An implant can include a single- or dual-layer braided body having a variable porosity. In a dual-layer body, first and second longitudinal sections, having respective first and second porosities, can be overlapped such that the first and second porosities overlap each other. The dual-layer construction can cumulatively provide a third porosity at a distal portion and a fourth porosity at a proximal portion. The third and fourth porosities can each be greater than each of the first and second porosities.