Cricopharyngeal Dysfunction and Zenker Diverticulum

Clinical Evaluation

Symptom assessment of a patient with dysphagia is essential for a correct diagnosis. In the case of oropharyngeal dysphagia, the patient clearly describes his/her difficulty in transferring food from the mouth to the pharynx and the esophagus and to initiate the involuntary (esophageal) phase of swallowing. The patient is usually very accurate in describing the accumulation of food in the mouth, an inability to control the bolus in the oral cavity, the aspiration of food before, during, or after the swallowing act, and the location where the bolus has gotten stuck. Often patients with esophageal dysphagia also locate the level of food arrest at the cervical region, making the perceived location of food arrest inaccurate for determining the etiology of the process. Associated symptoms of oropharyngeal dysphagia include nasal regurgitation and cough related to the inadequacy of protective mechanisms, and dysarthria or nasal speech related to weakness of the palate. A gurgle sound may suggest a Zenker diverticulum (ZD; see later). Other symptoms, when present, may be useful for the final diagnosis, such as a speech disorder or other signs of impairment of cranial nerves. Often dysphagia is only part of the symptom complex of the patient, and the diagnosis of a neuromuscular disorder is well evident; however, sometimes dysphagia is the first symptom that causes the patient to be seen by a doctor, and only the subsequent physical and neurologic examination may reveal the underlying disease. Finally, weight loss may be the only sign of a swallowing disorder, since patients may avoid eating because of the difficulties they experience.

Endoscopic Evaluation

Since dysphagia is an ominous sign, endoscopy is mandatory to rule out any anatomic abnormality or organic disease, especially cancer. It must be performed with the maximum care, avoiding undue efforts to penetrate the cervical esophagus if resistance or abnormalities are encountered, since iatrogenic perforation may occur, especially if a ZD is present. Careful examination of the entire esophageal body and cardia must be performed to rule out other gastroesophageal diseases, namely reflux, that may affect the swallowing capabilities of the patient. Rarely, rigid endoscopy under general anesthesia may be required. Laryngoscopy usually completes the endoscopic evaluation of the patient with oropharyngeal dysphagia. This can be also part of a functional evaluation of the swallowing act (see subsequent text).

Radiologic Studies

The definitive diagnosis and the exact quantification of the swallowing disorder are possible only through a careful examination. Conventional studies (barium swallow) are usually inadequate because of the rapidity of events during these initial phases of swallowing. They may reveal, however, possible anatomic abnormalities, such as strictures, webs, diverticula, or the so-called cricopharyngeal bar ( Fig. 11.1 ). Videofluoroscopic evaluation of swallowing, with digital high-frequency recording, is the test of choice, since it allows recording of the rapid movements of mouth, pharynx, palate, epiglottis, larynx, and cervical esophagus during the act of swallowing a liquid or solid contrast bolus, typically using varied volume and consistency, and can identify the presence and mechanism of dysfunction. The patient should be studied in both the anterior-posterior (AP) and lateral positions. Possible swallowing dysfunction can be categorized into four groups: (1) motility disorders, (2) stasis in the pharyngeal recesses, (3) pharyngeal stasis, and (4) incoordination (aspiration or laryngeal penetration). The motility disorders may be represented by a delayed beginning of the swallowing itself; repetitive attempts may be observed with the tongue moving backward for several times before an effective swallow begins. A “lazy,” or a completely disorganized, motor activity can be seen, which is often followed by stasis or aspiration. Pharyngeal stasis without a distal organic obstruction is another radiologic sign of a motility pharyngeal disorder. Finally, incoordination with penetration of the bolus into the larynx and aspiration is one of the most common alterations seen in a patient with pharyngoesophageal dysphagia. In a high percentage of patients, these alterations may be variously combined.

