An implantable, radially distensible stent includes a plurality of helically wound elongate members. The members include an overlapping portion having a longitudinal extent, opposed and convexly rounded sides defining a width of the members and opposed luminal and exterior surfaces. The members include shape memory polymer. The side of one elongate member slidingly overlaps the side of an adjacent elongate member to form a self-supporting wall structure of a stent. The stent wall is self-supporting without other support structure incorporated into or abutting the elongate members. Further, the shape memory polymer may include a biodegradable or bioabsorbable elements.