Abstract: A resilient prosthesis such as a stent for widening a channel in a living body, particularly a stenotic portion of a blood vessel, is disclosed. The prosthesis (5) consists of a number of lengths of resilient thread (1, 2, 3, 4) helically wound in the same direction, which threads are axially inserted between one another in a substantially cylindrical arrangement without intersecting one another. The threads may be separate or joined together at the ends of the prosthesis. The turns of the threads have a shorter pitch P.sub.1 in the mid-portion (6) of the prosthesis than in the other portions thereof (7, 8), so that one separate thread cannot be "screwed" between the others. The ends (10, 11) of the threads all lie in the same plane or are axially offset. The prosthesis may be manufactured at low cost and is useful for performing angioplastic, urological or gynaecological treatments, and generally for widening or supporting any channel in the human or animal body.