The pharyngeal pouch
A pharyngeal pouch is a pulsion diverticulum of the pharyngeal mucosa through a weakening between the cricopharyngeus and thyropharyngeus muscles at the top of the oesophagus.1 These muscles collectively form the upper oesophageal sphincter. The pressure generated by swallowing can over time result in an out-pouching of the underlying mucosa through this weakness in the muscles. The exact reason why some people get pharyngeal pouches and others do not is unknown, but several theories exist. The more well known include incoordination of the swallowing reflex, resulting in more pressure in the superior oesophageal sphincter, which results in a pulsion diverticulum forming.
Pharyngeal pouch affects about 1 in 200 000 people a year in the United Kingdom.2 It usually occurs in elderly people. The prevalence is greater in men than in women and is greater in the West and Europe than elsewhere. Because Asian emigrants to the West share the raised