Are pharyngeal abnormalities often found in achalasia ?
M. W. Dormer, B.J. Jones, W.J. Ravich (Baltimore)
Achalasia of the esophagus is characterized by absence of progressive peristalsis and by failure of the lower esophageal sphincter to relax in response to swallowing. Widening of the esophageal lumen with retention of saliva or food and air is usually observed in these patients. Associated radiographic changes of pharyngeal structure and function, however, have received little attention in the past.
Our observations during dynamic imaging of the pharynx in achalasia of the esophagus revealed unsuspected findings in half of twenty-one consecutive patients . One-third of them had been previously treated by bougienage or pneumostatic dilatation of the lower esophageal sphincter. Radiographic findings in order of frequency were: lateral pharyngeal pouches (nine out of twenty-one, figure /), abnormality of the pharyngo-esophageal segment (eight out of twenty-one), asymmetry of epiglottic tilt (two out of twenty-one, figure 1), and Zenker's diverticulum (2 out of twenty-one, figure 2). Pharyngeal penetration during swallowing was also seen (two out of twenty-one).
Radiographic changes in the pharynx resulting from esophageal disorders have previously been described in patients with other causes of esophageal disease, such as gastroesophageal reflux, spasm of the esophagus, and organic esophageal obstruction, including Schatzki's ring, strictures, and cancer . Based on that experience, findings of simultaneous disorders of pharynx and esophagus in achalasia seem to support our concept of a causal, functional interrelationship between these two compartments of the swallowing chain which consists of the pharynx and esophagus.
Figure 1. Bilateral pharyngeal pouches (black arrows) and asymmetric tilt of epiglottis (open arrows).
Figure 2. Large Zenker's diverticulum. Asymmetry of lateral pharyngeal walls. Note : low position of left piriform sinus.
Common to all disorders of the esophagus mentioned in this context is the response of the cricopharyngeal sphincter to esophageal dilatation, gastroesophageal reflux against the undersurface of the sphincter or stasis of swallowed bolus in cases of esophageal obstruction evoking reflex contraction and spasm of the cricopharyngeal muscle. Contraction and spasm of the sphincter increase intraluminal pressure in the sphincter segment , Over time, prominence of the cricopharyngeal muscle can be seen radiologically as a soft tissue filling defect posteriorly. To overcome the hypertensive sphincter mechanism as a partly obstructive barrier to bolus flow from the pharynx into the esophagus, prolonged and increased pharyngeal constriction is required. The resultant rise of intraluminal pressure within the pharyngeal cavity will be transmitted to and ultimately affect the walls of the pharynx. Ballooning and out-pouching of their weakest segments will follow. Asymmetry of the pharynx during swallowing may develop due to uneven wall weakness. It is our impression that such weakness is caused by esophageal regurgitation or prolonged retention of bolus in the valleculae or piriform sinuses. Inflammation and occasional scarring of the pharyngeal wall will follow.
Regurgitation of barium from the distended esophagus, often filled to capacity with fluid and food particles, into the pharynx is frequently observed in achalasia patients during fluoroscopy. It happens more commonly with the patient in a recumbent position and, therefore, particularly at night. Regurgitation may occur in small amounts and may go unnoticed by the patient (silent regurgitation). It has been shown to be responsible for respiratory symptoms, including asthma, laryngeal granuloma, posterior laryngitis, and contact ulcers of the larynx.
Cricopharyngeal response to achalasia of the esophagus, i.e. protective sphincter spasm, increase of intraluminal sphincter pressure and subsequent narrowing of the pharyngoesophageal segment, is symptomatic. Hence, symptoms localized to the neck may signal esophageal obstruction or gastroesophageal reflux, referred to as « high dysphagia »[4-6]. Occasionally referred to as « globus sensation », the symptoms are real and not psychogenic in nature.
Although symptoms in patients with achalasia vary greatly or may be absent over prolonged periods of time throughout the course of the illness, pharyngeal abnormalities may be seen during fluoroscopy and on dynamic recordings.
Some of them may become symptomatic because of cricopharyngeal sphincter prominence or a large Zenker's diverticulum, others are incidental findings during barium swallow examinations such as small pharyngeal pouches and pharyngeal wall asymmetry. While regurgitation of esophageal contents into the pharyngeal cavity may result in only slowly progressive abnormalities, airway penetration and aspiration of liquids and food particles may be more significant, and early diagnosis during dynamic recording of barium swallowing examinations is desirable.
Pharyngeal findings in eleven of twenty-one patients with esophageal achalasia suggest disorders of pharyngo-esophageal interrelationship rather than coincidence. The radiographic examination should therefore include the pharynx and esophagus for early identification of all abnormalities in both structures.