A flexible stent graft for deployment in a body vessel at a treatment site includes a tubular body, at least a first portion of which comprises a graft material and a coiled stent comprising a plurality of helical turns with spacings between the turns. The coiled stent is affixed to the graft material of the first portion. The first portion has a first portion diameter and the coiled stent has a helix diameter which is substantially the same as the first portion diameter. The coiled stent comprises a ratio of helical pitch to helix diameter of from about 1:2 to about 1:20, where the helical pitch is the spacing between adjacent turns of the coiled stent.