Objective: To evaluate the relationship between the incidence of the CT high-density area that appears immediately after endovascular treatment for acute ischemic stroke with postprocedural hemorrhagic transformation and its significance in the clinical outcome.

Methods: Ten patients with ischemic stroke of the anterior circulation encountered between May 2014 and December 2015 in whom recanalization could be achieved within 8 hours after the onset were retrospectively analyzed. In addition, 695 patients presented in 13 reports were divided into thrombolysis and mechanical thrombectomy groups, and the postprocedural incidence of CT high-density areas was compared between the two groups.

Results: Postprocedural CT high-density areas were observed in six (60%) of our patients. Hemorrhagic transformation occurred in three of them, but no exacerbation of neurological symptoms was noted. The incidence of postprocedural CT high-density areas was 43.1% (191/443) in the thrombolysis group and 71.8% (188/262) in the mechanical thrombectomy group including our patients, being significantly higher in the latter group (p <0.01).

Conclusion: Although CT high-density areas appear more frequently after mechanical thrombectomy than after thrombolysis, they are considered to be infrequently developed into hemorrhagic transformation and exert relatively few negative effects on the neurological outcome.

Objective: Recurrence after coil embolization of unruptured cerebral aneurysm is observed at a certain frequency. Factors of the aneurysm itself (maximum diameter, volume, neck length), treatment-related factors (total coil length, coil packing rate), and smoking have been suggested as risk factors of recurrence, but all remain controversial. In this study, we examined the relationship between post coiling syndrome (PCS), which we reported previously, and recurrence after embolization.

Methods: The presence or absence of recurrence was retrospectively evaluated as of July 2015 in 36 consecutive patients who underwent coil embolization of unruptured aneurysms at our hospital between June 2008 and April 2010. The patients were followed up by magnetic resonance angiography and plain radiography of the head every 6 months, and the images immediately after the procedure and the latest images were examined using the Raymond classification.

Results: After a follow-up period of 53 ± 19 months, no recurrence that led to retreatment was observed, but recurrence was noted in eight patients (22.2%). While there was no significant difference in the frequency of recurrence according to the patients’ age, follow-up period, factors of the aneurysm itself (maximum diameter, volume, and neck length), treatment-related factors (total coil length, coil packing rate, percentage of the bioactive coil length relative to the total coil length), or smoking habit, recurrence was observed significantly more frequently in the PCS group.

Conclusion: PCS was suggested to be potentially useful as a predictive marker of recurrence.

Objective: An important point for consistent success in transvenous embolization (TVE) for dural arteriovenous fistulas (AVFs) is considered to be the identification of, and accurate guiding of the catheter to, the shunt point. We performed TVE using cone-beam CT and 3D roadmap function and evaluated its effectiveness and problems.

Methods: In 12 procedures of TVE performed in eight patients with dural AVF, we identified the shunt point by cone-beam CT performed intraoperatively using a diluted contrast agent and guided the microcatheter using 3D roadmap function. Only the shunt point was embolized in patients with a localized shunt point.

Results: The shunt point could be identified by cone-beam CT in all eight patients, and the shunt point was found to be localized in three patients. The shunt point was approached using intraoperative 3D roadmap function in six patients. 3D images of the affected sinuses and bones were superimposed on fluoroscopic images in four and two patients, respectively. The 12 procedures could be completed without complications in a mean procedure time of 300 minutes with a mean volume of contrast agent of 203.9 mL and a mean radiation dose of 3133 mGy.

Conclusion: Cone-beam CT using a diluted contrast agent is considered to have facilitated the identification of the shunt point, and the use of 3D roadmap function to have made decreases in the use of the contrast agent and radiation exposure possible. It also facilitated the confirmation of the arrival of the microcatheter at the shunt point.

Objective: Idiopathic recurrent internal carotid artery vasospasms refer to paroxysmal vasospasms of the internal carotid artery centering on the cervical segment, which are rare. We report a patient who underwent bilateral carotid artery stenting (CAS) for idiopathic recurrent internal carotid artery vasospasms.

