Fenestration in the P1 Segment of the Posterior Cerebral Artery

Abstract

The posterior cerebral artery (PCA) has been noted in literature to have anatomical variations, specifically fenestration. Cerebral arteries with fenestrations are uncommon, especially when associated with other vascular pathologies. We report a case here of fenestrations within the P1 segment of the right PCA associated with a right middle cerebral artery (MCA) aneurysm in an elder adult male who presented with a new onset of headaches. The patient was treated with vascular clipping of the MCA and has recovered well. Identifying anatomical variations with appropriate imaging is of particular importance in neuro-interventional procedures as it may have an impact on the procedure itself and consequently post-interventional outcomes.

Apropos of the Simultaneous Absence of Some Embryological Vascular Forerunners and Persistence of Other Ones on the Brain Base in Late Adulthood

“…Generally, the clinical importance of a fenestration relates to the appearance of the aneurysm on itself, as cited [5,6,11], but there were opposite cases. One of these was a case of the right P1 fenestration in a 56-year-old man, associated with an aneurysm of the right middle cerebral artery [10]. Vlajković et al [11] discovered 0.85% of PCA fenestrations among 468 (200 fetal and 268 adults) cadaveric specimens, while Gunnal et al [2] recorded 1.17% of PCA fenestrations among 170 adult cadavers; there were no aneurysms in adult cases in both studies.…”

“…Contrary to the absence of cerebral pathology in this case, the same was discovered in other cases. These examples were as follows: the right PCA fenestration was associated with MCA aneurysm in the case of a 56-year-old man [10], or the left MCA hypoplasia was associated with an aneurysm of post-communicating ACA part−M1 collateral in a 76-year-old man [18], or double ACoA was the basis of the aneurysm on itself artery in a 44-year-old woman [22] or dolichoectasia of the VA and BA was followed by obstructive hydrocephalus in a 60-year-old man [21].…”

“…Arterial abnormalities, such as (total or segmental) aplasia [2][3][4]9], or fenestration [2,5,7,10,11] can be associated with some of the previously mentioned variations. However, both states of arteries could be with [10], or with no cerebral pathology [7,11].…”

Limb Occlusion of P1 Posterior Cerebral Artery Fenestration as a Cause of Stroke

“…2 P1 and the P1 to P2 junction are the most frequent locations. 2,3 Basilar artery fenestration is more common and rarely associated with stroke with an unclear mechanism. [3][4][5] In our case, the caliber of the occluded vessel (Figure [A]) was 2 mm (Fig- ure [B]) and then included within large vessel occlusions.…”