Objective: This study investigates the deleterious effects of corticosteroids on tracheal anastomotic healing and the ability of vitamin A to reverse these effects in a rat model.
Methods: Forty-two adult Wistar rats were randomly divided into five groups. The animals underwent tracheal transection and primary anastomoses. The groups were assigned as follows: Group I, sham (N=6); Group II, control (N=6); Group III, dexamethasone, 0.1 mg/kg/day intramuscularly (N=10); Group IV, dexamethasone 0.1 mg/kg/day intramuscularly+vitamin A 10000 IU/kg/day by gavages (N=10); and Group V, vitamin A 10000 IU/kg/day by gavages for a week (N=10). After 7 days, anastomotic healing was assessed by measurement of bursting pressure, hydroxyproline content and subsequent histological grading using the modified Ehrlich/Hunt scale.
Results: Bursting pressures and hydroxyproline contents were as follows: Group I: 977+/-8 mmHg and 11.80+/-0.3 microg/mg (mean+/-standard error of the mean); Group II: 890+/-55 mmHg and 9.93+/-0.6 microg/mg; Group III: 555+/-26 mmHg and 11.90+/-1.3 microg/mg; Group IV: 873+/-73 mmHg and 10.24+/-2.2 microg/mg; Group V: 905+/-45 mmHg and 7.51+/-0.8 microg/mg, respectively. Bursting pressure of Group III was found to be significantly lower when compared to other groups (P<0.0001). However, statistical significance was not found among the study groups for the hydroxyproline content. Except for inflammatory cell infiltration, histological parameters including epithelial regeneration, fibroblast proliferation, collagen content, and angiogenesis demonstrated significant differences among the groups.
Conclusion: The present study demonstrates that dexamethasone significantly impairs the healing of tracheal anastomoses in rats and postoperative administration of vitamin A appreciably reverses this inhibitory effect. Patients receiving corticosteroids may benefit from vitamin A when undergoing prolonged intubation and laryngotracheal reconstruction.