Case Presentation: A 40-year-old male. Paroxysmal vasospasms of the internal carotid artery had occurred 5 or 6 times a month during the past 10 years, with headache, amaurosis fugax, hemiparesis, and aphasia. The attacks could not completely be reduced by drug therapy, and bilateral CAS was performed. The frequency of attacks decreased during a postoperative period of 6 months, and ischemic symptoms of the hemisphere had disappeared.

Conclusion: CAS for drug-resistant idiopathic recurrent internal carotid artery vasospasms may be useful for decreasing the frequency of attacks and preventing ischemic hemispheric symptoms.

Objective: Idiopathic intracranial internal carotid artery dissection presenting with ischemia is a rare brain disease. We herein report two cases that we recently encountered.

Case Presentations: Case 1: A 16-year-old male. He had the onset with consciousness disturbance and left hemiparesis. Cerebral infarction of the right basal ganglia and dissection of the right internal carotid artery at the terminal portion (C1-2) were detected. The symptoms were transient and antithrombotic therapy was carried out. The symptoms were exacerbated after five days and stent placement was performed at the site of the dissection. The symptoms were alleviated after the procedure, and the condition improved to modified Rankin Scale (mRS) score of 0 three months after the onset.

Case 2: A 43-year-old female. She had the onset with weakness of the right upper extremity and dysarthria. Left cerebral infarction and dissection of the left internal carotid artery at C1-2 portion were detected. Since the symptoms were mild, antithrombotic therapy was carried out, and she was discharged with mRS 0.

Conclusion: Since the clinical course of this disease varies among patients, an appropriate therapeutic strategy must be selected according to the condition of each patient.

Objective: We report two patients who underwent two-stage angioplasty and carotid artery stenting (CAS) for marked stenosis of the cervical internal carotid artery (ICA) related to acute intracranial artery occlusion.

Case Presentations: In Case 1, thrombectomy and angioplasty for cervical ICA occlusion were performed. Although the M2 region of the middle cerebral artery was occluded, thrombectomy led to recanalization. Later, CAS was conducted. In Case 2, angioplasty for stenosis at the ICA origin was performed, leading to recanalization of the main intracranial artery. Later, CAS was conducted.

Conclusion: Staged angioplasty may be selected as an option for stenosis of the cervical ICA with acute intracranial artery occlusion.

Objective: A tip shape of a microguidewire that is safe and highly versatile in coil embolization of cerebral aneurysms was evaluated.

Case Presentations: Case 1: A 65-year-old woman with subarachnoid hemorrhage due to rupture of an anterior communicating artery aneurysm which was coil-embolized 7 years before. The aneurysm recanalized and regrew thereafter, and an additional embolization was performed. Angiography before treatment showed 50% stenosis at the origin of the right internal carotid artery (ICA). In addition, the A1 of the right anterior cerebral artery divided from the ICA at a relatively sharp angle. Therefore, the tip of the microguidewire was shaped to a modified pigtail. With this single tip shape, the wire and microcatheter could be safely guided to the anterior communicating artery aneurysm, and satisfactory coil embolization could be achieved. Case 2: A 68-year-old woman with right hemiplegia had a sudden onset of occlusion of the M2 superior trunk of the left middle cerebral artery and underwent thrombectomy. A microguidewire with a tip shaped into a modified pigtail could cross the lesion safely through the occluded segment with no distal view of the course of the vessel. The thrombus was retrieved using a stent retriever, and thrombolysis in cerebral infarction (TICI) 3 could be achieved.

Conclusion: This microguidewire tip shaping technique is considered to be safe and effective in various phases of endovascular treatment.

Objective: We examined the usefulness of the T-stent technique for a large broad-necked aneurysm at the internal carotid (IC) posterior communicating artery (P-com) bifurcation.

Case Presentation: A 73-year-old female. Detailed examination for cerebral infarction indicated an unruptured cerebral aneurysm. As a fetal-type P-com artery was detected in the aneurysmal dome, coiling with a stent-balloon technique was performed. Finally, embolization using the T-stent technique, in which a stent inserted into the P-com was connected to the side of an IC artery stent, was successful, facilitating the preservation of the P-com.

Conclusion: The T-stent technique, in which stents are not overlapped, may be useful for performing safe, accurate embolization of large broad-necked aneurysms with branching vessels.