Cricopharyngeal Dysfunction in Chronic Obstructive Pulmonary Disease: DISCUSSION

5 Apr

Patients with COPD are commonly subject to frequent exacerbations which are assumed to be related to infection or bronchial hyperreactivity. Herein we have identified an additional factor, crico­pharyngeal achalasia, in 21 of 25 patients. In 17 of these patients, it was judged to be severe, and in retrospect, all were found to have some degree of symptomatic dysphagia. Surgical correction in ten of them was associated with definite clinical improve­ment of pulmonary symptoms in eight.

Aspiration of gastric secretions into the tracheo­bronchial tree is already considered a potential cause of chronic pulmonary disease. Hiatal hernia with gastroesophageal reflux has been associated with pul­monary fibrosis and with severe asthma. Symptoms suggestive of aspiration (specifically, recumbent cough) have been reported in 10 to 50 percent of the patients with reflux, and occult aspiration has been docu­mented by radionuclide studies. The predominant reflux-permissive condition identified in these reports has been incompetence of the lower esophageal sphincter, with or without associated hiatal hernia; however, dysfunction of the upper esophageal sphinc­ter, (in large part, the cricopharyngeal) has received much less attention.

The cricopharyngeal and adjacent muscles have been referred to as the “gatekeeper” of the esopha­gus. The cricopharyngeal muscle is normally con­tracted except during swallowing, vomiting, and belch­ing. It is believed that the primary function of this muscle is to prevent esophageal respiration. viagra 10 mg

The act of swallowing involves a complex mechanism requiring precise coordination of the tongue, larynx, pharynx, and upper esophagus. Esophageal manom­etry has identified as part of this mechanism a pressure zone corresponding to the cricopharyngeal muscle and adjacent pharyngeal and esophageal muscles. This zone has the characteristics of a sphincter. It relaxes with swallowing, just before and including the period of pharyngeal contraction, and subsequently contracts to initiate the primary peristaltic wave of the esopha­gus.

Many conditions may disrupt the coordinated events that characterize normal pharyngoesophageal func­tion. These include central nervous system lesions, conditions affecting muscle function directly, major oropharyngeal surgery, and idiopathic sphincteric in­coordination. Achalasia is the most common disorder of the muscle. It can be defined for most patients as failure of the muscle to relax quickly enough during deglutition to permit the bolus to pass freely through the hypopharynx into the esophagus. In others the cricopharyngeal muscle relaxes properly but then closes too quickly, before the whole bolus is able to move into the esophagus.

Although symptomatic cricopharyngeal achalasia is uncommon, a prominent cricopharyngeal bar can be seen in about 5 percent of barium studies of the pharyngoesophageal area. In addition, Paget and Pouillet, who made detailed upper gastrointestinal studies in 100 symptomless subjects more than 65 years old, found that 38 percent of the men and 15 percent of the women had neurologic dysfunction within the hypopharynx, with either pharyngeal hy- potonicity, failure of the cricopharyngeal muscle to relax, or puddling in the valleculae and piriform sinuses. buy antibiotics canada

The precise role or incidence of cricopharyngeal dysfunction in patients with COPD is not known at the present time. Cricopharyngeal dysfunction may precede the airways obstruction and contribute to subsequent progression and exacerbations of the air­ways abnormality. Alternatively, cricopharyngeal dys­function may be secondary to COPD in some patients. Another possibility is that the two conditions may be related to common etiologic factors.