An endovascular device , comprising: a hollow shaft having a proximal end and a distal end, the hollow shaft being sized for insertion into a blood vessel; a control line having a proximal end and a distal end, and extending through the hollow shaft; an actuatable working element located beyond the distal end of the hollow shaft, and configured to receive an actuation force transmitted via the distal end of the control line; and an actuator configured to exert the actuation force on the proximal end of the control line, to thereby cause relative movement between the control line and the hollow shaft and to actuate the working element, wherein the control line is formed of a single wire and the device comprises: at least one control line rotation restrictor (101-3) integral with the control line and located within the hollow shaft, the at least one control line rotation restrictor (101-3) including at least one deformation in a cross-sectional area of the single wire, wherein the at least one control line rotation restrictor (101-3) includes at least a first deformation in an elongated region of the control line within the hollow shaft and at least a second deformation of the control line in an elongated region of the working element; and at least one rotation restrictor element associated with at least one of the hollow shaft and the working element, and configured to engage with the control line rotation restrictor (101-3) to thereby substantially impede the control line from rotating relative to the working element, while permitting relative axial movement between the control line and the hollow shaft. a hollow shaft having a proximal end and a distal end, the hollow shaft being sized for insertion into a blood vessel; a control line having a proximal end and a distal end, and extending through the hollow shaft; an actuatable working element located beyond the distal end of the hollow shaft, and configured to receive an actuation force transmitted via the distal end of the control line; and an actuator configured to exert the actuation force on the proximal end of the control line, to thereby cause relative movement between the control line and the hollow shaft and to actuate the working element, wherein the control line is formed of a single wire and the device comprises: at least one control line rotation restrictor (101-3) integral with the control line and located within the hollow shaft, the at least one control line rotation restrictor (101-3) including at least one deformation in a cross-sectional area of the single wire, wherein the at least one control line rotation restrictor (101-3) includes at least a first deformation in an elongated region of the control line within the hollow shaft and at least a second deformation of the control line in an elongated region of the working element; and at least one rotation restrictor element associated with at least one of the hollow shaft and the working element, and configured to engage with the control line rotation restrictor (101-3) to thereby substantially impede the control line from rotating relative to the working element, while permitting relative axial movement between the control line and the hollow shaft. <EOS>