Objective: Little is known about the pharmacodynamic antiplatelet effects of clopidogrel loading in acute ischemic stroke. This study is aimed to evaluate the pharmacodynamic antiplatelet effects of clopidogrel loading dose in patients with acute ischemic stroke.
Methods: We evaluated 23 consecutive patients who received a loading dose of antiplatelets including ≥300 mg clopidogrel from June 2011 to December 2013 at our institution (13 with acute ischemic stroke and 10 with non-acute ischemic stroke undergoing elective neuroendovascular treatment). The VerifyNow system was used to assess antiplatelet effects in terms of aspirin reaction unit (ARU), P2Y₁₂ reaction unit (PRU), and % inhibition at baseline, 6 h, 24 h, and 48–72 h after loading. We also evaluated the clinical and genetic factors associated with high on-treatment platelet reactivity at 24 h after antiplatelet administration.
Results: Aspirin provided a sufficient antiplatelet effect at 6 h after loading (ARU <550). In contrast, the antiplatelet effect of clopidogrel was insufficient even at 48 h after loading (PRU >230, % inhibition <26%). Significant differences were observed in PRU levels between elective and acute stroke patients at 6 h (338.4±49.9 vs 251.3±89.9, p=0.032) and 24 h (298.9±54.2 vs 224.1±83.4, p=0.028) after loading. Moreover, % inhibition levels were significantly lower in acute stroke patients at all points (p=0.025 at baseline, 0.020 at 6 h, 0.013 at 24 h, and 0.017 at 48 h). Acute stroke (p=0.0018) and body mass index (p=0.005) were identified as independent factors for clopidogrel resistance, which was observed in 15 (65.2%) patients.
Conclusion: The antiplatelet effect of clopidogrel given in a loading dose reached a sufficient level within 24 h in elective patients but not in acute stroke patients. Furthermore, acute stroke was found to be correlated with clopidogrel resistance.

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Objective: We report the utility of low-concentration n-butyl 2-cyanoacrylate (NBCA) for preoperative embolization of meningioma.
Methods: Twelve patients who were preoperatively diagnosed with meningioma were included in the study. Preoperative meningioma embolization with NBCA at 10–20% concentration was performed for 22 feeding vessels in 12 patients. We assessed the extent of intratumoral embolization and its effect on tumor removal.
Results: Intratumoral embolization was possible in 17 feeding vessels (77.3%). In particular, 10–12.5% warmed NBCA effectively penetrated the tumor. The effect on tumor removal was good or excellent in 58.3% of patients.
Conclusion: Preoperative embolization of meningioma with ultra-low concentrations of NBCA was useful. Understanding the relationship between the adhesion, the viscosity and the concentration of NBCA is essential for effective preoperative embolization.

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Objective: We describe a rare case of ruptured subependymal artery (SEA) aneurysm associated with moyamoya disease. Aneurysm was embolized using n-butyl cyanoacrylate (NBCA).
Case presentation: A 26-year-old female presented with intraventricular hemorrhage. The CTA showed poorly developed main trunk of the right middle cerebral artery (MCA) and an aneurysm in the lateral ventricle. We suspected moyamoya disease. The angiography showed twig-like networks and aplastic main trunk of the right MCA, also visualizing an aneurysm at the right SEA. The right posterior communicating artery was of the fetal type, and the enlarged right SEA originated from the extension of right anterior choroidal artery (AChA). A microcatheter was navigated into the SEA via the AChA and then 25% NBCA was injected until complete occlusion. The post treatment MRI showed no ischemic lesion. The patient was discharged neurologically intact.
Conclusion: Endovascular embolization is an attractive treatment for aneurysms associated with moyamoya disease. Our case was a valuable experience in the management of such lesions, considering the pathophysiology of the existing plexiform vascular network.

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Objective: We report two cases of Angio-Seal closure related infectious aneurysm of femoral artery which required surgical treatment.
Case presentation: Case 1. A 71-year-old male presented with transient unconsciousness due to right internal carotid artery (ICA) occulusion and left ICA severe stenosis. We performed percutaneous transcatheter angioplasty (PTA) with right groin puncture for left internal carotid stenosis. We used Angio-Seal for femoral artery closure. Bacterial cellulitis appeared at his right groin after PTA. On the 61st hospital day, we found an infectious aneurysm. He was performed the graft replacement of right common femoral artery for his infectious aneurysm on the 90th hospital day. Case 2. A 51-year-old female presented with subarachnoid hemorrhage due to ruptured left ICA-paraclinoid aneurysm. We performed coil embolization, and used Angio-Seal for right femoral artery closure. We found a hematoma at groin puncture site on the 6th hospital day, which was complicated with bacterial infection. An antibiotic was prescribed, her inflammatory reaction diminished with a blood test. But, we found an infected aneurysm on right groin by ultrasonography and 3D CT on the 21st hospital day. She was performed the graft replacement of right common femoral artery for her infected aneurysm on the 25th hospital day.
Conclusion: The Angio-Seal closure device is useful for decreased demand for health-care personnel to place manual pressure on the groin site, but it is a foreign matter, and so may be at risk of infection. Advancing in severity, an infected aneurysm may develop, which may need surgical treatment. To avoid this complication, it is important to keep the wound clean and the patient on bed rest, and in high risk cases of infection, manual pressure should be selected for hemostasis instead of percutaneous vascular closure devices.

