Objective: The outcome of using a closed-cell type self-expanding stent (closed-cell stent) for tortuous internal carotid artery (ICA) stenosis is unknown. This study aimed to assess the association between the tortuosity of the carotid artery and microembolization identified on diffusion-weighted imaging during carotid artery stenting (CAS) using a closed-cell stent.
Method: We retrospectively analyzed data from a registry of 93 consecutive patients who underwent CAS using a closed-cell stent at our institute. We used the following as tortuosity indexes: the angle between the common carotid artery and the ICA (Angle A), the angle at the first bend in the ICA (Angle B), and the sum of Angle A and Angle B (Angle A + B). We assessed the relationship between the tortuosity index and microembolizations as well as the cut-off values of the tortuosity indexes by receiver operating characteristic (ROC) curve analysis and odds ratio (OR) of microembolization.
Result: Microembolizations were detected in 18 of 93 (19.4%) patients and significantly associated with Angle B (65.6 ± 24.2°, 47.9 ± 25.3°; p = 0.009) and Angle A + B (99.0 ± 39.0°, 76.2 ± 33.6°; p = 0.028) but not Angle A (33.4 ± 17.6°, 28.2 ± 13.7°; p = 0.174). ROC curve analysis showed that the best cut-off values for Angle B and Angle A + B were 40.5° and 60.5°, respectively. The OR of microembolization in patients with Angle B >40.5° and Angle A + B >60.5° was 4.146 and 9.020, respectively.
Conclusion: In CAS using closed-cell stents, Angle B and Angle A + B are significantly associated with the incidence of microembolization.

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Background and purpose: Selection of the appropriate first coil in cerebral aneurysm embolization is essential to establishing a stable coil frame and thereby to providing recurrence-free treatment. However, the criteria for selecting the first coil have not been established. The aim of this study is to experimentally evaluate the coil-loaded mechanical force on the aneurysmal wall and to provide a reference for the rational selection of first coils.
Methods: Two experiments were performed using two coil systems (the Guglielmi Detachable coil [GDC] and Electro Detach coil [ED]). First, counterforces created by step-wise compression on the coils were measured. The diameter of the coils, ranging from 3.0 mm to 16.0 mm, was set to an uniform value of 3.0 mm before compression. Second, each coil was inserted into a silicon aneurysm model of 4 mm in diameter and then counterforces from the coil-filled silicon aneurysm were measured.
Results: Step-wise compression of a coil led to an almost linear increase in counterforce values. The diameter differences had little effect on these values as long as the stock-wire diameter and primary diameter of the coils were constant. Stock-wire diameter seemed to be the primary determinant of the value. In the experiment using the silicon aneurysm model, the counterforce was not dependent on coil diameter, but seemed to be determined by stock-wire diameter and length of the coils.
Conclusion: The force on the aneurysm wall caused by insertion of the coil into the aneurysm depends primarily on diameter of the stock-wire and not on the size of the coil.

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Objective: From April 2006 to February 2011, a total of 6 patients with internal carotid artery (ICA) stenosis who presented with acute deterioration of consciousness as well as neurological symptoms underwent emergent carotid artery stenting (CAS).
Methods: Preoperative and postoperative (after 90 days) National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores and perioperative events (including any stroke, cardiac infarction, and hyperperfusion syndrome) were evaluated.
Results: All patients were male with a mean age of 70.2 years. In all 6 patients, preoperative mRS was 5. However, the mRS score decreased postoperatively to 0 in 2 patients (33%), 1 in 2 patients (33%), 2 in 1 patient (17%), and 3 in 1 patient (17%). Mean NIHSS score before emergency CAS and at 90 days were 25 and 4, respectively. No patient demonstrated any perioperative events, and all patients recovered from acute deterioration of consciousness postoperatively.
Conclusions: Emergent CAS is a useful treatment option for acute stroke progression resulting from severe ICA stenosis.

