Fenestrations of the human posterior cerebral artery.

Background: The posterior cerebral artery (PCA), as a paired terminal branch of the basilar artery, runs through four segments (P1 to P4) to the inferior and medial surfaces of the occipital and a part of the temporal lobes. There are many PCA variants in its course. The literature data indicated that a fenestration of the PCA was very rare and that its clinical significance is unknown. The purpose of this investigation was to present the frequency, location, and some morphological features of PCA fenestration in the prenatal and postnatal period.

Method: Using brain bases of 468 (200 fetal and 268 adult) cadavers, we applied macroscopic and microscopic investigation.

Results: We found four (0.85 %) cases of PCA fenestrations-two at the left and right P1 segment of fetuses, respectively, then one adult at the left P2 segment, as well as one adult at one right PCA of the two existing arteries. There were associated multiple vascular abnormalities in one adult case. We did not find any case of PCA aneurysm originating from fenestration, as well as from PCA without fenestration.

Conclusion: The frequency, segment, and side location, as well as the size and shape of PCA fenestrations in specimens of our population did not significantly differ from the same in other populations. PCA fenestrations in our adult specimens were not the bases of aneurysms.