Improved airway healing using transforming growth factor beta-3 - In a rabbit model

Laryngeal wound healing is essential following laryngotracheal surgery. Pat ients with poor wound healing develop poor epithelial closure and increased granulation tissue which cause a stenosis of the repaired airway. Transfor ming growth factor-beta3 has been shown to enhance wound healing in cutaneo us wounds, but has never been used in the airway. This study utilized a rab bit laryngeal wound-healing model that has been shown to be reproducible wi th limited morbidity. Thirty-four rabbits underwent a cricoid-split operati on with collagen sponge insertion. All animals were classified randomly int o three groups: local administration of placebo (Group G1. n = 13), 0.18 mu g transforming growth factor-beta3 (Group G2, n = 11) and of 1.0 mug transf orming growth factor-beta3 (Group G3, n = 10). All animals survived the pos toperative period without respiratory distress. The airway was harvested si x days after surgery and assessed by light microscopy. Histologic evidence for healing was subjectively graded by two blinded, independent investigato rs, and the results were statistically analyzed for significance. A signifi cant improvement in the epithelial closure (p < 0.01) and subepithelial con nective tissue closure (p < 0.005) was found in the 1.0 mug transforming gr owth factor-beta3 group (G3) compared with the placebo group (G1). Analysis of the 0.18 mug transforming growth factor-beta3 group (G2) did not reveal any significant differences compared with the placebo group (G1). These re sults suggest an application for transforming growth factor-beta3 in accele rating wound healing in the larynx.