Objective: Coil embolization for wide-necked and bilobulated aneurysms remains a technical challenge even with stent assistance. Stent assistance prevents coil protrusion to the parent vessel, but restricts microcatheter movement. The restriction of microcatheter movement makes the role of the coil’s shape memory important on the coil distribution within the aneurysm. We aimed to determine which coils are appropriate for wide-necked and bilobulated aneurysms with stent assistance by investigating the distribution of coils with differing shape memory.
Methods: A silicone bilobulated aneurysm model was used to compare three types of coils (ED coil Infini, Axium Helix, and Axium 3D). Coil performance was assessed using three parameters: (1) the effect of stent assistance on coil distribution, (2) the difference in first coil distribution caused by a difference in shape memory, and (3) the influence of first coil distribution on second coil distribution.
Results: Without stent assistance, coil protrusion into the parent vessel was detected immediately after beginning coil insertion for ED coil Infini; however, this coil protrusion was prevented using stent assistance. With stent assistance, the lowest shape memory coil resulted in the most homogenous distribution. The distribution of second coil was influenced by first coil.
Conclusion: Without stent assistance, low shape memory coil was more likely to prolapse into the parent vessel compared to higher shape memory coil. When combined with a stent, the low shape memory coil demonstrated more homogenous distribution of the aneurysm compared to the higher shape memory coil, and allowed denser packing.

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Objective: The study was designed to evaluate the occlusive lesions in the subclavian or innominate artery, in 16 patients who were treated with percutaneous transluminal angioplasty with stent placement (stenting) from June 2009 to July 2012.
Methods: Pre- and postoperative neurological symptoms and embolic lesions were evaluated using diffusion-weighted imaging (DWI) in the 16 patients.
Results: Of the 16 patients, 10 had subclavian artery stenosis (8 with left and 2 with right artery stenosis), 4 had subclavian artery occlusion (3 with left and 1 with right artery occlusion), and 2 had innominate artery stenosis. The technical success rate of stenting was 100%, and the vertebral artery was not protected in any of the procedures. Preand postoperative neurological symptoms were not observed. New DWI lesions were not detected in any patient with subclavian or innominate artery stenosis; however, they were detected in all the patients with subclavian artery occlusion in the region of the vertebral and internal carotid artery.
Conclusion: New DWI lesions were detected and were widespread in all the patients with subclavian artery occlusion. It should be considered to protect the ipsilateral vertebral artery during the stenting, though the procedure of stenting of subclavian artery occlusion becomes complicated.

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Objective: We report a case of recurrent dural arteriovenous fistula (dAVF) at the transverse-sigmoid junction cured using transvenous n-butyl-cyanoacrylate (NBCA) injection in combination with platinum coils.
Case presentation: A 70-year-old man presented with headache and dizziness 32 months after embolization for dAVF, which had been considered obliterated. MRI of the head showed brain edema in the left cerebellar hemisphere and some flow voids on the surface of the left cerebellum. Cerebral angiography demonstrated a recurrent shunt with cortical venous reflux and transvenous embolization was performed. After we deployed coils in the compartmentalized transverse sinus, venography from the microcatheter showed the left occipital and middle meningeal artery filled in a retrograde manner. Septa inside the left transverse sinus made navigation of the microcatheter and deployment of coils in the left transverse sinus near the fistulous point difficult. We injected NBCA from the transverse sinus, beyond the fistulous point, to the most distal part of the feeders. Control angiography revealed elimination of the shunt.
Conclusion: In dAVF cases with an isolated sinus, transvenous injection of the NBCA can eliminate the shunt after occluding the cortical venous outlet. To avoid complications, sufficient anatomical knowledge and a sophisticated technique for NBCA injection are necessary.

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Objectives: We herein report a case of a ruptured intrameatal aneurysm of the distal anterior inferior cerebellar artery (AICA) treated by coil embolization with preservation of the parent artery in the acute stage. We also discuss the efficacy of endovascular treatment (EVT) for such a lesion.
Case presentation: An 83-year-old woman developed headache and vomiting of sudden onset and was urgently transported to our hospital. Head CT revealed subarachnoid hemorrhage, but cerebral angiography performed on the same day did not reveal the causative pathology. Vertebral angiography was performed 5 days later and demonstrated a small aneurysm of the right distal AICA. 3D-CT showed that the aneurysm was located in the internal auditory meatus. Considering the patient’s age, clinical course, and aneurysm site, we chose to perform EVT rather than direct surgery. Two sessions of coil embolization were required for complete packing of the aneurysm because of regrowth of the residual neck after the first EVT. After EVT, the patient developed right-sided ataxia due to a small infarction of the middle cerebellar peduncle. However, the ataxia resolved rapidly, and she was transferred for rehabilitation on day 28.
Conclusion: Intrameatal aneurysm is rare. EVT may be a good treatment choice for such an aneurysm because of its minimal invasiveness and its ability to prevent damage to cranial nerves VII and VIII in the acute stage.

