SUMMARY: The distal medial striate artery is part of the brain circulation, born from the anterior cerebral artery generally at the level of the anterior
communicating artery, although according to different studies its origin varies, being thus difficult to determine with accuracy.
The main branches of the internal carotid artery system in the brain are the ophthalmic artery, the anterior cerebral artery, the middle cerebral artery, the anterior choroidal artery, and the posterior
communicating artery. The basal ganglia are supplied by the deep perforating branch of the middle cerebral artery.
Foetal type posterior
communicating artery (FTPcomA) was considered when the posterior cerebral artery (PCA) originated from the ipsilateral internal carotid artery (ICA) instead of the basilar artery with diameter greater than the ipsilateral pre-communicating segment (P1) of the PCA.12 Vessel arising from ICA with equal or smaller diameter than the ipsilateral P1 of the PCA were classified as PcomAs.12 COW was then classified as complete, partially complete and incomplete configuration.
Structural imaging scans demonstrated that complete agenesis of P1 and absence of the posterior
communicating artery (PCoA) maybe found unilaterally (in 4-26% subjects) or bilaterally (in 2-4% cases) [1, 2, 5, 6].
MRI angiography revealed short high-grade stenosis of the right vertebral artery (VA) in the V3 segment (Figure 2(a)), a hypoplastic left VA, and a patent posterior
communicating artery on the right side.
V7 denotes the communicating segment of the ICA which rises from the posterior
communicating artery and bifurcates into the anterior cerebral artery and the middle cerebral artery.
The left MCA was noted to be supplied by a patent and prominent left posterior
communicating artery on CTA imaging (not shown).
The following morning a cerebral arteriogram confirmed a berry aneurysm, which was located on the posterior
communicating artery. She immediately went to the operating room where the aneurysm was clipped.
The grade of ICA stenosis and all parts of the CoW, including the anterior cerebral artery (ACA), posterior cerebral artery (PCA), middle cerebral artery (MCA), anterior
communicating artery (ACoA), and posterior
communicating artery (PCoA), were measured.
Angiographic examination showed saccular aneurysm at the bifurcation of the right middle cerebral artery (MCA) of 4.3 mm in size, with the 2.1 mm wide neck, aneurysm in the anterior
communicating artery (ACoA) of 4.3 mm in size with the 1.7 mm wide neck, and two aneurysmatic narrowings in the middle segment of basilar artery (BA), with the right one 3.6 mm (neck width 2 mm) and the left one 2.3 mm in size (neck width 1.8 mm), and embolized aneurysm at the BA bifurcation (Fig.