Objective. To estimate the efficacy of botulinum toxin type A in prevention of hypertrophic and keloid skin scars.

Material and methods. Experimental animals were 3 rabbits Soviet Chinchilla breed. Five ellipsoid wounds were inflicted and then sutured on the outer surface of each ear. The right ear was control, and the left ear was experimental. After 7 days, 2 units of botulinum toxin type A were injected into the scars on the experimental ear. At the control points (14, 28, 42 days), scars were assessed visually. Biopsy was performed with assessment of fibroblasts and myofibroblasts.

Results. Visual assessment of scars in the control group revealed hypertrophic scars in 4 out of 15 cases. In the experimental group, no hypertrophic scars were detected. In 42 days after botulinum toxin type A injection, there were fewer fibroblasts in the experimental group (p=0.01). The number of myofibroblasts in scar tissue of experimental animals in 14, 28 and 42 days after botulinum toxin type A injection was 2 times lower than in the control group (p=0.000003).

Conclusion. Botulinum toxin type A is effective for prevention of hypertrophic and keloid scars due to its effect on fibroblasts and myofibroblasts.

Keywords. botulinum toxin type A, scar correction, hypertrophic scars, keloid scars, prevention of pathological scars