Unruptured Arteriovenous Malformations

Brain arteriovenous malformations (bAVMs) are vascular lesions that carry significant morbidity and mortality risk upon rupture. bAVM rupture causes either intracerebral or intraventricular hemorrhage, or both. In 2014, the first results of the ARUBA trial (A Randomized Trial of Unruptured Brain Arteriovenous Malformations) were published in The Lancet , causing a paradigm shift in clinical practice and suggesting the superiority of medical treatment in terms of mortality or stroke compared with any intervention designed to obliterate the AVM. In 2020, the final results of the ARUBA trial were published. In this Viewpoint, we critically review the clinical equipoise behind the trial, highlight issues regarding external validity, and place the results of the trial in the context of other results in scientific literature of bAVMs using Bayesian inference. ARUBA is a trial of decision-making, and only proper knowledge of the nuances of its interpretation within the broader context of bAVM research can lead to proper decision-making when confronted with patients with unruptured bAVMs.