PMC10017120_01
Neuroimaging and intraoperative findings in Case 1.
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Computed tomography (CT) on admission reveals diffuse subarachnoid hemorrhage (SAH) and intracerebral hemorrhage in the right frontal lobe (A). CT angiography (CTA) shows an aneurysm at the non-branching site of the right intracranial internal carotid artery (ICA) anterior wall (bold arrow; B). After extradural anterior clinoidectomy, the extradural approach with dural incision reveals the ICA C3 portion (arrowhead; C). After securing the proximal ICA of the aneurysm with minimized frontal lobe retraction and applying the temporary clip (D), the ICA and aneurysm with clots are exposed (E). When the clots are removed after trapping of the aneurysm, there are no visible aneurysmal neck and wall on the ICA, suggesting a pseudoaneurysm (F; double thin arrow, the rupture point). The schema (G) presents securement of the ICA C3 portion (red arrowhead) and the direction of dissecting the aneurysm (blue arrow; from the ICA C3 portion to the distal C1 portion via space produced by anterior clinoidectomy). Postoperative CTA shows that the aneurysm is occluded (H). Double arrowhead, incised dura; thin arrow, distal dural ring. *Optic nerve.
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Computed tomography (CT) of the head revealed diffuse subarachnoid hemorrhage (SAH) with intracerebral hemorrhage [Fig. 1A]. CT angiography (CTA) showed right ICA anterior wall aneurysm with no neck and branching [Fig. 1B], suggesting an ICA PA based on the shape and site of origin. After performing an extracranial-intracranial (EC-IC) bypass using the great saphenous vein as a graft, EAC and the extradural approach with dural incision was performed to secure the ICA C3 portion [Fig. 1C]. After the proximal ICA of the aneurysm was secured with minimized retraction of the frontal lobe and the temporary clip was applied [Fig. 1D], the ICA and a PA with clots were exposed [Fig. 1E]. When the blood clots were removed after trapping, no aneurysmal neck and wall were observed on the ICA, confirming that the aneurysm was a PA [Fig. 1F]. PA dissection in this case is presented in the schema [Fig. 1G]. Postoperative CTA revealed the occluded ICA PA [Fig. 1H].
PMC10017120_02
Neuroimaging and intraoperative findings in Case 2.
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Computed tomography on admission shows diffuse subarachnoid hemorrhage (A). Digital subtraction angiography (DSA) on admission shows a slight aneurysmal dilatation (bold arrow) in the right internal carotid artery (ICA; B), which is increased in size on follow-up DSA (C). Through extradural anterior clinoidectomy and the extradural approach with dural incision, the ICA C3 portion (arrowhead) is secured (D; thin arrow, distal dural ring; double arrowhead, incised dura). After the optic canal opening, the rupture point is being checked by rotating the ICA inward (E) or outward (F). The rupture point (double thin arrow) on the posterior wall of the ICA is exposed (F; triple arrowhead, ophthalmic artery), followed by complete trapping (G). The schema (H) presents securement of the ICA C3 portion (red arrowhead) and the ICA mobility to expose the BBA (two-way arrow). Postoperative magnetic resonance angiography shows that the BBA is occluded (I). *Optic nerve.
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On admission, the patient was alert, and CT of the head revealed diffuse SAH [Fig. 2A]. Digital subtraction angiography (DSA) on admission showed right ICA stenosis distal to the ophthalmic artery (OphA) and a very small aneurysmal dilatation dorsal to the stenosis, which was equivocal if it was a BBA [Fig. 2B]. On the 10th day, follow-up DSA revealed enlarged aneurysmal dilatation of the posterior wall of the right ICA [Fig. 2C], which was identified as the source of bleeding. EC-IC bypass using a great saphenous vein and EAC and the extradural approach with dural incision were performed to secure the ICA C3 portion and OphA as in Case 1 [Fig. 2D], and the Sylvian fissure was opened via a trans-Sylvian approach. Optic canal opening resulted in the securement of sufficient optico-carotid space by obtaining the optic nerve mobility, and by incising the dural ring and rotating the ICA both inward [Fig. 2E] and outward [Fig. 2F], the rupture point on the posterior wall of the ICA was exposed [Fig. 2F], leading to complete trapping [Fig. 2G]. The operative approach in this case is presented in the schema [Fig. 2H]. Because of bronchial asthma, only magnetic resonance angiography was performed postoperatively to show that there was no obvious BBA recurrence [Fig. 2I].