This invention gives physicians in situ control to create differences in wall porosity between different areas of a stent wall. This enables a physician to customize the stent within a blood vessel to selectively block blood flow to an aneurysm with a low-porosity area of the stent wall, but allow blood flow to nearby branching vessels through one or more high-porosity areas of the stent wall. The method comprises inserting a stent into a blood vessel and, in situ, expanding the stent in a non-uniform manner, thereby causing one or more areas of the stent wall to have a lower post-expansion porosity than the rest of the stent wall. With this invention, physicians can selectively block blood flow into an aneurysm while maintaining blood flow into nearby branching vessels, even in tortuous and complex vessel configurations.
