Posterior cerebral artery aneurysm (P2P segment): case report and review of the literature

Case Presentation: A 55-years old man investigating chronic headache found a saccular aneurysm located just posterior to the most lateral portion of the right cerebral peduncle. Digital subtraction arteriography revealed a 7.8mm × 5.6m.m × 4.8mm posterior-medial projecting aneurysm of the right PCA, segment P2P. A subtemporal approach was performed with partial aspiration of the right parahippocampal gyrus for better exposure of vascular structures. Proximal temporary occlusion of PCA was performed at the segment P2A. The aneurysm was clipped two semi-curved clips. The patient presented an uneventful recovery and was discharged home on the third post-operative day not having any additional neurological deficits.

Discussion: Aneurysms of the posterior cerebral artery (PCA) represent approximately 1% of all intracranial aneurysms and usually present with subarachnoid hemorrhage. Because of its deep location, they remain anatomical relationship with brain stem and surrounding structures making the surgical approach complex and associated with the risk of serious complications. Considering the posterior segment of the PCA, both surgical and endovascular treatment are viable – each one with its nuances. A subtemporal approach is usually preferred for the surgical treatment of aneurysm of P2 or P3 segments. Complications include ischemic damage (usually due to manipulation of perforating arteries or clipping of the main vessel) and rebleeding in the surgical site.

Final Comments: PCA aneurysm is an uncommon vascular disease that challenges neurosurgeons’ ability due to its many anatomical nuances, vast number of perforators and risk of bleeding. However, the operative management of PCA aneurysm is technically feasible, safe and effective when performed respecting microsurgical principals.