Imaging Studies
Video fluoroscopic swallowing study
Traditionally, this study has been the primary tool in the diagnosis of cricopharyngeal achalasia. During VFSS, the patient is asked to swallow barium-coated material of different varieties, including liquid barium, while cineradiographic data are collected as the bolus is followed from swallow initiation in the oral cavity to the delivery of the bolus to the stomach. This provides real-time dynamic assessment of the swallow; the video can subsequently be slowed down and analyzed in more detail.
The classic finding on a diagnostic VFSS of cricopharyngeal achalasia is the presence of the horizontal bar (often called the cricopharyngeal bar) at the level of the cricoid cartilage. This makes a posterior indentation in the barium column that persists throughout the swallow. The VFSS also provides information about the presence or absence of laryngeal spillover, aspiration, nasopharyngeal regurgitation, and pharyngeal stasis, each of which may accompany cricopharyngeal dysfunction. [10]
Other Tests
Recent interest in manometric study of the upper esophageal sphincter (UES) has surfaced in the literature. Lack of data and standardization for this study has prevented the widespread use of manometry in the assessment of cricopharyngeal dysfunction. This is further complicated because manometric measurements may be taken in the anteroposterior direction, lateral direction, or as a radial force. In addition, the presence of the manometer may stimulate cricopharyngeal spasm. Several studies have also demonstrated that the results of UES manometry may contradict findings on VFSS examination. At this point, the diagnostic value of UES manometry has not been thoroughly assessed in the literature.
Histologic Findings
In most instances, a muscle biopsy is not taken during a standard cricopharyngeal myotomy. However, because some authors advocate removing a strip of muscle to prevent reattachment of the sectioned fibers, some data are available on the histopathology of the cricopharyngeus in cricopharyngeal dysfunction. In most cases, the cricopharyngeus muscle is normal on light microscopy. Patients with cricopharyngeal dysfunction related to neuromuscular disorders may demonstrate variable pathology including atrophy, hypertrophy, replacement with fibrotic tissue, or evidence of frank myositis. Special cases of myositis include muscle inflammation associated with dermatomyositis or inclusion body myositis.
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Anatomic location of the cricopharyngeus muscle.
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Typical appearance on swallowing videofluoroscopy of cricopharyngeal achalasia. Note the prominent posterior indentation in the barium column at the level of the larynx.
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Relation of the recurrent laryngeal nerve to the cricoid cartilage.
