Go Back Brain/17. Vessel/Normal, Technique, Anomaly/17.13 - Carotid-Basilar Anastomosis - Trigeminal/ Go to Index

34 year old female with headache.

Several transient segmental connections between anterior carotid and posterior vascular plexus of the hindbrain

Typically regress between 4th and 7th weeks

become congenital persistent anastomoses when they fail to become obliterated

Usually incidental finding with no clinical significance

May be associated with other vascular anomalies (20-25%)

Aneurysm, CCF, AVM.

Named according to the cranial nerve they parallel

From cephalic to caudal:

Trigeminal

Otic

Hypoglossal

Proatlantal intersegmental.

Most common carotid-basilar anastomosis

0.1-0.2%

Cavernous ICA - basilar artery

Posterolateral to trigeminal nerve or through dorsum sellae

“tau” sign on T1 sagittal MRI.

Saltzman type I

PTA supplies distal V-B system

PCOMs absent

BA below anastomosis hypoplastic

Saltzman type II

PTA fills SCAs

PCAs filled by PCOMs.

2nd most common

0.03-0.26%

Cervical ICA (C1-C2 level) - basilar artery.

Very rare

Petrous ICA through internal auditory canal meatus to caudal basilar artery.

Most caudal of anastomoses

Cervical ICA (C2-C3 level) or ECA

Connects to VA between occiput and C1.