Objective: Objectives: To investigate embolic complications related to carotid artery stenting (CAS) under Angioguard XP filter protection, and analyze the relationship between several potential risk factors and complications.
Methods: Forty-eight patients with 49 carotid stenoses, that underwent MR plaque imaging before CAS under Angioguard XP filter protection, were retrospectively reviewed. Embolic complications during CAS and MR plaque images, including signal ratio of the plaque to posterior cervical muscle (P/M ratio) and submandibular gland (P/S ratio) on T1 and T2 weighted images, were reviewed. Relationships between embolic complications and P/M, P/S ratios, and length of lesions were analyzed.
Results: Ten slow flow (20.4%), 3 embolism (6.1%), and 4 spasm (8.1%) incidents occurred during the procedures. All embolisms occurred concurrently with slow flow. T1 P/M ratio and T1 P/S ratio in patients with an embolism tended to be higher than those without (2.33 vs 1.62, p=0.107, 1.78 vs 1.19, p=0.092, respectively). T2 P/M ratio and T2 P/S ratio in patients with slow flow tended to be lower than those without (1.60 vs 2.49,p=0.259, 0.68 vs 0.96,p=0.328, respectively). Mean length of the stenosis was longer in cases with an embolism or slow flow, compared to cases without an embolism or slow flow (27.3 vs 20.2mm, p=0.153, 24.2 vs 19.7, p=0.130, respectively). Cases with plaque length 2 25mm and T1 P/M ratio 2 1.5 showed a statistically significant high risk of an embolism (p=0.003).
Conclusion: Plaque imaging findings and plaque length appeared to be related to embolic complications. Patients with plaques showing a high T1 P/M ratio 2 1.5 with long stenosis 2 25mm have a greater risk of an embolic complication. Techniques to be applied and indications for CAS need careful consideration in such cases.

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Objective: To determine whether platelet aggregation analysis is predictive of periprocedual ischemic or hemorrhagic events in patients undergoing carotid artery stenting (CAS), preoperative platelet aggregation in 18 patients scheduled for CAS was analyzed.
Methods: Blood samples were obtained from patients just before measurement of platelet aggregation with adenosine-diphosphoric acid (ADP) and collagen. All patients received diffusion-weighted image (DWI) on MRI at 1-3 days after the procedure.
Results: Maximum platelet aggregation rate was statistically higher in patients with ischemic events. In contrast, there was no difference in the positive rate of asymptomatic high intensity spots on DWI.
Conclusion: Preoperative platelet aggregation correlated with periprocedual ischemic events after CAS.

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Objective: Carotid artery stenting (CAS) has emerged as an acceptable alternative treatment for patients with carotid artery stenosis. To ensure the safety of CAS, characteristics of restenotic lesions at long-term follow-up must be clearly understood. Suitability and efficacy of virtual histology intravascular ultrasound (VH-IVUS) for assessment of CAS follow-up results and restenosis after CAS were evaluated.
Methods: A Volcano Eagle Eye Gold IVUS catheter and Volcano IVG3 Oracle Imaging System were used. Follow-up VH-IUVS was performed in 26 patients that had received stents of 2 different design types (open-cell stent, n=13; closed-cell stent, n=13).
Results: VH-IVUS was an effective follow-up method and although invasive, yielded adequate information on the composition of restenotic tissue on color maps. Results were highly reproducible and objective, with the ratio of components in the entire lesion able to be determined quantitatively. Lesions were of a fibrotic neointimal hyperplastic nature, suggesting that their large fibro-fatty component presented an increased risk for progression to restenosis. Comparison of follow-up results in patients treated with open- and closed-cell stents showed that use of closed-cell stents resulted in a higher incidence of restenoses.
Conclusion: VH-IVUS yields highly reproducible objective results. It is an effective diagnostic method that helps to predict restenotic progression by providing information on the characteristics of lesions at post-CAS follow-up.

