Laryngoscopy, Bronchoscopy, and Esophagoscopy

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What are laryngoscopy, bronchoscopy, and esophagoscopy?

Laryngoscopy is an examination of the larynx. This can be performed indirectly using a head torch and mirror and directly using rigid or flexible laryngoscopes. Bronchoscopy is examination of the trachea, bronchi, and its branches performed using either rigid or flexible bronchoscopes. Esophagoscopy is the endoscopic examination of the esophagus, which may also be performed using either flexible or rigid esophagoscopes.

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When is office laryngoscopy indicated in adults?

Examination of the larynx in adults is part of the complete physical examination of the head and neck and can be performed using indirect or flexible laryngoscopy. In examining the larynx in an adult the supraglottis, oropharynx, and hypopharynx are often also visualized. Examination of the larynx and surrounding anatomic areas is indicated for complaints of dysphonia, chronic cough, globus sensation, chronic throat discomfort or pain, stridor, neck mass, thyroid mass, and obstructive sleep apnea.

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When is office laryngoscopy indicated in children?

Examination of the larynx in children is indicated for noisy breathing, voice abnormalities, and obstructive sleep apnea status post adenotonsillectomy.

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What are different types of laryngoscopy?

Direct laryngoscopy is visualization of the larynx achieved by direct line-of-sight. This requires the use of a laryngoscope to achieve a proper view. The patient is usually anesthetized, although some patients may tolerate laryngoscopy performed with the use of local and/or regional blocks. Direct laryngoscopy is performed to allow insertion of an endotracheal tube (ETT), inspect the larynx in its entirety, and properly expose the portion of the larynx that requires biopsy or excision of a mass.

Indirect laryngoscopy visualizes the larynx and involves instruments to achieve an “indirect” view of the larynx. The laryngeal mirror uses indirect light from an external source (usually a lamp located behind the patient) and a mirror to direct light into the larynx, providing illumination and visualization of the structures. Indirect laryngoscopy can be limited by a patient’s gag reflex. Other forms of indirect laryngoscopy involve the use of angled telescopes (70- or 90-degree) or flexible laryngoscopes to visualize the larynx. Rigid endoscopic evaluation with an angled telescope can achieve a high-definition view of the larynx.

Flexible laryngoscopy is often performed in the clinic using a flexible fiberoptic endoscope. The nasal cavity can be treated with a topical decongestant/anesthetic mixture to improve visualization and comfort of the examination. Lubrication of the telescope may also aid in comfort. Flexible laryngoscopy can also be used to evaluate swallowing using a procedure termed flexible endoscopic evaluation of swallowing (FEES). This procedure involves visualization of the larynx while feeding the patient various consistencies to determine if there is aspiration or penetration of the food bolus into the larynx.

Videolaryngoscopy involves attaching a camera to an angled rigid endoscope or a flexible endoscope to project the image onto a monitor. Digital recording devices can record the video, allowing the examination procedure to be stored for later visualization or review.

Videolaryngostroboscopy is videolaryngoscopy with the addition of a stroboscope. The stroboscope uses a microphone or electromyography (EMG) activity to detect the fundamental frequency of the vibrating vocal cords. The stroboscope flashes the light source based on the fundamental frequency, creating the appearance of a vocal cord wave in slow motion. This allows assessment of the mucosal wave of the vocal cord, which can help differentiate various pathologies of the vocal cord.

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What are laryngoscopes, and how do they differ?

Laryngoscopes are instruments used to visualize the larynx while the patient is in the supine position. There are multiple types of laryngoscopes, and their designs differ in order to achieve certain goals. Examples of laryngoscopes optimized for specific functions include an anterior commissure scope (which has an anterior flare and shorter interdental dimension, allowing better view of the anterior commissure), bivalved laryngoscopes for approaching supraglottic and hypopharyngeal tumors, and slotted laryngoscopes that allow for easier intubation. Many different types of laryngoscopes attach to a suspension arm so that the surgeon may perform surgical procedures using a two-handed technique.

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How is flexible laryngoscopy performed?

First the patient is counseled on the steps and side effects of this procedure, as there is minor discomfort involved. The nose is topically prepared using a combination of a local anesthetic and topical decongestant. Lubrication can be applied to the scope to allow for added comfort for the patient. The scope is inserted into the nasal cavity and advanced posteriorly, allowing visualization of the nasal cavity and nasopharynx. The scope is directed inferiorly to allow assessment of the oropharynx and then advanced to a position that allows proper assessment of the supraglottis and glottis. Voluntary vocalization and inspiration can confirm normal vocal cord mobility.

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What are the proper positions for direct laryngoscopy?

The proper patient positioning for rigid direct laryngoscopy is the sniffing position with the head extended on the neck and the neck flexed. A shoulder roll is not required for direct laryngoscopy. To obtain adequate anterior exposure it is sometimes necessary to increase neck flexion further by lifting the head off the table.

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What makes laryngoscopy difficult?

Difficult laryngoscopy does not allow visualization of the larynx. The factors contributing to this are usually anatomical factors. Trismus (inability to open the mouth widely), prominent dentition, micrognathia, tumors, infections, and trauma of the oropharynx and supraglottis can make laryngoscopy difficult.

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How is the laryngoscopic view of the larynx classified?

When using an intubating laryngoscope, the view of the glottic opening should be reported. The grade of the view is important for communicating with other medical providers regarding the future care of the patient and for minimizing the risk involved for patients with known difficult laryngeal exposures. A Grade I view occurs when the entirety of the vocal cords can be seen. A Grade II view occurs with a partial view of the true vocal cords. A Grade III view occurs when only the arytenoids are seen. A Grade IV view occurs when no laryngeal structures are visible.

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What should be reported while doing direct laryngoscopy that is part of the head and neck examination?

As otolaryngologists we are trained to examine the larynx in its entirety. This is most important in patients with head and neck cancers. A thorough examination includes visualization of the base of the tongue, vallecula, epiglottis (remarking on the lingual and laryngeal surfaces), supraglottis, glottis, and hypopharynx.

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