Flow dynamics in acute ischemic stroke due to embolic occlusion of a fetal posterior cerebral artery treated with endovascular thrombectomy - report of two cases

Acute tandem occlusion stroke in internal carotid artery and fetal posterior cerebral artery: endovascular management

INTRODUCTION

When the posterior cerebral artery arises from the internal carotid artery with an absent P1 segment, it is called fetal posterior cerebral artery (FPCA). It is unclear whether FPCA increases the risk of acute ischemic stroke, and the endovascular treatment of acute ischemic stroke due to acute occlusion of FPCA is not well established.

CASE REPORT

We report a case of acute ischemic stroke due to tandem occlusion of internal carotid artery and ipsilateral fetal posterior cerebral artery treated successfully with acute stenting of proximal lesion and mechanical thrombectomy of distal lesion with excellent neurological and functional outcomes.

CONCLUSION

Although further investigations are needed to determine the best treatment of these patients, endovascular treatment of fetal posterior cerebral artery occlusion is feasible.

Mechanical thrombectomy for acute fetal posterior cerebral artery occlusion with a hidden unruptured cerebral aneurysm: illustrative case

BACKGROUND

Fetal posterior cerebral artery occlusion is rare and often presents with severe neurological symptoms. Although acute recanalization therapy is commonly used for cerebral vessel occlusion, unruptured cerebral aneurysms can be hidden distal to the occluded vessels.

OBSERVATIONS

An 87-year-old man presented with consciousness disturbance and right hemiparesis. The authors diagnosed left fetal posterior cerebral artery occlusion and performed mechanical thrombectomy. A stent retriever was deployed from the middle cerebral artery M1 segment across the mural thrombus of the internal carotid artery. After the first pass, the fetal posterior cerebral artery remained occluded, with confirmation of a contrast effect around the thrombus. Because the anatomical course of the fetal posterior cerebral artery was unidentified, the procedure was stopped. At 1-week recovery, magnetic resonance imaging revealed complete recanalization and a fetal posterior cerebral artery aneurysm hidden within the occluded site. Blood flow was directed to the aneurysm, and the thrombus within the aneurysm simultaneously occluded the fetal posterior cerebral artery.

LESSONS

To avoid critical complications following mechanical thrombectomy for fetal posterior cerebral artery occlusion, hidden aneurysms should be suspected when a “fried egg–like” contrast effect is observed around the thrombus.