Longitudinal Study of Scar Hyperplasia Formation Following Cleft Lip Wound Healing.

Abstract

The purpose of this study was to observe the hyperplasia trend of scar after the cleft lip surgery in a rabbit animal model, and determine the time-point of the highest hypertrophic degree of scar after cleft lip repair. Forty New Zealand white rabbits from the same offspring were used to establish a cleft lip wound healing model using Millard surgery procedure. The scar volumes were measured and granulation tissues were observed visually in the 2, 3, 4, and 5 weeks after operation. The scar tissues were harvested at the indicated time-points. Immunohistochemical (IHC) and Western Blot analyses were performed to detect the expression level of α-smooth muscle actin (α-SMA) in the scar tissue. The scars shrunk and the volumes reduced at 3 to 4 weeks after surgery; however, at 5 weeks postsurgery, the volumes increased. IHC and Western blot analyses indicated the expression of α-SMA was significantly enhanced 3 to 4 weeks, but reduced in the 5 weeks after surgery. Overall, the degree of scar hyperplasia after cleft lip surgery in rabbits was normally distributed and the scarring was most severe in the 3 to 4 weeks after cleft lip surgery. The study confirms a novel animal model for the assessment of therapies for the treatment of scar hyperplasia of human cleft lip in future.