PMC8769485_01
Preoperative images. CT angiography in the posterior-anterior view reveals the low and early bifurcation of the anomalous ACA at the level of the ophthalmic artery (single white arrow), which turns upward, and an irregular-shaped aneurysm (double white arrow) arises at the junction between this anomalous ACA and bilateral A2 segment of ACAs (A). The left internal carotid angiography (horizontal inversion) shows two recurrent arteries of Heubner (black arrows) and a cortical artery which branch around the aneurysmal neck (B). Heavily T2-weighted magnetic resonance imaging (horizontal inversion) shows the IOA (single black arrowhead) branching from the left ICA (double black arrowheads) beneath the left optic nerve (C), which turns upward between the bilateral optic nerves (single white arrowhead) (D): an IOA aneurysm abuts on the superior part of the lamina terminalis (double white arrowheads) (E). ACA: anterior cerebral artery, CT: computed tomography, ICA: internal carotid artery, IOA: infra-optic course of ACA, L: left, R: right.
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F1
The initial head computed tomography (CT) revealed subarachnoid hemorrhage (SAH) of Fisher CT group 3, and three-dimensional CT angiography and digital subtraction angiography (DSA) showed an ACoA aneurysm, of which the maximum diameter was 5.3 mm, associated with the low bifurcation of the left ICA at the level of the origin of the ophthalmic artery, the left IOA filling bilateral ACA territories, and the right A1 aplasia (Figs. 1A and 1B). T2-weighted magnetic resonance images (Figs. 1C-1E). The patient was diagnosed with aneurysmal SAH of Hunt and Kosnik grade 2 and World Federation of Neurological Surgeons grade 2. As DSA revealed multiple recurrent arteries of Heubner (RAHs) arising around ACoA (Fig. 1B), anterior interhemispheric approach (AIH) was selected to visualize these perforators clearly.
Intraoperative view of the interhemispheric approach before (illustration; A) and after aneurysmal clipping (photograph; B), and postoperative magnetic resonance imaging (MRI; C). The left IOA (single arrow), left A2 segment with fenestration (double arrows), right A2 segment with fenestration (triple arrows), dura mater of the anterior cranial fossa (single black asterisk), optic chiasm (double black asterisks), the left optic nerve (triple black asterisks), a thrombus at the rupture site of the IOA aneurysm (white asterisk), a cortical artery adhering close to the rupture site (single white arrowhead), one of two RAHs branching from the aneurysm (double white arrowheads), and another RAH branching from the supraoptic portion of the IOA (triple white arrowheads) are illustrated (A). One of two RAHs branching from the aneurysm and the cortical artery adhering close to the rupture site are disconnected and the aneurysm is completely obliterated with multiple clipping (B): the marks in the figure are the same as in A. Postoperative diffusion-weighted MRI reveals acute infarction in the left caudate head and a part of the internal capsule and the putamen (C). IOA: infra-optic course of the anterior cerebral artery, L: left, R: right, RAHs: recurrent arteries of Heubner.
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A2 were found during microsurgical dissection. After full exposure of the aneurysm and main perforators, it was revealed that one of two RAHs branched off directly from the aneurysmal dome and that a small cortical branch adhered to nearby the rupture point (Fig. 2A). These vessels were interrupted and the ruptured aneurysm was completely obliterated with tandem clipping using 4 Sugita Titanium II clips (17-001-01, 17-001-03, 17-001-81, and 17-001-86; Mizuho Co., Ltd, Tokyo, Japan) to avoid kinking of the bilateral A2 (Fig. 2B). Postoperative magnetic resonance images showed acute infarction in the left caudate head and internal frontal basal cortex owing to the vessels sacrifice (Fig. 2C).