Assesment of pentoxifylline affect on the wound healing of vocal fold injury in rat model

Many vocal cord pathologies have become treatable with developments in phonosurgery over the past decades. In spite of this fact, vocal cord scarring still presents as a challenge in terms of treatment. The scar tissue builds up with injury and inflammation. Maloperated phonosurgery has its reasons for easily producing vocal cord scarring. Vocal cord scarring disrupts the lamina propria of the mucosa and increases the viscoelastic stability of the mucosa, causing the biomechanics of the cords to deteriorate and decreasing the vibratory ability of the cords and causes severe disphonia which is hard to cure.When treating these cases, ethiologic factors should be treated to eliminate the production of the scar tissue or the physician should intervene in the reparative and heailing processes in order to maintain the optimum results. The objective is to maintain the histologic structure of the vocal cord hence, protection of the biomechanic structure and the quality of sound.The objective in this case is to show the efficacy of Pentoxifylline on fibrosis, after an acute injury causing fibrosis in an experimentally produced vocal cord rat model. Also, we want to contribute to the possible treatment protocols for preventing the post phonosurgical scarring, which hadn' t been fully discovered yet.Forty-two Sprague Dawley type female rats had been used in the study. Chordotomy was made to the rats as the surgical procedure. with direct laryngoscopy view, chordotomy was performed on one cord to make full section tissue injury with microscissors to the first group and then Pentoxifylline of 0,5 cc was injected with long dental needles to the lateral zone of the cord. The same procedure was applied to the control group but 0,5 cc saline was injected.The specimens taken from the vocal cords in order to evaluate the healing process were stained with hematoxylin and eosin, Van Gieson elastic and Trichrome and were studied histopathologically. In this assessment epithelial regeneration, inflammation, granulation tissue formation, density of submucosal fibroblasts and collagen and elastics fibers were taken into consideration.In our study, epithelial regeneration was finished in an early stage. The inflammation from the second week in the Pentoxifylline group was rated as ?Mild? and ?Moderate? whereas in the control group there was ?Common? inflammation in the vocal cords in the second week and month. This situation didn' t reach statistically relevance but can be interpreted as pentoxifilin decreases the severity of the inflammation (p>0,05).The granulation and the density of submucosal fibroblasts were assessed statistically using Chi-square test and did not reach statistical relevance deposition of collagen and elastin were compared and there were no statistical difference between the control and the Pentoxifylline group (p>0,05). We also showed that elastin was not accumulated in an organized pattern.As a conclusion, further studies are needed to establish the up sides of Pentoxifylline in vocal cord surgery, which is already efficient in many different areas in the literature.