Brain arteriovenous malformations (bAVMs) have a low incidence, but the annual bleeding rate after rupture is 2% to 4%, and the risk of disability and death is high. Treatment options include microsurgical resection, stereotactic radiosurgery, and embolization. Due to the different individual risks of each case, there is currently no consensus on the indications and choice of treatment options, especially for unruptured cases. Since the results of the ARUBA study were published, the safety and effectiveness of endovascular treatment of bAVMs has been controversial.
Brain arteriovenous malformations (bAVMs) have diverse clinical manifestations, including intracranial hemorrhage, seizures, headaches or migraines, ischemic symptoms due to steal phenomenon or mass effect, murmurs, abnormal vision, congestive heart failure, etc. These symptoms are related to the degree of shunt, lesion location, size, patient age, and many other factors. The overall annual bleeding rate of bAVM is 2% to 4% per year, the mortality rate of arteriovenous malformation rupture is about 10%, and the disability rate is about 20% to 30%. Increasing age and female gender are two other important factors that increase the risk of bleeding. Angiographic features such as aneurysms, high-flow shunts, venous stenosis, and varicose aneurysms may be associated with an increased risk of bleeding.
Embolization of brain arteriovenous malformations (bAVM) is mostly a palliative treatment, such as embolizing the bleeding source in patients with rupture, or facilitating microsurgical resection or stereotactic radiosurgery. Only a few cases can be cured by embolization alone. The ARUBA trial showed that the incidence of death from any cause and any stroke was 10.1% in the medical treatment group and 30.7% in the group receiving any type of intervention; the risk of death or stroke in the medical treatment group was significantly lower than that in the intervention treatment group.
The use of dual microcatheters for embolization of cerebral AVMs has been reported, but the multiplug flow control technique goes a step further and aims to control blood flow in all significant AVMs. Using a transarterial approach, all or most of the feeding arteries are superselected using a detachable microcatheter or a double-lumen balloon catheter. The basic principle of this method is to control blood flow to the malformation, thereby slowing or preventing blood perfusion of the malformation from other feeding arteries. This reduces reflux to the arterial feeder and venous side, allowing the embolic agent to penetrate the lesion faster and more effectively.This allows for closer proximity to the occluded vein/venous plexus and feeding artery, thus greatly reducing the risk of arterial ischemia and venous compression.
AVM is a very heterogeneous disease with considerable risks in its natural course and any type of intervention, and the results of randomized controlled trials (RCTs) and systematic reviews/meta-analyses do not support endovascular treatment. Experts recommend that endovascular treatment of brain arteriovenous malformations should be performed under a treatment plan to eliminate the AVM and achieve cure through embolization alone or in combination with adjuvant treatments such as radiosurgery and microsurgery.