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Objective: Efficacy of angioplasty and stenting is assessed for treatment of intracranial atherosclerotic lesions.
Methods: Procedural outcome (recurrent ischemic stroke, restenosis, and complications) was retrospectively analyzed in 13 consecutive patients with 14 lesions that underwent intracranial stenting for symptomatic intracranial arterial stenosis.
Results: Average age was 70.1 years (13 males). Lesions treated involved 7 internal carotid arteries (ICA) and 7 vertebrobasilar arteries. Mean±SD pretreatment stenosis was 82.6±10.0%. Successful placement of the coronary stent was achieved in all 14 cases. All ICA lesions were also treated with proximal protection. Three patients treated without proximal protection developed ipsilateral asymptomatic infarction associated with the procedure. Eleven patients were treated in the chronic stage, and all had excellent outcomes (modified Rankin scale [mRS] 0-1). Three patients were treated in the acute stage, of whom one died of pneumonia, one suffered contralateral symptomatic stroke, and another had a poor outcome (mRS 3). Follow-up digital subtraction angiography in 10 lesions detected no restenosis (mean follow-up period, 9.5 months). Recurrent ipsilateral symptomatic stroke (mean follow-up period, 10.8 months) did not occur.
Conclusion: These findings suggest that intracranial stenting with proximal protection is an efficacious treatment option for intracranial atherosclerotic lesions.

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Objectives: This report documents initial experiences with balloon catheter disruption (BCD) of a thrombus for an unrecanalized intracranial artery, even after intravenous recombinant tissue plasminogen activator (IV-rtPA).
Methods: From August 2006 to February 2008, 12 patients with acute major vessel occlusion underwent IV-rtPA, and recanalization of the affected artery was not obtained in 8 patients. Seven of these 8 patients underwent BCD immediately after the completion of continuous rtPA infusion without the addition of thrombolytic agents.
Results: Of the 7 patients that underwent BCD, 4 patients (57%) showed complete or partial recanalization and relatively favorable clinical outcomes were obtained compared to patients without recanalization. No technical complications were observed in these patients.
Conclusions: Although the number of patients was limited, intra-arterial rescue therapy, BCD, may be effective for patients with an unrecanalized intracranial artery after IV-rtPA therapy.

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Objective: Two cases of dural arteriovenous fistula (DAVF) around the anterior condylar confluent (ACC) were treated with endovascular techniques and are described here.
Case presentation: Case 1. A 68-year-old woman presented with an audible pulse-synchronous bruit. Angiogram showed DAVF fed by the ascending pharyngeal artery (APA) and occipital artery (OA) with retrograde drainage to the inferior petrosal sinus. The patient was successfully treated with transvenous coil embolization. Case 2. A 26-year-old man presented with an audible pulse-synchronous bruit. A CT scan indicated enlargement of the posterior condylar canal with marked erosion. Angiogram showed a venous pouch: the posterior condylar vein as the fistulous points fed by the APA and the OA. The patient was successfully treated with transvenous and transarterial coil embolization.
Conclusion: DAVF around the ACC is relatively rare. It is therefore important to assess the venous anatomy and the fistulous points for a safe and effective treatment.

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Objective: A rare case of dural arteriovenous fistula (dAVF), which demonstrated high intensity areas in the brain stem, cervical spinal cord, and cerebellum on T2-weighted magnetic resonance imaging, was presented. Its mechanism was discussed in this paper.
Clinical presentation: A 74-year-old female was admitted due to severe dizziness and cerebellar ataxia. Cerebral angiography showed an isolated sigmoid sinus dAVF fed by the ascending pharyngeal, occipital, and tentorial arteries, and draining from the left petrosal vein to the confluence, contralateral superior petrosal sinus, and to the anterior and posterior spinal veins, via the veins around the brain stem and the numerous cerebellar cortical veins.
Intervention: Transvenous embolization was performed using detachable coils through the microcatheter, which was navigated through the occluded left transverse sinus via the transfemoral route. Symptoms improved markedly after endovascular treatment.
Conclusion: In this case, venous hypertension in the brain stem, cerebellum and cervical spinal cord, caused MRI abnormalities. With these MRI findings, dAVF should be included in the differential diagnoses.

