PMC4429336_01
AP and lateral left CCA injection demonstrating complete passage of blood from the left internal carotid artery (ICA) into the left cavernous sinus, with shunting into the right cavernous sinus. A vessel supplying the IMAX territory is noted to arise from the petrous segment of the left ICA
SNI-6-74-g001.jpg
PMC4429336_01_SNI-6-74-g001.jpg
F1
Additionally, the territory typically supplied by the left internal maxillary artery (IMAX) was fed by a prominent vessel originating from the horizontal segment of the left ICA [Figure 1a and b].
AP and lateral right CCA injection demonstrating hypoplastic ECA with absent IMAX. A vessel supplying the IMAX territory arises from the petrous ICA in the expected region of the vidian artery. This finding is better appreciated on the selective ICA injection
SNI-6-74-g002.jpg
PMC4429336_01_SNI-6-74-g002.jpg
F2
Diagnostic right common carotid angiogram demonstrated similar variant anatomy [Figure 2a and b] as well as cross-filling of the left anterior circulation via a patent anterior communicating artery.
Right vertebral artery angiogram showing a large fenestration or unfused middle segment of the basilar artery. The distal basilar artery was unfused and the superior cerebellar arteries arose from the P1 segments of the posterior cerebral arteries bilaterally. A very prominent left posterior communicating artery fills the left supraclinoid ICA and bilateral cavernous sinuses (via direct CCF) in a retrograde fashion
SNI-6-74-g003.jpg
PMC4429336_01_SNI-6-74-g003.jpg
F3
A very prominent left posterior communicating artery fills the left supraclinoid ICA and bilateral cavernous sinuses (via direct CCF) in a retrograde fashion [Figure 3].
Lateral left CCA injection reveals back-filling of CCF from branches of the putative internal maxillary artery via prominent anastomoses from external carotid artery at the same site
SNI-6-74-g004.jpg
PMC4429336_01_SNI-6-74-g004.jpg
F4
Subsequent left CCA injection revealed retrograde filling of the CCF from branches of the putative IMAX via prominent anastomoses from external carotid artery at the same site [Figure 4].
Lateral left CCA injection following coil embolization of the left ICA from below, at the origin of the putative left IMAX, results in occlusion of the cavernous carotid fistula
SNI-6-74-g005.jpg
PMC4429336_01_SNI-6-74-g005.jpg
F5
Successful occlusion of the left ICA, including the aberrant IMAX origin, resulted in obliteration of the CCF [Figure 5].