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Objective: We report a case of carotid cavernous fistula (CCF) in a patient with the vascular type Ehlers-Danlos syndrome (EDS), type IV .
Case presentation: A 41-year-old female complained of sudden onset of left eye pain and presented with conjunctival congestion without trauma. The left internal carotid artery showed a high flow direct carotid cavernous fistula draining into the left superior ophthalmic vein and the cortical vein retrogradely. The lesion was successfully treated with transarterial coil embolization. After endovascular surgery, hemorrhagic events (retroperitoneal hemorrhage, internal iliac artery extravasation, and splenic artery aneurysm) recurred. We suspected vascular type EDS, which was confirmed biochemically. A COL3A1 gene mutation was identified.
Conclusion: In view of the risks of hemorrhagic events after arteriography, early diagnosis of the vascular type EDS is important in patients with spontaneous direct carotid-cavernous fistulas.

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Objective: We report a case of thrombosis as a complication of unruptured aneurysm coil embolization successfully treated by additional use of antithrombotic agent.
Case presentation: An aneurysm of the right basilar-anterior inferior cerebellar artery (AICA) was incidentally revealed in a 66-year-old woman. The aneurysm was successfully embolized using coils, but thrombosis occurred at the AICA. After additional administration of heparin, Clopidogrel, and Ozagrel sodium, the AICA was recanalized. Fortunately, there was no ischemic complication and the patient was discharged without any neurological deficit.
Conclusion: The additional use of anti-thrombotic agents was effective therapy for thromboembolic complications of unruptured aneurysm coil embolization.

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Purpose: This article describes a case of internal carotid artery (ICA) pseudo-aneurysm in young adult after blunt trauma successfully treated with endovascular intervention.
Case presentation: A 19-year-old male had traumatic subarachnoid hemorrhage, intraventricular hemorrhage, and cerebral contusion caused by a traffic accident two years ago. An MRA showed a saccular aneurysm arising from the C4 portion of the left ICA, prompting consideration of the condition as a post-traumatic pseudo-aneurysm. Successful endovascular coil embolization of the pseudo-aneurysm was achieved without any complications.
Conclusion: An aneurysm after traumatic injury in a young adult should arouse suspicion that the condition is a pseudo-aneurysm. This case report suggests that this condition can be treated with endovascular coil embolization.

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Objective: To report the long-term results of non-hemorrhagic vertebral artery dissecting aneurysms (nhVADAs) treated by stenting alone.
Methods: Between January 2001 and December 2002, single or dual stents were placed in 2 of 5 patients with nhVADA who gave their informed consent. The patients were followed by 3-dimensional computed tomography (3D-CT), cerebral angiography, and intravascular ultrasonography.
Results: No ischemic or hemorrhagic complications were observed. At the 10-year follow-up, total or subtotal occlusion of the aneurysmal sac was achieved, and ectopic calcification was found in the thrombosed aneurysmal sac.
Discussion: In these cases, the use of balloon-mounted coronary stents led to straightening of the parent artery as well as alteration of the in-flow, which can contribute to flow stagnation and subsequent thrombosis of the aneurysms.
Conclusion: The use of stenting alone may afford a favorable long-term outcome for nhVADAs and could be a durable therapeutic choice.

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Objective: We report a case of right hemisphere hypoperfusion following right carotid artery stenting (CAS).
Case presentation: A 72-year-old man presented with severe asymptomatic stenosis in the right internal carotid artery. CAS was performed for stenosis of the right internal carotid artery using a distal filter and open cell stent. However, he experienced left hemispatial neglect, left hemianopsia, and left hemiparesis 13 hours after the CAS procedure. Angiography revealed diffuse vasospasm occurring primarily in the distal portion of the right middle cerebral artery. Perfusion CT images indicated hypoperfusion in the ipsilateral hemisphere. These findings were temporary, and the patient was discharged without any neurological deficits.
Conclusion: These results suggest that reversible cerebral vasoconstriction can occur after CAS, resulting in transient ischemic complications.

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