Endovascular intervention of acute ischemic stroke due to occlusion of fetal posterior cerebral artery

Abstract

A fetal posterior cerebral artery (FPCA) is an anatomic variant in which the posterior cerebral artery is an embryological derivative of the internal carotid artery. Although most cases of ischemic strokes in patients with FPCAs involve embolic infarcts, emergent large vessel occlusion of a FPCA is extremely rare. We present two cases of successful endovascular intervention for emergent occlusion of a FPCA, one of which is only the second reported case of a mechanical thrombectomy of a FPCA. We review the embryology of FPCA, the controversy regarding its association with cerebral infarcts, and various approaches used in the treatment of such occlusive lesions.

Keywords: Endovascular; fetal posterior cerebral artery; ischemic stroke; posterior cerebral artery; stent retriever; stroke; thrombectomy.

Figure 1.

(a) Computed tomography angiogram showing mural thrombus in right internal carotid artery (ICA), extending into fetal posterior cerebral artery (FPCA). (b), (c) Frontal and lateral views of digital subtraction angiogram (DSA) confirming the intracranial occlusion. Note the thrombus lucency at the expected location of the double density ostium of FPCA (arrow). (d) DSA showing deployed stent retriever within the ICA, across the ostium of the FPCA. (e), (f) Follow-up DSA after thrombectomy showing recanalization of FPCA with restoration of anterograde flow into parieto-occipital and inferior lateral temporal branches.

Figure 2.

(a) Computed tomography (CT) angiogram showing intraluminal thrombus located completely within a right fetal posterior cerebral artery (FPCA) (asterisk). (b) CT perfusion scan showing elevated mean transit time involving the posterior right frontal, right temporal, right parietal, and right occipital lobes. (c) Digital subtraction angiogram (DSA) of cervical right internal carotid artery showing severe stenosis with concomitant intraluminal thrombus. (d), (e) DSA in frontal and lateral views showing patency of traditional anterior circulation, with acute occlusion of FPCA (double arrows). (f) Lateral view in late arterial phase showing intralumal thrombus in FPCA with delayed opacification of P3 segments (dashed arrows). (g) Follow-up magnetic resonance image showing moderate infarct of the right thalamus and occipital lobe, with (h) coronal T2 sequence showing patent recanalization of the FPCA. Note the absence of ipsilateral P1 segment.