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Objective: We report a case of transbrachial right carotid artery stenting (CAS) without intra-aortic manipulation.
Case presentation: A 71-year-old man presented with right visual field disturbance due to occlusion of the branch retinal artery and symptomatic right internal carotid artery stenosis. Because he had undergone aortic arch replacement for an aortic aneurysm, we planned CAS using the transbrachial approach without intra-aortic manipulation. During the guiding-sheath cannulation, it was difficult to insert a diagnostic catheter directly from the right subclavian artery to the right common carotid artery owing to the acute angle of these arteries. Using the pigtail catheter, the guidewire was easily inserted into the external carotid artery, and stenting was performed successfully.
Conclusion: The pigtail catheter is an useful device for cannulating the guidewire through an acute-angled bifurcation.

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Objective: We report the utilization of a wireless mouse for manipulation of a 3D workstation at the tableside during neuroendovascular surgery.
Case presentation: For 70 consecutive patients undergoing neuroendovascular surgery between August 2013 and June 2014, we used a wireless mouse to manipulate the 3D workstation at the tableside. Using the wireless mouse, the 3D workstation could be manipulated even at the table-side in the same manner as at the console in the control booth in all the cases.
Conclusion: This method is feasible for efficient neuroendovascular surgery.

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Objective: We report two cases of coil protrusions which are successfully treated by using support catheters during endovascular treatment of intracranial aneurysms.
Case presentation: Case 1. An 81-year-old woman had developed an anterior communicating artery aneurysm besides a ruptured aneurysm. The fourth coil tail protruded into the left A2 during the endovascular surgery. The coil was successfully removed from the aneurysm by using a microsnare while pressing the support catheter tip against the coil mass in order to prevent protrusion of other coils. Case 2. A 73-year-old woman was admitted to our hospital due to an unruptured aneurysm located at the left superior cerebellar artery. The ninth coil tail protruded into the basilar artery during the procedure. The coil tail was pushed back into the aneurysmal cavity by using the support catheter and additional coils under microballoon assistance.
Conclusion: A support catheter can be an auxiliary tool to cope with protruded coils quickly, safely, and conveniently in some cases.

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Objective: Endovascular treatment for a very small aneurysm with a diameter less than 3 mm is challenging because of its technical difficulties and high complication rates. The smallest coil diameter available today is 1.0 mm, so we defined an aneurysm with a short axis of less than 1.0 mm and a long axis of less than 3.0 mm as “the ultra small aneurysm.” We present a case of ruptured ultra small aneurysm successfully embolized by a single Target nano coil (1.5 mm×3.0 cm) and discuss about the technical points of the embolization for the ultra small aneurysm.
Case: A 64-year-old woman presented with subarachnoid hemorrhage. Rupture site was an anterior communicating artery aneurysm with a long axis of 2.9 mm and a short axis of 1.0 mm. We performed coil embolization through the triple coaxial guiding system and used manually shaped microcatheter by hot air gun. A single Target nano coil was successfully inserted into the aneurysm from the microcatheter positioned just at the neck of the aneurysm, and the aneurysm was completely obliterated.
Conclusion: Target nano is a highly soft coil and useful for the embolization of a ultra small ruptured cerebral aneurysm.

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Objective: In neuroendovascular therapy, cases of above-threshold level of radiation-induced skin injuries have been reported. The aim of this study was to evaluate the actual radiation exposure of patients undergoing neurovascular interventional radiology and highlight the problems associated with this approach.
Methods: A multicenter questionnaire survey about the actual radiation exposure in neuroendovascular procedures was posted on the Web site of the Japanese Society of Circulatory Technology. We investigated the procedure time, fluoroscopy time, dose area product, number of frames, and correlations between exposure dose and properties of aneurysms in coil embolization. In addition, we calculated the total entrance skin doses and the crystalline lens doses by using dose area product values.
Results: A total of 285 data sets from 29 medical facilities were evaluated. For the cases, the procedure time, fluoroscopy time, dose area product, and number of frames were as follows (presented as mean±SD values): 190.4±85.0 min, 107.7±60.3 min, 36.5±20.3 mGy · m², and 1035.8±562.9 frames, respectively. Statistically positive correlations were observed between the dose area product and aneurysm volume, necksize, and number of coils used in embolization of cerebral aneurysm. No significant difference in total skin dose and crystalline lens dose was observed between the ruptured and nonruptured aneurysms. In addition, no difference in procedure time was observed between the single and biplane machines. The total entrance doses to the head skin and crystalline lens on the x-ray tube side were estimated as 3.8±2.1 and 0.91±0.55 Gy, respectively.
Conclusion: We demonstrated the potential occurrence of tissue reactions in neurovascular interventional procedures. In particular, the estimated dose to the crystalline lens exceeded the new threshold level (i.e., 0.5 Gy) in the International Commission on Radiological Protection statement on tissue reaction. To prevent radiation injuries, radiation safety management should be standardized especially in the field of neurointervention.

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