Killian's dehisense is seen in:
High-Yield Explanation
It is the area of weakness between the two pas of inferior constrictor muscle-subthyropharyngeus and cricopharyngeus. Since it is an area of weakness it is one of the sites of esophageal perforation duting instrumentation and scopy-hence also called gateway of tears. It is lined by stratified squamous epithelium. Ref Dhingra 5/e,p 253,6/e,p 238.