Carotid artery stenting (CAS) has recently emerged as a potential alternative to carotid endarterectomy (CEA) in Japan. However, one of its disadvantages is the higher incidence of ischemic complications than CEA, such as distal embolism during or after the procedure. Plaque protrusion (PP) through the stent strut after deployment of the stent has been suggested as one of the major causes of distal embolism, especially in patients with unstable plaques. The need for increased plaque coverage to reduce the risk of PP through the stent struts has led to the development of a double-layer micromesh stent (micromesh stent) system. This stent system has already been used clinically in European countries with good short- to medium-term follow-up results. Also clinical trials evaluating micromesh stents have been completed in Japan. Hence, usefulness of the micromesh stent for CAS is expected. According to the results of several clinical studies, CAS with the double-layer micromesh stent has the potential to minimize distal embolism during or after the procedure even in patients with unstable plaques. However, it may not be suitable for emergency CAS at this point. Also, since results of only short- to medium-term follow-up have been reported, longer-term follow-up will be required in the near future.

Objective: There have been no delayed ischemic complications related to stent-assisted coil embolization (SACE) of cerebral aneurysms at our institution. We demonstrate our strategies for stent placement and postoperative management of antiplatelet therapy to reduce the risk of ischemic complications.

Methods: We analyzed 57 cases of SACE retrospectively. In the procedure, an appropriate stent was selected and placed to fit the arterial wall without impeding on small arterial branches. Two different antiplatelet drugs, including clopidogrel, were used. Six to twelve months after surgery, follow-up angiography was performed to assess the safety of terminating antiplatelet therapy. In cases in which antiplatelet therapy was tapered, the two antiplatelet drugs were switched to clopidogrel alone, and it was subsequently tapered and finally discontinued.

Results: There were 49 cases of SACE in which postoperative antiplatelet therapy was tapered. Among these cases, antiplatelet therapy was discontinued in 35 cases. The mean duration of dual antiplatelet therapy was 10.6 ± 2.8 months, and the mean duration of total antiplatelet therapy was 15.0 ± 2.1 months. Three patients developed SACE-related ischemic stroke, which developed in the early phase after surgery in all.

Conclusion: Antiplatelet therapy can safely be terminated in most cases of SACE. In order to reduce the risk of ischemic complications, stent selection, stent placement, and management of antiplatelet therapy should be performed appropriately. Furthermore, careful follow-up should be continued even after the termination of antiplatelet therapy.

Objective: Internal carotid artery (ICA) dissection is known to cause binary types of stroke, cerebral infarction, and subarachnoid hemorrhage (SAH). However, it is rare that these two pathologies take place in a clinical scenario. We report a case of ICA dissection with ischemic onset, which was followed by SAH on the same day during diagnostic angiography.

Case Presentation: A 60-year-old woman with chronic hypertension rapidly developed right hemiplegia. She had been suffering from slight headache and abnormal sensation in the right limbs 1 week before the ictus. MRI demonstrated small acute infarctions in the left middle cerebral artery (MCA) territory. The left ICA was not visualized on MRA. Diffusion–perfusion mismatch was indicated by the automated image postprocessing system. Endovascular recanalization was planned to prevent the progression of cerebral infarction. After advancing a 5MAX ACE, initial left ICA angiography was performed, resulting in extravasation of contrast medium from the C2 segment of the left ICA. 3D rotational angiography revealed left ICA dissection of the C2 segment. To secure hemostasis, the patient underwent internal trapping at the C1 and C2 segments of the left ICA. Collateral flow to the left MCA via an anterior communicating artery was observed. On day 28, the patient was transferred to a rehabilitation hospital with right hemiplegia and motor aphasia.

Conclusion: In cases of tandem lesions with preceding neurological symptoms, ICA dissection should be considered as one of the causes. Careful injection of contrast medium may be necessary if ICA dissection is strongly suspected.

Objective: We report a case of vertebral artery dissecting aneurysm that caused right lateral medullary infarction, which was treated by endovascular therapy.

Case Presentations: A 57-year-old man developed right-side headache and dysarthria on the day before presentation, and exhibited mouth dropping and dysphagia the following day. Initial MRI demonstrated right lateral medullary infarction with atherothrombotic change with no vessel lesion, and we started infusion and medication administration. Later MRI revealed bilateral vertebral artery dissection, and we treated the growing right vertebral artery dissecting aneurysm by stenting and coils.

Conclusion: The possibility of dissecting lesions should be considered in cases of medullary infarction. Stenting and coil treatment is a useful option for bilateral dissecting vertebral aneurysms.

Objective: To report a case of ruptured anterior cerebral artery dissection treated with stent-assisted coil embolization with overlapping stents.

Case Presentation: A 51-year-old woman developed subarachnoid hemorrhage the day after transient left hemiparesis. Angiography revealed a ruptured anterior cerebral artery dissecting aneurysm. We conducted stent-assisted coil embolization with the overlapping stent technique on the day after the hemorrhage. She recovered steadily without rebleeding. Six months after embolization, no recurrence was found on angiography.

Conclusion: Although an acceptable result was achieved in this case, the safety and efficacy of this procedure are unconfirmed. A larger number of cases should be accumulated.

