Indigo Carmine Chromoendoscopy for the Diagnosis of Minor Structural Alterations of the Vocal Fold Cover. A New Application for the Technique.

INTRODUCTION: Minor structural alterations (MSA) of the laryngeal mucosa are entities involving epithelial vocal cord covering modifications. Among differentiated structural alterations of the vocal cords are sulcus vocalis, epidermoid cysts, micro diaphragms, mucosal bridges, and vasculodysgenesis. While many of these MSA are evident and can be easily visible using conventional endoscopic methods, diagnosis can be difficult even with the help of stroboscopy. MSA can often go unnoticed and may be associated with polyps, cysts or vascular alterations. Its impact on the voice could be significant. In many cases, direct suspension laryngoscopy under general anesthesia is necessary to obtain a definitive diagnosis.

OBJECTIVES: The purpose of this article is to describe a new diagnostic endoscopic method that uses contrast dyes, such as indigo carmine, for the detection of MSA of the vocal fold mucosal covering.

MATERIAL AND METHODS: This research work uses the contrast dye Indigo Carmine as an endoscopic tissue stain, which is applied to the mucosal surface of the vocal cords under local anesthesia in the office or under general anesthesia in the operating room. The dye fills the interstices, highlighting irregularities such as depressions and elevations in architecture.

RESULTS: Our study involved performing indigo carmine chromoendoscopy procedures on patients suspected of having vocal fold MSA-type sulcus vocalis, mucosal bridge, or bag-type sulcus. We identified cases where this technique is useful for diagnosing previously undetected alterations, shedding light on dysphonia "without an apparent cause."

CONCLUSIONS: Indigo carmine chromoendoscopy is a useful technique for detecting MSA of the mucosal surface of the vocal folds. It has the potential to diagnose MSA in patients where current in-office endoscopic techniques are insufficient.