Welding method

A medical device, the medical device being implantable within the human body and being formed of a fusion weldable material shaped in a substantially tubular configuration, the medical device having bent sections axially adjacent to one another, said bent sections being connected by fusion welding forming a weld line, the weld line having a first initiation point and a second initiation point and a substantially centrally located region between the first initiation point and the second initiation point along the weld line, wherein the weld line extends substantially the length of the bent sections, the centrally located region being in a relatively lower stress region of the weld line as compared to the first and second initiation points, the weld line further comprising a terminal pool located in the centrally located region.