Anatomy:
The pharynx is the superior part of the alimentary canal,
located posterior to the nasal and oral cavities and extending inferiorly past the larynx1.
The pharynx can be divided into three anatomic regions: nasopharynx,
oropharynx and hypopharynx.
1- Nasopharynx is located posterior to the nose and superior to the soft palate and uvula.
It contains the pharyngeal tonsils,
the opening of the eustachian tubes and the posterior aspect of the inferior turbinates of the nasal cavity5.
2- Oropharynx is located posterior to the mouth beginning at the level of the soft palate and extending inferiorly to the tip of the epiglottis.
It contains the base of the tongue,
lingual tonsils,
soft palate and uvula5
3- Hypopharynx or Laryngopharynx is located posterior to the larynx,
extending from the tip of the epiglottis to the upper esophagus.
It includes the larynx (epiglottis,
arytenoids,
true vocal cords) and the piriform sinuses.
5
The esophagus is a tube that connects the pharynx with the stomach.
Its compositions varies according to location: its upper third is made of striated (voluntary) muscle,
its lower third is composed of smooth (involuntary) muscle and the middle third is composed of a combination of striated and smooth muscle 10.
The esophagus can be further classified based on location as the cervical and thoracic esophagus.
The cervical esophagus refers to the upper third that begins at the level of C6,
its course has a slight inclination to the left side.
The thoracic esophagus begins at the superior thoracic aperture where the esophagus enters the superior mediastinum.
Dysphagia:
Dysphagia is a common clinical complaint,
which is increasing in prevalence,
specially with the aging population.
Dysphagia can be defined as difficulty swallowing or an abnormal delay in the transit of the bolus from the oropharynx to the esophagus.
Patients with dysphagia need to be evaluated with a thorough history inquiring about the chronicity,
frequency and severity of the symptoms; changes in the voice,
drooling,
aspiration,
weight loss,
compensatory mechanisms.
Dysphagia can be classified by localization as oropharyngeal or substernal.
Oropharyngeal dysphagia is defined as a sensation of blockage or discomfort in the throat.
Substernal dysphagia is defined as a sensation of blockage between the thoracic inlet and the xiphoid process 4.
Dysphagia can also be classified as functional or structural.Structural dysphagia also referred to as anatomic dysphagia refers to a cause that compromises the esophageal lumen,
hence the swallowing of solid foods is compromised before than that of liquids.
Functional dysphagia also referred to as motility dysphagia refers to a cause that compromises the expected peristalsis,
hence the swallowing of solid foods and liquid is compromised at the same time,
due to the fact that the neuromuscular forces that are required to propagate the bolus are the same 2.
Barium Swallow:
Fluoroscopy studies like barium swallow or esophagography are very helpful when evaluating a patient with dysphagia.
The utility of the esophagography is that it provides the opportunity for evaluating simultaneously the anatomic structure and the esophageal motility or function.
Esophagography provides information about the pharynx,
esophagus,
gastroesophageal junction and gastric cardia 4.
The normal esophagus appears as a thin white homogenous luminal contour.