Objective: The course of the vessel affects the success of recanalization and can cause complications in mechanical thrombectomy (MT); however, no study has been reported a method for outlining vessel course prior to MT. We propose magnetic resonance (MR) fusion images as a useful tool in MT for acute ischemic stroke.

Case Presentations: A 73-year-old woman and a 79-year-old man were admitted to our hospital with left hemiparesis. In both patients, MR revealed acute ischemic stroke due to right middle cerebral artery (MCA) occlusion. MR fusion images were created with 3D T2-weighted sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) and 3D time-of-flight (TOF) MRA acquired before MT clearly revealed the occluded right MCA. In both cases, the fusion image is enabled information about the course of the right MCA and its branches to be obtained prior to performing MT. The thrombi were removed with a stent retriever and reperfusion catheter with no complications, and there was remarkable resolution of symptoms in both patients immediately after the procedure.

Conclusion: A fusion image of T2-weighted SPACE and 3D TOF MRA appears to be a simple and effective method for determining the course of the occluded vessel prior to MT for acute ischemic stroke. This technique will enable good recanalization in MT for acute ischemic stroke and should reduce complications.

Objective: We report a case of a low-profile visualized intraluminal support device (LVIS) being deployed and protruded into an aneurysmal neck in a barrel-like shape to perform dense coil embolization while preserving the branch vessel from the aneurysmal dome in order to prevent aneurysmal enlargement.

Case Presentation: A 74-year-old woman had a recurrent large cerebral aneurysm at the bifurcation of the basilar artery and the left superior cerebellar artery (SCA). Therefore, an LVIS was deployed from the left posterior cerebral artery to the basilar artery and protruded into the aneurysmal neck in a barrel-like shape to increase its metal coverage ratio. As the barrel-shaped protruding LVIS served as a scaffold to support the coils, dense coil embolization was performed while preserving the SCA branching from the aneurysmal dome. Images obtained at 6 months and 1 year after the embolization confirmed preservation of the SCA and prevention of aneurysmal enlargement.

Conclusion: Protruding the LVIS into an aneurysmal neck in a barrel-like shape is a technique that may help preserve the branch vessel and facilitate dense coil embolization.

Objective: We report two cases of thrombectomy for upper extremity artery occlusion with major cerebral artery occlusion using mechanical thrombectomy devices for acute ischemic stroke.

Case Presentations: Case 1 was a 79-year-old woman admitted for left internal carotid artery occlusion and left upper extremity artery occlusion. Case 2 was an 87-year-old woman admitted for left middle cerebral artery occlusion and bilateral upper extremity artery occlusion. After performing mechanical thrombectomy for the cerebral artery, we achieved good recanalization of the brachial artery using the same devices in Case 1 and Case 2.

Conclusions: Thrombectomy using acute ischemic stroke mechanical thrombectomy devices for upper extremity artery occlusion is useful for recanalization.

Objective: The causes of restenosis following balloon angioplasty are reported to be vasospasm, thrombosis, and recurrence of atherosclerosis. We report a case of internal carotid artery (ICA) occlusion treated by emergency endovascular renacalization and carotid endarterectomy (CEA) for the restenosis, which revealed that the cause of restenosis was neointimal hyperplasia.

Case Presentation: A 70-year-old man was brought to our hospital because of sudden onset left hemiparesis. His National Institute of Health Stroke Scale (NIHSS) score was 13. Magnetic resonance imaging diffusion weighted imaging (MRI DWI) demonstrated hyper-intensity in the right basal ganglia, indicating acute ischemia. Neither the right ICA nor the MCA was visualized on MR angiography. Following intravenous tPA therapy, endovascular treatment was employed. First, the right ICA occlusion was treated by balloon angioplasty and the right M1 occlusion was recanalized by the stent-type thrombus retriever. Complete recanalization was achieved and the patient fully recovered. However, restenosis of the right ICA developed 5 months later and CEA was performed. The postoperative course was uneventful. Based on the pathological examination, the cause of restenosis was migration and proliferation of dedifferentiated smooth muscle (SM) cells, that is, neointimal hyperplasia.

Conclusion: Neointimal hyperplasia can be a cause of restenosis following balloon angioplasty.

Objective: We report the case of an aneurysm of the recurrent internal carotid artery (ICA)-posterior communicating artery (PCoA) treated using a liquid embolic delivery microcatheter (MC; Marathon).

Case Presentation: A 66-year-old female previously presented with subarachnoid hemorrhage, which had been treated using coil embolization for a ruptured ICA-PCoA aneurysm. She was referred to our hospital because the aneurysm recurred 13 years after treatment. Angiography revealed a de novo lobulated aneurysm at the ICA-PCoA bifurcation with a relatively thickened PCoA branching from the neck of the aneurysm. We performed coil embolization after stent placement with the Neuroform Atlas in the range of the ICA terminus and the PCoA. However, the coils were unequally distributed and it was necessary to navigate the MC to the aneurysm within the stent through the PCoA. We successfully approached the aneurysm using the Marathon. We additionally inserted six ED coils into the aneurysm and achieved favorable embolization.

Conclusion: The Marathon is useful for passage of a stent deployed in a small-caliber artery.