Laryngoscopy is a procedure used to view the inside of the larynx (the voice box).
The purpose of seeing inside the larynx is to assess the vocal cords and to detect tumors, foreign bodies, nerve or structural injury, or other abnormalities.
A patient undergoing a laryngoscopy should be assessed for allergies to local anesthetics or other pharmacologic agents in order to prevent possible allergic reactions.
Patients may have fears concerning this procedure. Prior to laryngoscopy, the physician should explain the procedure in detail and assure the patient that he or she will be closely monitored for respiratory or other problems.
Two methods of laryngoscopy allow the examiner to view the structures of the larynx and the surrounding areas. A light and lens affixed to a surgical viewing instrument called an endoscope are used in both methods.
Indirect laryngoscopy, the simplest form of laryngeal examination, involves the placement of a small, angled mirror at the back of the throat, allowing the examiner to reflect light onto the larynx and view its major structures. However, since the mirror must remain in the back of the throat, examination of the larynx during normal speech is hindered. Also, a strong gag reflex in some patients may limit the usefulness of this procedure.
A rigid endoscope may also be used to perform an indirect laryngoscopy. An examination using a rigid scope involves placement of the tip of the instrument through the mouth and into the back of the throat. A prism at the tip allows the examiner to view the larynx. This type of exam provides clear and highly magnified images of the vocal cords and allows better examination of the larynx during phonation (the production of vocal sounds). Another advantage to these instruments is that photographic or video recordings can be made through the endoscope for future review, also allowing more than one person to observe the laryngeal area.
Jennifer F. Wilson, The Gale Group Inc., Gale, Detroit,