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Objective: A case of dural sinus malformation (DSM) in a neonate is reported.
Case presentation: A boy with a prenatal diagnosis of DSM was born by cesarean section at a gestational period of 36 weeks. Birth weight was 2741g and head circumference was 38cm. Chest x-ray showed cardiomegaly and cardiac ultrasound examination demonstrated congestive heart failure. To improve his symptoms, endovascular treatment was performed on Day 0. Angiograms showed a huge venous pouch in the left parieto-occipital region, fed by numerous meningeal arteries. Transarterial embolization using N-butylcyanoacrylate and detachable platinum coils was performed via several meningeal feeders. This resulted in marked improvement of his heart failure. As there was Kasabach-Merritt phenomenon caused by the progression of thrombosis in the venous pouch, repeated blood transfusions were required. Subsequently, transarterial glue embolization and transvenous embolization were performed at the age of 5 and 8 months, respectively. Finally, the venous pouch was occluded with coils. These procedures resulted in a marked reduction of the arteriovenous shunts and shrinkage of the venous pouch. At the age of 21 months, the patient presented with mild developmental delay, but without any neurological deficits.
Conclusion: Staged endovascular treatment by transarterial and transvenous embolization was effective for this case of neonatal DSM.

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Purpose: A case of multiple brain infarction caused by embolism of a chondroma in the left vertebral artery is reported.
Case presentation: A 38-year-old woman was admitted for cerebral infarction. On angiography, a round filling defect was observed in the V2 segment of the patent left vertebral artery, thought to be a floating embolus. The patient was successfully treated with embolectomy by means of endovascular procedures immediately after angiography. Histopathologic evaluation indicated the embolus to be a piece of chondroma.
Conclusion: Cerebral embolism from tumor, especially chondroma, is extraordinarily rare. The source of the embolism in this patient is thought to most likely be the heart.

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Objective: A case of cavernous dural arteriovenous fistula (DAVF) that was successfully treated by targeted transvenous embolization using 3D rotational angiography (3D-RA) is described.
Clinical presentation: A 75-year-old woman presented with diplopia. Workup imaging indicated left cavernous DAVF with cortical venous reflux via the left superficial middle cerebral veins.
Results: 3D-RA showed that all the dural feeding arteries converged into a small superior posterior-lateral compartment of the left cavernous sinus. Platinum coils were transvenously placed in the small compartment where the shunt existed for complete obliteration of the fistula and at the origin of the left superficial cerebral veins for obliteration of the cortical reflux.
Conclusions: 3D-RA provided a better comprehension of angioarchitectural details as well as the location of the shunt and the origin of venous reflux. The delay time was considered to be one of the important parameters to obtain better 3D reconstructed images.

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Objective: Use of a catheter exchange technique for wide-necked large basilar tip aneurysms in which placement of a balloon catheter across the aneurysmal neck is difficult is described.
Case Report: A 71-year-old woman presenting with severe headache and vomiting was diagnosed with a subarachnoid hemorrhage by CT on admission. Preoperative angiography indicated a large saccular aneurysm at the tip of the basilar artery, and coil embolization was performed. As the broad neck of the aneurysm was located between the basilar and left posterior cerebral arteries, a neck remodelling technique was necessary. However, placement of a balloon catheter was extremely complicated, and endovascular treatment failed, despite the use of different kinds of microguidewires and microcatheters on the first attempt. On the second attempt, a catheter exchange technique was used and the balloon catheter was able to be easily positioned. Successful embolization was achieved using the neck remodelling technique.
Technique: First, a soft microcatheter was navigated through the basilar artery to the left posterior cerebral artery using a flexible microguidewire. Tips of the microguidewire and microcatheter were advanced to the distal part of the left posterior cerebral artery for stable positioning. The microguidewire was then exchanged for a long microguidewire, which was advanced into the microcatheter. The microcatheter was then removed over the wire. Next, a balloon catheter was advanced over the long microguidewire and positioned. Finary, coil embolization was achieved safely in the aneurysmal sac using the neck remodelling technique.
Conclusion: A technique to bypass the aneurysmal neck to perform balloon-assisted endovascular treatment of large aneurysms with broad necks in which other methods fail to obtain access distal to the aneurysm was described. For cases in which placement of a balloon catheter is difficult, the catheter exchange technique is considered to be highly effective.

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