Objective: Aggressive therapeutic intervention is recommended for infectious intracranial aneurysms (IIAs) because they have a higher hemorrhage risk than non-IIAs. In this study, we retrospectively reviewed patients with IIAs treated at our institution and evaluated the contents of treatment and the complications.

Methods: We evaluated 13 patients diagnosed with IIA based on clinical symptoms and imaging findings between March 2004 and December 2014.

Results: Endovascular treatment, direct surgery, and conservative management were performed in five, five, and three patients, respectively. In endovascular treatment patients, none developed any hemorrhagic or infectious complications. In the five direct surgery patients, we selected direct surgery because three patients needed hematoma evacuation, and the catheter navigation was not achievable in the remaining two patients.

Conclusion: Since IIAs often occur in peripheral arteries and are accompanied by local infection, aneurysmectomy by direct surgery used to be preferred. However, as embolization of cortical branches using a flexible catheter and small coils has become technically possible by the improvements of endovascular devices, endovascular parent artery occlusion might be a reasonable alternative for IIAs.

Objective: The objective of this study was to clarify the current status of endovascular thrombectomy for acute ischemic stroke due to large vessel occlusion in Japan.

Methods: A questionnaire was sent to members of the Japanese Society for Neuroendovascular Therapy (JSNET) by email, and the answers were collected.

Results: A questionnaire was sent to 1324 facilities, and answers were obtained from 159 (response rate: 12%). There were areas in which endovascular treatment (EVT) was impossible in almost all the prefectures. The mean number of endovascular thrombectomy procedures per facility was 14.1 ± 12.2 per year, and the initial imaging examination was CT at 81% and MRI at 91% of the facilities. Concerning the patients for whom EVT is recommended by the American Heart Association (AHA) guidelines, 119 facilities (76%) answered that all patients were treated by EVT. The baseline Alberta Stroke Program Early CT score (ASPECTS) of ≥6 was considered as an indication for EVT at 45%, and ≥5 at 22% of the facilities. The mean time from hospital arrival (door) to reperfusion was 174.3 ± 63.2 min, and that from arterial puncture to reperfusion was 71.8 ± 26.3 min. The successful reperfusion rate was 75% ± 14% (Thrombolysis in cerebral infarction [TICI] ≥2b) and 45% ± 15% (TICI = 3).

Conclusion: In acute stroke treatment for large vessel occlusion in Japan, MRI was performed as the initial imaging examination at about 90% of the facilities, the number of patients treated per facility was relatively small, and the time to reperfusion, particularly that from arterial puncture to reperfusion, was long. For the future, development of the diagnosis and treatment system for endovascular thrombectomy and approaches to shorten the time to reperfusion are necessary to improve neurologic outcome in EVT.

Objective: The relationships of the results of hemodynamic evaluation of cerebral aneurysms using computational fluid dynamics (CFD) analysis with the occurrence, enlargement, rupture status, and intraoperative findings are studied, but there have been no reports on their relationship with the severity of subarachnoid hemorrhage (SAH). We, therefore, examined morphologic characteristics of cerebral aneurysms and hemodynamic characteristics based on CFD analysis and evaluated their relationships with the severity of SAH.

Methods: Of the 200 consecutive cases of SAH encountered between 2007 and 2014, 119 cases of ruptured saccular aneurysms diagnosed by 3D-CTA using a 64-row multislice CT scanner within 72 hours after the onset were analyzed. They were classified according to the severity of the condition on admission using the World Federation of Neurosurgical Societies (WFNS) SAH grading scale (WFNSG) into mild (WFNSG1-3) and severe (WFNSG4-5) groups. Patient-specific statistical shape models were developed from 3D-CTA Digital Imaging and COmmunication in Medicine (DICOM) data, and steady-state analysis was performed by setting the end-diastolic physiologic blood flow volume according to the vascular luminal diameter as the entrance state. Morphologic evaluation was performed by calculating seven primary dimensions and four shape indexes from the morphologic data used for CFD analysis. As hemodynamic parameters, the wall shear stress (WSS), normalized WSS (NWSS), low shear area ratio (LSAR), flow velocity (FV), and invariant Q (IQ) were calculated. Statistical analysis was performed using the Mann–Whitney U-test at the P <0.05 level of significance.

Results: After excluding 6 cases in which segmentation for CFD analysis was impossible, the remaining 113 cases were classified into 74 mild and 39 severe cases. No significant difference was observed in the morphologic parameters including the primary dimensions such as the maximum size or shape indexes such as the aspect ratio and size ratio between the mild and severe groups. Concerning the hemodynamic parameters, the WSS and NWSS were lower, and LSAR was larger, in the severe group than in the mild group, but the differences were not significant. On separate analysis of internal carotid (n = 44), middle cerebral (n = 31), and anterior communicating (n = 24) artery aneurysms, the parent artery diameter (PD) was smaller in the severe group than in the mild group in middle cerebral artery aneurysms (2.56 mm vs. 2.03 mm, P = 0.039). In the internal carotid artery aneurysms, the size ratio was significantly larger (2.04 vs. 2.38, P = 0.040), NWSS was lower (0.289 vs. 0.168, P = 0.033), and LSAR was larger (0.284 vs. 0.542, P = 0.035), in the severe group than in the mild group.

Conclusion: CFD analysis using 3D-CTA in patients with severe ruptured cerebral aneurysms suggested characteristics including a small diameter of parent artery, a large shape index, and a low WSS.