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Objective: In the present report, we describe a case of progressive cerebral infarction wherein stent implantation was performed for a stenotic lesion at the origin of the persistent primitive proatlantal artery (PPPA), and resulted in internal carotid artery (ICA) stenosis due to postoperative plaque shift.
Case presentation: A 71-year-old man visited our hospital with an episode of transient left hemiplegia. During medical therapy, a progressive cerebral infarction was observed. Digital subtraction angiography revealed stenosis in the PPPA, suggesting a pathological basis for the arteriogenic embolism. A stent was implanted, and the stenotic lesion was well dilated. Subsequently, the plaque shifted to the ICA.
Conclusion: Although plaque shift is a rare phenomenon in neuroendovascular therapy, preoperative assessment of plaque localization appears to be important for stent implantation at a stenotic lesion at the carotid bifurcation.

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Objective: We report a case of neurofibromatosis type 1 with ruptured extracranial giant internal carotid artery (ICA) aneurysm, treated by endovascular trapping using a triple coaxial catheter system.
Case presentation: A 41-year-old female presented with dysphagia, and acutely appeared and enlarged left neck mass. Cerebral angiography, MRI, and contrast CT revealed ruptured extracranial giant ICA aneurysm. Since urgent treatment was necessary, endovascular coil-trapping was planned, considering the vulnerable aneurysmal wall. Initially, a microcatheter was easily kicked back and fallen down into the aneurysm during coil placement of the distal ICA. Next, we tried it with triple coaxial catheter system, using 4Fr inner catheter and balloon guiding catheter, which made the procedure of the distal and proximal ICA trapping stable and easy. Endovascular trapping was finished successfully and her symptoms were improved.
Conclusion: A triple coaxial catheter system was considered to be effective in endovascular trapping for treatment of a giant aneurysm with coils.

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Objective: Because the Excelsior XT-27 has a large lumen, it may generate a “ledge effect” when following a micro-guidewire, hampering its passage through the rim of an aneurysm neck or bifurcation. Here, we report a case of successful mitigation of the ledge effect using a double-wire technique (DWT).
Case: A 75-year-old woman underwent stent-assisted coil embolization that incidentally revealed a basilar tip aneurysm. The difference in diameters of the large XT-27 lumen and the micro-guidewire generated the ledge effect and prevented the XT-27 from passing through the rim of the aneurysm neck. We leveraged the large lumen of the XT-27 by inserting a second guidewire within it to mitigate the ledge effect. The XT-27 ultimately moved smoothly to the distal posterior cerebral artery.
Conclusion: The DWT described here is useful for overcoming the ledge effect when a large-lumen microcatheter is used within the intracranial arteries.

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Purpose: Here we describe a novel technique named “half-bridge stenting method,” in which the aneurysmal neck was partially covered by a single stent before coiling with a microcatheter through the open side.
Case presentation: Two cases of broad-necked terminal-type aneurysm and one broad-necked lateral wall-type aneurysm were treated. The stents were deployed from a unilateral branch or distal parent artery to the aneurysmal neck with a trumpet-like. All aneurysms were satisfactorily embolized with coils.
Conclusions: This technique can be used to smoothly insert coils into the aneurysms without restriction of the microcatheter by the stents. Furthermore, additional stenting and coiling can also be performed in case of retreatment.

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Objective: We present a new technique called balloon-assisted penetration technique for intraluminal crossing of chronic total occlusion of the subclavian artery.
Case presentation: A 74-year-old man was diagnosed as vertebrobasilar insufficiency due to the left subclavian artery occlusion. Via the transbrachial approach, balloon guiding catheter was positioned near the distal cap of the occluded segment and the balloon was inflated gently to fix against the vessel wall. The micro-guidewire was penetrated through the distal cap and crossed the true lumen of the occluded segment. Stenting was performed successfully without any complications. The balloon-guiding catheter was used for backup support and precise central targeting.
Conclusion: Balloon-assisted penetration technique is useful for intraluminal crossing of the chronic occluded vessels.

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