Anatomy and Physiology
The larynx and oesophagus are hidden areas to the general practitioner and therefore if someone has a complaint related to these areas it is difficult to visualize without the correct equipment.
The larynx is composed of three subsites the supraglottis (above the vocal cords) the glottis (the vocal folds) and the subglottis (below the vocal folds and is in continuity with the trachea). The larynx sits in front of the inlet of the oesophagus the so called hypopharynx (composed of the posterior pharyngeal wall, pyriform fossae and the post cricoid region).
With swallowing the larynx is protected by the epiglottis and false cords (from the supraglottis) and the closure of the vocal cords (glottis). Voice itself is created by air from the lungs being vibrated through the vocal folds and then articulated by the oral cavity, teeth and the paranasal areas.
Microlaryngoscopy and Oesophagoscopy
Occasionally it is necessary to visualize the oesophagus or the larynx to exclude or treat disease.
Oesophagoscopy is undertaken using a rigid oesophagus to carefully inspect areas of the hypopharynx and then the oesophagus lower.
Microlaryngoscopy uses a suspension frame and microscope with the benefits to the surgeon of the following
Bimanual handling of instruments
Depth of field
The ability to use other surgical implements such as the laser
Post-operatively the patient will have a sore throat and there is a risk of dental injury although this is small as is the risk of oesophageal perforation with an oesophagoscopy.