Brain arteriovenous malformations (bAVMs) are complex, heterogeneous, and uncommon intracranial lesions. They can be treated by one or a combination of the following treatment modalities, namely embolization, radiosurgery, or microsurgical resection. In Spetzler-Martin Grade 4 and 5 arteriovenous malformations (AVMs), conservative management may be the best option. A group of experts in the management of AVMs of different disciplines gathered in January 2019 in Hanoi to compile the "Expert Consensus on the Management of Brain Arteriovenous Malformations".

Intracranial hemangioblastomas (HBs) are hypervascular neoplasms mainly located in the posterior fossa of the central nervous system. Preoperative embolization of the feeding arteries is one proposal for reduction of intraoperative hemorrhage, although indications for the procedures should be evaluated carefully due to the potential complications. This retrospective study investigated clinical outcomes and complications of 15 patients with HBs in the posterior fossa to evaluate the safety and effectiveness of endovascular procedures as well as angiographical procedures. Surgical excision without presurgical embolization was performed in 8 cases, and excision with presurgical embolization was performed in 7 cases, using Guglielmi detachable coils with or without polyvinyl alcohol (GDC ± PVA) in 4 cases and only n-butyl 2-cyanoacrylate (NBCA) in 3 cases. The embolization was applied for selected cases in which feeding arteries were located in a deep site and hard to coagulate surgically. Partial embolization was achieved in 5 cases, and all feeders were successfully embolized in 2 cases. Total removal was achieved in 12 cases, and subtotal/partial removal was achieved in 3 cases. Subarachnoid hemorrhage with intratumoral hemorrhage occurred in 1 case during the angiographic procedure and in 1 case during the embolization procedures. The mean volume of intraoperative blood loss was clearly less in the NBCA group than in the GDC ± PVA group. HBs are mainly located in the posterior cranial fossa, so the risk of severe clinical complication may be high if vascular problems occur. In our series, presurgical embolization using NBCA made tumor removal safe and reduced bleeding volume in posterior fossa HBs.

The purpose of this study was to investigate the anatomical risk factors for ischemic lesions detected by diffusion-weighted imaging (DWI) associated with carotid artery stenting (CAS). DWI was performed within four days after CAS in 50 stenotic lesions between January 2008 and September 2013. We retrospectively analyzed the correlation between the anatomical factors and ischemic lesions associated with CAS. Post-procedural DWI revealed new ischemic lesions after 24 (48%) of the 50 CAS procedures. All three patients with common carotid artery tortuosity, defined as the presence of severe angulation (less than 90 degrees) in the common carotid artery, developed new ischemic lesions. However, there were no significant differences between the patients with and without tortuosity, likely due to the small number of cases. Meanwhile, seven of eight patients with internal carotid artery tortuosity, defined as the presence of severe angulation (less than 90 degrees) in the cervical segment of the internal carotid artery, developed new ischemic lesions. A multivariate analysis showed internal carotid artery tortuosity (odds ratio: 11.84, 95% confidence interval: 1.193–117.4, P= 0.035) to be an independent risk factor for the development of ischemic lesions associated with CAS. Anatomical factors, particularly severe angulation of the internal carotid artery, have an impact on the risk of CAS. The indications for CAS should be carefully evaluated in patients with these factors.

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are not appropriate treatment procedure for internal carotid artery stenosis (ICAS) in some patients. The importance of plaque vulnerability and the treatment risk evaluation has been reported. We analyzed whether treatment selection contributes to the outcome. We retrospectively examined 121 patients who underwent CEA or CAS. Treatment was selected based on plaque vulnerability and the treatment risk evaluation. We selected CAS for patients with stable plaques and CEA for patients with unstable plaques, and considered the other treatment for high-risk patients. The patients were classified as the stable plaque (Stable: n = 42), the unstable plaque and CEA low risk (Unstable/Low: n = 30), and the CEA high-risk (Unstable/High: n = 49). Frequency of perioperative stroke, myocardial infarction, death, and systemic complications was examined. CEA and CAS were performed in 35 and 86 patients, respectively. One patient (2.9%) had a stroke in CEA and five patients (5.8%) in CAS (P = 0.50). Systemic complications were observed in two patients (5.7%) in CEA and six (7.1%) in CAS (P = 0.80). There were no differences in stroke (Stable; 2.4%, Unstable/Low; 3.2%, and Unstable/High; 8.2%) and systemic complications (Stable; 9.5%, Unstable/Low; 3.3%, and Unstable/High; 6.1%) among three groups (P = 0.44 and P = 0.59, respectively). The treatment selection based on plaque vulnerability and the treatment risk evaluation could provide good treatment outcome for high-risk patients. It is ideal to select an appropriate treatment for ICAS by one neurovascular team.

A 76-year-old female presented with a large upper basilar artery (BA) aneurysm causing obstructive hydrocephalus after coil embolization manifesting as diplopia. Magnetic resonance (MR) imaging and MR angiography showed a large BA top aneurysm. Coil embolization was performed. More than 6 months after the first coil embolization, the aneurysm had re-grown and we performed a second coil embolization. Soon after that, obstructive hydrocephalus at the aqueduct of the midbrain occurred. MR imaging was performed to evaluate whether there was enough space at the prepontine cistern for a third ventriculostomy and also to verify the posterior direction of the aneurysm growth because of the risk of rupturing the aneurysm during the operative procedure. Then, we performed an endoscopic third ventriculostomy (ETV) via a left-sided approach. We could easily identify the infundibular recess, mamillary bodies, and tuber cinereum in the third ventricular floor. We detected a pulsating upper BA aneurysm that appeared to have caused a reddish color change in the right mammillary body and the right side of the thalamus and midbrain. If there is sufficient space in the prepontine cistern for the surgical procedure, ETV is a good choice for the treatment of obstructive hydrocephalus associated with cerebral aneurysms.