Objective: We reviewed the treatment results of internal carotid artery (ICA) aneurysms with a maximum diameter of 10 mm or greater for the future selection of patients with indications for Pipeline Flex (Medtronic, Irvine, CA, USA).

Methods: The treatment methods, treatment effects, complication rate, and retreatment rate were studied in lesions that were treated by coil embolization but are presently considered indications for treatment using Pipeline Flex among the 516 cerebral aneurysms treated at our hospital between July 2009 and May 2016. We also reviewed the literature concerning coil embolization for large and giant aneurysms and examined the results of coil embolization for aneurysms with indications for Pipeline.

Results: The subjects were 10 patients consisting of 5 with asymptomatic unruptured aneurysm, 2 with symptomatic unruptured aneurysm, and 3 patients with recurrence after treatment for ruptured aneurysm. The mean size of the aneurysms was 12.8 mm (10.5–17.8 mm), and the mean follow-up period was 49.1 ± 13.4 months. The treatments were balloon-assisted coil embolization in eight patients and stent-assisted coil embolization in two patients. None showed postoperative symptomatic ischemic lesions, and the permanent morbidity was 0%. Of the two patients with symptomatic aneurysms, the symptoms were alleviated after treatment in one patient, and retreatment was necessary in one patient. In the review of the literature, comparisons were made in 69 large or giant aneurysms treated by coil embolization between those with and without indications for Pipeline. The additional treatment rate was significantly lower in the lesions with indications for Pipeline (33.3% vs. 61.9%, P = 0.02). The retreatment rate was significantly lower at 15.4%, particularly in extradural aneurysms (Bouthillier C4, 5).

Conclusion: The results of this study suggest that the retreatment rate after conventional coil embolization for extradural unruptured large cerebral aneurysms was not high and that coil embolization is worth considering for asymptomatic aneurysms at these sites 10–15 mm in diameter.

Objective: A case of common carotid artery pseudoaneurysm that developed after treatment for malignant neoplasm of the neck in which rupture could be prevented by covered stent placement is reported.

Case Presentation: A 51-year-old woman developed pseudoaneurysm of the common carotid artery after radiotherapy and surgery for hypopharynx cancer. Since direct surgery was considered difficult due to the risk of rupture, endovascular treatment was performed. The lesion disappeared after placement of a covered stent (Fluency Plus; Bard Peripheral Vascular, Tempe, AZ, USA) in the common carotid artery via the femoral artery. No perioperative complication was observed, and the lesion remained obliterated after 5 months. While the patient died due to recurrence of cancer half a year after surgery, no ischemic stroke or rupture of pseudoaneurysm was noted.

Conclusion: Endovascular treatment using a covered stent was useful for the prevention of rupture of pseudoaneurysm that occurred after treatment for malignant tumor of the neck.

Objective: We report a case of multiple dural arteriovenous fistulas (dAVFs) treated with transvenous embolization (TVE) via the mastoid emissary vein (MEV) using a transfemoral venous approach.

Case Presentation: A 52-year-old male presented with intracranial hemorrhage in the right frontal lobe. Diagnostic angiography showed multiple dAVFs of the right transverse sigmoid sinus and the superior sagittal sinus, both associated with cortical venous reflux. Transfemoral TVE of the dAVF of the right transverse sinus sigmoid sinus was performed via the MEV, followed by secondary TVE of the dAVF of the superior sagittal sinus. Complete obliteration of both lesions was achieved without complication.

Conclusion: The MEV is a useful access route for TVE in a patient with isolated dAVF of the transverse sigmoid sinus.

Objective: A case of iatrogenic dural arteriovenous fistula that occurred during embolization of a feeding artery for transverse sinus (TS) dural arteriovenous fistula is reported.

Case Presentation: A 66-year-old woman suddenly noted pain of the left temporal region and nausea and was emergently transported to our hospital. CT of the head showed left subcortical hemorrhage, and DSA demonstrated a dural arteriovenous fistula at the left TS. Although embolization of the feeding artery was attempted via the middle meningeal artery (MMA), a middle meningeal arteriovenous fistula (MMAVF) developed as the MMA was damaged by intraoperative balloon inflation. The MMA was immediately embolized together with the fistulous opening using n-butyl-2-cyanoacrylate (NBCA) and coils, and no sequelae were observed postoperatively.

Conclusion: We experienced dural arteriovenous fistula caused by injury of the feeding artery during endovascular treatment. It must be remembered that iatrogenic arteriovenous fistula is a complication of endovascular treatment that is rare but requires attention.

Objective: A case in which angioscopy was useful for the evaluation of plaque protrusion during carotid artery stenting (CAS) is reported.

Case Presentations: The patient was a 67-year-old man. He presented with transient ischemic attacks and progression of bilateral internal carotid artery stenosis during a course of about 7 months. CAS was performed with dual protection using flow reversal system (modified Parodi method) and FilterWire EZ (Boson Scientific, Natick, MA, USA). After stent placement, plaque protrusion was detected by intravascular ultrasonography (IVUS) and optimal coherence tomography (OCT), and plaque protrusion and fluttering debris were also noted by angioscopy. Therefore, additional stenting was performed. Although the evaluation was difficult by subsequent IVUS or OCT, angiosopy revealed plaque protrusion and fluttering debris were both confirmed to be immobilized by the stents.

Conclusion: Since the vascular and stent lumens could be evaluated directly by the use of angioscopy, it may be useful for the examination of plaques and plaque protrusions particularly when multiple stents have been used.