A generally tubular endovascular prosthesis (100) is configured to transition between a radially-compressed state and a radially-expanded state. The prosthesis (100) includes a first generally cylindrical structural portion (101), which has first and second ends (102, 103), and a second generally cylindrical structural portion (104), which has first and second ends (105, 106). The first end (102) of the first structural portion (101) and the first end (105) of the second structural portion (104) meet each other at a juncture (107). The prosthesis (100) is configured to transition from (a) an initial folded state, in which the second structural portion (104) is folded into the first structural portion (101) at the juncture (107), to (b) an unfolded state, in which the second structural portion (104) is no longer positioned within the first structural portion (101), and the second end (103) of the first structural portion (101) and the second end (106) of the second structural portion (104) are positioned at opposite ends of the prosthesis (100). Other embodiments are also described.
