Effect of pentoxifylline and 5-fluorouracil/triamcinolone on laryngotracheal stenosis developing as a complication of tracheostomy: study in rats.

We aimed to investigate the prophylactic effect of pentoxifylline (PTX) and 5-fluorouracil (5-FU) on laryngotracheal stenosis in tracheotomised rats by evaluating blood glutathione peroxidase (GPx) and superoxide dismutase activities and by histopathological evaluation of laryngotracheal segment. Randomized prospective single-blind study. Standard vertical tracheotomy was performed on 24 rats. Then, the animals were randomly divided into three groups. Intraperitoneal PTX administered to group A (study group) for 10 days. 5-FU was injected in paratracheal tissues in group B (study group) for 10 days. In group C (control group), intraperitoneal saline was administered for 10 days. After 10 days, tracheal cannules were removed. For biochemical analysis, two blood samples were obtained. Three weeks later, all animals were euthanized and trachea specimens were harvested. Stenosis index and mean wall thickness in PTX group were lower as compared to other groups but the difference was statistically insignificant. Minimum inflammation and fibrosis plus maximum epithelial regeneration were seen in PTX group. In addition, GPx activity was at highest level in PTX group and a statistically significant difference was found between control and PTX groups (P = 0.024) though the difference between remaining groups was statistically insignificant (P = 0.121). Superoxide dismutase activity was highest in PTX group but no statistically significant difference was found between the three groups (P = 0.305). The administration of PTX increases GPx activity and it may have some effect on tracheal scar formation which develops following tracheostomy.