Apparatus comprising an endovascular system, which comprises: an endovascular implant, which is configured to assume a radially-compressed delivery state, and a radially-expanded deployment state; and a delivery tool, which comprises: a proximal main delivery catheter, having a distal portion in which the endovascular implant is disposed while in the radially-compressed delivery state; and a distal restraining assembly, which (a) comprises (i) a restraining-assembly tubular shaft, which is disposed distal to the proximal main delivery catheter, and which is shaped so as to define one or more longitudinal elongated-member lumens therethrough, and (ii) one or more flexible elongated members, which extend from a proximal end of the restraining-assembly tubular shaft, and (b) is configured to assume: an engaged state, in which (a) the distal restraining assembly prevents proximal displacement of the endovascular implant relative to the distal restraining assembly, and (b) the one or more flexible elongated members are slidably disposed through the one or more longitudinal elongated-member lumens and releasably couple an element of the endovascular system to a distal portion of the endovascular implant, the element selected from the group consisting of: the distal restraining assembly and the restraining-assembly tubular shaft, and a disengaged state, in which the distal restraining assembly allows proximal displacement of the endovascular implant relative to the distal restraining assembly. an endovascular implant, which is configured to assume a radially-compressed delivery state, and a radially-expanded deployment state; and a delivery tool, which comprises: a proximal main delivery catheter, having a distal portion in which the endovascular implant is disposed while in the radially-compressed delivery state; and a distal restraining assembly, which (a) comprises (i) a restraining-assembly tubular shaft, which is disposed distal to the proximal main delivery catheter, and which is shaped so as to define one or more longitudinal elongated-member lumens therethrough, and (ii) one or more flexible elongated members, which extend from a proximal end of the restraining-assembly tubular shaft, and (b) is configured to assume: an engaged state, in which (a) the distal restraining assembly prevents proximal displacement of the endovascular implant relative to the distal restraining assembly, and (b) the one or more flexible elongated members are slidably disposed through the one or more longitudinal elongated-member lumens and releasably couple an element of the endovascular system to a distal portion of the endovascular implant, the element selected from the group consisting of: the distal restraining assembly and the restraining-assembly tubular shaft, and a disengaged state, in which the distal restraining assembly allows proximal displacement of the endovascular implant relative to the distal restraining assembly. a proximal main delivery catheter, having a distal portion in which the endovascular implant is disposed while in the radially-compressed delivery state; and a distal restraining assembly, which (a) comprises (i) a restraining-assembly tubular shaft, which is disposed distal to the proximal main delivery catheter, and which is shaped so as to define one or more longitudinal elongated-member lumens therethrough, and (ii) one or more flexible elongated members, which extend from a proximal end of the restraining-assembly tubular shaft, and (b) is configured to assume: an engaged state, in which (a) the distal restraining assembly prevents proximal displacement of the endovascular implant relative to the distal restraining assembly, and (b) the one or more flexible elongated members are slidably disposed through the one or more longitudinal elongated-member lumens and releasably couple an element of the endovascular system to a distal portion of the endovascular implant, the element selected from the group consisting of: the distal restraining assembly and the restraining-assembly tubular shaft, and a disengaged state, in which the distal restraining assembly allows proximal displacement of the endovascular implant relative to the distal restraining assembly. an engaged state, in which (a) the distal restraining assembly prevents proximal displacement of the endovascular implant relative to the distal restraining assembly, and (b) the one or more flexible elongated members are slidably disposed through the one or more longitudinal elongated-member lumens and releasably couple an element of the endovascular system to a distal portion of the endovascular implant, the element selected from the group consisting of: the distal restraining assembly and the restraining-assembly tubular shaft, and a disengaged state, in which the distal restraining assembly allows proximal displacement of the endovascular implant relative to the distal restraining assembly.