Abstract: A catheter device includes a tube, and an extracorporeal unit coupled to a proximal end of the tube. An implant includes a series of anchors and a tether. The series of anchors includes a first anchor and other anchors, arranged along the extracorporeal unit. Each of the anchors includes a tissue-engaging element, and a head that defines an eyelet. The tether extends, along the extracorporeal unit, through the eyelet of each of the other anchors to the first anchor such that (i) the first anchor is advanceable, with a distal end of the tether, distally into and through the tube toward the tissue, and (ii) subsequently, the other anchors are slidable, sequentially, over and along the tether, distally into and through the tube toward the first anchor. Other applications are also described.