Videofluoroscopy has limitations, however, such as the need for radiation, the necessity to move the patient to the radiologic suite, and the mainly qualitative nature of information obtained. Numerical measures such as the timing of opening or closing of the glossopharyngeal junction, laryngeal vestibule, and UES are not routinely collected in clinical practice, presumably because they are considered too time-consuming and cumbersome. Some scoring systems have been proposed, however, and the Penetration-Aspiration Scale is the most used and validated scoring system to assess the presence and severity of aspiration and penetration related to swallowing.

Fiberoptic Endoscopic Evaluation of Swallowing

The fiberoptic endoscopic evaluation of swallowing (FEES) using a flexible laryngoscope has been also introduced. It allows evaluating pharyngeal and laryngeal structures before, during, and after deglutition, and is generally well-tolerated, easily repeatable, and can be performed at the bedside of the patient. During the test, the endoscope is introduced transnasally and advanced to enable visualization of the mucosal surface and movement of the tongue base, pharynx and larynx, as well as the bolus transit and airway protection. The patient is asked to swallow a variety of foods and liquids with a coloring contrast (blue dye). During the normal swallow, however, a blind period of approximately 0.5 second occurs when the epiglottis tilts backward and the pharynx squeezes, preventing the complete visualization of the actual passage of the bolus. The presence of secretion, residual colorized food in the pharynx, or its penetration or aspiration in the airway provides useful qualitative information on the deglutitive capacity of the patient and allows the calculation of a Penetration-Aspiration Scale, in a similar way as the videofluorography. The main limitation of FEES is that it does not allow a direct evaluation of the swallow physiology but only relies on indirect and subjective interpretation of findings such as residual food and/or penetration.

Manometry

Conventional, water-perfused manometry can evaluate the entire esophagus, in addition to the pharyngoesophageal region to rule out any esophageal motor disorders and to verify the function and competency of both the UES and the lower esophageal sphincter (LES). The evaluation of the pharyngoesophageal tract quantifies the strength and the coordination of the pharyngeal contractions, the completeness of the UES relaxation, and its coordination with the pharyngeal wave. The test can be very useful, provided some aspects are kept in consideration. First, during deglutition there is a 2-cm orad movement of the whole laryngopharyngoesophageal block; therefore if using a single recording point placed in the UES, this may be found to record the events in the cervical esophagus during swallowing. To avoid this problem, a sleeve sensor recording over a 6-cm length has been introduced and used in some important studies, but its use may be cumbersome in the routine practice. Furthermore, the radial asymmetry of the sphincter requires multiple recording sites on different directions, or a circumferential pressure sensing microtransducer. A second and more relevant problem is given by the rapidity of the pressure events. In the normal state, pharyngeal contractions may reach 600 mm Hg with a duration of 0.5 to 1.0 second: perfused systems may therefore underestimate the real amplitude and coordination of these contractions. Modern catheters, based on solid-state microtransducers, allow for a better and more reliable recording of these rapid events.

Because of all these caveats, the real frequency and type of pharyngoesophageal alterations are highly underestimated and unknown. Other manometric parameters have been introduced to better evaluate these patients. Cook et al. focused on the intrabolus pressure that is increased in patients with pharyngoesophageal dysfunction and in those with a ZD, as a counterpart of a reduced compliance of the pharyngoesophageal segment and the UES that, in combined manometric and radiologic studies, may be shown to be manometrically but not anatomically relaxed ( Fig. 11.2 ).

The advent of the high-resolution manometry (HRM) in the past decade has greatly enhanced the possibility of further investigating the muscular function of the pharynx and UES during swallowing. HRM measures contractile activity using a transnasal catheter with closely spaced pressure sensors along the entire length of pharynx, the UES segment, and the esophagus as well. HRM has improved the use of manometry in performing pharyngoesophageal function studies, but further work on its clinical implementation is needed. The possibility of combining this technique with videofluoroscopy has allowed for a more complete understanding of bolus transport because of the pharyngoesophageal motor patterns ( Fig. 11.3 ).