aetiology
Last reviewed 01/2018
A pharyngeal pouch arises as a result of increased cricopharyngeal pressure over a long period of time. Spasm or failure of relaxation results in increased pressure during deglutition by contraction of the pharyngeal constrictor muscles at the start of swallowing.
A diverticulum begins initially as a localised swelling at Killian's dehiscence, but increases gradually with time, often descending to the left side adjacent to the oesophagus due to deflection by the vertebral column. It may descend as far as the superior mediastinum.