A cerebral arteriovenous malformation (AVM) is an abnormal set of direct connections between the arteries and veins in the brain. These can cause a variety of neurologic symptoms, especially if they are large, and especially if they rupture.
Mohr et al. recently published the result of the ARUBA trial, which compared medical (i.e., medical treatment for symptoms as needed) to interventional (i.e., surgical) treatment of this condition.
Their intention-to-treat analysis favored event-free survival in the medical management (MM; red) group:
The actually-treated analysis favored event-free survival in the medical management (MM) group even more strongly:
The authors suggest on the basis of this data that a reasonable management approach for unruptured cerebral AVM is to wait to see if a hemorrhage occurs, which may be mild if it does occur, and only then consider surgical intervention.