Disclosed herein are medical devices comprising a single-lobed, thin-walled, expandable body ("ballstent" or "blockstent") and a flexible, elongated delivery device ("delivery catheter") and systems and methods of use for treating saccular vascular aneurysms and methods of use for occluding segments of blood vessels and other biological conduits. Expandable bodies comprising gold, platinum, or silver that can be compressed, positioned in the lumen of an aneurysm or blood vessel, and expanded to conform to the shape of the aneurysm or segment of blood vessel or biological conduit are disclosed.
