Relatively common, it is mostly a pouch-like tissue formed by the outward protrusion of the mucous membrane and submucosal layer between the thyropharyngeal muscle and cricopharyngeal muscle of the inferior pharyngeal constrictor in the hypopharynx. It is more frequently seen in middle-aged and elderly men.

bubble_chart Etiology

The occurrence of a posterior pharyngeal wall diverticulum is due to the weakness of the pharyngeal wall and increased pressure within the pharyngeal cavity. The thyropharyngeus and cricopharyngeus muscles of the inferior pharyngeal constrictor are prone to separation, while the lower border of the cricopharyngeus muscle is tightly attached to the upper border of the esophagus. If the thyropharyngeus muscle is weak, it can lead to varying degrees of pharyngeal cavity enlargement. When pressure in the laryngopharynx increases, the muscle fibers between the inferior pharyngeal constrictor and the cricopharyngeus muscle separate, causing the mucosa and submucosa to protrude outward, eventually forming a distinct pouch.

bubble_chart Clinical Manifestations

In the early stages, symptoms may include a foreign body sensation in the throat, a feeling of obstruction, and food regurgitation. Retention of food in the diverticulum can lead to fetid mouth odor, foul-smelling breath, and pain when the mucous membrane is inflamed. Difficulty swallowing solid foods is more pronounced than with liquids. Compression of the trachea by the diverticulum may result in an irritating cough or hoarseness. Physical examination may reveal fullness in the lower part of the posterior cervical triangle, with gas or liquid gushing from the mouth upon pressure, sometimes accompanied by a sound, and the mass may shrink.

The diagnosis can be made based on clinical manifestations. Barium meal fluoroscopy reveals barium filling the diverticulum or the presence of gas within it; esophagoscopy shows an opening in the midline of the posterior pharyngeal wall with overflow of retained contents.

bubble_chart Treatment Measures

Small and asymptomatic diverticula may not require immediate treatment, while larger and symptomatic cases can be treated surgically via an external cervical approach or endoscopic surgery. Endoscopic surgery is performed under an esophagoscope, with the longer anterior lip inserted into the esophagus and the posterior lip placed at the diverticulum. Under the scope, the diverticular wall appears as a horizontal ridge, which is then incised with scissors. Hemostasis is achieved through electrocautery, enlarging the opening of the diverticulum to connect with the esophagus, allowing food to pass into the esophagus rather than accumulating in the diverticulum.