Topical Heparin: A Promising Agent for the Prevention of Tracheal Stenosis in Airway Surgery

Background

The protective effects of topical mitomycin-C (MMC) have been well documented for tracheal stenosis; however, to the best of our knowledge, the use of heparin as an anti-inflammatory agent to support wound healing in upper airway surgery was not studied before. The aim of this study was to investigate the efficacy of topical heparin for healing of tracheal re-implants in a rabbit's model and its resultant histological changes compared with that of MMC.

Methods

In a rabbit model (n = 21), an elliptically shaped portion of the anterior tracheal wall was excised (3–4 tracheal cartilages) under anesthesia and immersed in an isotonic saline solution containing 0.4 mg/mL (0.04%) MMC (n = 7), heparin (liquemine) 5000 U/mL (n = 7), or none (n = 7) for 2 min and then re-implanted. The follow-up period was 2 wk for all animals and then both the larynx and the trachea were excised for histological evaluation. Hematoxylin-eosin (H and E) staining was applied to the excised tissues for microscopic evaluation.

Results

Compared with controls, the granulation tissue formation score in MMC group (P = 0.03), and epithelial regeneration and inflammation scores in heparin group (P = 0.032 and P = 0.022, respectively) were more favorable. The fibrosis index and tracheal lumen ratio values were also more favorable in both MMC (P = 0.019 and P = 0.0028, respectively) and heparin (P = 0.023 and P = 0.0021, respectively) groups compared with controls on the 15th d.

Conclusions

Topical heparin application may have favorable effects on healing of tracheal autografts in a rabbit model. We suggest that heparin therapy should be further researched for the prevention of tracheal stenosis in airway surgery.

Key Words: heparin, mitomycin-C, tracheal stenosis, airway surgery, reimplantation