ABSTRACT
Mitomycin C (MMC) is an antineoplastic agent with an antiproliferative effect on fibroblasts. It is routinely used topically in ophthalmology. The goal of this research project is to evaluate if topically applied MMC at the site of a maxillary antrostomy will inhibit the healing process of the mucosa and reduce the risk of postoperative stenosis. Antrostomies were carried out in both maxillary sinuses of 10 rabbits. For each rabbit, MMC is applied at the site of the antrostomy on one side while the other side serves as control. Antrostomies are re-evaluated 3 weeks later and their areas measured precisely. Seven of 10 control antrostomies were closed compared to only 1 of the 10 treated with MMC (p = .014). Comparison of the areas of the control and treated sides also proved to be statistically significant (p = .0039). Topical application of MMC was not associated with any systemic side effects and did not cause any permanent microscopic changes since the mucosa re-epithelialized normally. These results suggest that MMC slows the postoperative healing process of the nasal mucosa of the rabbit without affecting re-epithelialization. This could allow antrostomies to heal with a wider diameter, decreasing the risk of postoperative stenosis. Our next step will be to reproduce these results following functional endoscopic surgery on humans.
Subject(s)
Antibiotics, Antineoplastic/therapeutic use , Maxillary Sinus/surgery , Mitomycin/therapeutic use , Postoperative Complications/prevention & control , Wound Healing/drug effects , Administration, Topical , Animals , Antibiotics, Antineoplastic/administration & dosage , Cicatrix/etiology , Cicatrix/prevention & control , Male , Maxillary Sinus/pathology , Mitomycin/administration & dosage , Models, Animal , Nasal Obstruction/etiology , Nasal Obstruction/prevention & control , Ostomy/methods , RabbitsABSTRACT
An adjustable laryngeal implant made of titanium has been developed for the treatment of unilateral vocal fold paralysis. The implant includes three parts: a plate that allows fixation to the thyroid cartilage, a block of titanium which includes the adjustable part, and a micrometric screw in the middle of the lateral side of the block, which moves the adjustable part. Precise medialization is accomplished by regulating the screw which also permits easy secondary adjustments, if needed in the future. This retrospective study assesses clinical outcomes of medialization laryngoplasty with the titanium adjustable implant, in patients with unilateral vocal fold paralysis. This study has the limitations of a retrospective study. However, preliminary results are encouraging. Analysis of subjective responses confirmed marked improvement in laryngeal function, speech, and swallowing. Objective voice analysis confirmed improvement in the aerodynamic measures. The adjustable laryngeal implant has many advantages including: precise medialization, ease of secondary adjustment, and preseveration of the mucosal wave. This implant is biocompatible, no migration is possible (it is fixed to the cartilage) and no extrusion of the implant has occurred. Titanium is magnetic resonance imaging (MRI)-safe.
Subject(s)
Larynx/surgery , Prostheses and Implants , Titanium/therapeutic use , Vocal Cord Paralysis/surgery , Adult , Aged , Aged, 80 and over , Biocompatible Materials/therapeutic use , Female , Humans , Male , Middle Aged , Postoperative Complications/epidemiology , Vocal Cord Paralysis/complications , Voice Disorders/diagnosis , Voice Disorders/etiology , Voice QualityABSTRACT
Treatment of symptomatic unilateral vocal cord paralysis is most frequently surgical. Medialization of the vocal cord using Teflon injection has proved effective; however, studies have shown this technique to produce stiffness of the vocal fold with loss of the "mucosal wave" and concomitantly poor vocal function. As well, overcorrection may occur and is not reversible. Isshiki type 1 medialization thyroplasty has been shown to produce a substantial improvement in vocal quality, as well as preserve the mucosal wave. A number of problems encountered during the performance of Isshiki type 1 thyroplasty has led us to modify the original technique. We have developed a new implant that allows for precise, easily adjustable control of vocal cord medialization. To evaluate the degree of vocal cord medialization afforded by this implant, larynges of fresh male and female cadavers were used as an experimental model. In both larynges, vocal cord medialization was shown to occur in a predictable fashion for the anterior, middle, and posterior segments, as well as in the functionally important inter-arytenoid region. We believe the use of this implant in medialization thyroplasty will allow precise, atraumatic medialization of the paralyzed vocal cord. This greater control over positioning and ease of adjustment should contribute to enhanced vocal quality.
