrium of the third costal cartilage and closure of the perichondrium of the fifth costal cartilage with reimplantation of reshaped cartilage into the fifth costal perichondrial bed. Rabbits in group 2 underwent closure of the perichondrium of the third and fifth costal cartilages after the administration of human amniotic fluid into the perichondrial bed. Group 3 rabbits received both human amniotic fluid and underwent cartilage reimplantation. The third and fifth costal perichondriums in group 3 rabbits were closed after the administration of human amniotic fluid and the reimplantation of reshaped cartilages. Rabbits were sacrificed at two, eight and 12 weeks after operation. RESULTS: Numerical scores for the right perichondrial bed were significantly higher for group 2 compared to group 1 ( P < 0.05). But the difference was not significant for the left perichondrial bed ( P > 0.05). The diameter of chondrogenesis also did not differ significantly between left and right perichondrial bed for all groups. CONCLUSION: Our study shows that administration of human amniotic fluid into the perichondrial bed increases chondrogenesis in adult rabbits, an important finding which may contribute to improving chest wall flexibility after the surgical correction of pectus excavatum.