Objective: The use of a small stent in the free cell area is considered to be effective for the treatment of plaque protrusion. In order to reduce the free cell area, a stent several millimeters larger than the desired blood vessel diameter may be placed. However, whether the free cell area actually becomes smaller has not been examined. In this study, three types of Precise stents with different diameters were placed in simulated blood vessels of the same diameter, and the coverage rate of each stent was calculated to determine whether there was an actual difference in the free cell area.

Method: Three types of Precise stents with respective diameters of 6 mm, 8 mm, and 10 mm were deployed in a tube that was likened to a simulated blood vessel with an inner diameter of 6 mm, and photographed with a digital camera. The captured photos were imported into the Image J software, and the ratio (T/S) of the stent mesh area T to the total area S of the stent area was calculated as the coverage ratio of the stent.

Results: The coverage ratio of each stent was 23.82% for the 6 mm diameter, 23.05% for the 8 mm diameter, and 34.90% for the 10 mm diameter. For the 6 mm and 8 mm diameter stents, the P value was > 0.05, whereas for the 6 mm and 10 mm diameter stents, and the 8 mm and 10 mm diameter stents, the P value was < 0.05.

Conclusion: When placed in a 6 mm diameter tube, no difference was observed in the coverage ratio of the 6 mm diameter and 8 mm diameter stents. The 10 mm diameter stent had a significantly higher coverage ratio than the 6 mm and 8 mm diameter stents.

Objective: In recent years, there have been some reports of complications suspected to be caused by the hydrophilic coating material polyvinylpyrrolidone (PVP) that peeled off from the device after endovascular treatment. We tried to detect PVP that has peeled off during carotid artery stenting and examine preventive measures.

Methods: Three cases treated with Carotid Guardwire PS were examined. The blood sucked when the inner catheter was removed after guiding the guiding catheter and the blood sucked before deflating the Guardwire were filtered and investigated. The remaining debris was examined using a Fourier transform infrared (FTIR) spectroscopy to see if it matched the peak value of PVP.

Results: Small debris, which was macroscopically considered to be a foreign substance, was observed in the blood sucked when the inner catheter was removed. When examined by the FTIR spectroscopy, a component with the same peak value as PVP was detected.

Conclusion: In carotid artery stenting, a foreign body that seems to be PVP was detected in the blood when the inner catheter was removed. In order to reduce PVP scattering, it is necessary to take measures such as regurgitating blood when operating a device with a small lumen difference such as an inner catheter.

Objective: Few reports have described embolization prior to extraction of an intra-ventricular meningioma as this involves a rare site of origin. Embolization of the feeding arteries in such cases is difficult as the tumor is supplied by tiny branches of the cortical and choroidal arteries. Here, we discuss the embolization strategy adopted in treating a hypervascular meningioma at the trigone of the lateral ventricle in a pediatric patient.

Case Presentation: The patient was a 13-year-old girl presenting with the chief complaint of headaches and left-side hemiparesis. Magnetic resonance imaging (MRI) revealed a large meningioma and several flow void signals at the trigone of the right lateral ventricle. The maximum diameter of the meningioma was approximately 8 cm. During initial surgery without embolization, very little of the tumor could be removed due to massive bleeding. Proximal occlusion of the main feeders with 10% Eudragit E through the cortical branch of the posterior cerebral artery in a second procedure allowed the posterior two thirds to be removed. Two years later, the patient presented again, however, complaining of hemianopsia, and subsequent MRI revealed a residual tumor. In a subsequent third procedure, additional embolization through the posterior choroidal artery allowed complete removal of the residual tumor. She showed hemianopsia prior to being discharged.

Conclusion: We presented a case where, due to the vascular architecture, proximal occlusion by a simple push technique rather than intentional penetrating injection with liquid embolic materials was safe and effective in embolizing a meningioma at the trigone of the lateral ventricle before removal.

Objective: We report a case of dural arteriovenous fistula (DAVF) of the superior sagittal sinus (SSS) treated with transarterial embolization (TAE) via surgical cut down of the occipital artery (OA).

Case Presentation: A 54-year-old man complained of consciousness disorder and left hemiparesis. Brain computed tomography (CT) revealed cerebral hemorrhage of the right frontal and parietal lobes, and cerebral angiography showed DAVF of the SSS with reflex to the vein of the central sulcus. TAE via femoral artery resulted in palliative reduction of the shunt flow. As TAE was difficult to perform through the right OA due to complexity, we decided on surgical cut down of the right OA and TAE using n-butyl-2-cianoacrylate (NBCA) and achieved complete disappearance of DAVF.

