A self-expanding endovascular stent formed of stainless steel wire which is bent into an elongated zigzag pattern. The zigzag pattern has a plurality of substantially straight wire sections of various lengths separating a plurality of bends. The zigzag pattern is helically wound about a central axis to define a tubular shape such that a majority of the bends are disposed in a helix. Adjacent bends in the helix are interconnected with a filament. The stent is capable of being radially compressed such that the straight wire sections and the bends are tightly packed around a central axis. The stent resiliently self-expands to assume a tubular shape when released from the compressed state. Depending on the pattern of the lengths of the straight wire sections in the zigzag pattern, the final tubular shape can be made irregular to match a patient's vascular system. In other words, the diameter of the tube which is defined by the stent can be made to vary along the length of the stent. Stents of the present invention are used to expand a passageway, hold a passageway open, or create a passageway.