[Treatment of brain AVMS (TOBAS): A randomized controlled trial and registry]

The management of unruptured and ruptured brain arteriovenous malformations (AVMs) remains controversial. The Treatment of Brain AVM Study (TOBAS) was designed to assess curative treatments in the management of AVMs. The purpose of our study is to provide a care trial context to brain AVM patients.

TOBAS is a pragmatic, prospective study including 2 randomized controlled trials and a registry. All AVM patients can be recruited. The preferred management modality will be predetermined prior to randomization by the team based on clinical judgment. Patients eligible for both conservative and interventional management will be randomly allocated conservative or curative treatment. Randomization will be stratified by a treatment modality (surgery, radiosurgery or embolization) and minimized according to a history of previous rupture and Spetzler-Martin grade. A second randomization will allocate eligible patients to embolization/no embolization prior to surgery or radiosurgery. The primary outcome of the study is death (any cause) or disabling stroke (mRS>2) at 10 years. All patients managed according to clinical judgment alone will be included in the registry. The study is registered under: wwwTrials.gov, ID: NCT02098252.

A minimum recruitment of 540 patients is required to show that treatment can reduce the primary outcome by 10 % (from 25 to 15 %); 440 patients will be needed to show a 10 % increase in angiographic occlusion for a good clinical outcome with pre-embolization.

The trial is designed to offer optimal and verifiable care to patients with brain AVMs in spite of the uncertainty. We are currently seeking the participation of multiple centers.