Tracheal cartilage growth by intratracheal injection of basic fibroblast growth factor.

BACKGROUND/PURPOSE: We have previously shown that intratracheal injection of slowly released (in gelatin) basic fibroblast growth factor (bFGF) significantly enlarged the tracheal lumen by a slight margin. This study aimed to investigate differences in tracheal cartilage growth by the intratracheal injection of bFGF doses in a rabbit model.

METHODS: Water (group 1; n=7; control) or 100μg (group 2; n=8) or 200μg (group 3; n=8) of bFGF dissolved in water was injected into the posterior wall of the cervical trachea of New Zealand white rabbits using a tracheoscope. All animals were sacrificed four weeks later.

RESULTS: The mean circumferences of cervical tracheas for groups 1, 2, and 3 were 18.8±0.83, 21.1±2.0, and 22.1±1.3mm, respectively. A significant difference was found between groups 1 and 2 (P=0.034) and groups 1 and 3 (P=0.004). The mean luminal areas of cervical tracheas for groups 1, 2, and 3 were 27.0±2.1, 32.2±4.8, and 36.3±4.6mm(2), respectively. A significant difference was found between groups 1 and 3 (P=0.001).

CONCLUSION: Intratracheal injection of bFGF in the dose range used significantly promoted the growth of tracheal cartilage in a rabbit model.

LEVELS OF EVIDENCE: Level II at treatment study (animal experiment).