The present invention is directed to systems for occluding an aneurysm having an aneurysmal neck and an aneurysmal inner wall. Generally, a device in accordance with the present invention includes a mesh-like structure that is integrally composed of a shape-memory alloy such as NiTi. The device is deployed within the aneurysm through the aneurysmal neck. The device is configured to be in a deployed state and an undeployed state, and is configured to transition from the undeployed state to the deployed state by exposure to a higher temperature and/or by being unconstrained. The device may function to retain finer vaso-occlusive devices such as vaso-occlusive coils and/or embolic liquids. Furthermore, the device itself may function as a vaso-occlusive device.