Brain arteriovenous malformations (bAVMs) are uncommon vascular lesions found in young individuals exhibiting diverse clinical manifestations ranging from asymptomatic to spontaneous intracranial hemorrhage, seizures, or headaches. Despite improvements in endovascular tools and methods, standalone transarterial embolization seldom achieves success rates surpassing 50%, even when employing ethylene vinyl alcohol copolymers. Transvenous embolization (TVE) emerges as a promising option, especially for bAVMs situated distally or inaccessible through arterial routes. Despite the possibility of achieving high angiographic cure rates, concerns regarding hemorrhagic complications persist, limiting its adoption. This review article outlines the indications and methodology of TVE, discusses complications, and highlights the essential expertise needed for the safe execution of TVE along with strategies to mitigate associated risks. Clinical results reveal promising outcomes in terms of obliteration rates and favorable neurological results, although challenges persist, particularly regarding device accessibility and risk management. Despite these challenges, TVE remains a valuable alternative for managing bAVMs, particularly for cases resistant to surgical intervention, emphasizing the significance of careful patient selection and procedural expertise.

Onyx (Medtronic, Minneapolis, MN, USA) is a non-adhesive liquid embolic agent composed of an ethylene vinyl alcohol (EVOH) copolymer dissolved in dimethyl sulfoxide (DMSO). Onyx is explicitly designed for use in interventional neuroradiological procedures. Onyx’s unique formulation allows controlled delivery and solidification within the target vessel, providing durable occlusion of abnormal vascular structures such as arteriovenous malformations and dural arteriovenous fistulas. This report reviews the basic understanding of the use of Onyx in interventional neuroradiology. The hydrophilic properties of the agent facilitate its smooth delivery through microcatheters, ensuring precise navigation and deposition within vascular malformations under fluoroscopic guidance. When Onyx was injected into the target vessel, the vessel was embolized as the solvent (DMSO) diffused into the blood and EVOH precipitated to form a durable cast. Onyx liquid embolic agents substantially advance the endovascular treatment of intracranial vascular lesions.

Various types of embolic substances are used in endovascular therapy, and understanding their characteristics, including shape and kinetics, is essential for proper use. Cyanoacrylate is a typical liquid embolization agent that can be applied to many cerebral neurovascular lesions. It is injected as a mixture with ethiodized oil to provide radiopacity and regulate the polymerization rate. This review describes the characteristics, action mechanisms, techniques of use, and potential pitfalls of using cyanoacrylate-ethiodized oil mixtures for embolization.

This review discusses the use of N-butyl cyanoacrylate (NBCA) in various neuroendovascular treatments. Despite the increase in the ONYX, NBCA continues to have significant usage. It is particularly useful for the treatment of arteriovenous malformations (AVM) and dural arteriovenous fistulas (dAVFs). Comparative studies have suggested that ONYX and NBCA are equally effective and safe for the treatment of AVM. However, the choice between the two depends on specific situations, such as the characteristics of the feeding arteries. NBCA is recommended for tortuous feeders, high-flow fistulous feeders, and feeders with a short margin of reflux, owing to the procedural risks posed by ONYX. The use of NBCA is also prominent in dAVF embolization. While achieving total occlusion solely with NBCA can be challenging, NBCA adheres to the vessel wall and encourages thrombus formation, aiding in fistula obliteration. In addition to AVM and dAVF, NBCA is used to treat chronic subdural hematoma and craniofacial vascular injuries. Embolization using NBCA is beneficial because of its deep penetration into the target tissue. For craniofacial injuries, NBCA embolization provides secure hemostasis within a short time. Neuroendovascular physicians should understand the characteristics of NBCA as a liquid embolic material and have expertise in the technical aspects of NBCA embolization, even in the ONYX era.

