Objective: We investigated the efficacy of Embosphere and n-butyl-2-cyanoacrylate (NBCA) in the middle meningeal artery (MMA) embolization for refractory chronic subdural hematoma (CSDH).

Case presentation: A 65-year-old man underwent MMA embolization with Embosphere (300–500 μm) for left-sided refractory organized CSDH followed by craniotomy for hematoma removal. Histologic examination showed that Embosphere did not infiltrate into the outer membrane. The hematoma increased again about 6 weeks after craniotomy. The second angiography revealed the collateral blood flow from the right MMA to the left-sided hematoma membrane. We performed the right MMA embolization using NBCA. There were no further recurrences after embolization with NBCA.

Conclusion: Embosphere (300–500 μm) was too large to infiltrate into the outer membrane of CSDH. So smaller particles and liquid embolic agents are considered to be more effective. Involvement of contralateral MMA should be investigated in MMA embolization for refractory CSDH.

Objective: A post-catheterization femoral artery pseudoaneurysm is a rare but troublesome complication following percutaneous cannulation of the femoral artery. Here, we present three cases of a femoral artery pseudoaneurysm that developed following percutaneous intervention.

Case Presentations: Case 1: An 83-year-old woman received intravenous administration of recombinant tissue plasminogen activator, following which she underwent mechanical thrombectomy for acute ischemic stroke. However, 4 days after the catheterization, she developed a femoral artery pseudoaneurysm at the puncture site. The pseudoaneurysm was successfully thrombosed using ultrasound-guided compression (UGC). Case 2: An 83-year-old woman underwent coil embolization for an intracarotid artery aneurysm and developed a femoral artery pseudoaneurysm on the following day. The pseudoaneurysm was surgically repaired after UGC failure. Case 3: A 72-year-old woman with diabetes underwent transarterial embolization for a tentorial arteriovenous fistula. However, 16 days after the embolization, she developed an infected femoral pseudoaneurysm at the puncture site and was successfully treated using surgical repair.

Conclusion: We reported three cases of a post-catheterization femoral artery pseudoaneurysm that was successfully treated using UGC or surgical repair. Most femoral pseudoaneurysms can be successfully treated less invasively using UGC, ultrasound-guided thrombin injection, and para-aneurysmal saline injection. However, in certain cases, such as an infected femoral pseudoaneurysm, open surgical repair is necessary.

Objective: To present a case of traumatic dissecting internal carotid artery stenosis due to an elongated styloid process.

Case Presentation: A 49-year-old woman felt neck pain after neck movement during fishing, and then she developed right hemiparesis and aphasia. Head MRI showed no cerebral infarcts, and neck MRA showed left internal carotid artery stenosis with a dissecting aneurysm near her left elongated styloid process. Her symptoms gradually improved, and she was treated conservatively. However, on the 6th disease day, right hemiparesis and aphasia re-appeared. Since head MRI and neck MRA showed cerebral infarcts and progression of left internal carotid artery stenosis, carotid artery stenting was performed. A massive cerebral hemorrhage due to postoperative hyperperfusion was observed 2 hours after stenting.

Conclusion: Following percutaneous transluminal angioplasty or stenting for dissecting internal carotid artery stenosis that evolved over a short period, attention must be paid to intracranial bleeding due to postoperative hyperperfusion.

Objective: We report a case of acute M2 occlusion treated with endovascular therapy and discuss the usefulness of a perfusion study.

Case Presentation: An 84-year-old man developed dysarthria, but the symptoms had resolved on arrival at the hospital. Diffusion-weighted, high-intensity, brain magnetic resonance imaging showed a small lesion in the insula, and magnetic resonance angiography showed a right M2 trunk occlusion. CT perfusion study indicated decreased perfusion in the right middle cerebral artery area. We planned intravenous recombinant tissue plasminogen activator administration and subsequent mechanical embolectomy. The patient showed abrupt disturbance of consciousness, left hemispatial neglect, concomitant deviation, and left hemiplegia when he entered the interventional radiology room. The symptoms resolved after thrombolysis in cerebral infarction grade-3 reperfusion using a direct aspiration first pass technique, and the patient was discharged without symptoms (modified Rankin Scale score, 0).

Conclusion: The patient had no symptoms when he arrived at the hospital, but showed severe symptomatic worsening just before endovascular treatment. Rapid treatment was enabled using the CT perfusion study obtained before symptomatic worsening. The CT perfusion study is useful in a difficult situation when a decision regarding treatment is required.

Objective: We report a case of mechanical thrombectomy for basilar artery occlusion across the vertebral artery dissection.

Case Presentation: The patient was a 32-year-old woman without a history of trauma. She suddenly developed quadriplegia, and coma due to basilar artery occlusion. Since the condition was not an indication for intravenous thrombolysis with recombinant tissue plasminogen activator, mechanical thrombectomy was immediately performed. Pretreatment angiography showed left extracranial vertebral artery dissection and basilar artery occlusion. As contralateral vertebral artery was very hypoplastic, thrombectomy was performed across the dissecting artery with an aspiration catheter. Catheter passed through the false-to-true lumen, and almost complete recanalization could be achieved about 5 h after the onset of coma. She was fully recovered.

Conclusion: Although mechanical thrombectomy across the dissecting artery was risk of worsening the dissection, fortunately it led to a favorable outcome.

Objective: We report two cases of atherosclerotic vertebral artery ostium stenosis treated with open-cell type self-expanding stents (SES).

Case Presentation: Two cases of symptomatic vertebral ostium severe stenosis were treated. Both case showed serious vessel tortuosity, and the plaque extended proximally into the subclavian artery. We concerned about the vessel kinking at the distal stent edge and thromboembolic event from the plaque left behind in the subclavian artery, when we use balloon expandable stents. Therefore, we treated these cases using SESs placed from the vertebral ostium to the proximal subclavian artery. There were no perioperative complications or cerebral ischemic events during follow-up.

Conclusion: Vertebral artery ostium stenting using SES may be a useful choice from the viewpoint of stent followability to the tortuous vessel, conformability to the arterial wall, and covering property for the plaque extending to the subclavian artery.

Objective: We report a case of middle meningeal arteriovenous fistula deteriorated by sneezing.

Case Presentation: A 38-year-old man presented with temporal headache and subsequent tinnitus immediately after sneezing. MRA and cerebral angiography revealed left middle meningeal arteriovenous fistula (MMAVF). CT showed thinning and defect of temporal bone where the draining vein passing through the cranium. Transarterial embolization was performed to eliminate the pulsatile tinnitus. Two separate shunt points were detected during the embolization, which were completely shut-off with detachable coils.

Conclusion: MMAVF was suspected to be caused by sneezing from the clinical course, but the imaging and operative findings supported pre-existing MMAVF deteriorated by sneezing.

Objective: Adopting an appropriate working angle is often difficult during re-treatment of large paraclinoid aneurysm, due to the persisting coil mass from the first treatment. We report a case wherein a real-scale vessel model prepared using a 3D printer was useful for correct intracranial stent placement.

Case Presentation: A 45-year-old woman needed re-embolization for a large paraclinoid aneurysm. Coil embolization was performed with a stent-assisted technique. Adopting an appropriate working angle for stenting in the internal carotid artery was difficult due to a large coil mass remnant from a previous treatment for an aneurysm. A real-scale vessel model with proximal and distal end markings for the stent placement location was used to practice the stent placement. Neck-bridge was performed precisely using a stent and embolization was achieved with a total of 10 coils.

Conclusion: A real-scale vessel model prepared using a 3D printer was useful for stenting in a case of retreatment.