Conclusion: TAE via surgical cut down of the OA is a unique and effective alternative treatment for DAVF of the SSS.

Objective: In transvenous embolization of dural arteriovenous fistula, there is a risk of perforation when passing through the occluded sinus. We report two cases in which preoperative evaluation of the occluded venous sinus was performed using MRI of various sequences and treatment was successful.

Case Presentation: Both cases were dural arteriovenous fistulas with isolated sinus from the left transverse sinus to the sigmoid sinus. Phase-contrast MRA (PC MRA) showed no depiction in either the left transverse sinus or the sigmoid sinus, but contralateral approach was possible because a depiction of the occluded left transverse sinus was observed by contrast 3D variable refocusing flip angle turbo spin-echo (3D VRFA TSE) T1 and contrast 3D gradient echo (3D GRE) T1.

Conclusion: It was possible to evaluate the venous sinus by combining MRI of various sequences and to take a safe approach to isolated sinus.

Objective: We report a case of transverse-sigmoid sinus dural arteriovenous fistula (T-S dAVF) treated with transarterial Onyx embolization. The Onyx penetrated a branch of the posterior cerebral artery (PCA) through an acquired anastomosis, leading to arterial cerebral infarction.

Case Presentation: A 69-year-old man presented with subcortical hemorrhage in the right temporal lobe. Angiographic examination revealed right T-S dAVF. Although endovascular treatment was performed, the condition was not completely controlled. Five years later, imaging revealed an exacerbation of the T-S dAVF, and the patient was retreated. When transarterial Onyx embolization from the posterior convexity branch of the right middle meningeal artery was performed, the Onyx cast penetrated a branch of the PCA. The patient suffered from an acute cerebral infarction in the PCA region and presented with upper left quadrantanopsia. It was considered to have embolized through the anastomosis with the pial artery, which was not identified preoperatively. The adhesion between the dura mater and brain parenchyma was presumed to be the etiology.

Conclusion: Penetration of the parenchymal vessels can occur even in cases where the pial supply is not identified preoperatively.

Objective: We report two patients with moyamoya disease and a ruptured distal posterior choroidal artery(PChA) aneurysm successfully treated with endovascular embolization.

Case Presentations: Patient 1 was a 49-year-old female who presented with headache and vomiting. Imaging studies revealed intraventricular hemorrhage and a hematoma in the corpus callosum due to rupture of a distal medial PChA aneurysm. Aneurysmal embolization was performed using n-butyl cyanoacrylate (NBCA). The patient tolerated well and was discharged home on day 34 with a modified Rankin Scale score of 1. Patient 2 was a 46-year-old female who presented with consciousness disturbance. Imaging studies revealed intraventricular hemorrhage with hydrocephalus due to rupture of a distal lateral PChA aneurysm. Bilateral ventricular drainage and NBCA embolization were concomitantly performed in our hybrid operating room. Neuroendoscopic hematoma evacuation was performed the following day. Ventricular drainage was discontinued a few days later. The patient was eventually discharged home after spending several months in rehabilitation.

Conclusion: Embolization of ruptured PChA aneurysms in patients with moyamoya disease can be safe and effective. Embolization of these aneurysms requires an understanding of the vascular anatomy, particularly the anastomoses between the anterior and posterior choroidal arteries and cortical branches.

Objective: Endovascular thrombectomy is generally performed by the femoral artery approach, but in some cases it is difficult to access and cannot be treated. In that case, direct carotid puncture is effective. We report the usefulness of direct carotid puncture in endovascular thrombectomy.

Case Presentations: From January 2017 to December 2020, there were 3 cases of mechanical thrombectomy at our institution where the femoral artery was difficult to approach and the carotid artery was directly punctured during the procedure. Under intravenous anesthesia, the trachea was infused in advance and the neck was slightly bent backward. The direct common carotid artery puncture was performed, a 6Fr super sheath was inserted, and treatment was performed with a suction catheter and stent retriever. After treatment, we removed the sheath and stopped bleeding by manual compression for 20 minutes or longer. The procedure was performed on 3 cases whose target ages were 100 years, 86 years, and 100 years; the obstruction was middle cerebral artery M1 obstruction in 2 cases and anterior cerebral artery A1-A2 bifurcation in 1 case; recanalization was 3, 0, and 3, respectively, in the TICI classification, and complications were puncture site in 1 case. Intubation prevented airway compression. Outcomes were 2, 4, and 4 in mRS, respectively.

Conclusion: Direct carotid puncture may be effective when approaching from the femoral artery is difficult in endovascular thrombectomy.