An intravascular device for treating a cerebral aneurysm, the device comprising an externally controllable expandable member, the expandable member comprising a plurality of wires that define walls of the expandable member； wherein in a relaxed state of the expandable member the walls comprise at least a first wall portion in which openings defined between the wires are small enough to prevent coils positioned within the aneurysm from exiting the aneurysm, the first wall portion comprising an axial length at least as long as a neck of the aneurysm； and at least a second wall portion in which openings defined between the wires are large enough to allow blood flow through； the second wall portion axially aligned relative to the first wall portion. In some embodiments, openings of the first wall portion are small enough to reduce radial blood flow to and/or from the aneurysm.
