====== Persistent carotid-vertebrobasilar anastomoses ======

The persistent carotid-vertebrobasilar anastomoses are variant anatomical arterial communications between the anterior and posterior circulations due to abnormal embryological development of the vertebrobasilar system. They are named, with the exception of the proatlantal artery, using the cranial nerves with which they run:

[[persistent trigeminal artery]]

arises from proximal cavernous ICA
most common persistent carotid-vertebrobasilar anastomosis
two types - lateral and medial

Saltzman classification

type I: absent ipsilateral posterior communicating artery

type II: fetal origin of ipsilateral posterior communicating artery

persistent otic (acoustic) artery
controversial, perhaps non-existent
arises from petrous ICA
rare, as it is the first anastomosis to regress
persistent hypoglossal artery
arises from cervical ICA at C1 to C3 levels
persistent proatlantal artery

type I arises from internal carotid artery

type II arises from external carotid artery

A mnemonic to help remember these persistent carotid-vertebrobasilar anastomoses is HOT Pepper.