Objective: The safety of stenting for intracranial internal carotid artery stenosis using flow reversal embolic protection was evaluated.

Subjects and Methods: Of the 13 patients who underwent stenting between April 2011 and September 2016, those treated with (group F) and without (group N) flow reversal were compared retrospectively.

Results: An embolic complication was observed in one patient in the group N but none in the group F. The diffusion-weighted imaging (DWI)-positive rate was 0% in the F group.

Conclusion: Stenting for intracranial internal carotid artery stenosis using flow reversal is a safe and effective procedure.

Objective: We examined the prognosis and background factors associated with in-stent low-density areas (LDAs) on CTA in the subacute phase after carotid artery stenting (CAS).

Materials and Methods: Among 175 lesions for which CAS was performed between April 2008 and September 2016, 100 lesions for which CTA were conducted in the subacute phase after CAS were included for retrospective analysis.

Results: LDAs were observed in 36 (36.0%) of the 100 lesions. All patients received conservative medical treatment. There was no patient with new neurologic symptoms in the subacute phase. In most lesions, peak stenosis rate was observed relatively early, which gradually declined after 1 week. LDAs were observed and the stenosis rate was relatively high in all patients with plaque protrusion immediately after CAS. The use of open-cell stents significantly increased the formation of LDAs. Most LDAs were consistent at the level of the previous most stenotic sites.

Conclusion: LDAs in the subacute phase after CAS were relatively frequent. In this study, the course was asymptomatic in all patients, and remission was gradually achieved. However, LDAs may have been associated with serious ischemic complications in the subacute phase, as reported in the literature. Therefore, medical treatment, involving intensive antithrombotic therapy, and careful follow-up should be considered.

Objective: Plaque protrusion is one of the current problems with carotid artery stenting (CAS) for carotid artery stenosis, and it may induce delayed postprocedural cerebral infarction. In this study, we evaluate the possibility of using three-dimensional rotational angiography (3DRA) to examine the stent lumen during CAS.

Methods: First, as a basic experiment, we determined the optimal contrast medium concentration for 3DRA. We then studied the presence or absence of plaque protrusion in 43 patients who underwent CAS at our hospital using 3DRA, intravascular ultrasound (IVUS), or DSA.

Results: Optimal contrast medium concentration was determined to be 50% by the basic experiment. In clinical evaluation, plaque protrusion was detected in 12 patients (27.9%) by 3DRA, compared to 7 (16.2%) by IVUS and in 3 (6.9%) by DSA. In patients where plague protrusion was undetected by 3DRA, it was also undetected by IVUS and DSA after CAS.

Conclusion: 3DRA appears to be useful for in-stent plaque protrusion detection.

Objective: A rare complication, a carotid-cavernous fistula (CCF), that developed during stent retriever thrombectomy for acute ischemic stroke is reported.

Case Presentation: A 67-year-old woman with consciousness disturbance and left hemiparesis underwent stent retriever thrombectomy for acute right M1 proximal occlusion of the middle cerebral artery (MCA) 6 hours after onset. There were several tortuous vascular segments in the approach route. Strong resistance was felt while the stent retriever was withdrawn. The cavernous segment of the internal carotid artery (ICA) was stretched by anchoring of the balloon and the stent retriever. Angiography immediately after thrombectomy showed a CCF although successful recanalization was obtained. This was probably caused by pull-out vessel injury of the meningohypophyseal trunk branching from the cavernous segment of the ICA. The CCF was treated with transvenous coil embolization 3 weeks after thrombectomy and disappeared angiographically.

Conclusion: If there is strong resistance while pulling back a stent retriever, the risk of vascular injury, such as a CCF, should be kept in mind.

Objective: Dural arteriovenous fistulae at craniocervical junction (CCJ dAVF) cause subarachnoid hemorrhage (SAH). We present a case of CCJ dAVF with SAH in which endovascular treatment was initially performed, followed by surgical management, leading to radical cure.

Case Presentation: Transarterial embolization was initially performed because of unfavorable clinical condition of the patient, resulted in main feeder occlusion. As this made the shunting point clearer, surgical drainer occlusion consequently facilitated, and radical cure could be achieved.

Conclusion: To treat CCJ dAVF, endovascular treatment and surgical management were performed. The former alone did not result in radical cure, but decreased the shunt volume, facilitating the assessment of vascular anatomy.

Objective: We report endovascular treatment of a patient with acute basilar artery occlusion considered to be due to an embolus from radiation-induced vertebral artery stenosis.

Case Presentation: The patient was a 46-year-old male with a history of neck irradiation. He developed basilar artery occlusion. Temporary recanalization achieved by intravenous alteplase therapy and revascularization was followed by relapse. The origin of the vertebral artery was stenosed, and basilar artery was considered to have been embolized by a thrombus formed on the proximal side of the vertebral artery, where blood flow was stagnated due to reduced antegrade flow from the distal side of the stenotic vertebral artery and the increased collateral flow from the deep cervical artery. Recurrence of cerebellar infarction could be prevented by revascularization and occlusion of the parent artery.

Conclusion: Acute basilar artery occlusion considered to be due to an embolus from radiation-induced vertebral artery stenosis is a rare condition, but it must be recognized as a possible cause of posterior circulation infarction.

Objective: We report a patient in whom symptomatic delayed cerebral vasospasm was suspected after mechanical thrombectomy, and medical treatment led to an improvement.

Case Presentation: A 52-year-old female. To treat embolic cerebral infarction related to occlusion of the left internal carotid artery (ICA), mechanical thrombectomy was performed, and the recanalization of the occluded blood vessel was achieved. Immediately after treatment, findings suggestive of vasospasm of the left middle cerebral artery (MCA) were noted, but subsided 2 days after admission. Transient right hemiplegia occurred 5 days after admission, and restenosis at the same site was observed. Medical treatment resulted in the disappearance of stenosis 6 days after admission.

Conclusion: Considering the risk of delayed cerebral vasospasm after mechanical thrombectomy, follow-up should be carefully conducted.

Objective: Two cases in which right carotid artery stenting (CAS) was performed by navigating a 6 Fr guiding sheath through the transbrachial approach avoiding intraaortic arch manipulation are reported.

Case Presentations: Case 1: A 72-year-old male with asymptomatic right carotid artery stenosis was scheduled to undergo stenting. Bilateral femoral artery stenosis and brachiocephalic artery stenosis were noted, and since the angle between the right subclavian and right common carotid arteries was steep, transbrachial CAS was performed without manipulations in the aortic arch using a 5 Fr Cerulean catheter with a tip shaped into a pigtail form. Case 2: A 66-year-old male was scheduled to undergo stenting for symptomatic right carotid artery stenosis. Thoracic aortic aneurysm and brachiocephalic artery stenosis were noted, and as the angle between the right subclavian and right common carotid arteries was steep, transbrachial stenting was performed without manipulations in the aortic arch using a 5 Fr Cerulean catheter with a tip shaped into a pigtail form.

Conclusion: In direct navigation of a 6 Fr guiding sheath to the right common carotid artery for stenting by the transbrachial approach, a 5 Fr Cerulean catheter with a tip shaped into a pigtail form was useful.