A device to treat an aneurysm can include a plurality of soft and compressible fill members. A flow conduit can carry the fill members in a liquid flow. A flexible, expandable, and liquid-permeable net or mesh enclosure can be inserted into and to fit within the aneurysm. The net or mesh enclosure can receive and retain the plurality of fill members while openings in the net or mesh enclosure allow enough liquid flow through the net or mesh enclosure to transport the fill members into the net or mesh enclosure. A resulting accumulation of the plurality of fill members within the net or mesh enclosure causes the net or mesh enclosure to expand and to come into contact with and generally conform with an interior wall of the aneurysm. This can substantially occlude the aneurysm and retain the net or mesh enclosure within the aneurysm.