Neuroendovascular therapy is a key treatment for cerebrovascular disorders, driven by advancements in devices and techniques. The Japanese Society for Neuroendovascular Therapy (JSNET) established a certification system in 1997 to ensure operator competence and minimize complications, with the first examination in 2002. JSNET offers 2 main certifications: specialist and instructor. Specialists perform basic procedures, while instructors lead in practice, education, and research. In 2020, the mechanical thrombectomy practitioner qualification was added to promote mechanical thrombectomy. Applicants must have a JSNET membership, relevant certifications, training, and documented experience. The certification process includes rigorous written and practical examinations that now employ non-fluoroscopic models. Certification renewal every 5 years requires conference participation and a continuing education program. Public awareness and integration into stroke center designations have grown. Over 2200 specialists, including more than 500 instructors, have been certified, significantly advancing neuroendovascular therapy in Japan. JSNET aims to continue improving certification and education to maintain high standards.

In recent years, artificial intelligence (AI) has made remarkable progress. In the near future, AI will become an indispensable technology in daily clinical practice in the field of neuroendovascular therapy. Clinicians who understand the information processing and limitations of AI will create new and comfortable working styles. This article introduces current applications of AI in the field of neuroendovascular therapy and presents a vision for its future directions.

Clinical applications of telemedicine using digital technology are in demand in Japan and continue to expand. However, with some exceptions, it would be difficult to say that the current situation is adequate in terms of encouraging research and development, formulating guidelines that need to be established before telemedicine can spread, and providing support programs for these activities. The “Telestroke” telemedicine system for the treatment of stroke has been adopted in other countries due to the early establishment of a medical device program compatible with guidelines and the steady accumulation of evidence, creating a situation that leads the world. With optimization of the support program from the perspective of strategically produced evidence by governments and related organizations, and by taking these results as model cases for other regions, telemedicine in Japan is thought to progress to a new stage.

Interventional and therapeutic neuroradiology offers minimally invasive treatments for neurological disorders, and the World Federation of Interventional and Therapeutic Neuroradiology (WFITN) plays a crucial role in advancing this field globally. This article discusses WFITN’s mission to promote education, research, and collaboration among practitioners, establish clinical standards, and embrace technological innovations. It highlights the Federation Assembly’s role in governance and policy-making, as well as initiatives like mentorship programs aimed at empowering women in neurointerventional radiology. Facing challenges such as rapid technological changes and healthcare disparities, WFITN is committed to expanding its global impact and fostering an inclusive, innovative community to enhance patient outcomes worldwide.

In the field of abdominal and pelvic surgery, endoscopic procedures have increasingly utilized robotic surgery, including the da Vinci system (Intuitive Surgical, Sunnyvale, CA, USA). Unlike robotic surgery in these fields, endovascular treatment involves simple movements such as pushing and pulling or twisting catheters and wires, allowing for the creation of relatively straightforward robotic systems that can replicate these endovascular procedures. Recently, there have been clinical applications of this technology in coronary arteries. However, when applying it to cerebral vessels, which have significant curvature and fragility, it is essential to develop a system that can adequately assess and reflect the physical stress on the vessel wall. Furthermore, remote surgery (telesurgery) performed by specialists is one of the most sought-after applications of robotics, but issues remain due to poor communication environments, leading to delays in operation and control difficulties. Additionally, there are ethical concerns regarding the responsibility for adverse events related to robotic surgery, highlighting the urgent need for the establishment of guidelines.

Recent advances in artificial intelligence (AI) have significantly transformed neuroendovascular procedures, offering innovative solutions for image analysis, procedural assistance, and clinical decision-making. This review examines the current state and future potential of AI applications in neuroendovascular interventions, focusing on 3 topics: AI-based image recognition, real-time procedural assistance, and future developments. From a research perspective, deep learning algorithms have demonstrated reasonable accuracy in vascular structure analysis and device detection, successfully identifying critical conditions such as vascular perforation, aneurysm location, and vessel occlusions. Real-time AI assistance systems may have potential clinical utility in various procedures, including carotid artery stenting, aneurysm coiling, and liquid embolization, potentially enhancing procedural safety and operator awareness. The future of AI in neuroendovascular procedures shows promise in integration with robotic systems and applications in medical education. While current systems have some limitations, ongoing technological advances suggest an expanding role of AI in enhancing procedural safety, standardization, and patient outcomes.